三黄鸡是中国的优质地方鸡品种，因黄羽、黄爪和黄喙得名。然而，三黄鸡黄胫变“青胫”的异常现象一直是人们关注的问题，它严重降低了黄羽肉鸡的胴体质量和经济效益。在本研究中，首先系统地调查了鸡小腿异常肤色的原因。生理学解剖显示，鸡胫部皮肤异常主要是由于真皮下的黑色素沉积引起的。通过分析遗传（谱系和遗传标记）、环境（水质监测）和饲料成分（真菌毒素检测）等多种潜在原因，发现饲料中黄曲霉毒素B1(AFB1)严重超标，会伴随较高的L-2羟基苯丙氨酸（L-DOPA）（P<0.05）和黑色素含量（P<0.01）。因此推测过量的AFB1可能是导致小腿皮肤异常绿色的主要原因。

随后，进一步的结果表明，与正常的AFB1含量（<10μg kg^-1）相比，高浓度的AFB1（>170μg kg^-1）确实诱导了小腿胫部的异常皮肤颜色，且与黑色素沉积相关的MC1R和EDN3基因显著上调（P<0.01），酪氨酸酶（TyR）的含量和活性也显著增加（P<0.05）。同时，L-DOPA的含量和黑色素沉积也显著增加（P<0.01）。这也证实了过量AFB1对小腿皮肤黑色素沉积的影响。进一步的实验结果表明，AFB1对小腿皮肤黑色素沉积的负面影响可能会持续更长时间，不易消除。总之，本研究的结果解释了鸡小腿中异常AFB1相关青胫的发生及其可能机制。饲粮中过量的AFB1可能通过促进TyR含量和活性以及黑色素合成相关基因的表达，增加了鸡小腿中的L-DOPA含量和黑色素异常沉积。我们的研究结果有助于再次预警肉鸡生产中黄曲霉毒素B1危害。

本研究选取60只健康状况良好、体重（22.68±2.56 kg）相近的雄性小尾寒羊断奶羔羊，采用完全随机区组试验设计，将60只羔羊随机分为4组，每组15只。DOW替代精料的比例分别为0% (对照组, CON)、 10%（DOW1）、 15%（DOW2）和20%（DOW3）。饲养期共63 d，预试期15 d，正试期48 d，进行羔羊生长性能、血液指标、瘤胃发酵参数和瘤胃微生物菌群的测定。结果表明，DOW2组羔羊的干物质（DMI）摄入量显著高于其他组（P<0.05）。日增重 (ADG) 随着DOW替代精料比例的增加而呈线性增加或二次效应变化（P<0.05），DOW2组羔羊的ADG较对照组更高（P<0.05）。随着DOW替代精料比例的增加，羔羊血浆GH、IGF-1和Insulin的浓度（P<0.05）呈现线性提高或二次效应变化（P<0.05）， 且DOW2组血浆激素含量显著高于对照组。随着DOW替代精料比例的增加，血浆尿素氮（BUN）的浓度（P<0.05）呈线性降低和二次效应变化。DOW替代精料可有效的调节瘤胃代谢及菌群变化。随着DOW替代精料比例的增加，瘤胃NH₃-N的浓度在饲喂后0 h、4 h和8 h呈线性降低（P<0.05），在0 h和4 h时呈二次效应变化（P<0.05）；在饲喂后0 h和4 h后总挥发性脂肪酸（TVFAs）含量呈线性增加（P<0.05）；在饲喂0 h乙酸的含量呈线性增加（P<0.05），饲喂后4 h和8 h时呈二次效应变化（P<0.05）；丙酸的含量在饲喂0 h，4 h和8 h时呈线性降低，乙酸/丙酸比例在0 h，4 h和8 h均呈线性增加（P<0.05）。DOW2组瘤胃中厚壁菌门（Firmicutes）、琥珀酸菌属（Succiniclasticum）和反刍菌属（Ruminococcus_1）的相对丰度显著高于对照组，同时去铁杆菌门（Deferribacteres）、肠杆菌属（Intestinimonas）和反胃梭菌属（Ruminiclostridium）相对丰度显著低于对照组（P<0.05）。综上所述，麻山药下脚料可改善饲料适口性，增加DMI，进而调控瘤胃微生物菌群变化，提高瘤胃发酵效率，促进羔羊生长，在本试验条件下，综合生长性能、血液指标及瘤胃发酵参数，麻山药下脚料的适宜添加比例为15%。本试验首次对麻山药下脚料作为饲料原料对羔羊生长性能及瘤胃发酵参数进行了研究，为降低养殖成本，提高养殖效益，同时对农业废弃物的饲料化利用提供了思路。

分子标记辅助选择(MAS)可以显著提高无核葡萄的育种效率，加快育种进程。本研究基于VviAGL11基因的单碱基突变位点（Chr.18:26889437（A/C））开发了KASP_VviAGL11和VviAGL11_410标记，并以SSR标记p3_VvAGL11、5U_VviAGL11标记作对比，分别在101份葡萄品种和81份葡萄F₁杂交株系进行检测。结果认为KASP_VviAGL11和VviAGL11_410均检测出A等位基因时与葡萄无核性状紧密关联，且准确率为100%，而p3_VvAGL11、5U_VviAGL11由于容易产生假阳性导致准确率偏低。然后通过评估不同标记使用的技术优缺点，明确了KASP_VviAGL11标记具有更加简单、经济、高效、精确的优势。最终，本研究优化了以KASP_VviAGL11标记为核心的无核葡萄分子标记辅助选择育种过程，为加快无核葡萄新品种培育进程提供关键技术支持。

家畜脊椎数特别是胸腰椎数存在遗传变异，这些变异与家畜体长和产肉量有关。德州驴是我国著名的地方驴种之一，它的特点是体型大，适应性好，抗粗饲。德州驴群体中胸腰椎数也存在变异。【目的】本研究利用低深度重测序填充数据通过全基因组关联分析挖掘调控德州驴胸腰椎数性状相关的分子标记和候选基因，为未来多胸腰椎数驴的新品种培育奠定理论基础。【方法】对347头德州驴群体进行低深度的全基因组重测序，选用STITCH + Beagle的方法进行基因型的填充，对获得的SNPs进行质控后利用GEMMA软件的线性混合模型和GMMAT软件的logistic混合模型对胸腰椎数性状进行关联分析。SNPs数据进行了连锁不平衡过滤（=0.2）最终获得约35万个有效SNPs，用Bonferroni进行多重检验校正，设置了5%全基因组水平显著关联阈值线P ≤ 1.41×10-7（= 0.05/353,672）以及潜在显著关联的水平P ≤ 2.83×10-6（= 1/353,672）。最终对显著关联的SNPs进行候选基因的鉴定和单倍型分析。【结果】347头德州驴群体平均测序深度为4×，基因型填充后最终获得6,220,779 SNPs，利用18头高深度的德州驴群体对填充准确性进行评估，结果显示平均基因型相关系数是0.98。综合两个关联分析的模型，对于胸椎数性状，我们鉴定出38个全基因组水平显著关联的SNPs和64个潜在显著关联的SNPs，涉及7个基因（NLGN1、DCC、SLC26A7、TOX、WNT7A、LOC123286078和LOC123280142）。对于腰椎数性状，我们鉴定了9个全基因组水平显著关联的SNPs和38个潜在显著关联的SNPs，涉及8个基因（GABBR2、FBXO4、LOC123277146、LOC123277359、BMP7、B3GAT1、EML2和LRP5）。其中多个显著关联SNPs存在紧密的连锁不平衡关系。【结论】本研究利用测序填充数据进行全基因组关联分析，鉴定了多个与胸腰椎数性状显著关联的SNPs和候选基因，其中WNT7A、BMP7和LRP5已知的功能是通过Wnt信号通路和TGF-β信号通路在胚胎体节发育和骨形成过程中发挥作用，可能是驴差异胸腰椎数性状的关键候选基因。

ω-3（亚麻酸、二十二碳六烯酸、二十碳五烯酸）和ω-6（亚油酸、花生四烯酸）多不饱和脂肪酸对人体的健康和正常生理功能至关重要。我们对鸡肉中亚油酸的含量进行了全基因组关联分析 (Genome-wide association study, GWAS)。本研究共鉴定到19个重要SNPs (Single nucleotide polymorphisms, SNPs)，注释到绒毛蛋白样蛋白 (villin like, VILL)、磷脂酶C delta 1 (phospholipase C delta 1, PLCD1) 和氧化应激反应1 (oxidative stress responsive 1, OXSR1) 基因，这些SNPs形成了一个高度连锁的单倍型区间，并解释了亚油酸含量4.5%的表型变异。本研究发现，PLCD1基因表达与亚油酸含量呈负相关，即亚油酸含量低的鸡基因表达量高于含量高的鸡。通路富集分析结果表明PLCD1富集到代谢等通路。同时本研究发现亚油酸含量与挥发性物质（如辛醛等）相关，但与鸡肉中的肌内脂肪和甘油三酯无关。结果表明，PLCD1中存在调节亚油酸含量的关键SNP，它对脂肪沉积没有显著影响，但可能会影响挥发性物质的含量。

叶形是影响陆地棉植株冠层结构和产量的重要农艺性状，同时还与光合效率密切相关，是棉花高光效育种研究的重点。陆地棉叶形根据叶裂深度可分为常态叶、亚鸡脚叶、鸡脚叶和超鸡脚叶，主要由D基因组L-D₁位点的等位基因调控，其对陆地棉叶片形态、冠层结构和光合产量的影响尚不清楚。本研究利用病毒诱导基因沉默技术（VIGS）及叶形参数分析发现L-D₁等位基因对叶形的调控具有基因剂量效应；打顶前，鲁棉研22亚鸡脚叶品系叶面积系数比常态叶品系分别减少8.54%和4.91%，打顶后分别减少8.48%和11.19%；中部冠层透光率打顶前后分别增加71.35%和134.88%，下部冠层透光率打顶前后分别增加123.14%和41.81%；鲁棉研28号遗传背景下，亚鸡脚叶系中部冠层透光率打顶前后分别增加38.88和93.10%，下部冠层透光率打顶前后分别增加28.15和118.62%。鲁棉研22亚鸡脚叶系净光合速率在大部分生育期内可提高0.93～12.45%，在鲁棉研28遗传背景下可提高7.12～13.84%。在两种遗传背景下，亚鸡脚叶品系的最终生物量比常态叶对照分别增加9.43和19.35%，产量也分别增加8.6和7.05%，且同时对纤维品质无不良影响。

WOX基因家族是植物特有的一类转录因子，该家族基因在植物生长发育过程发挥重要的功能。本研究在全基因组水平共鉴定到18个苹果WOX家族基因，通过构建系统发育树将这些基因分为三类，保守结构域和基因结构分析得到的分类结果与系统发育结果一致。同线性分析结果表明全基因组复制和片段重复在苹果WOX家族扩张中发挥重要作用。通过实时荧光定量分析，发现苹果WOX基因呈现组织特异性表达，同时MdWOX4a, MdWOX4b, MdWOX5b, MdWOX11/12a和MdWOX11/12b可能在不定根发生过程起到重要的作用。通过转基因烟草不定根发生能力分析，表明过表达MdWOX4b基因显著增强不定根发生能力。以上研究为以后进一步研究MdWOX基因在苹果砧木发育中的功能奠定了基础。

随着杂交小麦的应用面积逐渐增加，倒伏正在成为其获得高产的主要限制因素之一。然而，关于茎秆相关性状的配合力及其与抗倒伏杂种优势形成的研究较少。本研究，按照不完全双列杂交设计（NCII），以茎秆相关性状显著差异的3个不育系（母本）和8个恢复系（父本）为试验材料，配置24个杂交组合。对基部第二节间长度、基部第二节间抗折力等茎秆相关的8个性状开展主成分分析（PCA）、配合力分析及杂种优势分析。PCA结果表明，8个变量可被提取为两个主要因子，分别为正相关因子（因子1）和负相关因子（因子2），分别解释总变异的52.3％和33.2％。PCA和指标权重分析表明，因子1相关性状在抗倒伏优势形成中起主要作用，研究还表明，茎秆相关性状的遗传以加性效应为主。以恢复系R1，R4，R6及R7与不育系M3配置组合可获得具有较高抗倒伏能力的杂交组合，与其因子2相关性状具有较低的一般配合力效应（GCA），及因子1相关性状具有较高的GCA密切相关。杂种优势分析表明，因子1相关性状（除基部第二节间壁厚外）的GCA或特殊配合力效应（SCA）与抗倒伏杂种优势呈正相关关系。一般而言，抗倒伏杂种优势与不育系因子1相关性状GCA的相关系数显著高于其与恢复系的，此外，不育系因子1相关性状具有更高的方差值，表明，在配置杂交组合时应特别关注不育系因子1相关性状的选择。遗传分析表明，基部第二节间直径和重心高度的狭义遗传力明显低于其他性状（<60％），表明，在亲本选育时这两个性状适合在高世代进行选择。这些发现可为亲本选育和抗倒伏杂种优势的利用提供理论依据。

To date, little attention has been paid to the effects of leaf source reduction on photosynthetic matter production, root function and post-silking N uptake characteristics at different planting densities. In a 2-year field experiment, Xianyu 335, a widely released hybrid in China, was planted at 60 000 plants ha^–1 (conventional planting density, CD) and 90 000 plants ha^–1 (high planting density, HD), respectively. Until all the filaments protruded from the ear, at which point the plants were subjected to the removal of 1/2 (T1), 1/3 (T2) and 1/4 (T3) each leaf length per plant, no leaf removal served as the control (CK). We evaluated the leaf source reduction on canopy photosynthetic matter production and N accumulation of different planting densities. Under CD, decreasing leaf source markedly decreased photosynthetic rate (P_n), effective quantum yield of photosystem II (ΦPSII) and the maximal efficiency of photosystem II photochemistry (F_v/F_m) at grain filling stage, reduced post-silking dry matter accumulation, harvest index (HI), and the yield. Compared with the CK, the 2-year average yields of T1, T2 and T3 treatments decreased by 35.4, 23.8 and 8.3%, respectively. Meanwhile, decreasing leaf source reduced the root bleeding sap intensity, the content of soluble sugar in the bleeding sap, post-silking N uptake, and N accumulation in grain. The grain N accumulation in T1, T2 and T3 decreased by 26.7, 16.5 and 12.8% compared with CK, respectively. Under HD, compared to other treatments, excising T3 markedly improved the leaf P_n, ΦPSII and F_v/F_m at late-grain filling stage, increased the post-silking dry matter accumulation, HI and the grain yield. The yield of T3 was 9.2, 35.7 and 20.1% higher than that of CK, T1 and T2 on average, respectively. The T3 treatment also increased the root bleeding sap intensity, the content of soluble sugar in the bleeding sap and post-silking N uptake and N accumulation in grain. Compared with CK, T1 and T2 treatments, the grain N accumulation in T3 increased by 13.1, 40.9 and 25.2% on average, respectively. In addition, under the same source reduction treatment, the maize yield of HD was significantly higher than that of CD. Therefore, planting density should be increased in maize production for higher grain yield. Under HD, moderate decreasing leaf source improved photosynthetic performance and increased the post-silking dry matter accumulation and HI, and thus the grain yield. In addition, the improvement of photosynthetic performance improved the root function and promoted post-silking N uptake, which led to the increase of N accumulation in grain.

东北平原是中国最大的玉米产区。近年来滴灌技术开始在该区推广应用，以解决玉米生产中干旱频发和水分利用效率(WUE)低下的问题。为确定高效和环境友好的灌溉措施，2016-2018年针对滴灌结合不同农田保水措施进行了大田试验研究，处理如下：(1)塑料薄膜覆盖+滴灌(PI)，(2)生物降解膜覆盖+滴灌(BI)，(3)秸秆深翻还田+滴灌(SI)，(4)浅埋滴灌(OI)，以传统沟灌(FI)为对照。PI和BI处理根长密度(RLD)和营养生长期间土温较高，其产量、WUE和氮素利用效率(NUE)最高。与BI相比，PI处理在20-60 cm和60-100 cm土层中消耗了更多的土壤水分，且0-20 cm土壤上层根系较大，生殖生长期间土温较高，根系和叶片衰老进程加快。SI处理能有效提高土壤水分和硝态氮含量，促进深层RLD增加，从而维持了花后较高的生理活性。FI处理与滴灌相比，60-100 cm土壤深层硝态氮含量较高，增加了氮素淋溶损失的风险。0-20 cm土层中，RLD与产量、WUE和NUE极显著正相关(P<0.001)，与根系氮利用效率(NRE)显著负相关(P<0.05)，这一相关性随土层加深而减弱。在干旱条件下，降解膜覆盖与滴灌耦合有利于玉米稳产和提高土壤水氮利用效率，是一项东北区玉米可持续生产与环境友好的推荐技术。

The objective of this study was to investigate the effect of lactic acid bacteria (LAB) inoculums on fermentation quality and in vitro digestibility of corn stover silage. Corn stover was ensiled without (control) or with Lactobacillus plantarum (LP), Enterococcus faecalis (EF), and Enterococcus mundtii (EM) for 45 days. The fermentation characteristics were assessed, and subsequent in vitro dry matter digestibility (DM-D), neutral detergent fiber digestibility (NDF-D), volatile fatty acids (VFA), methane (CH₄ ) production, cellulolytic bacteria proportions and their activities per corn stover silage were also determined. There was no significant difference (P>0.05) among the silage pH, lactic acid, crude protein (CP), water soluble carbohydrates (WSC) and lignocelluloses contents of different treatments. The relative proportions of Ruminococcus flavefaciens and Fibrobacter succinogenes, carboxymethyl-ocellulose and β-glycosidase activities, DM-D, NDF-D, and VFA production of in vitro incubation was higher (P<0.05) for silages inoculated with LP and EF than those of the control silage. Silage inoculated with LP showed the lowest (P<0.05) CH₄ production per unit yield of VFA, which was positively corresponded to the lowest (P<0.05) ratio of acetate to propionate. In summary, the ensiling fermentation quality and subsequent utilization of corn stover silage were efficiently improved by inoculated with L. plantarum.

Because of the yield increase of 3.5–15% compared to conventional wheat, hybrid wheat is considered to be one of the main ways to greatly improve the wheat yield in the future.  In this study, we performed a principal component analysis (PCA) on two-line hybrids wheat and their parents using the grain weight (GW), the length of spike (LS), the kernel number of spike (KSN), and spike number (SPN) as variables.  The results showed that the variables could be classified into three main factors, the weight factor (factor 1), the quantity factor 1 (factor 2) and the quantity factor 2 (factor 3), which accounted for 37.1, 22.6 and 18.5%, respectively of the total variance in different agronomic variables, suggesting that the GW is an important indicator for evaluating hybrid combinations, and the grain weight of restorer line (RGW) could be used as a reference for parents selection.  The hybrid combination with a higher score in factor 1 direction and larger mid-parent heterosis (MPH) of the GW and its parents were used to carry out the analysis of grain filling, 1-aminocylopropane-1-carboxylicacid (ACC) and polyamine synthesis related genes.  The results suggested that the GW of superior grain was significantly higher than that of inferior grains in BS1453×JS1 (H) and its parents.  Both grain types showed a weight of H between BS1453 (M) and JS1(R), and a larger MPH, which may be caused by their differences in the active filling stage and the grain filling rate.  The ADP-glucose pyrophosphorylase (AGPase), granule bound starch synthase I (GBSSI), starch synthase III (SSS), and starch branching enzyme-I (SBE-I) expression levels of H were intermediated between M and R, which might be closely related to MPH formation of the GW.  Compared with R and H, the GW of M at maturity was the lowest.  The expression levels of spermidine synthase 2 (Spd2), ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC) had significantly positive correlations with the grain filling rate (r=0.77*, 0.51*, 0.59*), suggesting their major roles in the grain filling and heterosis formation.  These provide a theoretical basis for improving the GW of photo-thermo-sensitive male sterile lines (PTSMSL) by changing the endogenous polyamine synthesis in commercial applications.

Powdery mildew, caused by Blumeria graminis f. sp. tritici, is one of the most severe wheat diseases.  Mining powdery mildew resistance genes in wheat cultivars and their appliance in breeding program is a promising way to control this disease.  Genetic analysis revealed that a single dominant resistance gene named PmTm4 originated from Chinese wheat line Tangmai 4 confers resistance to prevailing isolates of B. graminis f. sp. tritici isolate E09.  Detailed comparative genomics analyses helped to develop closely linked markers to PmTm4 and a fine genetic map was constructed using large F₂ population, in which PmTm4 was located into a 0.66-cM genetic interval.  The orthologous subgenome region of PmTm4 in Aegilops tauschii was identified, and two resistance gene analogs (RGA) were characterized from the corresponding sequence scaffolds of Ae. tauschii draft assembly.  The closely linked markers and identified Ae. tauschii orthologs in the mapping interval provide an entry point for chromosome landing and map-based cloning of PmTm4.

Cuticular wax plays an important role in protecting land plant against biotic and abiotic stresses.  Cuticular wax production on plant surface is often visualized by a characteristic glaucous appearance.  This study identified quantitative trait loci (QTLs) for wheat (Triticum aestivum L.) flag leaf glaucousness (FLG) using a high-density genetic linkage map developed from a recombinant inbred line (RIL) population derived from the cross Heyne×Lakin by single-seed descent.  The map consisted of 2 068 single nucleotide polymorphism (SNP) markers and 157 simple sequence repeat (SSR) markers on all 21 wheat chromosomes and covered a genetic distance of 2 381.19 cM, with an average marker interval of 1.07 cM. Two additive QTLs for FLG were identified on chromosomes 3AL and 2DS with the increasing FLG allele contributed from Lakin.  The major QTL on 3AL, QFlg.hwwgr-3AL, explained 17.5–37.8% of the phenotypic variation in different environments.  QFlg.hwwgr-3AL was located in a 4.4-cM interval on chromosome 3AL that was flanked by two markers IWA1831 and IWA8374.  Another QTL for FLG on 2DS, designated as QFlg.hwwgr-2DS which was identified only in Yangling in 2014 (YL14), was flanked by IWA1939 and Xgwm261 and accounted for 11.3% of the phenotypic variation for FLG.  QFlg.hwwgr-3AL and QFlg.hwwgr-2DS showed Additive×Environment (AE) interactions, explaining 3.5 and 4.4% of the phenotypic variance, respectively.  Our results indicated that different genes/QTLs may contribute different scores of FLG in a cultivar and that the environment may play a role in FLG.

   Loquat (Eriobotrya japonica Lindl.) can be divided into yellow- and white-fleshed cultivars by flesh color. However, a Dongting loquat mutant, which involved bud sport and growing white-fleshed fruit in the central region of the trunk (as wild loquat bears yellow-fleshed fruits naturally), was discovered in the preliminary study. The study cloned the coding sequence (CDS) of NAD⁺-dependent sorbitol dehydrogenase (NAD⁺-SDH ) gene from the selected materials of mutant loquat, wild loquat and other nine loquat cultivars/accessions, and found that the CDS of NAD⁺-SDH gene from the mutant loquat, other than the rest two types of materials, had three single nucleotide polymorphisms (SNPs) loci; in addition, the amino acid encoded at variation loci changed accordingly. NAD⁺-SDH plays an active role in converting sorbitol into fructose in loquat cultivars. For the mutant white-fleshed loquat, the activity of NAD⁺-SDH rises first and then drops, the sorbitol content decreases steadily, and its fructose content is higher than that in wild loquat from coloration to maturation stage. As demonstrated by the real-time fluorescence quantification PCR analysis, the expression level of NAD⁺-SDH gene at maturation stage is about 5-fold lower than wild type. It may be assumed that, the three SNPs loci might lead to excessive conversion of sorbitol into fructose under the catalytic action of NAD⁺-SDH of white-fleshed mutant loquat at maturation stage, resulting in the increase of fructose content and reduced expression abundance of mRNA after transcription. Besides, NAD⁺-SDH gene may be related to flesh color and carbohydrate variation of white-fleshed mutant loquat.

This study was carried out to evaluate the effects of graded levels of fiber from rice hull and the caecectomy on metabolizable energy (ME) and amino acid digestibility (AAD) in 42 Wuzong geese (21 intact and 21 caecectomized). The experiment was a 3×2 factorial randomized design with 3 fiber levels and 2 treatments of geese (caecectomized and intact). Each of the 3 diets was tube-fed (60 g) to 7 caecectomized and 7 intact adult Wuzong geese that had been fasted for 24 h. Excreta were collected for the next 48 h. The same geese were also fasted for estimation of endogenous losses of amino acids (AA) and energy after short period recovery. AA content and metabolizable energy value were determined in the excreta. In general, significant effects were found for fiber levels on apparent digestibility of Thr, Leu, Pro, Glu,Val, Ala and total AA (P<0.05). Apparent metabolizable energy (AME) and true metabolizable energy (TME) were both significantly influenced by increased fiber levels (P<0.01). Compared with caecectomized geese, markedly increases of AME and TME were found in intact geese (P<0.01 for AME and P<0.05 for TME), but no difference in the AAD were found between intact and caecectomized geese (P>0.05), except for Lys and Try (P<0.05). These observations suggested that dietary fiber level played an important role in digestibility of AAD and ME. Intact geese should be chosen for the nutrient evaluation of feedstuffs in practice, resulting from the significant difference between caecectomized and intact geese.

Powdery mildew, caused by Blumeria graminis f. sp. tritici, is one of the most devastating wheat diseases. Wild emmer wheat (Triticum turgidum ssp. dicoccoides) is a promising source of disease resistance for wheat. A powdery mildew resistance gene conferring resistance to B. graminis f. sp. tritici isolate E09, originating from wild emmer wheat, has been transferred into the hexaploid wheat line WE4 through crossing and backcrossing. Genetic analyses indicated that the powdery mildew resistance was controlled by a single dominant gene, temporarily designated MlWE4. By mean of comparative genomics and bulked segregant analysis, a genetic linkage map of MlWE4 was constructed, and MlWE4 was mapped on the distal region of chromosome arm 5BL. Comparative genetic linkage maps showed that genes MlWE4, Pm36 and Ml3D232 were co-segregated with markers XBD37670 and XBD37680, indicating they are likely the same gene or alleles in the same locus. The co-segregated markers provide a starting point for chromosome landing and map-based cloning of MlWE4, Pm36 and Ml3D232.

Infectious bursal disease virus (IBDV) is responsible for the highly contagious infectious bursal disease of chickens. Further understanding the gene-function is necessary to design the tailored vaccine. The amino acid residue 279, located on strand PF of VP2, is one of the three residues that have been reported to be involved in cell-tropism but with some inconsistency. In this study, to further clarify the amino acids involved in the cell tropism of IBDV, a series of mutations about residue 279 were introduced into the VP2 of vvIBDV Gx strain. With the reverse genetic system, we found single mutation of D279N, double mutations of D279N/A284T or Q253H/D279N were not enough to adapt IBDV to chicken embryo fibroblast (CEF) cell. To evaluate whether residue 279 could influence the replication and virulence of IBDV, the virus rGxHT-279 with three mutations (Q253H/D279N/A284T) was rescued and evaluated. Results showed that the mutation of residue 279 in VP2 had no efficient effects on both the replication efficiency in vitro and the virulence to SPF chickens of IBDV. In summary, the results demonstrated that residue 279 of VP2 did not contribute efficiently to cell tropism, replication efficiency, and virulence of IBDV at least in some strains. These findings provided further information for understanding the gene function of IBDV.

Soybean seed storage protein is one of the most important plant vegetable proteins, and β subunit is of great significance to enhance soybean protein quality and processing property. F2 segregated population and residual heterozygous lines (RHL) derived from the cross between Yangyandou (low level of β subunit) and Zhonghuang 13 (normal level of β subunit) were used for mapping of β subunit content. Our results showed that β subunit content was controlled by a single dominant locus, qBSC-1 (β subunit content), which was mapped to a region of 11.9 cM on chromosome 20 in F2 population of 85 individuals. This region was narrowed down to 2.5 cM between BARCSOYSSR_20_0997 and BARCSOYSSR_20_0910 in RHL with a larger population size of 246 individuals. There were 48 predicted genes within qBSC-1 region based on the reference genome (Glyma 1.0, Williams 82), including the two copies of β subunit coding gene CG4. An InDel marker developed from a thymine (TT) insertion in one copy of CG4 promoter region in Yangyandou cosegregrated with BARCSOYSSR_20_0975 within qBSC-1 region, suggesting that this InDel marker maybe useful for marker-assisted selection (MAS).

Estrogen plays an important role in regulating testicular Sertoli cell number. Furthermore, S-phase kinase-associated protein 2 (SKP2) plays a central role in mammalian cell cycle progression. The objective of this study was to determine whether 17β-estradiol can regulate the expression of SKP2, and the Sertoli cell cycle, via estrogen receptor β (ERβ), the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) and extracellular signal-regulated kinase (ERK1/2) pathway. When cultured immature boar Sertoli cells were treated with 17β-estradiol, a time-dependent increase in SKP2 mRNA and protein level was observed by real-time PCR and Western blot, and 17β-estradiol activity peaked at 30 min. Treatment with ICI182780 and ERβ antagonist reduced 17β-estradiol-induced expression of SKP2 and proliferating cell nuclear antigen (PCNA), while increasing the protein concentration of p27kip1. However, the effect of ERa antagonist on these parameters was lower than that of ICI182780 and ERβ. Forskolin had a similar effect as 17β-estradiol on the expression of SKP2, PCNA and p27kip1. Rp-cAMP, H-89 and U0126 treatment reduced 17β-estradiol-induced changes, while H-89 also inhibited ERK1/2 activation. Therefore, 17β-estradiol mainly regulates SKP2 mRNA and protein expression via ERβ-cAMP-PKA and ERK1/2 activation. SKP2 and PCNA expression were positively correlated, while increased SKP2 expression likely resulted in p27kip1 degradation.

The striped stem borer (SSB), Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), is a major pest of rice in China. Variation in host-plant quality may affect the body size of herbivorous insects, which in turn, can determine their lifehistory parameters such as survival, fecundity and fitness. In this study, we tested the effects of high-quality aromatic rice varieties on the fitness of SSB in China. Results showed that 1st instar larvae had higher penetrating rates and survival rates on the high-quality aromatic rice varieties (EX-1 and WX-988) than that on the non-aromatic rice varieties (EZ-5 and LYP-9). In addition, shorter developmental periods, greater female pupal weights and higher of other life-history parameters (hatching rate, pupation rate, eclosion rate and increase index) were found on the high-quality aromatic rice varieties, although only female pupal weight showed a significant difference between the two varieties. The highest dead heart rate was found on the aromatic rice variety of EX-1. These results indicate that SSB sustains a lower fitness cost when consuming the high-quality aromatic rice varieties (EX-1 and WX-988) than on the non-aromatic rice varieties (EZ-5 and LYP-9) in Central China.

Inter simple sequence repeat (ISSR) analysis was applied to samples of foxtail millet and its wild ancestor and other close relatives of the genus Setaria in order to detect domestication-related geographical structure and phylogenetic relationship of those species. Eighty-one accessions of nine Setaria species that originated from different regions were used in this study. Fourteen out of the 27 ISSR primers screened amplified successfully and a total of 156 markers were scored for all the accessions, with a high level of polymorphism being detected. The dendrogram based on UPGMA cluster analysis showed clear geographic structure among foxtail millet and its wild ancestor green foxtail, which implies that northern China is the domestication center for both the Chinese and European foxtail millet landraces used in this study. This result did not support the hypothesis that China and Europe are independent domestication centers for foxtail millet proposed by several previous studies based on morphological and isozyme data. The dendrogram also clearly classified the Setaria sample used into two groups, a viridis and a pumila groups. The viridis group was composed of S. viridis, S. italica, S. faberii, S. verticillata, S. leucopila, and S. queenslandica, and the pumila group consisted of S. parviflora and S. pumila, which is consistent with the recently proposed hypothesis of multiple origin of Setaria species. The phylogenetic relationships among different species are discussed.

Cuscuta campestris, a dodder, can parasitize and suppress a scrambling herbaceous to semi-woody perennial vine, Mikania micrantha, one of the most destructive weeds in the world. To assess the effects of the mixed residue of C. campestris and M. micrantha on the subsequent plant community, we conducted a one-year experiment on the germination and seedling growth of subsequent plant community after the application of C. campestris. Seven treatments of varying proportions of C. campestris and M. micrantha residue on 21 subject trees and shrubs, which were commonly found in South China, resulted in a germination rate of 35.3% for all 8715 seeds from 18 species, ranging from 5.7 to 81.9%; the remaining 3 species failed to germinate. ANOVA analysis showed that the residue did not affect the germination, growth, or mortality of the trees and shrubs. The germinated C. campestris seeds from the residue coiled the seedlings of most of the species, but less than 4% host death caused by C. campestris. In addition, the residue did not affect the germination of the herbaceous seedlings originating from the loam, and the similarity coefficients of the germinated seedlings between the treatments were very high. These results suggested that the residue had no negative impact on the germination and early seedling stages of the tree, shrub and grass species of the subsequent plant community. The use of C. campestris residue had a positive effect on the growth of M. micrantha, but it did not change the trend of M. micrantha being suppressed because re-parasitization occurred soon after the growth restarted. No negative effect was detected on the other species as a result of the parasitization of C. campestris or by the use of the mixed residue. This suggests that C. campestris is likely to be an effective and promising ecologically safe native herbaceous agent for controlling M. micrantha.

The higher survival rates of Helicoverpa amigera larvae were usually observed after adverse climate which was related to extreme temperature (T) and relative humidity (RH) stresses in transgenic Bacillus thuringiensis (Bt) cotton. The unstable resistance of Bt cotton to bollworms has been correlated with the reduced expression of CryIAc d-endotoxin. The objective of this study was to investigate the effects of combined temperature and relative humidity stresses on the leaf CryIAc insecticidal protein expression during critical developmental stages. The study was undertaken on two transgenic cotton cultivars that share same parental background, Sikang 1 (a conventional cultivar) and Sikang 3 (a hybrid cultivar), during the 2007 and 2008 growing seasons at the Yangzhou University Farm, Yangzhou, China. The study was arranged with two factors that consisted of temperature (two levels) and relative humidity (three levels). The six T/RH treatments were 37°C/95%, 37°C/70%, 37°C/50%, 18°C/95%, 18°C/70%, and 18°C/50%. In 2007, the six treatments were imposed to the plants at peak flowering stage for 24 h; in 2008, the six treatments were applied to the plants at peak square, peak flowering, and peak boll stages for 48 h. The results of the study indicated that the leaf insecticidal protein expression in CryIAc was significantly affected by extreme temperature only at peak flowering stage, and by both extreme temperature and relative humidity during boll filling stage. The greatest reductions were observed when the stresses were applied at peak boll stage. In 2008, after 48 h stress treatment, the leaf Bt endotoxin expression reduced by 25.9-36.7 and 23.6-40.5% at peak boll stage, but only by 14.9-26.5 and 12.8-24.0% at peak flowering stage for Sikang 1 and Sikang 3, respectively. The greatest reduction was found under the low temperature combined with low relative humidity condition for both years. It is believed that the temperature and relative humidity stresses may be attributed to the reduced efficacy of Bt cotton in growing conditions in China, where extreme temperatures often increase up to 35-40°C and/or decrease down to 15-20°C, and relative humidity may reach to 85-95% and/or reduce to 40-55% during the cotton growing season.