The foundation parents play key roles in the genetic improvement of both yield potential and end-use quality in wheat.  Characterizing the genetic basis that underlies certain beneficial traits in the foundation parents will provide theoretical reference for molecular breeding by a design approach.  ‘Kenong 9204’ (KN9204) is a candidate foundation parent characterized by ideotype, high yield potential, and particularly high nitrogen fertilizer utilization.  To better understand the genetic basis of its high yield potential, high throughput whole-genome re-sequencing (10×) was performed on KN9204, its parental lines and its derivatives.  A high-resolution genetic composition map of KN9204 was constructed, which showed the parental origin of the favorable genomic segments based on the identification of excellent yield-related quantitative trait loci (QTL) from a bi-parental mapping population.  Xiaoyan 693 (XY693), a wheat–Thinopyrum ponticum partial amphidiploid, contributed a great deal to the high yield potential of KN9204, and three major stable QTLs from XY693 were fine mapped.  The transmissibility of key genomic segments from KN9204 to its derivatives were delineated, indicating that haplotype blocks containing beneficial gene combinations were conserved along with directional selection by breeders.  Evidence for selection sweeps in the breeding programs was identified.  This study provides a theoretical reference for the breeding of high-yield wheat varieties by a molecular design approach.

Soil organic carbon (SOC) is the most important indicators of soil quality and health.  Identifying the spatial distribution of SOC and its influencing factors in cropland is crucial to understand the terrestrial carbon cycle and optimize agronomic management.  Yunnan Province, characterized by mountainous topography and varied elevation, is one of the highest SOC regions in China.  Yet its SOC stock of cropland and influencing factors has not been fully studied due to the lack of adequate soil investigation.  In this study, the digital mapping of SOC at 1 km resolution and the estimation of total SOC stock in cropland of Yunnan Province was undertaken using 8 637 topsoil (0–20 cm) samples and a series of spatial data through Random Forest (RF) model.  It was showed that across the cropland of Yunnan Province, the mean SOC density and total stock were 4.84 kg m^–2 and 337.5 Mt, respectively.  The spatial distribution indicated that relatively high SOC density regions resided in the northwest and northeast parts of Yunnan Province.  Elevation (19.5%), temperature (17.3%), rainfall (14.5%), and Topographic wetness index (9.9%) were the most important factors which controlled spatial variability of SOC density.  Agronomic practices (e.g., crop straw treatments, fertilizer management) should be optimized for the sustainable development of crop production with high SOC sequestration capacity in Yunnan Province.

Distribution system will affect the labor incentive that has been heatedly discussed by recent literatures. Using a unique micro dataset, this paper demonstrates that the equalitarian distribution system is one of the reasons for the insufficient labor incentive during the Chinese Collective Agriculture period. Specifically speaking, in the distribution of basic rations, the proportion for children (aged 1–3 and 4–7 years) was often beyond their nutrition demand, resulting the dissatisfaction of other families with more laborers and less children, thus these households will reduce their labor supply gradually. At the same time, the existence of outstanding accounts makes it a failure to use work points to buy distributions, which is the mechanism of the distribution system and insufficient labor incentive. All the results have been accepted by the robustness tests. The study will help to understand the distribution system and labor incentive, as well as the failure of the Chinese collective agriculture.

Cotton plants are recalcitrant with regards to transformation and induced regeneration.  In the present study, 5-enolpyruvylshikimate-3-phosphate (EPSPS), a glyphosate resistant gene from the bacterium Agrobacterium sp. strain CP4, was introduced into an elite Bt transgenic cotton cultivar with a modified technique involving in planta Agrobacterium-mediated transformation of shoot apex.  Primary transformants were initially screened using a 0.26% glyphosate spray and subsequently by PCR analysis.  Five out of 4 000 transformants from T₁ seeds were obtained resulting in an in planta transformation rate of 0.125%.  Four homozygous lines were produced by continuous self-fertilization and both PCR-based selection and glyphosate resistance.  Transgene insertion was analyzed by Southern blot analysis.  Gene transcription and protein expression levels in the transgenic cotton lines were further investigated by RT-PCR, Western blot, and ELISA methods.  Transgenic T₃ plants were resistant to as much as 0.4% of glyphosate treatments in field trials.  Our results indicate that the cotton shoot apex transformation technique which is both tissue-culture and genotype-independent would enable the exploitation of transgene technology in different cotton cultivars.  Since this method does not require sterile conditions, the use of specialized growth media or the application of plant hormones, it can be conducted under the greenhouse condition.

This experiment was conducted to investigate the effects of feed conditioners (single-layer, double-layer and retention-conditioner) on the growth performance, meat quality and intestinal morphology of pigs throughout the growing to finishing phase.  A total of 96 growing pigs ((28.70±3.20) kg) were selected and randomized into three treatment groups with four replicates per group.  Eight pigs were used per replicate for the 17-week feeding trial.  The grower diet was given at 0 to 6 weeks and a finisher diet was given at 6 to 17 weeks.  The treatments were as follows: SC diet (control; single-layer conditioning), DC diet (double-layer conditioning), and RC diet (retention-conditioning).  Starch gelatinization was significantly higher (P<0.05) in the RC treatment than in the SC treatment, however, there was no significant difference in the starch gelatinization between the DC group and the RC group.  In the growing phase, the feed to gain index (F:G) was significantly lower (P<0.05) in the RC group than in the SC and DC groups.  Between growing and finishing, the F:G was the lowest (P<0.05) in the SC group compared to the RC or DC group.  Drip loss, a measurement of meat quality, was significantly lower (P<0.05) in longissimus dorsi tissue collected from pigs fed the RC diet than in tissues collected from pigs fed the SC diet.  The intestinal quality of the duodenum and jejunum tissues showed a significant increase (P<0.05) in the crypt depth and villus height in the RC group compared to the SC- or DC-treated pigs.  These results demonstrated that the retention-conditioner treatment decreased the F:G in growing pigs, improved intestinal morphology and enhanced the meat quality in the finishing pigs.  However, the retention-conditioner treatment had a negative impact on growth performance in the finishing pigs.

Traditionally, Chinese indigenous cattle is geographically widespread.  The present study analyzed based on genome-wide variants to evaluate the genetic background among 157 individuals from four representative indigenous cattle breeds of Hubei Province of China: Yiling yellow cattle (YL), Bashan cattle (BS), Wuling cattle (WL), Zaobei cattle (ZB), and 21 individuals of Qinchuan cattle (QC) from the nearby Shanxi Province of China.  Linkage disequilibrium (LD) analysis showed the LD of YL was the lowest (r2=0.32) when the distance between markers was approximately 2 kb.  Principle component analysis (PCA), and neighbor-joining (NJ)-tree revealed a separation of Yiling yellow cattle from other geographic nearby local cattle breeds.  In PCA plot, the YL and QC groups were segregated as expected; moreover, YL individuals clustered  together more obviously.  In the NJ-tree, the YL group formed an independent branch and BS, WL, ZB groups were mixed.  We then used the FST statistic approach to reveal long-term selection sweep of YL and other 4 cattle breeds.  According to the selective sweep, we identified the unique pathways of YL, associated with production traits.  Based on the results, it can be proposed that YL has its unique genetic characteristics of excellence resource, and it is an indispensable cattle breed in China.   

Plant structures and chemicals, which are developed from the shoot apical meristem (SAM), form the main barriers to insect feeding.  A plant chimera containing cells of different genetic origins in the SAM will be morphologically and chemically different compared with the parents and thus may result in differential resistance to herbivores.  In this study, we explore if particular elements of plant resistance are localized in one of the layers of SAM; the replacement of one cell layer in a chimera may be linked to change of a single resistance trait to herbivores.  The morphology and glucosinolate profiles of two periclinal chimeras (labeled as TTC and TCC, respectively) and grafted parents tuber mustard (labeled as TTT) and red cabbage (labeled as CCC) were compared and the performance of whitefly (Bemisia tabaci) in host selection, oviposition preference and development were assessed under controlled conditions.  Both chimeras possessed leaf trichomes as parent tuber mustard TTT, however, TTC had significantly more trichomes than TCC and parent TTT.  Leaf wax content of both chimeras was intermediate between the two parents.  Five aliphatic and two indole glucosinolates were detected in both chimeras, whereas three aliphatic glucosinolates (3-methyl-sulfinylpropyl, 4-methyl-sulfinylbutyl and 2-hydroxy-3-butenyl) were not detected in tuber mustard, and one aliphatic glucosinolate (3-butenyl) was not detected in red cabbage.  Unexpectedly for a chimera, the quantities of two aliphatic glucosinolates (3-methyl-sulfinylpropyl and 4-methyl-sulfinylbutyl) in both TTC and TCC were 3- to 5-fold higher than parents.  In olfactory preference assays, B. tabaci showed preference to CCC, followed by TCC, TTC and TTT, and number of eggs laid showed the same pattern: CCC>TCC>TTC>TTT.  Interestingly, more whiteflies landed on TTT plants than the other three types in a free choice experiment and the developmental duration from egg to adult was the shortest on TTT and increased in the order TTT<TTC<TCC<CCC.  Our results indicate plant defenses traits of leaf waxes, trichomes and glucosinolates are not controlled by one cell layer of SAM, but are influenced by interactions amongst cell layers.  The overall findings suggest that periclinal chimera systems can be a valuable approach for the study of plant-insect interactions and may also be useful for future resistance breeding. 

    This study was conducted to evaluate the effect of lactic acid bacteria and propionic acid on the fermentation quality, aerobic stability and in vitro gas production kinetics and digestibility of whole-crop corn based total mixed ration (TMR) silage. Total mixed ration was ensiled with four treatments: (1) no additives (control); (2) an inoculant (Lactobacillus plantarum) (L); (3) propionic acid (P); (4) propionic acid+lactic acid bacteria (PL). All treatments were ensiled in laboratory-scale silos for 45 days, and then subjected to an aerobic stability test for 12 days. Further, four TMR silages were incubated in vitro with buffered rumen fluid to study in vitro gas production kinetics and digestibility. The results indicated that all TMR silages had good fermentation characteristics with low pH (<3.80) and ammonia nitrogen (NH₃-N) contents, and high lactic acid contents as well as Flieg points. Addition of L further improved TMR silage quality with more lactic acid production. Addition of P and PL decreased lactic acid and NH3-N contents of TMR silage compared to the control (P<0.05). After 12 days aerobic exposure, P and PL silages remained stable, but L and the control silages deteriorated as indicated by a reduction in lactic acid and an increase in pH, and numbers of yeast. Compared to the control, addition of L had no effects on TMR silage in terms of 72 h cumulative gas production, in vitro dry matter digestibility, metabolizable energy, net energy for lactation and short chain fatty acids, whereas addition of PL significantly (P<0.05) increased them. L silage had higher (P<0.05) in vitro neutral detergent fiber digestibility than the control silage. The results of our study suggested that TMR silage prepared with whole-crop corn can be well preserved with or without additives. Furthermore, the findings of this study suggested that propionic acid is compatible with lactic acid bacteria inoculants, and when used together, although they reduced lactic acid production of TMR silage, they improved aerobic stability and in vitro nutrients digestibility of TMR silage.

We carried out a pool culture experiment to determine the optimal water treatment depth in loam and clay soils during the late growth stage of super rice.  Three controlled water depth treatments of 0–5, 0–10 and 0–15 cm below the soil surface were established using alternate wetting and drying irrigation, and the soil water potential (0 to –25 kPa) was measured at 5, 10 and 15 cm.  A 2-cm water layer was used as the control.  We measured soil enzyme activities, root antioxidant enzyme activities, chlorophyll fluorescence parameters, and rice yield.  The results showed that the 0–5-cm water depth treatment significantly increased root antioxidant enzyme activities in loam soil compared with the control, whereas soil enzyme activities, chlorophyll fluorescence parameters and yield did not differ from those of the control.  The 0–10- and 0–15-cm water depth treatments also increased root antioxidant enzyme activities, whereas soil enzyme activities, chlorophyll fluorescence parameters and yield decreased.  In clay soil, the soil enzyme activities, root antioxidant enzyme activities, chlorophyll fluorescence parameters, and yield did not change with the 0–5-cm water treatment, whereas the 0–10- and 0–15-cm water treatments improved these parameters.  Therefore, the appropriate depths for soil water during the late growth period of rice with a 0 to –25 kPa water potential were 5 cm in loam and 15 cm in clay soil.

Genomic selection has been demonstrated as a powerful technology to revolutionize animal breeding.  However, marker density and minor allele frequency can affect the predictive ability of genomic estimated breeding values (GEBVs).  To investigate the impact of marker density and minor allele frequency on predictive ability, we estimated GEBVs by constructing the different subsets of single nucleotide polymorphisms (SNPs) based on varying markers densities and minor allele frequency (MAF) for average daily gain (ADG), live weight (LW) and carcass weight (CW) in 1 059 Chinese Simmental beef cattle.  Two strategies were proposed for SNP selection to construct different marker densities: 1) select evenly-spaced SNPs (Strategy 1), and 2) select SNPs with large effects estimated from BayesB (Strategy 2).  Furthermore, predictive ability was assessed in terms of the correlation between predicted genomic values and corrected phenotypes from 10-fold cross-validation.  Predictive ability for ADG, LW and CW using autosomal SNPs were 0.13±0.002, 0.21±0.003 and 0.25±0.003, respectively.  In our study, the predictive ability increased dramatically as more SNPs were included in analysis until 200K for Strategy 1.  Under Strategy 2, we found the predictive ability slightly increased when marker densities increased from 5K to 20K, which indicated the predictive ability of 20K (3% of 770K) SNPs with large effects was equal to the predictive ability of using all SNPs.  For different MAF bins, we obtained the highest predictive ability for three traits with MAF bin 0.01–0.1.  Our result suggested that designing a low-density chip by selecting low frequency markers with large SNP effects sizes should be helpful for commercial application in Chinese Simmental cattle.

This experiment was conducted to study the effect of molasses on the fermentation characteristics of mixed silage ensiled rice straw and vegetable by-products with alfalfa.  Mixture (202 g kg^–1 dry matter (DM)) consisting of rice straw, broccoli residue and alfalfa at the ratio of 5:4:1 was ensiled with three experimental treatments: (1) no additives (control); (2) molasses at 2.5% (M1); (3) molasses at 5% (M2) on a fresh matter basis of mixture, respectively.  All treatments were packed into laboratory-scale silos, and three silos per treatment were sampled on days 1, 3, 5, 14 and 30.  The result showed that the pH value of all mixed silages decreased gradually with the time of ensiling except for the control silage, in which a significant increase (P<0.05) on day 30 occurred.  The lactic acid content increased gradually with the time of ensiling and reached the highest value on day 14, and a marked decrease (P<0.05) was found in the control silage on day 30.  The changes of acetic acid content showed similar pattern with lactic acid content.  A trace amount of propionic and butyric acid contents were found in the three mixed silages during the fermentation period.  Comparing to the control, M1 and M2 treatments improved the fermentation quality of mixed silages as indicated by higher (P<0.05) lactic acid contents and lower (P<0.05) pH and ammonia-N contents.  The Flieg points also showed that M1 and M2 silages were well preserved, whereas the control silage had a bad quality.  Overall, the findings of this study suggested that adding molasses could improve fermentation quality of mixed silage, and M1 was more suitable for practical application.

We compared the ground-dwelling beetle assemblages under four scenarios in which transgenic Bt (Cry 1Ac) cotton (33B), transgenic Bt (Cry 1Ac)+CpTI cotton (SGK321), conventional cotton (33), conventional cotton (Shiyuan 321) in North China. During the survey in two years (2009–2010), 24 ground beetle species were captured with pitfall traps in 20 plots which included five replicates for each cotton type. No significant difference was observed in the number of ground beetle species captured, activity density, evenness and Shannon-Wiener diversity among the four cotton varieties. Chlaenius posticalis was less abundant in transgenic Bt+CpTI cotton (SGK321) fields than its conventional cotton (Shiyuan 321), but more abundant in transgenic Bt cotton (33B) fields compared with its conventional cotton (33). There was no significant difference for other abundant species between in transgenic cotton and in conventional cotton fields. Based on non-metric multidimensional scaling (NMDS) analysis, ground-dwelling beetle assemblages were similar in transgenic and conventional cotton over the two years, but the ground-dwelling beetle assemblages in transgenic cotton 33B significantly differed from that in the conventional cotton (strain 33) in 2010. No strong evidence that the transgenic cotton effect on ground-dwelling beetle assemblages was found in this study.

  Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) are essential components required for normal cellular function and have been shown to have important therapeutic and nutritional benefits in humans. But humans or mammals cannot naturally produce ω-3 PUFAs, due to the lack of the ω-3 fatty acid desaturase gene (fat-1 gene). Previously, fat-1 gene has been cloned from Caenorhabditis elegans and transferred into mice, pigs and sheep, but not yet into beef cattle. We attempt to transfer it into beef cattle. The object of this paper is to edit the fat-1 gene from C. elegans to express more efficiently in beef cattle and verify its biological function in mice model. As a result, the fat-1 gene from C. elegans was modified by synonymous codon usage and named it Bfat-1. We have demonstrated that degree of codon bias of Bfat-1 gene was increased in beef cattle. Moreover, Bfat-1 gene could be transiently expressed in mouse liver and muscle, the ω-6/ω-3 PUFAs ratio of 18 and 20 carbon was decreased significantly in liver (P<0.05), and the ratio of 20 carbon decreased significantly in muscle 24 and 72 h after injection (P<0.05). This confirms that the Bfat-1 gene modification was successful, and the protein encoded was able to catalyze the conversion of ω-6 PUFAs to ω-3 PUFAs.

Skin grafting has been used as one of the most reliable tests to determine the genetic stability of laboratory animal such as mice and rats inbred line, but no identification of swine inbred lines by skin grafting has been reported. At present, Wuzhishan miniature pig (WZSP) inbred line has acquired the F24 individuals in China. In order to verify whether WZSP inbred line had been cultivated successfully, allogeneic skin grafts and related research were performed on F20 individuals of WZSP inbreeding population, compared with a control group of autologous transplantation. We observed the transplant recipients’ wounds, detected peripheral blood-related indicators interleukin-2, 4 and 10, CD4+ and CD8+ lymphocytes, and conducted hematoxylin-eosin (HE) and Masson’s staining of skin to judge whether the immune rejection reactions occurred within 28 days after transplantation. Chr. 7 genomic heterozygosity of 48 WZSP individuals from F20 to F22 was analyzed by high-density single nucleotide polymorphism (SNP) chips (60 000 SNPs). The result showed that there were no significant differences in graft skin, the plasma interleukin-2, 4, 10, CD4+ and CD8+, HE and Masson’s staining results between the allograft and autograft groups, and no immune rejection occurred on the allograft group. We found that 11 genes in Chr. 7 of major histocompatibility complex (MHC) I and MHC II were homozygous which confirmed that immune antibody of the allograft and autograft groups were highly identical and also provided a theoretical basis to no immune rejection occurred on the allograft in the inbred WZSP. The result proved that the WZSP inbred line had been cultivated successfully for the first time in the world. The test methods also provide a scientific basis for the identification of swine and mammal inbred lines.

Rice panicles are composed of many branches with two types of extreme grains, the superior and the inferior. Traditionally, it has been well accepted that earlier flowers result in superior grains and late flowers generate inferior grains. However, these correlations have never been strictly examined in practice. In order to determine the accurate relationship between superior and inferior grains and the flowering order, we localized all the seeds in a panicle in four distinct rice species and systematically documented the rice flowering order, flower locations and the final grain weight for their relationships. Our results demonstrated that the grain weight is more heavily determined by the position of the seeds than by the flowering order. Despite earlier flowering has a positive correlation with the grain weight in general, grains from flowers blooming on the second day after anthesis generally gained the highest weight. This suggests earlier flowers may not result in superior grains. Therefore, we concluded that superior and inferior grains, commonly determined by grain weight, are not fully correlated with the flowering order in rice. Following the order of the grain weight, the superior grains are generally localized at the middle parts of the primary branches, whereas inferior grains were mainly on the last two secondary branches of the lower half part of the panicle. In addition, the weight of inferior grains were affected by spikelet thinning and spraying with exogenous plant growth regulators, indicating that physiological incompetence might be the major reason for the occurrence of the inferior grains.

Heading date of rice is a key agronomic trait determining cultivated areas and seasons and affecting yield. In the present study, five primary single segment substitution lines with the same genetic background were used to detect quantitative trait loci (QTLs) for heading date in rice. Two QTLs, qHD3 and qHD6 on the short arm of chromosome 3 and the short arm of chromosome 6, respectively, were identified under natural long-day (NLD). Nineteen secondary single segment substitution lines (SSSLs) and seven double segments pyramiding lines were designed to map the two QTLs and to evaluate their epistatic interaction between them. By overlapping mapping, qHD3 was mapped in a 791-kb interval between SSR markers RM3894 and RM569 and qHD6 in a 1 125-kb interval between RM587 and RM225. Results revealed the existence of epistatic interaction between qHD3 and qHD6 under natural long-day (NLD). It was also found that qHD3 and qHD6 had significant effects on plant height and yield traits, indicating that both of the QTLs have pleiotropic effects.

Fadrozole, an aromatase inhibitor, can masculinize genetic female chickens and high-dose decreases the hatchability. Therefore, it is important to study the growth and development of sex-reversed females after hatch. Chick embryos from a population of CAU3 egg-type were treated with different concentrations of Fadrozole prior to the sexual differentiation at E3.0 (st18). At hatch, the phenotypic sex and genetic sex were identified by vent sexing and genetic diagnosis with CHD1, respectively. Body weight and shank length of sex reversal were tested at 8 and 20 wk, respectively. Testicular development, oviduct and ovarian degeneration were observed and serum concentration of estradiol and testosterone were tested with radioimmunoassay (RIA) at 30 wk. The results showed that body weight and shank length of sexreversed females were not significantly different between low-dose groups (0.1, 0.3, and 0.5 mg for F1, F2, and F3, respectively) and high-dose groups (1.0 and 1.3 mg for F4 and F5, respectively) (P>0.05). Left and right testes or ovotestes in F2, F3, F4, and F5 groups were heavier than that of in F1 group (P<0.05). While the gonad weight of treatment groups were less than that in male control (P<0.05), oviduct weight in F2, F3, F4, and F5 groups were significant differences compared with female control and F1 group (P<0.05). Egg number from onset of laying egg to 30 wk in F4 and F5 groups were less than in female control, F1 and F2 groups (P<0.05). Serum testosterone level in F5 group was significant higher compared with female control, F1, F2, F3, and F4 groups (P<0.05), but significant lower compared with male control (P<0.05). While concentration of serum estradiol in F5 group was significant lower compared with female control, F1, F2, and F4 groups (P<0.05). In conclusion, the concentration of Fadrozole do not affect postnatal growth of sex-reversed female chicken and the degree of sex-reversed females elevate with the increase of Fadrozole concentration at sex maturity.

The symbiotic matching for nodulation of Bradyrhizobium japonicum strains is a synergy of multi-proteins and plays a key role in symbiotic nitrogen fixation in nature. Studies on mechanism of symbiotic matching are significant in both theory and practice. In this paper, B. japonicum USDA110-A with high symbiotic matching with high-oil content soybean cultivar Suinong 20 and B. japonicum 2178 with low symbiotic matching were selected for proteomic to reveal mechanism of different symbiotic nodulation. The results showed that the amount and categories of proteins identified in this test were different when the two strains were treated by symbiotic nodulation. There were 10 up-regulated proteins and 5 down-regulated proteins with significant difference for B. japonicum USDA110-A. Proteins associated with nodulation and metabolism of energy and material, which were propitious to symbiotic nodulation, were all up-regulated, such as PHDPS synthase, metal-dependent phosphohydrolase, glycosyl transferase family. In contrast, only 5 up-regulated and 7 down-regulated differential proteins were detected in B. japonicum 2178. Molecular chaperones and defensive proteins, which influence the folding of nascent polypeptide chains and the active of azotase were down-regulated. To a certain extent, the different responses of B. japonicum to daidzein were one of the most important reasons that cause varieties in symbiotic matching ability.

China is one of the most important rapeseed producing countries in the world. Effective mechanical harvesting time for decreasing harvesting loss of winter oilseed rape has been becoming a critical factor. An elite cultivar Zhongshuang 11 (Brassica napus L.) was employed in two rounds of field experiments from 2009 to 2011. Seeds were sown with machine, three combine harvesting times namely combine harvesting A, B, and C (CHA, CHB, and CHC) were designed and manual harvesting (MH) as control was performed at maturity. The harvesting treatments were determined according to color of pod and seed in the field. Seed yield loss and quality in different treatments were evaluated. Results showed that both seed yields and harvesting losses in 2009-2010 were higher than that in 2010-2011, whereas seed oil contents in 2010-2011 were higher than that in 2009-2010. The highest yield appeared in CHB, which was significantly higher than that in MH. Furthermore, harvesting loss in CHB were 50% that in MH. Seed oil content and chlorophyll exhibited no obvious difference between CHB and MH. Economic profit analysis demonstrated that mechanical sowing/combine harvesting (MS/CH) showed an input/output ratio of 1:1.6, and it was 1:1.2 in mechanical sowing/manual harvesting (MS/MH). Labor-cost accounted for more than 70% of the total cost in MS/MH, which led to low profitability to a great extent. Our results suggested that CHB was the optimum harvesting time for winter oilseed rape along the Yangtze River.

Identification of new chlorophyll-deficient mutants will provide materials for studying signaling components and pathways between plastid and nucleus. A novel chlorophyll-deficient mutant, named Mt6172, was obtained by spaceflight environment induction. Genetic analysis showed that its inheritance was controlled by nuclear and cytoplamic genes. Leaf color of its self-fertilized progenies was albino, narrow-white striped, or green. Only a few cells with abnormal chloroplasts were observed in albino plants and white section of narrow-white striped plants. These chloroplasts had obvious flaws in inner structure, and granum lamellae was extremely disordered. The narrow-white striped plants were characterized with greenand- narrow-white striped leaves, and the width of stripes between different plants was even, their plant height, number of productive tillers, and 1 000-grain weight were lower than those of the wild type. The narrow-white striped plants and the wild type had significant difference in the value of potential activity of photosystem II at all tested stages. At elongation stage, which was impacted the most seriously, effective quantum yield significantly decreased, whereas the energy for photoprotection and photodamage significantly increased. Under different photosynthetic active radiation conditions, changes of electron transport rate, photochemical dissipation, and effective quantum yield were different, electron transport rate was more impacted than other parameters. Therefore, the leaf morphology and inheritance of mutant Mt6172 was different from the other reported mutants in wheat, and it was a novel mutant of chlorophyll deficiency.

Cold stress responses help insects to survive under low temperatures that would be lethal otherwise. This phenomenon might contribute to the invasion of some Bemisia tabaci cryptic species from subtropical areas to temperate regions. However, the molecular mechanisms regulating cold stress responses in whitefly are yet unclear. Mitogen-activated protein kinases (MAPKs) which including p38, ERK, and JNK, are well known for their roles in regulating metabolic responses to cold stress in many insects. In this study, we explored the possible roles of the MAPKs in response to low temperature stresses in the Mediterranean cryptic species (the Q-biotype) of the B. tabaci species complex. First, we cloned the p38 and ERK genes from the whitefly cDNA library. Next, we analyzed the activation of MAPKs during cold stress in the Mediterranean cryptic species by immuno-blotting. After cold stress, the level of phospho-p38 increased but no significant change was observed in the phosphorylation of ERK and JNK, thus suggesting that the p38 might be responsible for the defense response to low temperature stress. Furthermore, we demonstrated that: i) 3 min chilling at 0°C was sufficient for the activation of p38 MAPK pathway in this whitefly; and ii) the amount of phosphorylated p38 increased significantly in the first 20 min of chilling, reversed by 60 min, and then returned to the original level by 120 min. Taken together, our results suggest that the p38 pathway is important during response to low temperature stress in the Mediterranean cryptic species of the B. tabaci species complex.

Competitiveness for nodulation of Bradyrhizobium japonicum strains plays a key role in symbiotic nitrogen fixation. Inorder to reveal the difference in competitiveness, B. japonicum 4534 with high competitiveness and B. japonicum 4222with low competitiveness for nodulation were analyzed by proteomic technique. The results showed that differentialproteins were fewer when two strains were treated with just daidzein. Only 24 and 10 differential proteins were detectedwith an up-regulated rate of 58 and 40% in B. japonicum 4534 and B. japonicum 4222, respectively. However, moredifferential proteins were detected upon treatment with daidzein and mutual extracellular materials simultaneously. Therewere 78 differential proteins detected in B. japonicum 4534 with 43 being up-regulated and 35 being down-regulated.These differential proteins, such as metabolism-related proteins, transporters, transcription-related proteins, translationrelatedproteins, and flagellin, were found to be associated with nodulation process. 25 up-regulated and 22 down-regulatedproteins were detected in B. japonicum 4222. Some of these proteins were not related to nodulation. More differentialproteins associated with nodulation in B. japonicum 4534 may be the reason for its high competitiveness. The results canprovide a guide to the selection and inoculation of effective strains and are significant to biological nitrogen fixation.

Synthetic hexaploid wheat (SHW) represents a valuable source of new resistances to a range of biotic and abiotic stresses. A recombinant inbred line (RIL) population with 127 recombinant inbred lines derived from a SHW-derived variety Chuanmai 42 crossing with a Chinese spring wheat variety Chuannong 16 was used to map QTLs for agronomic traits including grain yield, grains per square meter, thousand-kernel weight, spikes per square meter, grain number per spike, grains weight per spike, and biomass yield. The population was genotyped using 184 simple-sequence repeat (SSR) markers and 34 sequence-related amplified polymorphism (SRAP) markers. Of 76 QTLs (LOD>2.5) identified, 42 were found to have a positive effect from Chuanmai 42. The QTL QGy.saas-4D.2 associated with grain yield on chromosome 4D was detected in four of the six environments and the combined analysis, and the mean yield, across six environments, of individuals carrying the Chuanmai 42 allele at this locus was 8.9% higher than that of those lines carrying the Chuannong 16 allele. Seven clusters of the yield-coincident QTLs were detected on 1A, 4A, 3B, 5B, 4D, and 7D.