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。

微生物在胃肠道发育早期的定植和演替过程对于宿主免疫系统的发育十分重要。本试验以湖羊为研究对象，选择10只初生湖羊母羔（2.87 ± 0.28 kg），利用16S rDNA测序手段，测定0,3,10,20,30,45,60,90,120日龄羔羊粪便细菌区系，探究羔羊从出生至120日龄，体重、血清指标和粪便细菌群落的动态变化，及三者之间的关系。研究结果表明，羔羊生长性能、血清指标、粪便细菌群落和粪便细菌功能均受羔羊日龄的影响(P<0.05)。羔羊平均日增重在60-90日龄时最低(P<0.05)，可能是断奶应激造成。羔羊的免疫反应在30日龄时最高，此时羔羊血清中免疫球蛋白（免疫球蛋白A，免疫球蛋白G，免疫球蛋白M）、细胞因子（白细胞介素-1β，白细胞介素-6，白细胞介素-12、白细胞介素-17、肿瘤坏死因子-α）和肠道通透性指标（D-乳酸和内毒素）水平高于其它日龄组(P<0.05)。各日龄组内粪便细菌群落相似性分析表明，同日龄组内相似性在断奶前较低，在断奶（60日龄）后显著增加(P<0.05)。各日龄与120日龄粪便细菌群落相似性表明，30日龄后，与120日龄的相似性显著增加(P<0.05)。粪便细菌属Lachnospiraceae UCG-010, Eubacterium coprostanoligenes group, Ruminococcaceae UCG-005, Ruminococcaceae UCG-009, Ruminococcaceae UCG-013, Ruminiclostridium 6, Ruminococcaceae UCG-008和Oscillibacter与血清中内毒素、D-乳酸、免疫球蛋白（免疫球蛋白A，免疫球蛋白G，免疫球蛋白M）、细胞免疫因子（白细胞介素-1β，白细胞介素-6，白细胞介素-12和白细胞介素-17）和肿瘤坏死因子-α水平呈负相关(P<0.05)，并且这些属的相对丰度从45日龄时增加。本研究结果表明，与血清免疫指标相关属的相对丰度从45日龄起随羔羊年龄增加，羔羊出生至45日龄可能存在关键调控时期，为调控羔羊微生物以提高羔羊免疫性能提供机会。本研究分析比较了羔羊初生至120日龄，粪便细菌建立过程及其与羔羊体重和血清免疫指标的关系，分析发现了调控羔羊微生物区系的关键时期。

本研究以‘矮玉香’和‘翠冠’为父母本，通过杂交获得矮化性状的后代（DPP）和乔化表型的后代（APP）。与APP相比，DPP植株高度降低了62.8%，节间长度显著缩短。茎尖组织切片观察显示，DPP细胞形状不规则，细胞平均长度较大，但纵向排布的细胞数量显著减少。两种表型梨之间的交叉嫁接试验表明，‘矮生梨’的矮化表型主要由地上部分决定，与根系无关。根据二者茎尖的RNAseq数据共鉴定出1401个差异表达基因,其中包含101转录因子。功能富集分析显示，植物激素、细胞分裂、细胞壁代谢等相关通路中的基因显著差异表达。在DPP中，若干BR信号转导和细胞周期相关基因表达显著下调；同时，一些调控BR和GA降解的基因表达上调。结合切片观察的结果与RNA-seq的数据推断，DPP的矮化表型主要归因于细胞分裂的不足。为进一步缩小候选基因集，将差异表达基因映射到前人所做的‘Le Nain Vert’矮化性状定位区间，共鉴定出4个关键基因。结合功能注释分析，发现其中一个DELLA基因可能在调控‘矮生梨’矮化表型中发挥重要的作用。本研究结果为进一步探索梨矮化的遗传和分子机制奠定了基础。

胃肠道真菌群落对于动物的健康和生长性能十分重要，但目前其在消化道内的定植过程尚不清楚。本研究目的是探究生长羔羊从出生至四月龄胃肠道真菌群落的发育规律。本实验选择10只初生湖羊母羔（2.87 ± 0.28 kg）作为实验动物，利用IT1S rDNA测序手段，测定0,3,10,20,30,45,60,90,120日龄羔羊瘤胃和直肠内容物真菌区系，联合随机森林分析，探究10只湖羊母羔从出生至4月龄瘤胃和直肠真菌群落的动态变化，确定真菌区系在胃肠道的建立过程。结果表明，随着羔羊日龄的增加，胃肠道真菌群落的组成、多样性和菌群丰度受到显著影响(P<0.05)。在门水平上，Ascomycota和Basidiomycota在瘤胃和直肠样品中均占主导地位。各日龄组内瘤胃真菌群落相似性在45日龄时显著增加(P<0.05)，而各日龄组内直肠真菌群落相似性在60日龄后显著增加(P<0.05)。随年龄变化的属，Acremonium, Microascus, Valsonectria, Myrmecridium, Scopulariopsis, Myrothecium, Saccharomyces 和 Stephanonectria在瘤胃和直肠中均随羔羊年龄变化而改变，说明这些真菌可能在羔羊生长发育过程中起到关键性作用，并且说明上消化道的微生物可能会对下消化道的微生物区系产生影响。主坐标分析结果表示，瘤胃和直肠真菌群落存在显著差异(P<0.05)。本研究表明，真菌群落在胃肠道演替过程可以分为三个阶段：定植阶段（0-10日龄），过渡阶段（10-45日龄），和相对稳定的逐渐成熟阶段（45-120日龄）。本实验结果表明，羔羊的年龄和胃肠道的不同部位均会影响真菌群落组成，为真菌在羔羊早期生长发育过程的调控奠定理论基础。本研究较全面的比较分析了120日龄之前，湖羊羔羊胃肠道真菌建立过程和此过程中逐步行使主导作用的优势菌群，分析发现了不同日龄阶段胃肠道真菌结构的特征。

Understanding yield potential, yield gap and the priority of management factors for reducing the yield gap in current intensive maize production is essential for meeting future food demand with the limited resources. In this study, we conducted field experiments using different planting modes, which were basic productivity (CK), farmer practice (FP), high yield and high efficiency (HH), and super high yield (SH), to estimate the yield gap. Different factorial experiments (fertilizer, planting density, hybrids, and irrigation) were also conducted to evaluate the priority of individual management factors for reducing the yield gap between the different planting modes. We found significant differences between the maize yields of different planting modes. The treatments of CK, FP, HH, and SH achieved 54.26, 58.76, 65.77, and 71.99% of the yield potential, respectively. The yield gaps between three pairs: CK and FP, FP and HH, and HH and SH, were 0.76, 1.23 and 0.85 t ha^–1, respectively. By further analyzing the priority of management factors for reducing the yield gap between FP and HH, as well as HH and SH, we found that the priorities of the management factors (contribution rates) were plant density (13.29%)>fertilizer (11.95%)>hybrids (8.19%)>irrigation (4%) for FP to HH, and hybrids (8.94%)>plant density (4.84%)>fertilizer (1.91%) for HH to SH. Therefore, increasing the planting density of FP was the key factor for decreasing the yield gap between FP and HH, while choosing hybrids with density and lodging tolerance was the key factor for decreasing the yield gap between HH and SH.

目前缺水已成为制约作物产量进一步提高的主要因素，如何提高水资源利用效率(WUE)已成为我国农业亟待解决的问题。为研究玉米产量和水分利用效率对气象因素及群体变化的响应，我们在全国25个试验点安排了不同玉米群体的多点试验，不同的玉米群体由不同株型玉米品种(紧凑型和半紧凑型)和不同种植密度(30000株/ha、60000株/ha和90000株/ha)构成。研究发现：随着降雨量的增加，玉米产量呈现先增加后降低的趋势，水分利用效率随着降雨量的增加显著降低，60000株/ha种植密度的产量和WUE>90000株/ha>30000株/ha。通过分析WUE与主要气象因子的关系发现：水分利用效率与在各生育阶段(播种-吐丝、吐丝-成熟/收获、播种-成熟/收获和全年)的降水量(和R)呈显著负相关，与温度(T_m、T_M–m和GDD)、太阳辐射(Ra)呈正相关。为了研究不同玉米群体的水分蒸散特征，我们进一步安排了不同玉米群体的定点试验，研究发现：随着玉米群体的增大，玉米需水量显著增加，而土壤蒸发量显著减少。不同株型品种间及不同种植密度间玉米需水量和土壤蒸发量也存在显著差异。分析品种和种植密度对WUE的影响发现：选择抗旱杂交品种和适宜种植密度WUE分别提高21.70%和14.92%，表明选用抗旱杂交种比改变种植密度对WUE的提高作用更显著。综合考虑气象影响，采用ZD958等抗旱品种和60000株/ha的种植密度是提高我国北部玉米产量和WUE的有效途径。

花生是重要的油料作物，培育高油品种是花生育种的主要目标之一。研究表明，干旱胁迫下花生叶片渗透压与其籽仁含油量呈显著负相关。基于这一原理，我们创建了利用离体诱变和渗透压定向筛选培育高油花生新品种的有效方法。以花生品种花育20号的种子胚小叶为外植体，平阳霉素(PYM)为诱变剂，羟脯氨酸(HYP)为渗透压调节剂进行离体诱变和定向筛选，最终获得15株HYP耐性再生植株。每个再生植株均有含油量 >55%的后代（而花育20号含油量为49.5%）。从HYP耐性植株后代中培育出3个高产高油花生新品种，宇花4号、宇花9号、宇花14号，含油量分别为57.7%、61.1%、59.3%。结果表明，PYM离体诱变后进行HYP离体定向筛选，是培育高油花生品种的有效途径。

Genes controlling fruit appearance determine fruit shape and size.  In ethylmethane sulfonate (EMS)-mutagenized lines of Fragaria vesca accession Yellow Wonder (YW), two fruit shapes are observed: wild-type long fruit and mutated shortened fruit (sf).  In this study, we first characterized sf based on morphology, histology, cytology and physiology.  The sf was identified as a gibberellin (GA)-deficient mutant, and four complementary DNA (cDNA) libraries separately constructed from flower buds and small green fruits of YW and sf were sequenced to comparatively analyze transcriptome differences.  A total of 29 differentially expressed GA pathway genes were identified by comparisons between YW1 and sf1, and 28 differentially expressed GA pathway genes were identified between YW2 and sf 2.  In addition, the expression patterns of 45 differentially expressed genes were validated by quantificational real-time PCR (qRT-PCR), and the results were highly concordant with the RNA-Seq results.  This transcriptome analysis provides valuable information for understanding the molecular mechanisms of fruit development of strawberry.

The sheep genome harbours approximately 20 copies of endogenous beta-retroviruses (enJSRVs), and circumstantial evidence suggests that enJSRVs might play a role in mammalian reproduction, particularly placental morphogenesis. This study was aimed to assess the expression of mRNAs of an enJSRV and its receptor, HYAL2, in the uterus and conceptuses of Mongolian ewes throughout gestation, using real-time reverse transcription polymerase chain reaction and in situ hybridization analysis. The results showed that enJSRV and HYAL2 mRNAs were found to be expressed throughout gestation in the endometrium, chorion, placenta, and conceptus. The enJSRV mRNA was most abundant in the placenta on day 90 of pregnancy, in the endometrium on day 30 and 50, and in the chorion on day 70 and 110. However, HYAL2 mRNA was most abundant in the endometrium on day 30. These differences were all significantly different from each other (P<0.01). In situ hybridization showed that enJSRV and HYAL2 mRNAs were specifically expressed in endometrial luminal epithelium and glandular epithelium, trophoblastic giant binucleated cells (BNCs), endometrial caruncles, placental cotyledons, stroma, trophectoderm, as well as multinucleated syncytia of the placenta and blood vessel endothelial cells. Collectively, little is known about the molecular mechanisms by which trophoblastic differentiation and multinucleated syncytia formation are regulated by enJSRVs. However, the temporal and spatial distributions of enJSRV expression in the uterus and conceptus indicate that differentiation of BNCs and the formation of a multinucleated syncytiotrophoblast involve enJSRV and possibly its cellular receptor, HYAL2. Therefore, enJSRV and HYAL2 appear to play important roles in the female reproductive physiology in this breed of sheep.

A total of 36 four-mon-old hybrid lambs (Dorset×Thin-tailed Han sheep) with similar body weight (BW) were randomly allocated to three dietary treatments with different energy (7.21, 10.33 and 13.49 MJ d-1 ME) but similar protein levels. The animals were slaughtered and subcutaneous fat, longissimus dorsi muscle, femoral biceps muscle and cardiac muscle tissue samples were taken after being treated for 40 d. The samples were then subjected to quantitative PCR to determine mRNA expression of hormone-sensitive lipase (HSL) in different tissues in the laboratory. The findings showed that the abundance of HSL mRNA decreased with the elevation of dietary energy. In the subcutaneous fatty tissue, the HSL mRNA levels showed significant differences among the three groups (P<0.01); in the longissimus dorsi and femoral biceps muscles, the HSL mRNA level in the low energy group was significantly higher than that in the moderate and high energy groups (P<0.01). In the cardiac muscle, the HSL mRNA level in the moderate energy group was significantly different from the low and high energy groups (P<0.05). The number of HSL copies (Qty) in different tissues of sheep was different, it was greater in the subcutaneous fat than in longissimus dorsi muscle, femoral biceps muscle and heart.