For Selected: Toggle Thumbnails
    Crop Genetics · Breeding · Germplasm Resources
    Thellungiella halophila ThPIP1 gene enhances the tolerance of the transgenic rice to salt stress
    QIANG Xiao-jing, YU Guo-hong, JIANG Lin-lin, SUN Lin-lin, ZHANG Shu-hui, LI Wei, CHENG Xian-guo
    2015, 14(10): 1911-1922.  DOI: 10.1016/S2095-3119(15)61045-0
    Abstract ( )   PDF in ScienceDirect  
    Aquaporin proteins were demonstrated to play an important regulatory role in transporting water and other small molecules. To better understand physiological functions of aquaporins in extremophile plants, a novel ThPIP1 gene from the Thellungiella halophila was isolated and functionally characterized in the transgenic rice. Data showed that the ThPIP1 protein encoded 284 amino acids, and was identified to be located on the plasma membrane. The expression of ThPIP1 gene in the shoots and roots of T. halophila seedlings were induced by high salinity. The transgenic rice overexpressing ThPIP1 gene significantly increased plants tolerance to salt stress through the pathway regulating the osmotic potentials, accumulation of organic small molecules substances and the ratio of K+/Na+ in the plant cells. Moreover, split-ubiquitin yeast two-hybrid assay showed that ThPIP1 protein specifically interacted with ThPIP2 and a non-specific lipid-transfer protein 2, suggesting that ThPIP1 probably play a key role in responding to the reactions of multiple external stimulus and in participating in different physiological processes of plants exposed to salt stress.
    Assessment of wheat variety distinctness using SSR markers
    WANG Li-xin1, QIU Jun2, CHANG Li-fang3, LIU Li-hua1, LI Hong-bo1, PANG Bin-shuang1, ZHAO Chang-ping1
    2015, 14(10): 1923-1935.  DOI: 10.1016/S2095-3119(15)61057-7
    Abstract ( )   PDF in ScienceDirect  
    Assessment of variety distinctness is important for both the registration and the protection of particular variety. However, the current testing system, which assesses a range of morphological characters of each pair of varieties grown side-by-side, is time-consuming and is not suitable for the assessment of hundreds of samples. The objective of this study was to develop a procedure for the assessment of wheat variety distinctness using simple sequence repeat (SSR) markers. A comparison between the molecular and morphological profile of 797 varieties was made. On the basis of the comparison, pairs of varieties with a genetic similarity value (GSV) ≤90% were deemed to be distinct, accounting for ~85% of varieties assessed in wheat regional trials. For the remaining ~15% of varieties, GSVs between different varieties were >90%, among which ~35% were not distinct and the other ~65% were distinct. Therefore, if given a GSV>90%, the pairs of varieties should be morphologically assessed in the field. To avoid any errors in the assessments, we proposed the elimination of contaminant plants from the sample before comparing the varietal genotypes, scoring of the genotype at each locus with a pair of allele numbers when constructing a molecular profile, and faithfully recording two alleles at a non-homozygous locus. To reduce the workload and cost, a three-grade markers comparison among varieties is suggested. In addition, 80 SSR markers and a technical procedure for assessment of wheat variety distinctness have been proposed. Based on the procedure, the distinctness assessment of ~85% of all wheat varieties is completed in our laboratory annually. Consequently, total field assessment has been reduced considerably.
    Association analysis of grain traits with SSR markers between Aegilops tauschii and hexaploid wheat (Triticum aestivum L.)
    ZHAO Jing-lan, WANG Hong-wei, ZHANG Xiao-cun, DU Xu-ye, LI An-fei, KONG Ling-rang
    2015, 14(10): 1936-1948.  DOI: 10.1016/S2095-3119(15)61070-X
    Abstract ( )   PDF in ScienceDirect  
    Seven important grain traits, including grain length (GL), grain width (GW), grain perimeter (GP), grain area (GA), grain length/width ratio (GLW), roundness (GR), and thousand-grain weight (TGW), were analyzed using a set of 139 simple sequence repeat (SSR) markers in 130 hexaploid wheat varieties and 193 Aegilops tauschii accessions worldwide. In total, 1 612 alleles in Ae. tauschii and 1 360 alleles in hexaploid wheat (Triticum aestivum L.) were detected throughout the D genome. 197 marker-trait associations in Ae. tauschii were identified with 58 different SSR loci in 3 environments, and the average phenotypic variation value (R2) ranged from 0.68 to 15.12%. In contrast, 208 marker-trait associations were identified in wheat with 66 different SSR markers in 4 environments and the average phenotypic R2 ranged from 0.90 to 19.92%. Further analysis indicated that there are 6 common SSR loci present in both Ae. tauschii and hexaploid wheat, which are significantly associated with the 5 investigated grain traits (i.e., GA, GP, GR, GL, and TGW) and in total, 16 alleles derived from the 6 aforementioned SSR loci were shared by Ae. tauschii and hexaploid wheat. These preliminary data suggest the existence of common alleles may explain the evolutionary process and the selection between Ae. tauschii and hexaploid wheat. Furthermore, the genetic differentiation of grain shape and thousand-grain weight were observed in the evolutionary developmental process from Ae. tauschii to hexaploid wheat.
    A maize bundle sheath defective mutation mapped on chromosome 1 between SSR markers umc1395 and umc1603
    PAN Yu, CHEN Xu-qing, XIE Hua, DENG Lei, LI Xiang-long, ZHANG Xiao-dong, HAN Li-xin, YANG Feng-ping, XUE Jing, ZHANG Li-quan
    2015, 14(10): 1949-1957.  DOI: 10.1016/S2095-3119(15)61130-3
    Abstract ( )   PDF in ScienceDirect  
    The bsd-pg (bundle sheath defective pale green) mutant is a novel maize mutation, controlled by a single recessive gene, which was isolated from offspring of maize plantlets regenerated from tissue callus of the maize inbred line 501. The characterization was that the biogenesis and development of the chloroplasts was mainly interfered in bundle sheath cells rather than in mesophyll cells. For mapping the bsd-pg, an F2 population was derived from a cross between the mutant bsd-pg and an inbred line Xianzao 17. Using specific locus amplified fragment sequencing (SLAF-Seq) technology, a total of 5 783 polymorphic SLAFs were analysed with 1 771 homozygous alleles between maternal and paternal parents. There were 49 SLAFs, which had a ratio of paternal to maternal alleles of 2:1 in bulked normal lines, and three trait-related candidate regions were obtained on chromosome 1 with a size of 3.945 Mb. For the fine mapping, new simple sequence repeats (SSRs) markers were designed by utilizing information of the B73 genome and the candidate regions were localized a size of 850 934 bp on chromosome 1 between umc1603 and umc1395, including 35 candidate genes. These results provide a foundation for the cloning of bsd-pg by map-based strategy, which is essential for revealing the functional differentiation and coordination of the two cell types, and helps to elucidate a comprehensive understanding of the C4 photosynthesis pathway and related processes in maize leaves.
    Physiological basis for the differences of productive capacity among tillers in winter wheat
    XU Hai-cheng, CAI Tie, WANG Zhen-lin, HE Ming-rong
    2015, 14(10): 1958-1970.  DOI: 10.1016/S2095-3119(15)61094-2
    Abstract ( )   PDF in ScienceDirect  
    The quality or structure of a wheat population is significantly affected by the compositions of tillers. Little has been known about the physiological basis for the differences of productive capacity among tillers. Two winter wheat cultivars, Shannong 15 (SN15) and Shannong 8355 (SN8355), were used to investigate the differences of productive capacity among tillers and analyze the physiological mechanisms that determine the superior tiller group. Low-position tillers (early initiated tillers) had a higher yield per spike than high-position tillers (late initiated tillers) in both cultivars, which was due to their more grain number per spike, more fertile spikelet per spike, less sterile spikelet per spike and higher grain weight. According to cluster analysis, tillers of SN15 were classified into 2 groups: superior tiller group including main stem (0), the first primary tiller (I) and the second primary tiller (II); and inferior tiller group including the third primary tiller (III) and the first secondary tiller (I-p). Tillers of SN8355 were classified into 3 groups: superior tiller group (0 and I), intermediate tiller group (II and III) and inferior tiller group (I-p). In comparison with other tiller groups, the superior tiller group had higher photosynthetic rate of flag leaves, higher antioxidant enzyme (SOD, POD and CAT) activities and lower levels of lipid peroxidation in leaves, higher grain filling rate in both superior and inferior grains during grain filling, higher single-stem biological yield and larger single-stem economic coefficient. Correlation analysis showed that yield per spike was positively and significantly correlated with the flag leaf photosynthetic rate, grain filling rate, the antioxidant enzyme activities and soluble protein content (except for SN15 at 5 days post-anthesis (DPA)) of flag leaf, the single-stem biological yield, and the single-stem economic coefficient. Remarkable negative correlation was also found between yield per spike and MDA content of flag leaf. These results suggested that superior tiller group had stronger leaf photosynthetic capacity, more predominance in terms of grain filling, slower senescence rate, higher biological yield and larger economic coefficient, and therefore, showed greater productive capacity than other tiller groups.
    The effects of high temperature level on square Bt protein concentration of Bt cotton
    WANG Jun, CHEN Yuan, YAO Meng-hao, LI Yuan, WEN Yu-jin, CHEN Yuan, ZHANG Xiang, CHEN De-hua
    2015, 14(10): 1971-1979.  DOI: 10.1016/S2095-3119(15)61049-8
    Abstract ( )   PDF in ScienceDirect  
    Higher boll worm survival rates were detected after high temperature presented during square period in Bt cotton. The objective of this study was to investigate the effects of high temperature level on the Bt efficacy of two different types of Bt cotton cultivars at squaring stage. During the 2011 to 2013 cotton growth seasons, high temperature treatments ranged from 34 to 44°C in climate chambers, and field experiments under high temperature weather with various temperature levels were conducted to investigate the effects of the high temperature level on square Bt protein concentration and nitrogen metabolism. The climate chamber experiments showed that the square insecticidal protein contents reduced after 24 h elevated temperature treatments for both cultivars, whereas significant declines of the square insecticidal protein contents were detected at temperature >38°C, and only slightly numerical reductions were observed when temperature below 38°C. Similar high temperature responses were also observed at the two field experimental sites in 2013. Correspondingly, high temperature below 38°C seems have little effect on the square amino acid concentrations, soluble protein contents, glutamic- pyruvic transaminase (GPT) and glutamic-oxalacetic transaminase (GOT) activities as well as protease and peptidase activities; however, when the temperature was above 38°C, reduced soluble protein contents, enhanced amino acid concentrations, decreased GPT and GOT activities, bolstered protease and peptidase activities in square were detected. In general, the higher the temperature is (>38°C), the larger the changes for the above compound contents and key enzymes activities of the square protein cycle. The findings indicated that the unstable insect resistance of the square was related to high temperature level during square stage.
    Over-expression of GhDWF4 gene improved tomato fruit quality and accelerated fruit ripening
    YE Shu-e, LI Fang, LI Xian-bi, HONG Qi-bin, ZHAI Yun-lan, HU Ming-yu, WEI Ting, DENG Sha-sha, PEI Yan, LUO Ming
    2015, 14(10): 1980-1991.  DOI: 10.1016/S2095-3119(15)61059-0
    Abstract ( )   PDF in ScienceDirect  
    Brassinosteroids (BRs), a class of steroidal phytohormones are essential for many biological processes in plant. However, little is known about their roles in fruit development. Tomato is a highly valuable vegetable and has been adopted as the model species for studying fruit growth, development, and ripening. To understand the role of endogenous BRs in the development of tomato fruit, the expression patterns of three homologues of DWF4 gene were investigated and the transgenic tomato plants were generated in which the GhDWF4 gene from upland cotton (Gossypium hirsutum L.) was ectopically expressed. The contents of main quality components were analyzed in fruits of transgenic tomato line and non-transgenic line (control plant, CP) when the fruit was mature. SlCYP90B3 that possesses high homology with GhDWF4 preferentially expressed in mature fruit. Significantly higher contents of soluble sugar, soluble proteins, and vitamin C were obtained in fruit of transgenic tomato lines compared with those in the CP. Furthermore, overexpressing GhDWF4 promoted fruit growth and ripening. The weight per fruit was increased by about 23% in transgenic lines. In addition, overexpressing GhDWF4 promoted the germination of transgenic tomato seeds and hypocotyl elongation of seedlings. These results indicated that overexpressing GhDWF4 gene in tomato could increase the contents of many nutrients in fruit and accelerate fruit ripening. It is suggested that increased endogenous BRs in fruit affect the growth and development of tomato fruit and therefore improved the nutrient quality of tomato.
    Plant Protection
    Postulation of seedling leaf rust resistance genes in 84 Chinese winter wheat cultivars
    REN Xiao-li, LIU Tai-guo, LIU Bo, GAO Li, CHEN Wan-quan
    2015, 14(10): 1992-2001.  DOI: 10.1016/S2095-3119(14)61002-9
    Abstract ( )   PDF in ScienceDirect  
    Wheat leaf rust (caused by Puccinia triticina) is one of the most important fungal diseases in China. There are tens of winter wheat cultivars which are approved to be released by the government at a national level and more than 100 wheat cultivars at the provincial level. But there is no information about leaf rust (Lr) genes in these cultivars, which makes it difficult for farmers and breeders to select which cultivars they should plant in their fields and use in their breeding programs. The objective of this paper was to identify the leaf rust resistant genes at seedling stage present in the 84 commercial wheat cultivars from China that have been released in the past few years. A set of 20 near isogenic lines with Thatcher background and 6 lines with known Lr genes were used to test the virulence of 12 races of P. triticina (Pt). By comparing the infection types (ITs) produced on the 84 cultivars by the 12 Pt races with the ITs on the differential sets, the Lr genes were postulated. In addition, 8 molecular markers of Lr genes such as Lr9, Lr10, Lr19, Lr20, Lr21, Lr24, Lr26 and Lr29, which are closely linked to or co-segregated with the Lr gene, were used for further validation of the genes in the 84 Chinese winter wheat cultivars. Twelve Lr genes, including Lr1, Lr3, (Lr3bg), (Lr3ka), Lr11, Lr13, Lr14a, Lr16, Lr26, Lr27, Lr30 and Lr31 were postulated to be present either singly or in combinations in these Chinese wheat cultivars. Lr3 and Lr26 were detected most often in the tested cultivars, with frequencies of 51.2 and 38.1%, respectively. No wheat Lr genes were detected in 16 cultivars, and 4 cultivars may carry unknown Lr genes other than those used in this study. Lr9, Lr20, Lr21, Lr24, Lr25 and Lr29 were not present in any of the 84 tested accessions.
    High genetic variation and recombination events in the vicinity of non-autonomous transposable elements from ‘Candidatus Liberibacter asiaticus’
    WANG Xue-feng, CHEN Jiao-yue, TAN Jin , DUAN Suo, DENG Xiao-ling, CHEN Jian-chi, ZHOU Chang-yong
    2015, 14(10): 2002-2010.  DOI: 10.1016/S2095-3119(14)60979-5
    Abstract ( )   PDF in ScienceDirect  
    Two miniature inverted-repeat transposable elements (MITEs), MCLas-A and MCLas-B, were recently identified from ‘Candidatus Liberibacter asiaticus’ known to be associated with citrus Huanglongbing (HLB, yellow shoot disease). MCLas-A was suggested as an active MITE because of its mobility. The immediate upstream gene of the two MITEs was predicted to be a putative transposase. The goal of this study is to analyze the sequence variation in the upstream putative transposase of MITEs and explore the possible correlation between sequence variation of transposase gene and MITE activity. PCR and sequence analysis showed that 12 sequence types were found in six major amplicon types from 43 representative ‘Ca. L. asiaticus’ isolates from China, the United States and Brazil. Out of the 12 sequence types, three (T4, T5-2, T6) were reported for the first time. Recombination events were found in the two unique sequence types (T5-2 and T6) which were detected in all Brazilian isolates. Notably, no sequence variation or recombination events were detected in the upstream putative transposase gene of MCLas-A, suggesting the conservation of the transposase gene might be closely related with the MITE activity. Phylogenetic analysis demonstrated two well supported clades including five subclades were identified, clearly reflecting the geographical origins of isolates, especially that of Ruili isolates, São Paulo isolates and a few Florida isolates.
    Cry1Ab rice does not impact biological characters and functional response of Cyrtorhinus lividipennis preying on Nilaparvata lugens eggs
    CHEN Yang, LAI Feng-xiang, SUN Yan-qun, HONG Li-ying, TIAN Jun-ce, ZHANG Zhi-tao, FU Qiang
    2015, 14(10): 2011-2018.  DOI: 10.1016/S2095-3119(14)60978-3
    Abstract ( )   PDF in ScienceDirect  
    One concern about the use of transgenic plants is their potential risk to natural enemies. In this study, using the eggs of the rice brown planthopper, Nilaparvata lugens, as a food source, we investigated the effects of Cry1Ab rice on the biological characteristics and functional response of an important predator Cyrtorhinus lividipennis. The results showed that the survival ability (adult emergence rate and egg hatching rate), development (egg duration, nymphal developmental duration), adult fresh weight, adult longevity and fecundity of C. lividipennis on Bt rice plants were not significantly different compared to those on non-Bt rice plants. Furthermore, two important parameters of functional response (instantaneous search rate and handling time) were not significantly affected by Bt rice. In conclusion, the tested Cry1Ab rice does not adversely impact the biological character and functional response of C. lividipennis.
    Functional and numerical responses of Cyrtorhinus lividipennis to eggs of Nilaparvata lugens are not affected by genetically modified herbicide-tolerant rice
    JIANG Xian-bin, HUANG Qian, LING Yan, CHEN Yu-chong, XIAO Guo-ying, HUANG Suo-sheng, WU Bi-qiu, HUANG Feng-kuan, CAI Jian-he, LONG Li-ping
    2015, 14(10): 2019-2026.  DOI: 10.1016/S2095-3119(14)60953-9
    Abstract ( )   PDF in ScienceDirect  
    To safely and sustainably utilize genetic breeding techniques for crop production, greater understanding of the potential effects of genetically modified herbicide-tolerant (GMHT) crops on the ecological functions of predators is required. In the laboratory, we examined the functional and numerical responses of Cyrtorhinus lividipennis Reuter to eggs of brown planthopper (BPH), Nilaparvata lugens (Stål), which were reared on GMHT rice Bar68-1; the untransformed parental cultivar, D68; or a BPH-susceptive rice variety, Taichung Native 1. All stages of nymphs and female adult of C. lividipennis, either on GMHT rice or control plants, exhibited typical type II functional responses when fed on BPH eggs; the attacking rate and handling time of C. lividipennis on GMHT rice Bar68-1 was not significantly different from that on D68. The numerical responses of C. lividipennis on GMHT rice or controls fit Beddington’s model; there were no significant differences in the parameters of numerical responses between GMHT rice Bar68-1 and D68. The results indicated that the functional and numerical responses of C. lividipennis to BPH eggs are not affected by GMHT rice Bar68-1.
    Animal Science · Veterinary Science
    Quantitative trait loci for the number of vertebrae on Sus scrofa chromosomes 1 and 7 independently influence the numbers of thoracic and lumbar vertebrae in pigs
    ZHANG Long-chao, LIU Xin, LIANG Jing, YAN Hua, ZHAO Ke-bin, LI Na, PU Lei, SHI Hui-bi, ZHANG Yue-bo, WANG Li-gang, WANG Li-xian
    2015, 14(10): 2027-2033.  DOI: 10.1016/S2095-3119(15)61084-X
    Abstract ( )   PDF in ScienceDirect  
    Although quantitative trait loci (QTLs) for number of thoracic-lumbar vertebrae have been identified on Sus scrofa chromosomes (SSCs) 1 and 7, the influence of these QTLs on the thoracic and lumbar vertebrae is not clear. The aim of this study was to identify single nucleotide polymorphisms (SNPs) associated with total number of thoracic-lumbar vertebrae and for each trait (number of thoracic and lumbar vertebrae) separately. A total of 581 individuals from an F2 Large White×Minzhu population were genotyped using an SNP60K chip. Performing a genome-wide association study (GWAS) for total number of thoracic-lumbar vertebrae, 38 significant SNPs were identified in two QTL regions located on SSC1 and SSC7. Performing a GWAS for number of thoracic vertebrae only, 72 significant SNPs were located on SSC7. While performing a GWAS for number of lumbar vertebrae only, 17 significant SNPs were identified on SSC1. Gene mining suggested that the gene encoding orphan nuclear receptor, germ cell nuclear factor (NR6A1) on SSC1 was a strong candidate affecting the number of lumbar vertebrae in pigs. Additionally, genes encoding vertnin (VRTN), prospero homeobox 2 (PROX2), Finkel-Biskis-Jinkins murine osteosarcoma viral oncogene homolog (FOS), and transforming growth factor beta 3 (TGFB3) may be important candidates affecting the number of thoracic vertebrae in pigs. QTLs on SSC1 and SSC7 independently influenced the numbers of thoracic and lumbar vertebrae. These results shed light on the complex genetic background of vertebrae development in pigs.
    Production of early monozygotic twin bovine embryos in vitro by the blastomere separation and coculture technique
    ZHAO Shan-jiang, ZHAO Xue-ming, DU Wei-hua, HAO Hai-sheng, LIU Yan, QIN Tong, WANG Dong
    2015, 14(10): 2034-2041.  DOI: 10.1016/S2095-3119(14)60970-9
    Abstract ( )   PDF in ScienceDirect  
    The objective of this study was to establish an efficient system of producing early monozygotic twin bovine embryos in vitro using the blastomere separation and coculture technique. In this study, early eight-cell embryos were chosen to optimize the separation method, and multi-coculture tactics were applied to improve the efficiency of this production system. Bovine embryo blastomeres (groups of at least 30 at the eight-cell stage) were separated into eight segments (to regard an eight-cell embryo as a tangerine, a blastomere as one segment) and one, two and four segments (blastomeres) were cultured respectively in microwells on the bottom of the four-well dish (Nunc, Denmark) with 400 μL of culture medium under paraffin oil. Four different types of coculture tactics (cocultured with nothing, intact embryos, bovine cumulus cells (bCCs), intact embryos & bCCs) were applied to the group of four segments (blastomeres). Finally, diameter and inner cell mass (ICM):trophectoderm (TE) cell ratio was measured as a criterion to assess the quality of the twin embryos which were derived from bovine separated blastomeres. Our results showed that rate of blastocyst formation of the four segments group was significantly greater than one or two group (P<0.05). In addition, rate of blastocyst formation was significantly increased when the four segments were cocultured with intact embryo & bCCs (P<0.05). Although the ICM, TE and total cells of blastocysts derived from separated blastomeres was less than the control group from intact embryo (P<0.05), more important quality indicator of the blastocyst diameter and ICM:TE cell ratio was similar between our experimental group and the control group (P>0.05). Thus, these results suggest that combined with intact embryos & bCCs coculture system, culturing four isolated segments (blastomeres) per microwell is an efficient system of producing early monozygotic twin bovine embryos. Furthermore, our results also indicate that the quality of blastocysts derived from separated blastomere may be similar to those derived from intact eight-cell embryos.
    Relative bioavailability of tribasic zinc sulfate for broilers fed a conventional corn-soybean meal diet
    LI Wen-xiang, MA Xin-yan, LU Lin, ZHANG Li-yang, LUO Xu-gang
    2015, 14(10): 2042-2049.  DOI: 10.1016/S2095-3119(15)61033-4
    Abstract ( )   PDF in ScienceDirect  
    An experiment was carried out to investigate the relative bioavailability of tribasic zinc (Zn) sulfate relative to Zn sulfate for broilers fed a conventional corn-soybean meal diet. A total of 504 1-d-old Arbor Acres commercial male chicks were randomly assigned by body weight of birds to one of seven treatments involving a 2×3 factorial arrangement with three levels of added Zn (30, 60, or 90 mg of Zn kg–1) and two Zn sources (tribasic Zn sulfate and Zn sulfate) plus a control with no added Zn for an experimental phase of 14 d. Plasma Zn, tibia ash Zn, pancreas Zn, and pancreas metallothionein (MT) messenger RNA (mRNA) were analyzed at 6 or 14 d of age post-hatching. The results showed that plasma Zn, tibia ash Zn, pancreas Zn, and pancreas MT mRNA increased linearly (P<0.002) as dietary Zn concentration increased at 6 or 14 d of age. The R2 for a linear model was greater on d 6 than on d 14 for the above 4 responsive criteria, and among these indices, the fitting of the tibia ash Zn concentration was the best (R2=0.99). Therefore, based on slope ratios from the multiple linear regressions of the above 4 indices of the birds at 6 d of age on daily intake of dietary Zn, the bioavailabilities of tribasic Zn sulfate relative to Zn sulfate (100%) were 95.6% (P=0.18), 83.5% (P=0.01), 87.9% (P=0.53), and 75.9% (P=0.38) for the tibia ash Zn, pancreas Zn, plasma Zn, and pancreas MT mRNA, respectively. The results indicated that generally, Zn from tribasic Zn sulfate was as available as Zn from Zn sulfate for broilers.
    Effectiveness of dietary xylo-oligosaccharides for broilers fed a conventional corn-soybean meal diet
    SUO Hai-qing, LU Lin, XU Guo-hui, XIAO Lin, CHEN Xiao-gang, XIA Rui-rui, ZHANG Li-yang, LUO Xu-gang
    2015, 14(10): 2050-2057.  DOI: 10.1016/S2095-3119(15)61101-7
    Abstract ( )   PDF in ScienceDirect  
    An experiment was conducted to investigate the effect of dietary supplementation of xylo-oligosaccharides (XOS) on growth performance, meat quality, immune functions, duodenal morphology and intestinal microbial populations of broilers fed a conventional corn-soybean meal basal diet. A total of 450 1-day-old commercial Arbor Acres male broiler chicks were randomly allocated by bodyweight to 1 of 5 treatments with 6 replicate cages (15 broilers per cage) for each of 5 treatments in a completely randomized design. Chicks were fed the basal corn-soybean meal diets supplemented with 0, 25, 50, 75, or 100 mg of XOS kg–1 of diet, respectively, for an experimental duration of 42 days. The results showed that supplementation of XOS affected feed conversion rate (feed/gain, F/G) during days 22–42 and 1–42 (P<0.03), drip loss in thigh muscle (P=0.02), and duodenal crypt depth (P=0.005) on day 42, but had no effect (P>0.05) on all other measured indices. The chicks fed the diet supplemented with 100 mg of XOS kg–1 had the lowest (P<0.05) F/G and drip loss in thigh muscle. The drip loss in thigh muscle decreased linearly (P=0.003) as the supplemented XOS increased. Duodenal crypt depth decreased (P<0.05) at the supplemental level of 75 mg of XOS kg–1. The results indicate that dietary supplementations of 75 and 100 mg of XOS kg–1 are beneficial to broilers fed a conventional corn-soybean meal diet.
    Tissue distribution of deoxynivalenol in piglets following intravenous administration
    DENG Xian-bai, DIN Huan-zhong, HUANG Xian-hui, MA Yong-jiang, FAN Xiao-long, YAN Hai-kuo, LU Pei-cheng, LI Wei-cheng, ZENG Zhen-ling
    2015, 14(10): 2058-2064.  DOI: 10.1016/S2095-3119(14)60942-4
    Abstract ( )   PDF in ScienceDirect  
    Contamination of deoxynivalenol (DON) in grains is common worldwide and pigs are particularly susceptible to this mycotoxin. The distribution of DON in porcine tissues following intravenous administration was investigated in this study. Fifteen pigs were randomly divided into three groups. Animals in groups A and B were administrated with DON at the dose of 250 and 750 μg kg–1 body weight, respectively, while group C served as blank control. Plasma, bile and 27 tissues were collected at 30 min post-administration. DON concentrations in all samples were tested using high-performance liquid chromatography- tandem mass spectrometry (HPLC-MS/MS). To observe the distribution of DON in tissues, these samples were further subjected to the immunohistochemical analyses. Totally, the bile and 13 tissues were sampled for DON-based detection, including kidney, mesenteric lymph nodes, muscle, stomach, jejunum, colon, plasma, spleen, rectum, cecum, liver, ileum, and duodenum. No significant difference was observed for the concentrations of DON in duodenum, ileum and liver samples between groups A and B; while the DON concentrations in cecum and rectum of group B were significantly higher (P-value <0.05) than those in group A. In addition, the DON concentrations in stomach, jejunum, colon, mesenteric lymph nodes, muscle, kidney, spleen, bile, and plasma of group B were remarkably higher than those of group A (P-value<0.01). Levels of DON in other 14 tissues including medulla oblongata, midbrain, diencephalon, pons, tip and tongue body, tongue, soft palate, tonsils, pharyngeal mucosa, oral buccal mucosa, thymus, thyroid, esophagus and adrenal gland were all below the limit of detection. The results of immunohistochemistry showed that 11 tissue samples (medullaoblongata, tonsil, adrenal medulla, thyroid gland, thyroid, stomach, duodenum, jejunum, kidney, spleen, and mesenteric lymph nodes) were positive and DON was mainly distributed around blood vessels in these tissues. Therefore, we believed that concentrations of DON in tissues differ when pigs are in exposure to various dosages and DON causes lesions in many pig tissues.
    Soil & Fertilization﹒Irrigation﹒Plant Nutrition﹒ Agro-Ecology & Environment
    Water consumption in summer maize and winter wheat cropping system based on SEBAL model in Huang-Huai-Hai Plain, China
    YANG Jian-ying, MEI Xu-rong, HUO Zhi-guo, YAN Chang-rong, JU Hui, ZHAO Feng-hua, LIU Qin
    2015, 14(10): 2065-2076.  DOI: 10.1016/S2095-3119(14)60951-5
    Abstract ( )   PDF in ScienceDirect  
    Crop consumptive water use is recognized as a key element to understand regional water management performance. This study documents an attempt to apply a regional evapotranspiration model (SEBAL) and crop information for assessment of regional crop (summer maize and winter wheat) actual evapotranspiration (ETa) in Huang-Huai-Hai (3H) Plain, China. The average seasonal ETa of summer maize and winter wheat were 354.8 and 521.5 mm respectively in 3H Plain. A high-ETa belt of summer maize occurs in piedmont plain, while a low ETa area was found in the hill-irrigable land and dry land area. For winter wheat, a high-ETa area was located in the middle part of 3H Plain, including low plain-hydropenia irrigable land and dry land, hill-irrigable land and dry land, and basin-irrigable land and dry land. Spatial analysis demonstrated a linear relationship between crop ETa, normalized difference vegetation index (NDVI), and the land surface temperature (LST). A stronger relationship between ETa and NDVI was found in the metaphase and last phase than other crop growing phase, as indicated by higher correlation coefficient values. Additionally, higher correlation coefficients were detected between ETa and LST than that between ETa and NDVI, and this significant relationship ran through the entire crop growing season. ETa in the summer maize growing season showed a significant relationship with longitude, while ETa in the winter wheat growing season showed a significant relationship with latitude. The results of this study will serve as baseline information for water resources management of 3H Plain.
    Effects of water application intensity of microsprinkler irrigation on water and salt environment and crop growth in coastal saline soils
    CHU Lin-lin, KANG Yao-hu, WAN Shu-qin
    2015, 14(10): 2077-2089.  DOI: 10.1016/S2095-3119(15)61062-0
    Abstract ( )   PDF in ScienceDirect  
    Laboratory and field experiments were conducted to investigate the effects of water application intensity (WAI) on soil salinity management and the growth of Festuca arundinacea (festuca) under three stages of water and salt management strategies using microsprinkler irrigation in Hebei Province, North China. The soil water content (è) and salinity of homogeneous coastal saline soils were evaluated under different water application intensities in the laboratory experiment. The results indicated that the WAI of microsprinkler irrigation influenced the è, electrical conductivity (ECe) and pH of saline soils. As the WAI increased, the average values of è and ECe in the 0–40 cm profile also increased, while their average values in the 40–60 cm profile decreased. The pH value also slightly decreased as depth increased, but no significant differences were observed between the different treatments. The time periods of the water redistribution treatments had no obvious effects. Based on the results for è, ECe and pH, a smaller WAI was more desirable. The field experiment was conducted after being considered the results of the technical parameter experiment and evaporation, wind and leaching duration. The field experiment included three stages of water and salt regulation, based on three soil matric potentials (SMP), in which the SMP at a 20-cm depth below the surface was used to trigger irrigation. The results showed that the microsprinkler irrigation created an appropriate environment for festuca growth through the three stages of water and salt regulation. The low-salinity conditions that occurred at 0–10 cm depth during the first stage (−5 kPa) continued to expand through the next two stages. The average pH value was less than 8.5. The tiller number of festuca increased as SMP decreased from the first stage to the third stage. After the three stages of water and salt regulation, the highly saline soil gradually changed to a low-saline soil. Overall, based on the salt desalinization, the microsprinkler irrigation and three stages of water and salt regulation could be successfully used to cultivate plants for the reclamation of coastal saline land in North China.
    Evaluation of nitrogen requirement and efficiency of rice in the region of Yangtze River Valley based on large-scale field experiments
    CONG Ri-huan, ZHANG Zhi, LU Jian-wei, LI Xiao-kun, REN Tao, WANG Wei-ni
    2015, 14(10): 2090-2098.  DOI: 10.1016/S2095-3119(14)60946-1
    Abstract ( )   PDF in ScienceDirect  
    Overestimation of nitrogen (N) uptake requirement is one of the driving forces of the overuse of N fertilization and the low efficiency of N use in China. In this study, we collected data from 1 844 site-years of rice (Oryza sativa L.) under various rotation cropping systems across the Yangtze River Valley. Selected treatments included without (N0 treatment) and with N application (N treatment) which were recommended by local technicians, with a wide grain range of 1.5–11.9 t ha–1. Across the 1 844 site-years, over 96% of the sites showed yield increase (relative yield>105%) with N fertilization, and the increase rates decreased from 78.9 to 16.2% within the lowest range <4.0 to the highest >6.5 t ha–1. To produce one ton of grain, the rice absorbed approximately 17.8 kg N in the N0 treatment and 20.4 kg N in the N treatment. The value of partial factor productivity by N (PFPN) reached a range of 35.2–51.4 kg grain kg–1 with N application under the current recommended N rate. Averaged recovery rate of N (REN) was above 36.0% in yields below 6.0 t ha–1 and lower than 31.7% in those above 6.0 t ha–1. Soil properties only affected yield increments within low rice yield levels (<5.5 t ha–1). There is a poor relationship between N application rates and indigenous nitrogen supply (INS). From these observations and considering the local INS, we concluded there was a great potential for improvement in regional grain yield and N efficiency.
    Responses of plant diversity and primary productivity to nutrient addition in a Stipa baicalensis grassland, China
    YU Li, SONG Xiao-long, ZHAO Jian-ning, WANG Hui, BAI Long, YANG Dian-lin
    2015, 14(10): 2099-2108.  DOI: 10.1016/S2095-3119(14)61001-7
    Abstract ( )   PDF in ScienceDirect  
    Nutrient addition can affect the structure and diversity of grassland plant communities, thus alter the grassland productivity. Studies on grassland plant community composition, structure and diversity in response to nutrient addition have an important theoretical and practical significance for the scientific management of grassland, protection of plant diversity and the recovery of degraded grassland. A randomized block design experiment was conducted with six blocks of eight treatments each: control (no nutrient addition) and K, P, N, PK, NK, NP, and NPK addition. We evaluated plant composition, height, coverage, density, and aboveground biomass to estimate primary productivity and plant diversity. Results showed that all treatments increased primary productivity significantly (P<0.05) with the exception of the K and the NPK treatments had the greatest effect, increasing aboveground biomass 2.46 times compared with the control (P<0.05). One-way ANOVA and factorial analysis were used for the species richness, Shannon-Wiener index, Pielou index and aboveground biomass, and the relationships between the diversity indices and aboveground biomass were determined through linear regression. We found that fertilization altered the community structure; N (but not P or K) addition increased the proportion of perennial rhizome grasses and significantly reduced that of perennial forbs (P<0.05), thus it presented a trend of decrease in species richness, Shannon-Wiener and Pielou indexex, respectively. Only the main effects of N had significant impacts on both the diversity indices and the aboveground biomass (P<0.05), and the interactions between N-P, N-K, P-K and N-P-K could be neglected. With fertilization, plant diversity (correlation coefficient, –0.61), species richness (–0.49), and species evenness (–0.51) were all negatively linearly correlated with primary productivity. The correlations were all significant (P<0.01). Scientific nutrient management is an effective way to improve grassland productivity, protect the plant diversity as well as recover the degraded grassland.
    Agricultural Economics And Management
    Is the crop insurance program effective in China? Evidence from farmers analysis in five provinces
    WANG Ke, ZHANG Qiao, Shingo Kimura, Suraya Akter
    2015, 14(10): 2109-2120.  DOI: 10.1016/S2095-3119(14)60842-X
    Abstract ( )   PDF in ScienceDirect  
    This paper aims to evaluate the effectiveness of the Chinese crop insurance program in terms of farmers’ utility and welfare. A simulation model based on the power utility function was first developed to evaluate the effectiveness of crop insurance. Then, the Monte Carlo approach was used to generate the datasets of area, price, yield, cost, and income based on the characteristics of representative farmers, which were clustered and calibrated using the farm-level data of 574 individual farmers from five Chinese provinces. Finally, the effectiveness of Chinese crop insurance was evaluated by comparing the certainty equivalence (CE) of farmers’ utility/welfare under alternative crop insurance scenarios. Government subsidy is a necessary premise for implementing the crop insurance program. The government should subsidize more than 50% of the crop insurance premium to motivate more farmers to participate in the program. The findings also show that the current crop insurance program in China has increased the farmers’ welfare but still need to be improved to achieve the Pareto improvement and to make full use of the financial fund of the government. This paper is believed to not only extend academic research but also has significant implications for policymakers, especially in the context of rapid development of Chinese crop insurance with much issues such as rate, subsidy and coverage level needed to be improved.
    Empirical study on optimal reinsurance for crop insurance in China from an insurer’s perspective
    ZHOU Xian-hua, WANG Yun-bo, ZHANG Hua-dong, WANG Ke
    2015, 14(10): 2121-2133.  DOI: 10.1016/S2095-3119(14)60998-9
    Abstract ( )   PDF in ScienceDirect  
    This study investigates the optimal reinsurance for crop insurance in China in an insurer’s perspective using the data from Inner Mongolia, Jilin, and Liaoning, China. On the basis of the loss ratio distributions modeled by AnHua Crop Risk Evaluation System, we use the empirical model developed by Tan and Weng (2014) to study the optimal reinsurance design for crop insurance in China. We find that, when the primary insurer’s loss function, the principle of the reinsurance premium calculation, and the risk measure are given, the level of risk tolerance of the primary insurer, the safety loading coefficient of the reinsurer, and the constraint on reinsurance premium budget affect the optimal reinsurance design. When a strict constraint on reinsurance premium budget is implemented, which often occurs in reality, the limited stop loss reinsurance is optimal, consistent with the common practice in reality. This study provides suggestions for decision making regarding the crop reinsurance in China. It also provides empirical evidence for the literature on optimal reinsurance from the insurance market of China. This evidence undoubtedly has an important practical significance for the development of China’s crop insurance.