Ca²⁺离子在维持细胞壁以及细胞膜的完整性中具有重要作用，是植物生长和发育中必不可少的矿质营养元素之一。解析Ca²⁺离子在糖代谢和脂代谢中的作用能够为理解棉花纤维快速伸长阶段细胞膜和细胞壁的动态变化提供有意义的参考。本研究利用胚珠培养系统发现缺Ca²⁺会促进纤维和胚珠细胞的膨大，但同时也会诱导组织的褐化。RNA-seq差异表达基因分析发现缺Ca²⁺使细胞处于一个较高的氧化态，并且激活与糖代谢和脂代谢相关的基因的表达。尤其以糖酵解途径变化最为显著，其代谢途径中的9个酶相关的基因上调表达，缺Ca²⁺处理细胞中的葡萄糖含量显著下降，改变了糖酵解途径的流动。低K⁺能够恢复缺Ca²⁺诱导糖酵解途径相关基因的表达以及葡萄糖的含量。采用电喷雾电离串联质谱技术检测了不同Ca²⁺、K⁺离子处理条件下细胞中脂质组成分的动态变化。缺Ca²⁺处理细胞中自由脂肪酸（FA）、二酰甘油（DAG）和糖脂含量降低，三酰甘油（DAG）磷脂酰乙醇胺（PE）、磷脂酰甘油（PG）、磷脂酰胆碱（PC）含量增加。低K⁺与缺Ca²⁺的互作信号能够恢复FA、磷脂、糖脂含量至正常水平，有效缓解缺Ca²⁺效应。本研究通过在转录和代谢水平的比较分析，揭示了Ca²⁺和K⁺信号互作在维持纤维快速伸长过程中糖酵解和脂代谢中发挥着重要作用。

重庆地区广泛种植的柑橘果实为锦橙，目前因锦橙挥发性成分的贡献构成其特有的香气而深受消费者的青睐。发育和成熟过程中锦橙香气的变化情况是表征其果实成熟和采收的指标。然而，近年来鲜有有关发育阶段对锦橙挥发性化合物影响的相关报道。此外，挥发性化合物来源于脂肪酸，如大部分脂肪酸是挥发性化合物的合成前体。在此基础上，采用气相色谱联用质谱(GC-MS)分析了挥发性化合物及其合成前体脂肪酸的变化。在此研究中，9个发育阶段(AF1-AF9)共鉴定了60种挥发性化合物和8种脂肪酸。其中，萜类化合物和饱和脂肪酸分别占总挥发物的92.00%和脂肪酸的87.50%以上。从主成分分析（PCA）图可知，AF5、AF6和AF9阶段完全分离且呈现差异。此外，几乎绝大部分挥发性化合物和脂肪酸在发育初期呈现增加的趋势，从AF6发育期呈现降低趋势，最后在AF9成熟阶段再呈现增加趋势。在发育阶段，锦橙果皮精油中萜类、醇类、醛类、酮类和饱和脂肪酸含量最高的分别是d-柠檬烯、芳樟醇、辛醛、环己酮和硬脂酸。本研究结果表明，不同发育阶段对锦橙果皮精油中挥发性成分及其合成前体脂肪酸有显著性影响。

由于水稻直播在节约劳动力、节约水资源、保护环境和大幅减少温室气体排放等方面具有巨大潜力。因此，正成为许多国家水稻生产的主要栽培技术。挖掘和利用中胚轴伸长基因是加快直播稻育种和满足直播水稻生产要求的最有效途径之一。黑龙江省农业科学院利用丽江新团黑谷（LTH）和沈农265（SN265）衍生的144个重组自交系(RIL)群体及其配套的包含2,828个bin标记的连锁图谱分别在2019年和2020年检测了与中胚轴长度相关的数量性状基因座(QTL)。采用30°C黑暗环境下培养10天后测量中胚轴长度。在第1(2)、2(4)、3(2)、4、5、6、7、9、11(2)和12号染色体上共鉴定出16个中胚轴长度QTL。其中7个QTLs可以在两年中被重复检测到，包括qML1a、qML1b、qML2d、qML3a、qML3b、qML5和qML11b。主效QTL-qML3a还可以在不同作图方法中被重复检测到。进一步分析发现，qML3a被定位在88.18kb的范围内，这一区间包含13个预测基因。利用近等基因系也证明了qML3a的真实存在和调控中胚轴伸长的效果。最后，通过分析SN265、LTH 和日本晴之间的DNA序列变异，表明LOC_Os03g50550是qML3a的候选基因。该基因编码有丝分裂原活化的蛋白激酶。使用qRT-RCR分析进一步揭示了LTH中胚轴中LOC_Os03g50550基因的表达水平显著低于SN265中胚轴中的表达水平。这些结果进一步加强了我们对水稻中胚轴伸长遗传机制的认识，也将有助于加快直播专用新品种的育种进程。

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。

目的：分析我国鸡源重要致病菌大肠杆菌耐药性及耐药基因，解析潜在的水平扩散风险。方法：规模化养鸡场棉拭子泄殖腔取样，麦康凯培养基分离单菌，Phoenix-100 全自动细菌鉴定/药敏系统鉴定细菌种类，K-B纸片法检测目的细菌药物敏感性，牛津纳米孔测序技术构建细菌基因组精细图，生物信息学软件及平台解析基因环境及水平转移元件，细菌结合实验验证耐药基因扩散风险。结果：2019年10月-2020年10月，共采集671个泄殖腔样本，分离出302株大肠杆菌单菌，鉴定出一株广泛耐药（An extensively drug-resistant, XDR）大肠杆菌（命名为258E）。MLST分析结果表明，大肠杆菌258E属于ST602型，该分型目前仅见于国外文献报道。K-B纸片法检测结果显示，258E菌株对磷霉素、四环素、β-内酰胺类、氨基糖苷类、喹诺酮类、利福霉素、甲氧苄啶、大环内酯类和头孢菌素类药物均表现出高度耐药。全基因组测序结果表明，大肠杆菌258E染色体全长4,715,664 bp，含有三个质粒（pEC258-1、pEC258-2、pEC258-3）,其中pEC258-1和 pEC258-2不含有常见耐药基因，而pEC258-3除了含有常见耐药基因，如qnrS1、 dfrA14、 arr-3、acc (6')-Ib等，还含有bla_CTX-M-3、 bla_KPC-2、bla_TEM-1B三个重要的耐药基因。质粒分型结果表明，pEC258-3为ST7型，属于质粒不相容群N (incompatibility group N, IncN)。同源性分析结果显示pEC258-3序列与人源肺炎克雷伯菌质粒pCRKP-1-KPC同源性高达99.96%，其不同之处在于：相对pEC258-3，pCRKP-1-KPC质粒在31kb-32kb位点缺失了一个整合酶TinR蛋白编码框。细菌结合实验证实，pEC258-3可使得宿主菌显著提高药物敏感性。同时，流行病学溯源分析结果显示，大肠杆菌258E与英国菌株具有相近的亲缘关系。结论：本研究第一次报道了一株动物源ST602型广泛耐药大肠杆菌，其所含有的质粒可介导宿主菌对多种抗生素产生耐药性，暗示其潜在的耐药性水平扩散风险，也间接证明动物源细菌是耐药性基因的重要储存库和风险传播源头之一。

创新性：本论文是我国第一例动物源ST602型广泛耐药大肠杆菌的报道，丰富和充实了“同一健康” 框架下细菌耐药性对人类公共健康的风险研究。

为鉴定和利用武都白茧的抗条锈病基因，本研究将武都白茧与高感条锈病品种铭贤169杂交，分别于2015年和2016年在陕西杨凌和甘肃天水四个环境中对武都白茧、铭贤169和以及铭贤169/武都白茧杂交F_2:3代家系进行成株期抗条锈病测试。田间多年多点鉴定结果表明，武都白茧表现稳定的成株期抗条锈性，铭贤169/武都白茧F_2:3代在2015年杨凌、2016年杨凌、2015年天水和2016年天水四个环境下的相对病害曲线下面积（rAUDPC）均呈连续分布，表明武都白茧对条锈病的成株期抗性由多个QTL控制。利用集群分离分析法结合小麦660K SNP芯片、KASP和SSR标记鉴定与抗性位点连锁的多态性标记，运用完备区间作图法（BIP）和多环境表型鉴定数据（MET）两种QTL技术方法，检测到两个稳定的QTLs：QYrwdbj.nwafu-5A与QYrwdbj.nwafu-2B.1 。其中QYrwdbj.nwafu-5A位于小麦染色体5AS的缺失系5AS1-0.40-0.75和5AS3-0.75-0.98相邻的区域，解释15.02%-40.26%的表型变异；QYrwdbj.nwafu-2B.1位于小麦染色体2BS的缺失系C-2BS1-0.53上，解释9.54%-10.40%的表型变异。通过分子检测、抗病基因染色体定位和上位性分析表明，QYrwdbj.nwafu-5A很可能是一个需要与其它位点结合互作才能发挥抗条锈作用的新QTL。本研究将为进一步克隆武都白茧主效QTL，以及利用武都白茧主效QTL与其他有效抗条锈病基因或者QTL结合，培育持久抗条锈病品种提供科学依据。本研究的创新点是考虑环境对QTL的加性效应，从而提供QTL位置和效应方面更为全面遗传分析。

本研究调查了香味和抗寒无核品种选育中不同浓度的多效唑及胚采集时期对胚形成、萌发和成苗率的影响。结果显示，不同浓度的多效唑对不同葡萄品种子房和胚的发育影响不一致。红无籽露×北冰红和昆香无核×泰山-2组合在1.5 mg L^-1多效唑处理下胚形成率最高。红无籽露×北冰红组合在1.0 μmol L^-1多效唑处理下萌芽率和成苗率最高，但红无籽露×昆香无核组合在0.2 μmol L^-1多效唑处理下萌芽率最好。不同的杂交组合取胚时间也不同。火焰无核×玫瑰香最佳取胚时间为授粉后39 d，昆香无核×北冰红为授粉后46 d，红宝石无核×北冰红及奇妙无核×双优为授粉后41 d。另外，向培养基中补充0.5 mg L^-1吲哚丁酸可以帮助畸形苗恢复为正常幼苗并获得生长健壮的子代。研究结果将为利用胚挽救技术选育无核葡萄新品种奠定基础。

采后新鲜金针菇孢含水量高，质地脆嫩，仍具有较高的生理活性和呼吸作用，从而极易发生衰老和品质劣化。本研究使用1-甲基环丙烯（1-MCP）和聚丙烯（PP）保鲜盒处理金针菇，分析了金针菇在贮藏过程中木质化和软化的变化情况。主要研究结果如下：PP保鲜盒包装能有效地延长金针菇的贮藏时间；1-MCP处理、PP保鲜盒包装及两种处理组合均能显著抑制木质素的积累，并降低纤维素、果胶含量，对木质化及软化相关酶（苯丙氨酸解氨酶（PAL）、肉桂醇脱氢酶（CAD）、纤维素酶（Cx）、果胶甲基酯酶（PME）和聚半乳糖醛酸（PG）活性有一定的抑制作用。其中，PP保鲜盒包装的抑制效果高于1-MCP处理，且两种处理组合效果最好。透射电镜（TEM）和扫描电镜（SEM）结果表明，PP保鲜盒包装和1-MCP处理相结合能有效地保持金针菇细胞结构的完整性和稳定性，防止质膜分离及细胞膜破裂。转录水平分析结果表明，PP保鲜盒包装和1-MCP处理相结合，能明显影响金针菇木质化和软化相关酶基因的表达。综上，1-MCP和PP保鲜盒包装可以有效的延缓金针菇在贮藏过程中的木质化和软化现象，延长贮藏期。

由于劳动力投入少、经济效益高，水稻直播已成为中国南方地区主要的种植方式。旱直播方式在单季水稻栽培技术方面运用广泛。然而，对早籼稻机械旱直播试验的研究还少有报导。通过两年大田间试验，以2个籼稻品种（中嘉早17和株两优819）为材料，研究旱直播、淹水直播和湿直播模式下的水稻倒伏特性和产量形成。结果表明，在旱直播方式下，株两优819和中嘉早17的年均产量分别比湿直播和淹水直播高14.42-26.34%和6.64-24.58%，这主要是由于穗数的提高。旱直播方式显著提高了早籼稻品种的出苗率，增加总干重和作物生长速率。同时，与淹水直播和湿直播相比，旱直播基部节间较短，茎粗和茎壁较厚，倒伏指数较低。尤其是旱直播提高了茎秆的抗倒伏能力。本研究结果表明，适宜的直播方式有利于提高早籼稻的产量和抗倒伏能力。

重大农业入侵害虫草地贪夜蛾原产于美洲，自2016年首次被发现入侵尼日利亚和加纳以来，短短3年时间内迅速入侵至47个非洲国家和18个亚洲国家。由于该虫寄主范围广（至少包含353种寄主植物）、能够适应多种生境、超强的迁飞能力、高繁殖力、暴食性，以及快速发展的农药抗性和病毒抗性等内在优势，是导致其具有入侵性的重要原因，目前已被公认为全球范围内的超级害虫。该害虫的综合治理策略主要依靠监测调查、农业防治、化学防治、病毒制剂、性诱剂、生物防治（寄生性天敌、捕食性天敌和昆虫病原体），以及植物源农药等多种防治策略的综合应用。目前尚需要进一步研究的主要内容包括：（1）明确草地贪夜蛾的入侵机制，（2）如何阻止其进一步扩散，（3）提供更有效的防治策略。本文总结了草地贪夜蛾的生物学特性，潜在的入侵性机制，以及综合治理策略，以期为今后的治理提供参考。

Pear is an important fruit crop in the world. An uncharacterized disease has been observed on pear fruits during cold storage in Suning, Shenzhou, Xinji and other locations in Hebei Province, China. The incidence rate of the disease has reached 10%, and sometimes up to 20%. A particular fungus was consistently isolated from the infected pear fruit and cultured. Based on its morphology, molecular characteristics, pathogenicity and ITS sequence, the fungus was identified as Athelia bombacina. To our knowledge, this is the first report of Athelia bombacina causing postharvest fruit rot on pear.

Maintenance of green color is the primary indicator of quality in the market evaluation of Korla Xiang pears at present and can generally be achieved through early harvesting and decreasing the storage temperature, but the fruit quality was reduced by early harvesting, and the decreasing storage temperature increased the risk of chilling injury.  The objectives of this study were to determine the optimal storage parameters for different storage times and to find ways to preserve the green skin color of pears.  Specifically, we analyzed the effects of the ethylene inhibitor, 1-methylcyclopropene (1-MCP), combined with low temperature on quality and maintenance of the green color of Korla Xiang pears during storage.  We found that 1-MCP and/or low temperature reduced the loss of green color at 20°C after being removed from cold storage.  In addition, 1-MCP significantly inhibited the decline of titratable acid and ascorbic acid but had no significant effect on fruit firmness and total soluble solids.  Low temperature with or without 1-MCP inhibited the release of ethylene, inhibited the decline in the stalk preservation index, inhibited the increase in decay rate and weight loss rate during storage, and inhibited the increase in the core browning index after 225 days of storage.  Different storage temperatures had different effects on the quality of Korla Xiang pears.  Despite inhibiting ethylene release, a storage temperature of –1.5°C increased the respiration rate.  Storage at –1.5°C caused core browning early during storage due to chilling injury, whereas at 2°C core browning occurred late during storage due to senescence.  In late storage, 1-MCP had no significant effect on the maintenance of Korla Xiang pear quality at 2°C.  Based on these results, we determined the optimal combinations of low temperature and 1-MCP treatment to maintain pear quality while avoiding chilling injury.  For different marketing times, the optimal conditions for storage until New Year’s Day (a storage duration of 90 days) are 2°C or 1-MCP combined with 2°C.  For storage until the Spring Festival (a storage duration of 150 days), the optimal conditions are 0°C or 1-MCP combined with 0°C, and for storage until May (a storage duration of 225 days), the best conditions are 1-MCP combined with –1.5°C.   

Seasonal soil freeze-thaw events may enhance soil nitrogen transformation and thus stimulate nitrous oxide (N₂O) emissions in cold regions.  However, the mechanisms of soil N₂O emission during the freeze-thaw cycling in the field remain unclear.  We evaluated N₂O emissions and soil biotic and abiotic factors in maize and paddy fields over 20 months in Northeast China, and the structural equation model (SEM) was used to determine which factors affected N₂O production during non-growing season.  Our results verified that the seasonal freeze-thaw cycles mitigated the available soil nitrogen and carbon limitation during spring thawing period, but simultaneously increased the gaseous N₂O-N losses at the annual time scale under field condition.  The N₂O-N cumulative losses during the non-growing season amounted to 0.71 and 0.55 kg N ha^–1 for the paddy and maize fields, respectively, and contributed to 66 and 18% of the annual total.  The highest emission rates (199.2–257.4 μg m^–2 h^–1) were observed during soil thawing for both fields, but we did not observe an emission peak during soil freezing in early winter.  Although the pulses of N₂O emission in spring were short-lived (18 d), it resulted in approximately 80% of the non-growing season N₂O-N loss.  The N₂O burst during the spring thawing was triggered by the combined impact of high soil moisture, flush available nitrogen and carbon, and rapid recovery of microbial biomass.  SEM analysis indicated that the soil moisture, available substrates including NH₄⁺ and dissolved organic carbon (DOC), and microbial biomass nitrogen (MBN) explained 32, 36, 16 and 51% of the N₂O flux variation, respectively, during the non-growing season.  Our results suggested that N₂O emission during the spring thawing make a vital contribution of the annual nitrogen budget, and the vast seasonally frozen and snow-covered croplands will have high potential to exert a positive feedback on climate change considering the sensitive response of nitrogen biogeochemical cycling to the freeze-thaw disturbance.   

    As pesticide residues in bayberry has raised serious concern from the public in China, a monitoring survey was carried out during 2013–2014 and 157 samples were analyzed in total.  Twenty-three pesticides were detected among the 44 pesticides analyzed and at least one pesticide was detected in 63% of 99 samples.  Whereas 45.6% of samples were found with two or more pesticide residues, and 23.6% of samples with four or more pesticide residues.  Probabilistic risk assessments indicated that estimated daily intake (EDI) of cyhalothrin at the P97.5th percentile level is 1.11 times larger than the acceptable daily intake (ADI) for children, the estimated short-term intake (ESTI) at the P97.5th percentile level is 1.9 and 1.78 times larger than the acute reference dose (ARfD) for adult and children, respectively, indicating the potential risk concern from pyrethroids.  EDI of the pesticides with anti-androgenic effects ranged from 0.15–2.46 of ADI, the probability of exposure exceeding the ADI was 7.1 and 31.1% for adults and children, respectively, the probability of exposure of pyrethroids exceeding the ADI was 3.8% for children.  Exposures for other pesticides and groups were below 1.0.  Because the co-occurrence of frequency of cyhalothrin and cypermethrin was 9.55%, the combinations of pesticides detected with anti-androgenic effects has not been found in the present monitoring, the results indicate that the pesticide residues in bayberry will not constitute serious public health risk, however, they are significant for the management of pesticide use on bayberry and dietary health risk in China. 

    The structural characteristics of protein body accumulation in different endosperm regions of hard wheat cultivar (XM33) and soft wheat cultivar (NM13) under drought stress were investigated. Drought stress treatment was implemented from plant regreening to the caryopsis mature stage. Microscope images of endosperm cells were obtained using resin semi-thin slice technology to observe the distribution and relative area of protein body (PB). Compared with NM13, relative PB area of XM33 was significantly higher in sub-aleurone endosperm region. The amount of accumulation, including the size and relative area of PB, in two wheat cultivars was higher in sub-aleurone region than that in central region at 18 days post anthesis (DPA). Drought stress significantly enhanced the sizes and relative areas of PBs in the dorsal and abdominal endosperms in two wheat cultivars. Particularly for dorsal endosperm, drought stress enhanced the relative PB area at 18 DPA and NM13 (5.0% vs. 6.73%) showed less enhancement than XM33 (5.49% vs. 8.96%). However, NM13 (9.58% vs. 12.02%) showed greater enhancement than XM33 (10.25% vs. 11.7%) at 28 DPA. The protein content in the dorsal and abdominal endosperms of the two wheat cultivars decreased at 12 DPA and then increased until 38 DPA. Drought stress significantly increased the protein contents in the two main regions. From 12 to 38 DPA, the amount of PB accumulation and the protein content were higher in XM33 than those in NM13. The results revealed that PB distribution varied in different endosperm tissues and that the amount of PB accumulation was remarkably augmented by drought stress.

Late-maturity type of Yongyou japonica/indica hybrids series (LMYS) have shown great yield potential, and are being widely planted in the lower reaches of Yangtze River, China. Knowledge about suitable growing zone and evaluation of yield advantage is of practical importance for LMYS in this region. Fifteen LMYS, two high-yielding inbred japonica check varieties (CK-J) and two high-yielding hybrid indica check varieties (CK-I) were grown at Xinghua (119.57°E, 33.05°N) of Lixiahe region, Yangzhou (119.25°E, 32.30°N) of Yanjiang region, Changshu (120.46°E, 31.41°N) of Taihu Lake region, and Ningbo (121.31°E, 29.45°N) of Ningshao Plain in 2013 and 2014. The results showed that maturity dates of the 15 were later than the secure maturity date at Xinghua and 6, 14 and 15 LMYS were mature before the secure maturity date at Yangzhou, Changshu and Ningbo, respectively. One variety was identified as high-yielding variety among LMYS (HYYS) at Yangzhou, 8 HYYS in 2013 and 9 HYYS in 2014 at Changshu, 9 HYYS at Ningbo. HYYS here referred to the variety among LMYS that was mature before the secure maturity date and had at least 8% higher grain yield than both CK-J and CK-I at each experimental site. Grain yield of HYYS at each experimental site was about 12.0 t ha–1 or higher, and was significantly higher than CK varieties. High yield of HYYS was mainly attributed to larger sink size due to more spikelets per panicle. Plant height of HYYS was about 140 cm, and was significantly higher than check varieties. Significant positive correlations were recorded between duration from heading to maturity stage and grain yield, and also between whole growth periods and grain yield. HYYS had obvious advantage over check varieties in biomass accumulation and leaf area duration from heading to maturity stage. Comprehensive consideration about safe maturity and yield performance of LMYS at each experimental site, Taihu Lake region (representative site Changshu) and Ningshao Plain (representative site Ningbo) were thought suitable growing zones for LMYS in the lower reaches of Yangtze River. The main factors underlying high yield of HYYS were larger sink size, higher plant height, longer duration from heading to maturity stage and whole growth periods, and higher biomass accumulation and leaf area duration during grain filling stage.

Novel promoters that confer root-specific expression would be useful for engineering resistance against problems of nutrient and water absorption by roots. In this study, the reverse transcriptase polymerase chain reaction was used to identify seven genes with root-specific expression in rice. The isolation and characterization of upstream promoter regions of five selected genes rice root-specific promoter (rRSP) 1 to 5 (rRSP1-rRSP5) and A2P (the promoter of OsAct2) revealed that rRSP1, rRSP3, and rRSP5 are particularly important with respect to root-specific activities. Furthermore, rRSP1, rRSP3, and rRSP5 were observed to make different contributions to root activities in various species. These three promoters could be used for root-specific enhancement of target gene(s).

This study investigated effects of dietary fibre and grit on growth performance, gastrointestinal tract (GIT) development, serum indexes and grit retention of Sichuan white goslings in China. The experiment was a 3×2 factorial design consisting of dietary crude fibre (CF) at 2.0, 4.0 and 6.0% levels by adding grass meal and with or without grit supplementation. A total of 720 1-d-old male goslings were randomly allocated into 36 pens of 20 goslings/pen (n=6 pens/treatment). At 21 d of age, GIT, blood samples and grit in gizzards were collected. Body weight (BW), empty BW (without GIT), average daily gain (ADG) and average daily feed intake (ADFI) were affected by CF levels and the medium (4.0%) had the highest value. Adding grit improved BW, empty BW, ADG and ADFI. CF affected relative weight or length of proventriculus, gizzard and duodenum. Increasing CF levels decreased jejunum villus height and affected caecal crypt depth and villus height to crypt depth ratio. Higher CF levels decreased serum triglyceride. Adding grit increased relative weight of abdominal fat. Grit addition increased grit weight in gizzard and the ratio of grit in 0.45-1 and 1-2 mm while decreasing the ratio of grit <0.45 and 2-3 mm. In conclusion, moderate CF level and grit addition increased performance of goslings without interaction. Dietary CF levels affected the development of upper GIT and serum triglyceride. Grit needed by goslings should be less than 2 mm. Goslings’ gizzard would accumulate grit from feed when other grit could not be acquired.

Coexisting natural enemies that share a common host resource in the same guild usually exhibit variation in their life history traits, due to their need to share a similar ecological niche. In this study, we compared the immature development times and adult life history traits of two coexisting, host-feeding parasitoids, Diglyphus isaea Walker and Neochrysocharis formosa Westwood (Hymenoptera: Eulophidae), of which both attack larvae of the same agromyzid leafminers. These two species are both synovigenic, idiobiont parasitoids, whose adults consume host fluids (“host feeding”) and lay anhydropic eggs. Of the two, D. isaea has a larger body but little or no initial egg load, and engages in similar lifetime host-feeding events. However, it achieves higher fecundity, longer adult longevity, and higher host suppression ability than N. formosa, which has a smaller body and higher initial egg load. Although D. isaea engages in similar lifetime host-feeding events with N. formosa, all of its gains in life history traits per host-feeding event of D. isaea were larger than those of N. formosa. The age-specific fecundity and host mortality curves of N. formosa were more skewed in early life than those of D. isaea. In addition, the ovigeny index of N. formosa was negatively correlated to body size. Our results confirmed that two coexisting parasitoids, which share the same host resource, show different immature development patterns and life history traits, suggesting that different resource allocation mode could be a general rule of coexisting species sharing the same habitat or host.

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.

To accurately evaluate the carbon sequestration potential and better elucidate the relationship between the carbon cycle and regional climate change, using eddy covariance system, we conducted a long-term measurement of CO2 fluxes in the rain-fed winter wheat field of the Chinese Loess Plateau. The results showed that the annual net ecosystem CO2 exchange (NEE) was (-71.6±5.7) and (-65.3±5.3) g C m-2 y-1 for 2008-2009 and 2009-2010 crop years, respectively, suggesting that the agro-ecosystem was a carbon sink (117.4-126.2 g C m-2 yr-1). However, after considering the harvested grain, the agroecosystem turned into a moderate carbon source. The variations in NEE and ecosystem respiration (Reco) were sensitive to changes in soil water content (SWC). When SWC ranged form 0.15 to 0.21 m3 m-3, we found a highly significant relationship between NEE and photosynthetically active radiation (PAR), and a highly significant relationship between Reco and soil temperature (Ts). However, the highly significant relationships were not observed when SWC was outside the range of 0.15-0.21 m3 m-3. Further, in spring, the Reco instantly responded to a rapid increase in SWC after effective rainfall events, which could induce 2 to 4-fold increase in daily Reco, whereas the Reco was also inhibited by heavy summer rainfall when soils were saturated. Accumulated Reco in summer fallow period decreased carbon fixed in growing season by 16- 25%, indicating that the period imposed negative impacts on annual carbon sequestration.

This report reviews the characteristics of JS399-19, a novel cyanoacrylate fungicide. JS399-19 strongly inhibits the mycelial growth of the fungal plant pathogens of the genus Fusarium and exhibits great potential in controlling Fusarium head blight (FHB) on wheat and other cereals. The mode of action of JS399-19 is evidently different from that of benzimidazole (for example, carbendazim) and other sort of fungicides, making it a possible replacement for carbendazim in China to manage carbendazim-resistant subpopulations of Fusarium graminearum and F. asiaticum. JS399-19 has excellent protective and curative activity against these pathogens. Incorrect use of this fungicide, however, is likely to select for resistance. Among JS399-19-resistant mutants of F. asiaticum induced in the laboratory, the resistant level of mutants was high and the phenotype of resistance against JS399-19 was conferred by a major gene by genetic analysis. The fitness of laboratory-induced JS399-19-resistant mutants of F. asiaticum was nearly equal to that of their parents. JS399-19 lacks cross resistance with other sort fungicides. To control FHB with JS399-19 and to delay the development of the fungicide-resistance, farmers should use tank mixtures containing JS399-19 and carbendazim, metconazole, tebuconazole, or prothioconazole.