一般在断奶后，牧场为便于生产管理，将来自不同群体大小的犊牛进行混群或重新分组，这种常规操作对犊牛的福利存在负面影响。混群前的社交经验可能会缓解混群应激，但仍需要更多研究验证这一假设，因此本文通过出生后单栏饲养或群养犊牛在混群后的生理和行为指标的变化，探究早期社会环境对犊牛抗应激能力的影响。将132头初生犊牛随机分为单栏饲养、3头群养、6头群养、12头群养，共4个处理组（S、G3、G6、G12组，每组6个重复）。60日龄时，将每个处理组(S、G3、G6和G12)每2个重复引入较大的围栏中，形成44头犊牛规模的新群体。分别记录重组前后生理参数，包括心率(HR)、唾液皮质醇（S-CORT）、唾液分泌免疫球蛋白A(SIgA)、白介素-2（IL-2）、白介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）水平和行为反应。重组后，无论是单栏饲养还是群养组犊牛HR和S-CORT立即升高(P<0.05)，但与群养犊牛相比，单栏饲养犊牛差异更显著(P<0.05)。单栏饲养犊牛的SIgA和IL-2水平下降(P<0.05)，且IL-2在所有组中最低(P<0.05)。此外，犊牛混群后具有不同的行为表现，包括活动时间和休息时间的变化，与新环境应激引发的负面情绪有关。群居犊牛的互相修饰、玩耍、探索行为和趴卧时间较多(P<0.05)，而单栏饲养犊牛的自我梳理、攻击行为、站立和行走时间则显著增加(P < 0.05)。研究表明，单栏饲养犊牛可能比群养犊牛更易产生混群应激，从而对行为和神经生理产生影响，而出生后的群居经验则可能帮助犊牛缓解这种应激。

甜瓜果肉硬度（Flesh firmness, FF）是农业生产者和消费者关注的一个复杂且重要的性状，但目前针对甜瓜果肉硬度性状的遗传机制尚不清楚。本研究以软果肉甜瓜“P5”和硬果肉甜瓜“P10”配置杂交组合，构建F₂分离群体，通过QTL-SLAF测序和分子标记连锁分析，共鉴定112,844个SLAF位点，使用5,919个SNP标记构建了总遗传距离为1356.49 cM的连锁图谱。结合两年田间表型分析显示，控制果实长度（Fruit Length, FL）和宽度（Fruit Diameter, FD）的QTLs位点位于同一区间，控制单果重（Single-Fruit Weight, SFW）性状的QTL位于两条不同的染色体上。对于果肉硬度检测到一个主要QTL位点ff2.1，位于甜瓜2号染色体0.17 Mb的候选区域。利用429个F₂单株，将ff2.1候选区间缩小到28.3 kb区域，包含3个候选基因。本研究不仅鉴定了一个控制甜瓜果肉硬度的QTLs位点，同时也为甜瓜基因功能基因的研究提供了理论基础。

西瓜果肉颜色是由一系列类胡萝卜素类物质决定的一种重要性状。本文通过浅黄色果肉西瓜COS和白色果肉西PI 186490作为亲本配制F₂代分离群体进行BSA-seq分析。BSA-seq结果分析发现在西瓜的6号染色体2.45 Mb区间内存在一个与果肉颜色性状形成的相关区段，该区域初步定位在382 kb范围内。然后利用1260株F2代精细定位群体进行精细定位，将定位区间缩短至66.8 kb。该区间内共包含9个候选基因，其中仅有Cla007528（叶绿素酶基因）在双亲中发生差异表达，并存在非同义突变位点。同时基于RNA-seq数据和qRT-PCR验证我们对类胡萝卜素代谢中的关键基因表达模式进行分析发现，叶黄素循环中的三个基因（ClCHYB，ClNCED-1和ClNCED-7）在双亲果实不同成熟阶段发生差异表达。随着类胡萝卜的不断积累，ClPSY1，ClPDS，ClZDS，ClCHXE，ClCRTISO和ClLCYB也表现出显著差异的表达模式。

为有效验证Sentinel-2影像与CERES-Wheat模型同化进而提高区域作物估产的精度，本文以中国黄土高原东南部三个县（襄汾县、新绛县和闻喜县）为研究区，应用集合卡尔曼滤波算法同化Sentinel-2影像反演的LAI和CERES-Wheat模型模拟的LAI，得到冬小麦生长期逐日的LAI同化值。对比改进的层次分析法、熵值法和归一组合赋权法对不同生育期LAI赋权，并与冬小麦实测单产值进行模型构建，进而对作物进行准确估产。研究结果表明：（1）同化LAI遵循了模拟LAI在冬小麦生育期的生长变化趋势，且在Sentinel-2影像反演LAI的修正下，返青期至抽穗-灌浆期的LAI得到提高，乳熟期的LAI下降减缓，更符合冬小麦LAI的实际生长变化情况；（2）基于实测LAI数据的检验表明，同化LAI比模拟值和反演值的RMSE分别降低了0. 43 m²/m²、0.29 m²/m²，同化过程提高了时间序列LAI的估测精度；（3）归一组合赋权法计算的加权同化LAI与实测单产构建的回归模型决定系数最高R²为0.8627，RMSE最小472.92kg/ha，应用此模型对研究区冬小麦进行估产，县域估测平均单产与统计单产相对误差均小于1%，证明高时空分辨率的Sentinel-2数据融入作物模型能得到更高精度的区域估产结果。

The phytohormone auxin plays a central role in coordinating plant growth and development. GH3 is one of the three gene families that respond rapidly during auxin stimulation. Here, we report the identification and characterization of the GH3 gene family in maize. A total of 12 GH3 genes were identified, which are not evenly distributed over the 10 maize chromosomes. Maize GH3 protein sequences share a conserved domain which occupies nearly the entire protein. Diversified cis-elements were found in promoters of maize GH3 genes. In this study, the 12 maize GH3 proteins were primarily classified into two phylogenetic groups, similar to the 13 rice GH3 proteins, while 9 of the 19 Arabidopsis GH3 proteins were observed in the third phylogenetic group. Microarray analysis showed that expression of maize GH3 genes is temporally and spatially modulated. Additionally, maize GH3 genes displayed variable changes at transcript level upon pathogen infection. Results presented here provide insight into the diversification and evolution of GH3 proteins, and lay a foundation for the functional characterization of these GH3 genes in future, especially for elucidating the mechanisms of GH3-mediated pathogenesis.

    The vacuolar proton pump ATPase (V-H⁺-ATPase), which is a multi-subunit membrane protein complex, plays a major role in the activation of ion and nutrient transport and has been suggested to be involved in several physiological processes, such as cell expansion and salt tolerance. In this study, three genes encoding V-H⁺-ATPase subunits B (ScVHA-B, GenBank: JF826506), C (ScVHA-C, GenBank: JF826507) and H (ScVHA-H, GenBank: JF826508) were isolated from the halophyte Suaeda corniculata. The transcript levels of ScVHA-B, ScVHA-C and ScVHA-H were increased by salt, drought and saline-alkali treatments. V-H⁺-ATPase activity was also examined under salt, drought and saline-alkali stresses. The results showed that V-H⁺-ATPase activity was correlated with salt, drought and saline-alkali stress. Furthermore, V-H⁺-ATPase subunits B, C and H (ScVHA-B, ScVHA-C and ScVHA-H) from S. corniculata were introduced separately into the alfalfa genome. The transgenic alfalfa was verified by Southern and Northern blot analysis. During salt and saline-alkali stresses, transgenic linevacuolar proton pump, salt tolerance, saline-alkali tolerance, alfalfa
s carrying the B, C and H subunits had higher germination rates than the wild type (WT). More free proline, higher superoxide dismutase (SOD) activity and lower malondialdehyde (MDA) levels were detected in the transgenic plants under salt and saline-alkali treatments. Moreover, the ScVHA-B transgenic lines showed greater tolerance to salt and saline-alkali stresses than the WT. These results suggest that overexpression of ScVHA-B, ScVHA-C and ScVHA-H improves tolerance to salt and saline-alkali stresses in transgenic alfalfa.

Coat color is a key economic trait in sheep. Some candidate genes associated with animal’s coat color were found. Particularly, v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT) and microphthalmia-associated transcription factor (MITF) play a key role in the modulation of hair pigmentation in mammals. This study investigated those two candidate genes’ mutations and expressions associated with wool color in Tibetan sheep. First, the gene polymorphisms of those two genes were analyzed, and then, relative mRNA expression levels of those two genes in skin tissue with different coat colors were compared. Thirdly, KIT and MITF protein expression levels were detected through Western blot and immunehistochemical. Allele C was predominant allele in the white coat color Tibetan sheep population of the MITF coding region g. 1548 C/T loci. The relative MITF mRNA expression in black coat skin tissue was significantly higher than white (P<0.01). However, no significant differences were detected in the KIT gene’s mRNA expression of these two different coat color skin tissues (P>0.05), while the level of KIT protein expression in skin tissues of white and black coats was also roughly equivalent. Our study observed that, the level of MITF protein expression in black coat skin tissue was significantly higher than that in white coat skin tissue, and positive staining for MITF protein expression was detected mainly in the epidermis and the dermal papilla, bulb, and outer root sheath of hair follicles. We conclude that the black coat of Tibetan sheep is related to high MITF expression in the hair follicles, and MITF may be important for coat color formation of Tibetan sheep.

The photosynthetic characteristics of flag leaf and the accumulation and remobilization of pre-anthesis dry mass (DM) and nitrogen (N) in vegetable organs in nine wheat cultivars under different source-sink manipulation treatments including defoliation (DF), spike shading (SS) and half spikelets removal (SR) were investigated. Results showed that the SS treatment increased the photosynthetic rate (Pn) of flag leaf in source limited cultivar, but had no significant effect on sink limited cultivar. The SR treatment decreased the Pn of flag leaf. Grain DM accumulation was limited by source in some cultivars, in other cultivars, it was limited by sink. Grain N accumulation was mainly limited by source supply. The contribution of pre-anthesis dry mass to grain yield from high to low was stem, leaf and chaff, while the contribution of pre-anthesis N to grain N from high to low was leaf, stem and chaff. Cultivars S7221 and TA9818 can increase the contribution of remobilization of DM and N to grain at the maximum ratio under reducing source treatments, which may be the major reason for these cultivars having lower decrease in grain yield and N content under reducing source treatments.

Vitis vinifera cv. Chardonnay suspension cultures were established from proembryogenic mass and employed for optimizing Agrobacterium-mediated transformation system. One-factor-at-a-time experiment revealed that OD600 of Agrobacterium,time of inoculation, co-cultivation, and cell-drying before inoculation significantly affected the transformation efficiencywhich reached maximum 21.5% at the following conditions: 0.8 of OD600, 25 min of inoculation, 2 d of co-cultivation, and 10min of cell drying. Response surface methodology experiments based on a five-level, four-factor central-compositerotatable design were then used to optimize these selected factors. The optimized conditions for Chardonnay grapetransformation were: 0.8711 of OD600, 28.9 min of inoculation, 2.25 d of co-cultivation and 11.76 min of cell drying. Afteroptimization, transformation efficiency was 26.2% and there were no interactions among different factors.