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71.
【目的】基因拷贝数变异是一种常见又重要的基因结构变异,往往影响个体表型。低分子量麦谷蛋白(low-molecular-weight glutenin subunit,LMW-GS)是小麦贮藏蛋白的主要组成部分,位于Glu-3位点。小麦作为异源六倍体,其庞大且复杂的基因组结构导致难以利用传统方法检测目的基因的拷贝数,针对小麦基因组,筛选可靠稳定的内参基因和体系,探索适合复杂基因组的拷贝数变异测定技术,测定Glu-3位点LWM-GS基因拷贝数。【方法】以Acc1为内参基因,根据基因序列设计内参引物和探针,通过定性和定量PCR测定内参基因在12个普通小麦品种中的拷贝数,分析该基因拷贝数在不同品种间的稳定性;又以小麦品种篙优2018的5个稀释浓度的基因组DNA为模板,利用qRT-PCR验证Acc1内参系统的重复性和准确性;根据Glu-A3位点LMW-GS基因序列设计特异性引物及探针,利用qRT-PCR和ddPCR 2种方法检测8个小麦品种Glu-A3位点基因拷贝数,比较后选择更优的高通量基因拷贝数检测方法;再根据Glu-B3和Glu-D3位点LMW-GS基因序列设计相应的特异性引物及探针,并利用ddPCR技术检测和分析了231份小麦品种的Glu-A3、Glu-B3和Glu-D3位点上LMW-GS基因拷贝数。【结果】Acc1在12个普通小麦品种间、同一品种5个DNA稀释浓度间的拷贝数测定结果一致,技术重复间的变异系数仅为0.07%—0.77%,所构建的Acc1内参系统稳定;比较qRT-PCR和ddPCR 2种拷贝数检测方法,8个品种所测的Glu-A3位点拷贝数结果一致,分别为3、5、3、4、3、3、3和3;且ddPCR检测重复间的变异系数为0.30%—1.67%,远低于qRT-PCR的3.14%—12.72%,更加可靠;利用ddPCR对231份普通小麦品种的Glu-A3、Glu-B3和Glu-D3位点上LMW-GS基因拷贝检测后分析发现,大多数小麦品种在3个位点上的拷贝数为4,所占频率分别为51.95%、32.03%和28.57%,Glu-3位点总拷贝数变异范围为10—21,变异系数为16.12%。【结论】Acc1内参系统具有良好的稳定性和重复性,可以用作小麦Glu-3位点和其他目的基因拷贝数检测的内参;qRT-PCR和ddPCR均可用于小麦基因拷贝数的检测,但后者更稳定、可靠,且操作简单、检测通量高。 相似文献
72.
针对冬小麦因播期推迟造成产量损失的问题,以2个不同分蘖能力的冬小麦品种中麦8号和航麦501为供试材料,研究苗期覆膜和补施氮肥对晚播小麦产量及氮素利用的影响。试验设置3个播期:10月5日适期播种(S0,对照)、10月15日适当晚播(S1)和10月25日过晚播(S2)。结果表明:随着播期推迟,小麦产量逐渐降低。晚播条件下,苗期覆膜和补施氮肥可调控冬小麦产量构成因素、农艺性状、茎蘖生长、成穗率以及氮素的吸收利用。综合而言,晚播条件下,覆膜和补施氮肥有利于提高小麦穗长、总小穗数及冬前群体数量;同时,覆膜可显著提高2个品种晚播条件下的分蘖成穗率和过晚播条件下的植株氮素积累量(PNA)及氮肥偏生产力(PFP),增幅分别为46.4%~89.1%、12.7%~26.5%和19.5%~20.1%;补施氮肥在过晚播条件下有利于成穗率的提高,增幅为18.5%~34.7%。2种调控措施均有利于增加晚播小麦产量,增幅达1.4%~19.5%。但不同分蘖力的小麦对2种调控措施的响应存在差异。综合考虑产量及氮素利用等各方面因素,在晚播条件下,相比于补施氮肥,苗期覆膜更有利于提高晚播小麦产量,弥补晚播造成的产量损失,但在实际操作和节约生产成本方面,前者优于后者。 相似文献
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Drip-irrigation is increasingly applied in maize (Zea mays L.) production in sub-humid region. It is critical to quantify irrigation requirements during different growth stages under diverse climatic conditions. In this study, the Hybrid-Maize model was calibrated and applied in a sub-humid Heilongjiang Province in Northeast China to estimate irrigation requirements for drip-irrigated maize during different crop physiological development stages and under diverse agro-climatic conditions. Using dimensionless scales, the whole growing season of maize was divided into diverse development stages from planting to maturity. Drip-irrigation dates and irrigation amounts in each irrigation event were simulated and summarized in 30-year simulation from 1981 to 2010. The maize harvest area of Heilongjiang Province was divided into 10 agro-climatic zones based on growing degree days, arid index, and temperature seasonality. The simulated results indicated that seasonal irrigation requirements and water stress during different growth stages were highly related to initial soil water content and distribution of seasonal precipitation. In the experimental site, the average irrigation amounts and times ranged from 48 to 150 mm with initial soil water content decreasing from 100 to 20% of the maximum soil available water. Additionally, the earliest drip-irrigation event might occur during 3- to 8-leaf stage. The water stress could occur at any growth stages of maize, even in wet years with abundant total seasonal rainfall but poor distribution. And over 50% of grain yield loss could be caused by extended water stress during the kernel setting window and grain filling period. It is estimated that more than 94% of the maize harvested area in Heilongjiang Province needs to be irrigated although the yield increase varied (0 to 109%) in diverse agro-climatic zones. Consequently, at least 14% of more maize production could be achieved through drip-irrigation systems in Heilongjiang Province compared to rainfed conditions. 相似文献
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钟杨 《农业图书情报学刊》2018,30(9):154-157
知识供应链管理是以知识创新为目的、以满足用户知识需求为出发点和归宿的一种系统化、集成化的管理模式。图书馆应用知识供应链开展知识服务,应该采取实施业务流程重组、加强特色馆藏建设、建立知识交流机制、推进集成化知识供应链管理、提高馆员专业素质,以建立一套适合图书馆实际的知识供应链运行机制。图书馆引入知识供应链理论是必要的和可行的。 相似文献
80.
Effects of adding sucrose on Penaeus monodon (Fabricius, 1798) growth performance and water quality in a biofloc system 下载免费PDF全文
Zhenhua Ma Falin Zhou Lishi Yang Jipeng Deng Shigui Jiang 《Aquaculture Research》2017,48(5):2316-2327
A 60‐day indoor growth trial was conducted to study the effects of biofloc on the growth performance of a Penaeus monodon (Fabricius, 1798), water quality and biological indicators including biofloc volume, chlorophyll‐a, heterotrophic bacteria and Bacillus quantity. Two concentrations of sucrose (0 and 75%) were added daily to the P. monodon culture systems (2.94 ± 0.11 g), which were conducted indoors in fibre‐glass tanks (500 L). Results showed that the final body weight and weight gain of the adding 75% sucrose group were significantly higher (P < 0.05) than that of the control, as well as significantly (P < 0.05) improved specific growth rates and survival rates, and reduced feed coefficient. Adding 75% sucrose promoted heterotrophic bacteria, Bacillus and phytoplankton reproduction, and significantly (P < 0.05) reduced the concentration of ammonia‐N (NH4‐N), nitrite‐N (NO2‐N) and nitrate‐N (NO3‐N). The changes of water quality indicators in the two groups showed the similar trend at the end of the experiment, and the ammonia‐N, nitrite‐N, nitrate‐N and phosphate‐P concentrations in the 75% sucrose group were significantly (P < 0.05) lower than those of the control group, Chlorophyll‐a concentrations peaked at 389.12 μg/L in the biofloc sucrose group at 18:00 h, and heterotrophic bacteria peaked 8 h after sucrose was added. The addition of sucrose also reduced the pH of the water. Our research showed that adding sucrose promoted biofloc formation and shortened the formation time; increased the number of heterotrophic bacteria and algae which might play a role in improving water quality by assimilating ammonia‐N and other harmful substances in the water; supplemented food for P monodon growth; and reduced the feed coefficient. 相似文献