Scientia Agricultura Sinica

Studies on Climate Change Impact on Crop and Animal Production from China

PAN Gen-Xing

Scientia Agricultura Sinica. 2013, 46(21): 4397-4398. doi:10.3864/j.issn.0578-1752.2013.21.001

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Tendency of Use Efficiency of Rice Growth Season in Southern China Under the Background of Global Warming

YE Qing-12, YANG Xiao-Guang-2, JIE Wen-Juan-23, LI Yong-24, LIU Zi-Qi-2, DONG Chao-Yang-2, SUN Shuang-2

Scientia Agricultura Sinica. 2013, 46(21): 4399-4415. doi:10.3864/j.issn.0578-1752.2013.21.002

Abstract ( 470 )

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【Objective】Based on the analysis of the spatial and temporal patterns of the use efficiency of rice growth season in the rice production region of Southern China during 1951 to 2010, this study could provide a insight to improve rationally arrange rice production activities under global warming. 【Method】 In this study, classification method of cropping system referred to previous work was used to divide the rice production region of Southern China into 16 zones. And assuming the breed collocation is unchanged in different cropping systems, the ratio of the potential length of growing season to theoretical length and a ecometeorological simulation method of the rice growth period were used to evaluate the distribution characteristics and the evolution trend of the use efficiency of the rice growth period in sub regions under the background of climate change in the study area.【Result】In this study, ArcGIS was used to calculate the geographic distribution function of the potential growing season length from 1951 to 2010, and got the 10 km×10 km spatial distribution data of the rice growing season length in 80% guaranteed rate in southern rice area. Results show that the potential growth season length of rice increased first and then reduced under the background of climate change in Southern China, and increased greater in single rice planting regions compared with that in double rice planting regions. In addition, there was a decreasing trend in the theoretical growth season length in different cropping systems, and the shorten days in the single rice planting regions was more than the double rice planting regions. The extension of the potential growth season length and shortening of the theoretical growth season length result in the increasing trend of the use efficiency of the rice growth period.【Conclusion】The use efficiency of the rice growth period in Southern China has an increasing trend under the background of global warming. Arranging accommodative cropping system and increasing the multiple crop indexes are the main measures to increase the use efficiency of the rice growth period.

Quantifying the Effects of Low Level of Radiation After Anthesis on Yield Components and Grain Quality of Weak Gluten Wheat

GU Yun-Qian-1, LIU Xue-1, ZHANG Wei-1, QI Chun-Jie-1, TANG Kai-Lei-1, ZHAO Yang-1, ZHANG Yan-1, LI Gang-1, WANG Bin-1, ZHAO Chun-Jiang-2, ZHOU Jian-Min-3, LUO Wei-Hong-1

Scientia Agricultura Sinica. 2013, 46(21): 4416-4426. doi:10.3864/j.issn.0578-1752.2013.21.003

Abstract ( 432 )

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【Objective】The objective of this study is to develop a model for predicting the effects of low level of radiation on yield components and grain quality of wheat so as to quantitatively assess the impacts of low level of radiation on wheat crop production.【Method】Field experiments with weak gluten winter wheat (Triticum aestivum L. cv Yangmai 15) were conducted during three growing seasons. Shading treatments with three levels of radiation intensity (50%, 34% and 16% of natural radiation) and four durations (2 d, 4 d, 6 d and 8 d) after anthesis in the three growing seasons were designed to simulate the low level of radiation caused by cloudy or rainy weather conditions. Based on the experimental data, the impacts of low level of radiation on yield components and grain nitrogen accumulation, and their relations with grain quality traits were quantitatively analyzed and the corresponding functions were determined. These functions were then integrated into the simulation model of wheat crop biomass production and under low levels of radiation weather conditions developed in a previous study, to develop a dynamic model for predicting the effects of low level of radiation after anthesis on the yield components and grain quality of weak gluten wheat. Independent experimental data were used to validate the model.【Result】The critical daily total photosynthetically active radiation (PAR) and duration were determined for keeping normal levels of grain number per spike and grain nitrogen content based on the experimental data. Model validation results showed that the determination coefficient (R2) between the predicted and measured values of grain number per spike, thousand grain weight, test weight, falling number, protein content and wet gluten content were 0.89, 0.75, 0.72, 0.73, 0.93 and 0.84, respectively, and the corresponding relative root mean squared errors (rRMSE) were 2.86%, 3.41%, 1.01%, 2.50%, 2.64% and 5.05%, respectively.【Conclusion】The model developed in this study gave satisfactory predictions of the effects of low level of radiation after anthesis on yield components and grain quality of weak gluten wheat, hence, can be used for assessing the impacts of low level of radiation caused by cloudy or rainy weather conditions on weak gluten wheat production.

Effect of Light on Yield and Characteristics of Grain-Filling of Summer Maize from Flowering to Maturity

SHI Jian-Guo, CUI Hai-Yan, ZHAO Bin, DONG Shu-Ting, LIU Peng, ZHANG Ji-Wang

Scientia Agricultura Sinica. 2013, 46(21): 4427-4434. doi:10.3864/j.issn.0578-1752.2013.21.004

Abstract ( 482 )

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【Objective】Owing to the solar radiation has decreased in North China Plain Area, this study is to explore the effects of light on yield and characteristics of grain-filling of summer maize from flowering to maturity stage.【Method】Denghai605 (DH605) was used as experimental material, two treatments of both shading (S) and increasing light (L) from flowering to maturity stage were arranged. The shading degree was 60% and the illumination intensity of the increasing light on cloudy day could reach 80 000- 100 000 lx. One non-shading and non-increasing light treatment was used as control. Effects of light on yield and characteristics of grain-filling of summer maize from flowering to maturity stage were investigated.【Result】Yield, dry matter accumulation, maximum grain-filling rate decreased with different degrees, respectively, after shading from flowering to maturity stage; however, the yield, dry matter accumulation, maximum grain-filling rate increased after increasing light from flowering to maturity stage. Compared to CK, the yields of S were reduced by 59.39% and 79.03% in 2011 and 2012, while the yields of L were increased by 16.29% and 12.93% in two years. The dry matter in response to different treatments showed: L＞CK＞S. The proportions of different treatments kernel in total dry matter accumulation of DH605 were significantly different during the late growing stage, and the mean values of S, CK and L were 22.92%, 48.49% and 51.80%, respectively. The grain-filling progress of shading and increasing light was obviously different. The maximum grain-filling rate of shading was lower than that of increasing light, and the days before the appearance of maximum grain-filling rate of shading lengthened, the growth increment when the grain-filling rate of increasing light reached its maximum increased. 【Conclusion】Shading decreased the yield of summer maize by reducing the dry matter accumulation and maximum grain-filling rate; increasing light increased grain yield of summer maize by improving the dry matter accumulation and maximum grain-filling rate.

Effect of Waterlogging on Grain Filling and Quality of Summer Maize

REN Bai-Chao, ZHANG Ji-Wang, LI Xia, FAN Xia, DONG Shu-Ting, ZHAO Bin, LIU Peng

Scientia Agricultura Sinica. 2013, 46(21): 4435-4445. doi:10.3864/j.issn.0578-1752.2013.21.005

Abstract ( 534 )

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【Objective】This study is to investigate the effects of waterlogging on grain filling characteristics and quality of summer maize under field conditions.【Method】Two summer maize cultivars, Denghai605(DH605) and Zhengdan958(ZD958), were used as experimental materials. The field experiment was performed to explore the effects of waterlogging in different durations (3 and 6 days) on grain dry weight and volume, grain filling parameters, and grain quality of summer maize stalk at the three-leaf stage (V3), six-leaf stage (V6), and ten days after the tasseling stage (10VT).【Result】Results showed that the grain dry weight growth rate and grain filling parameters reduced significantly after waterlogging, and the decrease of two cultivars was the most in the treatment of waterlogging at V3 for 6 days. Days of maximum grain filling (Tmax), maximum grain filling (Gmax), weight of maximum grain filling rate (Wmax), and active grain filling period (P) of DH605 decreased by 25.18%, 18.44%, 48.21%, and 36.45%, while that of ZD958 decreased by 18.18%, 1.69%, 32.68% and 31.80%, respectively. Waterlogging increased barrenness, and decreased grain yield, kernel number per ear and 1000-grain weight, and the response to different waterlogging treatments showed: waterlogging at V3＞waterlogging at V6＞waterlogging at 10VT and waterlogging for 6 days＞waterlogging for 3 days. Waterlogging significantly decreased grain crude protein, total starch, grain total soluble sugar and sucrose content. The decrease of amylopectin and increase of amylase led to the decrease of their ratio; the decrease of grain crude fat content of two cultivars was the most in the treatment of waterlogging at V3 for 6 days, with 49.08% in DH605 and 33.08% in ZD958. 【Conclusion】 Waterlogging significantly reduced Gmax and Wmax, suppressed the grain-filling with decrease of accumulation grain dry matter, resulted in lower yields. Waterlogging decreased the grain soluble total sugar, sucrose and starch content. Grain protein content and the ratio of amylopectin and amylose significantly reduced after waterlogging, while the crude fat content increased significantly. It was most susceptible to be waterlogged at V3, followed by V6 and 10VT, and decreased with the increase of waterlogging duration.

Physiological Indicator of Cotton Plant in Recovery from Waterlogging Damage

HU Jiang-Long, GUO Lin-Tao, WANG You-Hua, ZHOU Zhi-Guo

Scientia Agricultura Sinica. 2013, 46(21): 4446-4453. doi:10.3864/j.issn.0578-1752.2013.21.006

Abstract ( 409 )

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【Objective】The objective of this study was to screen suitable evaluation indexes indicating the stress and recovery degree after waterlogging, which would provide a theoretical basis for taking appropriate cultivation measures to reduce the impact of flood disasters on cotton production.【Method】By using cotton cultivar Siza 3 as material and four waterlogging treatments were applied (0, 6, 9, 12 days, respectively), the experiment was carried out in Dafeng, Jiangsu province (120°28′E, 33°12′N). The 14 stress related physiological indexes of cotton functional leaf, such as photosynthetic gas exchange parameters, MDA content, antioxidant enzyme activities, were evaluated by gray relational grade analysis and hierarchical cluster analysis.【Result】The results indicated that each of the 14 stress related physiological traits, had significant difference under different stress levels or at different recovery stages after waterlogging, and significant difference was also observed in the correlation degree between the indexes and the recover level. The relative correlation degree of the stress related physiological indexes and the stress level at different recovery stages were very similar, indicating that the 14 indexes could be grouped by the correlation degree and those indexes presented higher correlation degree with stress level could be used as key physiological indexes to indicate the stress or recovery level in cotton plant after waterlogging. The traits with higher correlation degree to recovery index were Pn(0.8105) and MDA(0.7717), which presented lower variation than others. They were ranked the first category according to hierarchical cluster analysis.【Conclusion】With the data in this research, it was concluded that Pn and MDA content could be used as key physiological indexes in evaluating the stress and recovery degree after waterlogging.

Influence of Meteorological Factors on Soil Moisture Dynamics of Upland Soil in Taihu Lake Region

ZHANG Cong-Cong, CHEN Xiao-Min, ZHANG Yong, QIU Jin-Si, YU Xiao, PAN Gen-Xing, ZHANG Xu-Hui

Scientia Agricultura Sinica. 2013, 46(21): 4454-4463. doi:10.3864/j.issn.0578-1752.2013.21.007

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【Objective】The purpose of this study is to integrate and then select the main meteorological factors of soil moisture by analyzing the effects of meteorological factors on soil moisture in dry farmland, and to provide a scientific basis for water management under the climate change conditions. 【Method】 The monitoring data (including the daily meteorological data and the soil moisture data) of drought crop growing season on the field experimental platform were extracted, and analyzed by using the correlation analysis, stepwise regression analysis and path analysis methods. The direct path coefficient, indirect path coefficient and determination coefficient between meteorological factors and soil moisture were calculated. 【Result】 The soil moisture of experimental base was highly positively correlated with daily precipitation and daily maximum air humidity, and was extremely negatively correlated with daily evaporation, sunshine duration and average wind speed (The correlation coefficients were 0.648, 0.371, -0.566, -0.454 and -0.331, respectively), but no significant correlation was observed between the soil moisture and the daily maximum air temperature. The path analysis showed that the decreasing influence sequence of meteorological factors on soil moisture was as follows: daily precipitation, average wind speed, sunshine duration, daily evaporation, daily mean air humidity, daily minimum air temperature, daily minimum air humidity, daily maximum air temperature, daily maximum air humidity and daily mean temperature, and that the daily precipitation had the largest comprehensive influencing ability on soil moisture. The multiple regression function between soil moisture and meteorological factors was Y=10.17+0.386X4 +1.095X7-0.509X8-0.766X9-0.345X10, reached a significant level (R2 = 0.912, P＜0.01). 【Conclusion】The effect of meteorological factors on controlling the soil moisture of upland soil in Taihu Lake plain was obvious, and the daily precipitation was the most important factor. The established multiple regression models could be used to forecast the changes of soil moisture in upland soil when some or all of the meteorological factors vary, but it needs to be further validated with longer-term monitoring data.

Effects of Elevated CO₂ Concentration on Development, Reproduction and Food Utilization of the Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae)

LI Bao-Ping, GUO Qing, MENG Ling

Scientia Agricultura Sinica. 2013, 46(21): 4464-4470. doi:10.3864/j.issn.0578-1752.2013.21.008

Abstract ( 449 )

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【Objective】 This study was designed to reveal the potential influence of CO2 enrichment on life history of the rice leaf-folder (Cnaphalocrocis medinalis), with the goal of providing data for projecting its trend under the climate change. 【Method】 Two levels of CO2 concentration-ambient (390 μL•L-1) and doubling (780 μL•L-1) were manipulated in incubators, where rice plants were grown for feeding larvae. Developmental and reproductive performances were examined, and food consumption and nutritional utilization indices were measured for the 4th instar larva. 【Result】The doubling CO2 treatment significantly influenced body weight of larvae till 5th instar, pupal time and body weight, but did not influence larval time and pupation rate. The body weight of the final instar (5th) larva decreased by 16.1%, pupal duration by 28.7%, and pupal weight by 9.9%, under the elevated CO2 as opposed to the ambient CO2. The CO2 elevation did not affect sex ratio and fecundity, but significantly influenced the larva-to-adult emergence survival and egg hatching. The larva-to-adult emergence survival rate decreased by 44.0% and the egg hatching rate reduced by 26.8% under the elevated CO2 as compared to the ambient CO2. The trial of the 4th instar larva showed significant effects of elevated CO2 on food consumption and utilization. The food consumption increased but the relative consumption rate was not changed by the elevated CO2. The relative growth rate increased by 21.2% and the approximate digestibility increased by 15.7%, but the efficiency of conversion of ingested food to body substance decreased by 24.8% and the efficiency of conversion of digested food to body substance decreased by 37.1%. 【Conclusion】 The CO2 enrichment may have negative effects on life history traits of C. medinalis, but the population dynamics of insect is complex and other effect such as temperature should be considered.

Effects of CO₂ Concentration and Pesticide Resistance on Penetration Behaviors in Nilaparvata lugens (Homoptera: Delphacidae)

LIU Jing, WU Shan-Shan, MENG Ling, LI Bao-Ping

Scientia Agricultura Sinica. 2013, 46(21): 4471-4477. doi:10.3864/j.issn.0578-1752.2013.21.009

Abstract ( 426 )

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【Objective】This study was designed to clarify if the CO2 enrichment influences the feeding behaviors of Nilaparvata lugens and if there are differences in feeding behaviors between the planthopper varied in pesticide-resistance, which would provide data for an assessment of the virulence to rice plant of pesticide resistant N. lugens under the climate change. 【Method】Using the electrical penetration graph (EPG) technique stylet penetration behaviors were recorded to evaluate the performances of buprofezin-susceptible and -resistant strains (a 480-fold difference in resistance) on rice leaves under either ambient (390 μL•L-1) or elevated CO2 concentration (780 μL•L-1). Two-way ANOVAs were used to test the effects of CO2 and pesticide resistance on the six waveforms associated with the plant penetration activities in the total time and frequency. 【Result】N. lugens exhibited a tendency to shorten the phloem sap ingestion duration under the CO2 elevation, and the buprofezin-resistant N. lugens decreased the frequency of the penetration initiation under the elevated CO2 concentration (780 μL•L-1) as opposed to the ambient CO2 (390 μL•L-1). In comparison with the buprofezin-susceptible insect, the buprofezin-resistant spent more time for the salvation plus penetration movement and the stylet activity in xylem region, increased the frequency of the intracellular activity in phloem region, but decreased the frequency of the phloem sap ingestion and the stylet activity in xylem region. 【Conclusion】 The buprofezin-resistant N. lugens can be stronger in virulence to rice than the buprofezin-susceptible. The CO2 enrichment may slightly minimize the virulence of the buprofezin-susceptible N. lugens but have no obvious effects on the virulence of the buprofezin-resistant N. lugens.

Effect of Heat Stress on Rumen Epithelial Cell Barrier Permeability in Dairy Goat

MA Yan-Fen-1, CHEN Qi-2, DU Rui-Ping-1, GAO Min-1

Scientia Agricultura Sinica. 2013, 46(21): 4478-4485. doi:10.3864/j.issn.0578-1752.2013.21.010

Abstract ( 589 )

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【Objective】Effect of heat stress on rumen epithelial cell barrier permeability in dairy goat were studied in order to provide a rational and experimental basis for animals in hot environments to maintain normal physiological function and to explore methods of resistance to heat stress. 【Method】Effect of heat stress on the concentration of D- lactic acid, DAO, endotoxin and inflammatory cytokines of blood serum, and the expression of tight junction protein occludin were studied with mid- or late-lactation dairy goats by molecular biology method in this project. 【Result】 Heat stress significantly increased the concentration of D- lactic acid, DAO of blood serum. Heat stress significantly increased the concentration of endotoxin and inflammatory cytokines, such as TNF-α, IL-1α, IL-6, IL-1β and interferon-γ. Heat stress damaged the tight junction structure between rumen epithelial, and significantly reduced the proteins expression and mRNA expression of occludin protein in tight junction. 【Conclusion】 The mechanisms of the damage of rumen mucous membrane barrier function, the increase of rumen mucous membrane permeability and the occurrence of bacterial translocation by heat stress may be due to the declined expression of tight junction protein occludin mRNA.

Effect of Heat Stress on Dairy Goat Performance and Rumen Epithelial Cell Morphology

MA Yan-Fen, DU Rui-Ping, GAO Min

Scientia Agricultura Sinica. 2013, 46(21): 4486-4495. doi:10.3864/j.issn.0578-1752.2013.21.011

Abstract ( 657 )

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【Objective】Effect of heat stress on dairy goat production performance and rumen epithelial cell morphology were studied in order to provide a rational and experimental basis for animals in hot environments to maintain normal physiological function and to explore methods of resistance to heat stress. 【Method】 The animal modes were estabished when temperature and humidity index ＞72 (THI＞72) of early, medium and evening for a week. The effect of heat stress on rumen fermentation pattern, digestion and metabolism of nutritive materials, performance, morphology and structure of rumen epithelial cell were studied with mid- and late-lactation dairy goats by animal nutrition methods in this project. 【Result】 The results showed that THI of test sheep was between 72 and 87 during the tests, and in the mild and high heat stress, which showed dairy goat in continuous heat stress state during the whole experiment period. Heat stress significantly increased rectal temperature and respiration rate (P＜0.01), significantly reduced DM, CP, OM, NDF and ADF digestibility (P＜0.01), dry matter intake and milk yield of dairy goats (P＜0.01 ), and significantly reduced dairy goat milk protein and milk fat content (P＜0.05), but the effect on lactose content was not significant (P＞0.05). Heat stress significantly decreased pH value, NH3-N concentration and TVFAs concentration (P＜0.05) at each time point in a day. Compared with the control group, rumen fluid of dairy goat was found gruel shape and strongly sour flavor, and the rumen mucosa nipples showed a wide range of necrotic and fall off when in heat stress for 30 days, and the situations of mucosa papillary necrosis and fall off were more serious when in heat stress for 45 days. This showed that heat stress caused a certain degree injury to the animal rumen mucosa. In the heat stress for 30 days and 45 days, the length and width of rumen dorsal sac and ventral sacs villus were shorter than that of control group (P＜0.05), and with the prolonged heat stress, the length and width of rumen dorsal sac and ventral sac villus were shortened more short (P＜0.05). 【Conclusion】Heat stress can significantly improve rectal temperature and respiration rate, significantly reduce dietary nutrient digestibility, rumen fermentation parameters, dry matter intake, milk quality and performance of the dairy goat. Heat stress can damage morphology of rumen epithelial cell, make the mucosal villi atrophy, shed and even necrosis, which increase permeability of the rumen epithelial cell.

Seperation and Identification Systems for Waxy Protein Originated from Rye (Secale cereale L.) Seeds

MENG Min-1, DONG Jian-12, GAO Xiang-12, ZHAO Wan-Chun-12, LI Xiao-Yan-12, CHEN Qi-Jiao-12, CHEN Liang-Guo-12, SHI Yin-Gang-12

Scientia Agricultura Sinica. 2013, 46(21): 4496-4505. doi:10.3864/j.issn.0578-1752.2013.21.012

Abstract ( 474 )

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【Objective】The purpose of the present investigation was to construct the large-scale isolation and high-throughput identification systems for the Waxy proteins in rye seeds so as to provide more information about how to understand its bio-chemical features, functions and genetic diversity in rye cultivars. 【Method】Waxy gene was isolated by using a set of gene specific primers from the full-length cDNA library derived from the immature seeds of Austria rye, followed by prokaryotic expression in Escherichia coli system. The extracted product of the DuoFlow system from Austria rye seeds, together with the purified recombinant Waxy protein by Ni-NTA resin, were confirmed by SDS-PAGE and matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS), and then followed by the alignment of protein sequences which deduced from the Waxy gene originated from Austria rye and common wheat. The above Waxy protein purified by DuoFlow workstation was then employed as the sample to construct the optimal capillary electrophoresis (CE) system for the waxy of rye seeds. Both the DuoFlow isolation system and CE identification system were verified based on the analysis results of rye cultivars. 【Result】 Sequence analysis revealed that the gene isolated from Austria cDNA (KF559182) encoded a 60 kD mature Waxy protein. The optimal isolation system for DuoFlow Workstation was the following: fixation Waxy proteins using 20 mM Tris-Hcl buffer (pH 9.5), and then elution the target components using 20 mmol•L-1 Tris + 1 mol•L-1 NaCl buffer (pH 9.5) from the UNO Q1 anion exchange column. All the above results, including SDS-PAGE, MS identified peptides and seqeunces semilarity of deduced amino acids based on the Waxy sequence, confirmed that the purified products by DuoFlow system in the present study was consistant with the characters of rye Waxy and therefore belongs to the Waxy protein itself. The CE was carried out using the purified protein by DuoFlow system under the conditions of 25℃, 20 kV and 0.5 psi × 5 s, together with the electrophoresis buffer 0.05 mM borax + 15% acetonitrile + 1% SDS solution (pH 9.5), and a single chromatographic peak was obtained aroud 11-12 min through the above CE system. The results also showed that the Waxy protein which extracted from the seeds could be used directly for the identification of rye Waxy in CE system. Meanwhile, the testing results of rye cultivars showed that the DuoFlow and CE system were suitable for the separation and identification of rye Waxy subunits, respectively. 【Conclusion】The present study successfully isolated the complete coding sequence of Waxy gene from cDNA library of Austria rye using the gene-specific primers, and constructed the DuoFlow large-scale isolation system and CE high-throughput identification system for Waxy subunits of rye grains.

Expression of Soluble Acid Invertase Gene and Its Relationship with Sugar Accumulation in Sweet Sorghum Stem

NIE Yuan-Dong-1, ZHONG Hai-Li-1, 顿Bao-Qing-1 , YE Kai-2, WANG Zhi-1, ZHU Li-3, LI Gui-Ying-1

Scientia Agricultura Sinica. 2013, 46(21): 4506-4514. doi:10.3864/j.issn.0578-1752.2013.21.013

Abstract ( 463 )

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【Objective】To better understand the mechanism of sucrose accumulation in sweet sorghum stem, the correlation between sugar content and soluble acid invertase(SAI) gene expression was analyzed by monitoring the expression of SAI in leaves and stems and the sugar content in stems.【Method】The sugar content and expression of SAI gene was investigated by using high performance liquid chromatography (HPLC) and qRT-PCR respectively.【Result】Reducing sugar was the major component at the elongation stage, and sucrose level was lower, then sucrose content was increased significantly at heading and flowering stages, until reached the maximum level at milking and ripening stages, while it declined after ripening. The expression of SAI gene in high-sugar varieties was higher than mid, low, and pith dry varieties in leaves, while it was just the reverse in stems. The sugar content of sweet sorghum at ripening stage was significantly negatively correlated with the expression of SAI gene in stems (r=-0.5971), and was significantly positively correlated with the expression of SAI gene in leaves (r=0.7239).【Conclusion】Sucrose accumulation was correlated with the expression of SAI gene in leaves and stems: a significantly positive correlation between sucrose and the expression of SAI gene in leaves, while a significant negative correlation between sucrose and the expression of SAI gene in stems, the correlation coefficient with leaves was higher than with stem.

Expression and Analysis of Candida cloacae Long-Chain Fatty Alcohol Oxidase FAO1 by Nuclear Expression Vector in Chlamydomonas reinhardtii

LI Ming-Ze, CHENG Qi

Scientia Agricultura Sinica. 2013, 46(21): 4515-4522. doi:10.3864/j.issn.0578-1752.2013.21.014

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【Objective】 fao1 encods a iron-containing long-chain fatty alcohol oxidase in C.cloacae. By constructing the nuclear expression vector, according to the biological activity of protein we can judge whether fao1 can take full advantage of iron in Chlamydomonas reinhardtii chloroplast. Meanwhile it will provide a new direction for researches on the gene of iron-containing proteins.【Method】The PsaD transit peptide gene(TP), C. cloacae fatty-alcohol oxidase (fao1) gene and His-tag were cloned separately by polymerase chain reaction (PCR). The 3-piece fusion gene TFHis was inserted into pDBle. This construct was transformed into C. reinhardtii CW15 by glass beads method. The transgenic Chlamydomonas was obtained under the selection of zeocin and they were confirmed positive by PCR amplification and RT-PCR. The activity of the purified recombinant protein was tested by a color-linked assay. 【Result】 The correctness of the constructed pDBle-TFHis was confirmed by DNA sequencing. PCR and RT-PCR analysis of the genomic DNA and RNA from transgenic Chlamydomonas showed that the recombinant plasmid has been integrated into C. reinhardtii CW15 genome and transcribed successfully. Protein purification elution made substrate reaction turn blue.【Conclusion】In this study, fao1-bearing nuclear expression vector pDBle-TFHis was correctly constructed and integrated into C. reinhardtii CW15 genome and fao1 transcript was detected successfully. The recombinant protein was purified by an affinity column and the activity was tested.

Genetic Diversity of Puccinia polysora Underw. in China

GUO Yun-Yan-12, CHEN Mao-Gong-2, SUN Su-Li-2, WU Xiao-Fei-2, JIANG Kai-2, ZHU Zhen-Dong-2, LI Hong-Jie-2, HE Yue-Qiu-1, WANG Xiao-Ming-2

Scientia Agricultura Sinica. 2013, 46(21): 4523-4533. doi:10.3864/j.issn.0578-1752.2013.21.015

Abstract ( 570 )

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【Objective】The objective of this study is to understand the genetic diversity of Puccinia polysora, the causal agent of Southern corn rust which is outbreaked recently in China, molecular techniques were used to analyze the genetic differences among the pathogen populations. 【Method】Seventy-two populations of P. polysora, collected from twelve provinces during 2011 and 2012, were amplified using eighteen polymorphic ISSR primers and the results were analyzed with software. 【Result】Seventy-two populations were clustered into ten branches at 81% Dice’s similarity coefficient, including two groups and five subgroups. There were some relationships in subgroup populations on collected loci and years and the higher genetic variations were tested among different populations. The higher genetic similarities were detected between Shandong and Anhui, Fujian and Zhejiang populations respectively, and the lowest similarities were between Hainan and others. The genetic relationship between provincial populations was lower based on the gene flow information.【Conclusion】There were higher genetic variations in populations of P. polysora, causal agent of southern corn rust, in China. Based on the molecular data, the pathogen did not complete the disease cycle in the field, and the population of P. polysora in Hainan was not the primary infection source in other provinces as well as the populations of P. polysora in Guangdong and Guangxi were not for summer-growing maize area. It was concluded that the primary infection source of P. polysora in mainland and Hainan island of China might come from other areas.

Prokaryocyte Expression and Immune Localization of HsbA in Beauveria bassiana

ZHANG Ye-1, LEI Zhong-Ren-1, WANG Hai-Hong-1, JI Qing-Zhan-12

Scientia Agricultura Sinica. 2013, 46(21): 4534-4541. doi:10.3864/j.issn.0578-1752.2013.21.016

Abstract ( 507 )

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【Objective】The objective of this study is to clarify the pathogenic process of hydrophobic surface binding protein A (HsbA) in Beauveria bassiana which is an important fungus used for agricultural pests control.【Method】 Cloning, subcloning and prokaryotic expression were conducted in HsbA. Polyclonal anti-peptide antibody of HsbA was generated according to the purified protein, tested using Western blot, and then used for immune-localization of HsbA protein under transmission electron microscope (TEM). 【Result】HsbA fusion protein was successfully expressed in pET-30a, and the polyclonal antibody specifically bound purified HsbA protein in a Western blot experiment. The immune-localization demonstrated that HsbA protein was randomly distributed in both spore and hypha. The concentration of HsbA protein in hypha was significantly greater than that in spores. The concentration of HsbA protein in spores that in the pathogenic process was significantly higher than in spores that under normal condition, while the concentration of HsbA protein in hypha under either conditions was very high. In addition, at the infected host insect (Frankiniella occidentalis Pergande), HsbA protein was mainly located in the cuticle, where the spores infected the insect body. 【Conclusion】HsbA was efficiently expressed in prokartotic system and also the polyclonal anti-peptide antibody of HsbA had good immunogenicity. In addition, the results of immune localization that HsbA is related to hypha growth. Also, during the pathogenesis, it may promote the spores’ infection at the cuticle of host insects.

Selection of Reference Genes and Study of the Expression Levels of Detoxifying Enzymes of Tetranychus urticae (Acari: Tetranychidae)

YUE Xiu-Li-1, GAO Xin-Ju-1, WANG Jin-Jun-2, 吕Juan-Juan-1 , SHEN Hui-Min-1

Scientia Agricultura Sinica. 2013, 46(21): 4542-4549. doi:10.3864/j.issn.0578-1752.2013.21.017

Abstract ( 495 )

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【Objective】The objective of this study is to select suitable reference genes for studying the expression levels of detoxifying enzymes on fenpropathrin susceptible (SS) and resistant strains (Fe-R) of Tetranychus urticae by using quantitative real-time PCR (RT-qPCR).【Method】The mRNA expression stability of eight candidate reference genes 5.8S rRNA, α-tubulin, β-actin, ELF, GAPDH, RPL13a, SDHA and TBP of T. urticae were detected by RT-qPCR, the relative expression of the main detoxifying enzymes CCEs, GSTs and P450s were analyzed. GeNorm and NormFinder softwares were used to analyze and evaluate the data for reference genes and comparison of Ct value method was used for the calculation of relative expression levels.【Result】α-tubulin was one of the most stable genes among the eight reference genes. When α-tubulin was used as a reference gene, the expression levels of TuGSTo1, TuGSTd1and CYP3D2 in Fe-R strain were significantly higher than that in SS strain while TuCCE1 was downregulated.【Conclusion】The gene α-tubulin can be used as an ideal reference in both SS and Fe-R strains of T. urticae. Futhermore, the elevated relative expression levels of TuGSTo1, TuGSTd1 and CYP3D2 may be the molecular mechanism of T. urticae that with high resistance to fenpropathrin.

Extensive Citrus Triploid Breeding by Crossing Monoembryonic Diploid Females with Allotetraploid Male Parents

JIE Kai-Dong-1, WANG Hui-Qin-1, WANG Xiao-Pei-1, LIANG Wu-Jun-1, XIE Zong-Zhou-1, YI Hua-Lin-1, DENG Xiu-Xin-1, Grosser Jude W2, GUO Wen-Wu-1

Scientia Agricultura Sinica. 2013, 46(21): 4550-4557. doi:10.3864/j.issn.0578-1752.2013.21.018

Abstract ( 748 )

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【Objective】 The objective of this experiment is to produce citrus triploid hybrids by interploid crossing between elite monoembryonic diploid varieties as female parents and allotetraploid somatic hybrids. 【Method】 Pollinations were carried out between the selected male and female parents. Fruits were collected at 70-100 d after pollination and immature seeds were cultured in vitro. Ploidy level of the plantlets was determined by flow cytometry and chromosome counting. The genetic origin of triploids and tetraploids was analyzed by SSR markers.【Result】 In successive four years from 2009 to 2012, 14 ploidy crosses using eight diploid cultivars as seed parents and four allotetraploid somatic hybrids as pollen parents, were carried out with a total of 3 347 flowers pollinated. With 678 fruits harvested, an average fruit set ratio of 20.26% was obtained. As a result, 1 022 plants were recovered from 12 357 seeds cultured in vitro, which derived from 505 fruits. By flow cytometry analysis and chromosome counting, a total of 755 triploids and 19 tetraploids were verified. The results of SSR markers showed that all the triploids and tetraploids from the cross of Huanong red pummelo × NH were of hybrid origin. 【Conclusion】 The triploids obtained from these crosses are valuable materials for the selection of new seedless citrus varieties. The tetraploid hybrids are also of great value as potential parents for citrus triploid breeding.

Changes of Histological Structure and Water Potential of Huping Jujube Fruit Cracking

WANG Bao-Ming-1, DING Gai-Xiu-1, WANG Xiao-Yuan-1, FU Chun-Bao-1, QIN Guo-Jie-1, YANG Jun-Qiang-1, CANG Guo-Ying-1, 2 , WEN Peng-Fei-2

Scientia Agricultura Sinica. 2013, 46(21): 4558-4568. doi:10.3864/j.issn.0578-1752.2013.21.019

Abstract ( 552 )

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【Objective】 The changes of histological structure and water potential during Huping jujube fruit development were studied in order to provide a reliable evidence for better understanding of the mechanism of fruit cracking. 【Method】 The changes in composition of cell wall and the histological structure, as well as the pericarp cell apoptosis were studied during the fruit development by paraffin slice, TUNEL detection and regular physiological and biochemical technology. 【Result】 The fruit cracking of Huping jujube occurred mainly at the part-red stage to the full-red stage, and no obvious cracking was observed at the young fruit and swelling stages. During the fruit development, the content of protopectin and cellulose in pericarp decreased gradually, while the water soluble pectin increased. Furthermore, the activity of SOD, POD, and CAT decreased, and the cell membrane relative permeability increased. The results of paraffin slice indicated that there was a significant change in the histological structure during fruit development, and the obviously shrinking was found in the epidermal and hypodermic layer cells at part-red stage. The TUNEL analysis showed that there was obvious cell apoptosis in the pericarp cells at the part-red and full-red stages. The water absorbing ability of pulp was significantly higher than the pericarp, and a water potential gradient was founded between different parts of pulp, which caused the formation of water permeation system between outside, pericarp, and pulp.【Conclusion】All the results suggested that the apoptosis or death of pericarp cells at part-red stage resulted in the increasing of cell membrane relative permeability, and the free water adhered on the fruit surface driven by the water potential gradient through the ‘outside-pericarp-pulp’ system, was absorbed largely by pulp, which resulted in the fruit cracking, finally.

Optimization of Ultrasound-Assisted Extraction Technology of Polyphenols from Apple Pomace by Response Surface Methodology

LI Zhen, HA Yi-Ming, LI An, LI Wei-Ming, WANG Feng, LI Qing-Peng

Scientia Agricultura Sinica. 2013, 46(21): 4569-4577. doi:10.3864/j.issn.0578-1752.2013.21.020

Abstract ( 535 )

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【Objective】The objective of this study is to optimize ultrasound-assisted ethanol extraction of polyphenols from apple pomace. 【Method】Residues from juice extraction of apple were used in this paper. On the basis of single-factor test, the response surface methodology was used to investigate the effects of processing parameters, including extraction time, temperature, ultrasound power and solvent/material ratio. The extraction rate of polyphenols was chosen as response value, mathematical model was established by implementing four factors and three levels. 【Result】 The model was of great difference, and the established regression equation for polyphenols yield had an excellent goodness of fit. Therefore the polyphenols from apple pomance could be analyzed and predicted by the model. Factors influencing the extraction of polyphenols from the apple pomace were in the order as follows: extraction temperature＞solvent/material ratio＞ultrasound power＞extraction time. The response surface plots showed that the interaction between extraction time and ultrasound power was not significant, while the interaction between extraction temperature and ultrasound power was outstanding, and the main effect of solvent/material ratio was greater than the temperature. The optimum technological conditions were extraction time of 10 min, extraction temperature of 65℃, ultrasonic power of 503 W, solvent/material ratio of 1﹕30(g•mL-1).【Conclusion】The extraction ratio of apple polyphenols was up to 4.53 mg•g-1, which is highly consistent with the predictive value of 4.55 mg•g-1.

Establishment of a Taqman Real-time PCR with Internal Amplification Control for the Detection of Chicken and Pork Ingredient in Food Products

HE Wei-Ling-1, HU Xu-Jian-2, CHENG Xin-1, HUANG Ming-1, ZHOU Guang-Hong-1

Scientia Agricultura Sinica. 2013, 46(21): 4578-4585. doi:10.3864/j.issn.0578-1752.2013.21.021

Abstract ( 476 )

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【Objective】A Taqman real-time PCR with IAC (Internal amplification control) was developed to identify pork and chicken ingredient in meat products. 【Method】 Specific primers and probes were designed based on the sequence of beta actin gene of pig DNA and transforming growth factor gene of chicken DNA, respectively. The specificity and sensitivity of the primers and probes were evaluated. An IAC was designed and constructed, and the real-time PCR system with IAC was established by optimizing the concentration of IAC in the system. The DNA of raw and cooked samples was evaluated by applying the Taqman real-time PCR system with IAC. Meanwhile, 38 food samples from market were assayed. 【Result】The pork and chicken ingredient in food was detected effectively by the Taqman real-time PCR with IAC. No cross-reaction was observed between species specific primer-probe systems in 40 cycles. The limit of detection was 0.5 ng of template DNA. No significant difference was observed between the Ct values of raw and cooked samples. The accuracy of the method was verified by examination of 38 food samples from the market.【Conclusion】An accurate and reliable method was developed to identify pork and chicken ingredient in food products.

Characterization, Expression of TGF-β1 Gene and Its Association with Ovulation Rate in Hu Sheep

GUO Jing-1, LI Xin-Yu-1, LI Yin-Xia-2, PAN Zeng-Xiang-1, JUE Ken-3, LIU Ji-Ying-1, LI 二Lin-1, XIE Zhuang-1, CHEN Ling-4, LI Qi-Fa-1

Scientia Agricultura Sinica. 2013, 46(21): 4586-4593. doi:10.3864/j.issn.0578-1752.2013.21.022

Abstract ( 386 )

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【Objective】 The present study was performed to clone the TGF-β1 sequence in Hu sheep and to comprehend the sequence character of Hu sheep so as to investigate the relationships between the mRNA level of TGF-β1 gene and ovulation number in ovaries of Hu sheep. 【Method】The sequence of TGF-β1 in Hu sheep was cloned and sequenced, and the sequence was analyzed by bioinformatics. The tissue distributions of TGF-β1 were detected by RT-PCR, and the gene expression level differences in the ovaries between the high- and the low-fecundity groups and the relationships with the ovulation rate were detected by real-time qPCR.【Result】The length of TGF-β1 gene coding sequence was 1 173 bp, encoding 390 amino acids which include some typical domains such as TGF-β propeptide and TGF-β like. RT-PCR assays revealed that TGF-β1 highly expressed in the ovary tissue. The ovarian mRNA expression level of TGF-β1 in high-fecundity group was significantly greater than that in low-fecundity group (P＜0.05), and mRNA expression level was significantly positively correlated with ovulation rate (P＜0.01). 【Conclusion】The ovarian mRNA expression level of TGF-β1 in high-fecundity group was significantly greater than that in low-fecundity group and significantly positively correlated with ovulation rate. These findings indicate that TGF-β1 of Hu sheep play an important role in follicular development, maturation or ovulation, which probably is associated with high fecundity of Hu sheep.

Cloning and Identification of Arylphorin from Silkworm Infected by Cytoplasmic Polyhedrosis Virus

GAO Kun-123, DENG Xiang-Yuan-1, WU Ping-23, QIN Guang-Xing-23, HOU Cheng-Xiang-23, QIAN He-Ying-23, GENG Tao-23, GUO Xi-Jie-23

Scientia Agricultura Sinica. 2013, 46(21): 4594-4602. doi:10.3864/j.issn.0578-1752.2013.21.023

Abstract ( 441 )

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【Objective】 The objective of this study is to clone the full-length cDNA sequence of Arylphorin in silkworm (Bombyx mori) to analyze the gene sequence by bioinformatics and to investigate the mRNA expression level after the B. mori infected by cytoplasmic polyhedrosis virus (BmCPV), and to provide a new foundation for the further study of its biological function. 【Method】 Rapid ampli?cation of cDNA ends (RACE) approach was employed to clone the full-length cDNA of Arylphorin from the total RNA of the silkworm midgut. Fluorescent quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the expression profiling of Arylphorin in different tissues and at different time points after the BmCPV infection. 【Result】 The full-length cDNA of Arylphorin was obtained and named as BmAryl with accession number of JN581664 in GenBank. It consisted of a 5′-terminal untranslated region (UTR) of 26 bp and a 3′-UTR of 143 bp with polyadenylation signal sequences AATAAA and a poly (A) tail. The longest open reading frame (ORF) encoded a polypeptide of 696 amino acids with a theoretical isoelectric point of 6.07 and the predicted molecular weight of 82.8 kD. Sequence comparison showed that BmAryl was 66% identical to B. mori sex-specific storage-protein 2 precursor. mRNA transcripts of BmAryl were detected mainly in fat body and hemolymph and the expression level had no difference between the testicle and ovary. For the silkworm larvae infected by BmCPV, the relative expression level of BmAryl was signi?cantly down-regulated in the midgut. 【Conclusion】 The full-length cDNA of BmAryl was successfully cloned from silkworm, which encodes a protein that belongs to the aromatic protein family. BmAryl expression were detected mainly in fat body and hemolymph, not sex-specific but down-regulated in the midgut due to BmCPV infection. These results has provided not only helpful information for further studying the function of BmAryl in silkworm but also be helpful for understanding of the role in response to BmCPV infection.

Cloning and Expression Analysis of Fe Superoxide Dismutase (Fe-SOD) Gene from Winter Turnip Rape (Brassica rapa L.)

ZENG Xiu-Cun-1, 2 , SUN Wan-Cang-1, SUN Jia-3, XU Yao-Zhao-2, FANG Yan-1, SHI Peng-Hui-1, YANG Gang-1, KONG De-Jing-1, WU Jun-Yan-1, LIU Zi-Gang-1

Scientia Agricultura Sinica. 2013, 46(21): 4603-4611. doi:10.3864/j.issn.0578-1752.2013.21.024

Abstract ( 559 )

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【Objective】The objectives of the present study were to clone the Fe-SOD gene of SOD family from an extremely low temperature (-32℃) resistant winter turnip rape (B. rapa L.) cultivar Longyou 7 and analyze its expression under low temperature conditions .【Method】The cDNA sequence of Fe-SOD was isolated by RT-PCR, and the obtained cDNA sequence and the deduced amino acid sequence was analyzed. Semi-quantitative and real time RT-PCR were used to assess the expression of Fe-SOD in response to low temperature stress. The superoxide dismutase enzyme activity was measured by NBT deoxidization method in leaves and roots. 【Result】The Fe-SOD gene was isolated from winter turnip rape (GenBank accession number. KF178713). The cDNA sequence of this gene was 645 bp in length, containing a 639 bp opening reading frame (ORF) , encoded a polypeptide of 212 amino acid，and with 99 % of amino sequence similarity to a vegetable cultivar of B. rapa (Chiifu). The protein encoded by this gene was a hydrophilic protein without signal-peptide and transmembrane region. The prediction of the second structures indicated that the Fe-SOD was a steady protein with more α-helices. Semi-quantitative and real time RT-PCR result showed that Fe-SOD was expressed upregulatedly in response to early low temperature stress (4℃). However, the expression of this gene was inhibited at the lower temperature stress (-4℃ and -8℃). The result of measured enzyme activity showed that superoxide dismutase enzyme activity in roots was higher than that of leaves，which could make winter turnip rape successfully overwinter. 【Conclusion】The Fe-SOD gene cloned from winter turnip rape had genetic characteristics similar with other known species and it might play a role in cold tolerance of the B. rapa cultivar Longyou 7.

A New Method for Analysis of Phenolic Acids in the Soil —Soil from Replanted Apple Orchards was Investigated

YIN Cheng-Miao-1, WANG Gong-Shuai-1, LI Yuan-Yuan-2, CHE Jin-Shui-3, SHEN Xiang-1, CHEN Xue-Sen-1, MAO Zhi-Quan-1, WU Shu-Jing-1

Scientia Agricultura Sinica. 2013, 46(21): 4612-4619. doi:10.3864/j.issn.0578-1752.2013.21.025

Abstract ( 498 )

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【Objective】To establish a new protocol based on the ASE-HPLC method, which could determine the content of phenolic acids in orchard soil rapidly and efficiently.【Method】Phlorizin was set as an sample for analysis, which is one of the characteristic phenolic acids in apple orchard soil. Accelerated solvent extraction (ASE) combined with high performance liquid chromatography (HPLC) was used to assess it. Specifically, the parameters of extraction solvent, extraction temperature, pressure and number of cycles were optimized, aiming at exploring the optimal conditions of ASE extraction for phenolic acids.【Result】The optimal conditions of ASE extraction for phenolic acids were as follows: Ethanol as extraction solvent initially, and methanol was the subsequent extraction solvent，extraction temperature at 120℃, a pressure of 10.3 MPa, 2 cycles, every 5 min static time, 60% purge volume, and purge time for 90 s. 【Conclusion】The process was more simple, and with good reproducibility and linearity, correlation coefficient up to 0.99, recovery efficiency between 83% and 98%, detection limit to the amount of 1.3 × 10-4 -2.5 × 10-2 μg•mL-1. ASE-HPLC is an accurate and rapid new protocol to mensurate phenolic acids, which is an improved and practical method.

Research on Proper Dietary NFC/NDF Ratio for 35-50 kg Dorper × Small Tail Han Crossbred Lambs

ZHANG Li-Tao-1, WANG Jin-Wen-2, LI Yan-Ling-1, ZHANG Li-Xia-1, TU Yan-1, CUI Xu-Kui-2, MENG Xian-Feng-2, DIAO Qi-Yu-1

Scientia Agricultura Sinica. 2013, 46(21): 4620-4632. doi:10.3864/j.issn.0578-1752.2013.21.026

Abstract ( 473 )

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【Objective】Dorper × Small Tail Han sheep crossbred lambs from 35 to 50 kg of live weight were used in a feeding trail, combined with in vitro gas production, to study proper dietary non-fiber carbohydrate to neutral detergent fiber(NFC/NDF) ratio.【Method】 Fifty female lambs and 25 male lambs were randomly assigned into five groups of ten female lambs and five male lambs each (five lambs/replication). Female and male lambs were separated in feeding. Each group was fed with one of the five diets which have the same crude protein level(11.90%) and different NFC/NDF ratios. The NFC/NDF ratios of the five diets were 1.36:1, 1.07:1, 0.82:1, 0.60:1, and 0.46:1，respectively. The experiment lasted for 56 d. Growth performance was measured, and a digestive trail was conducted after the sheep reached 50 kg of live weight. 【Result】 The in vitro gas production results showed as follows: As the dietary NFC/NDF ratio decreased, the gas production at 72 h, the ratio of gas production, in vitro digestibility of organic matter (IVDOM), total volatile fatty acids (TVFA),the ratios of propionate to butyrate were decreased significantly(P＜0.01), but the pH values of fermentation liquor, the ratio of acetate and acetate/propionate(A/P) were increased significantly(P＜0.01), the microbial crude protein(MCP) was higher than other groups when the NFC/NDF ratio was 0.82﹕1. The feeding trail results showed as follows: There were no significant effects of dietary NFC/NDF ratios on net body gains, average daily gains (P＞0.05) of the lambs; but gender of lambs played a significant role on this(P＜0.05). The order of body gains was 0.82＞1.36＞1.07＞0.60＞0.46 groups. Dry matter intake of the lambs had a positive correlation with dietary NFC/NDF ratios(R2=0.6573, P=0.0002), and showed a notable difference among five groups (P＜0.01), but dietary NFC/NDF ratios had no significant effects on feed conversion ratios (P＞0.05). NFC/NDF ratios had significant effects on apparent nutrient digestibility of dry matter, organic matter, crude protein, ether extract and fiber (P＜0.01), they were the highest in 0.82 group than in others. 【Conclusion】From the results of the experiment it is recommended that 0.82 is the proper dietary NFC/NDF ratio or 43.21% is the proper dietary NDF level for 35-50 kg Dorper × Small Tail Han sheep crossbred lambs while the dietary crude protein level is 11.90% and the NDF comes from Chinese wildrye and alfalfa hay.

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