小麦群体图像特征识别方法的研究 ——小麦群体总茎数的估测

作物群体特征一肌指群体内个体的数量、种类、生育状况及其空间排列、分布和个体间的关联程度等.群体内光照、温度、湿度、风和二氧化碳浓度等要素的分布均与作物群体性状紧密相连,因此,对群体结构特征的考察一直受到关注,也研制了许多考察的方法[1~3],这些方法都曾为农业科研和生产做出过贡献.     

玉米不同生育阶段养分效应评价方法研究

了解作物养分效应机制是提高作物养分利用效率的重要基础。本文以玉米品种"农华101"为试验材料, 进行不同播期、密度、肥料试验, 记录了生育时期的日均温, 并对玉米不同生育时期叶片及其他器官中氮、磷、钾元素含量进行了测定, 然后基于改进后的BLUP方法, 在考虑植株干物质日均积累量与自身效应、环境效应关系的基础上, 引入群体效应和温度效应, 探讨并建立了玉米不同生育阶段养分效应评价方法。在此基础上, 进一步对养分效应评价效果进行分析。结果表明: 干物质日均积累量理论值与实际值的相关性r值为0.72~0.99; 各生育阶段配对t检验的α值均大于0.05, 各生育阶段的干物质日均积累量的理论值和实测值差异均不显著(P>0.05)。研究结果表明, 用建立的玉米不同生育阶段的养分效应评价方法得到的各养分特征效应值存在较大差异, 其中: 三叶期到拔节期各养分效应值为0~0.58, 拔节期到大口期为 0.43~2.57, 大口期到吐丝期为 0.45~4.58, 吐丝期到成熟期为 0.86~4.71。综上, 利用改进后的BLUP法提出的养分效应评价方法对玉米各阶段养分效应的评价结果具有一定的指导意义, 该方法可作为玉米养分效应评价的参考手段。     

Synthesis and fungicidal activity of macrolactams and macrolactones with an oxime ether side chain

Three series of novel macrolactams and macrolactones--12-alkoxyimino-tetradecanlactam, 12-alkoxyiminopentadecanlactam, and 12-alkoxyiminodecanlactone derivatives (7A, 7B, and 7C)--were synthesized from corresponding 12-oxomacrolactams and 12-oxomacrolactone. Their structures were confirmed by 1H NMR and elemental analysis. The Z and E isomers of 7A and 7B were separated, and their configurations were determined by 1H NMR. These compounds showed fair to excellent fungicidal activities against Rhizoctonia solani Kühn. It is interesting that the Z and E isomers of most of the compounds have quite different fungicidal activities. The fact that the compounds have a gradual increase of fungicidal activity in the order of 7A, 7C, and 7B indicated that the macrocyclic derivatives with a hydrogen-bonding acceptor (=N-O-) and a hydrogen-bonding donor (-CONH-) on the ring, and a three methylenes distance (CH2CH2CH2) between these two functional groups, exhibited the best fungicidal activity. The bioassay also showed that 7B not only has good fungicidal activity but also may have a broad spectrum of fungicidal activities.     

1982-2013年新疆不同植被生长时空变化

基于逐像元一元线性回归模型,应用MODIS NDVI数据对AVHRR-GIMMS NDVI 数据进行时间序列拓展,建立了1982-2013年间长时间序列生长季最大NDVI数据集,分析了新疆不同分区的生长季植被NDVI变化及其对气候变化的响应。结果表明,1)北疆平原地区、南疆平原地区和南疆山地地区的植被NDVI变化呈显著增长趋势,北疆山地地区的植被呈下降趋势。2)水分条件和最低气温是影响新疆植被生长的重要因素,但不同分区的影响程度不同。北疆平原地区植被受水分条件影响较大,其中最低气温对农田植被影响较大;南疆平原地区植被受气温和降水的双重作用;山地地区植被受水分条件影响较大。3)从不同植被类型来看,水分条件对草地的影响最大,其次是林地,农田植被受水分条件的限制较小,与灌溉有着直接关系。4)增温增湿的气候条件有利于植被生长;北疆山地地区植被退化趋势受气候变化、火灾、平原草地围栏保护后放牧压力向山地转移等综合因素的影响。     

rolB基因导入对农垦58S内源激素水平、株型和育性的影响

对以农杆菌介导法获得的rolB转基因农垦58S的研究表明，rolB能明显改变水稻内源激素水平。其中，叶片和长日照条件下幼穗IAA水平有明显升高，同时长日照条件下iPAs及GA含量也有不同程度增加，但ABA水平无明显改变。rolB对水稻株型有明显影响，表现为株型紧凑，叶片直立、深绿，多数后代株系分蘖减少，叶片和颖花等器官变小，     

Insect antifeedants from Munronia henryi: structure of munroniamide

A novel A,B-seco-tetranortriterpenoid lactam, named munroniamide (1), along with three known ceramides (2-4), was isolated from the methanolic extract of the whole bodies of Munronia henryi. The structure of 1 was established using spectroscopic methods. Compound 2 exhibited significant antifeeding activity, and 1 exhibited moderate activity, whereas 3 and 4 showed negative activity against Pieris brassicae L.     

预应力CFRP加固钢筋混凝土无梁楼盖设计方法的研究

本文研究预应力CFRP加固钢筋混凝土无梁楼盖的技术和设计方法,首先介绍预应力CFRP加固钢筋混凝土无梁楼盖的材料及加固方式,用等代框架法确定计算模型,计算荷载,按正常使用极限状态和承载能力极限状态的荷载效应组合分别计算板的内力。按正常使用极限状态的抗裂要求确定预应力CFRP的加固数量。最后给出屈服弯矩及极限承载能力的计算公式。     

夏玉米不同品种各阶段氮素效应综合评价方法

了解作物养分效应机制是合理施肥的重要理论基础。本文以浚单20、农华101和中农大4号3个玉米栽培品种为材料,综合品种遗传特征、光温及群体大小3个主要影响植株氮素效应的因素,以BLUP方法为基础,建立玉米品种间、不同器官在各生育阶段的氮素效应综合评价方法。结果表明,氮素效应评价模型中,各阶段日平均干物质积累量的理论值与实测值的相关性r值分别为0.988、0.881、0.973、0.929;用独立试验样本对氮素效应评价模型检验,其配对t检验的P值均大于0.05,差异不显著;不同生育阶段、不同玉米品种氮素效应参数值有较大差异;氮素固定效应值在不同生育阶段、同一阶段的不同氮素构成中均表现出较大差异。综上,利用本文改进后的BLUP方法进行氮素效应评价及特征分析可以深入阐释不同玉米品种在各生长阶段积累的氮素对干物质生产的作用及影响,并进一步明确玉米氮素效应的共性特征、品种间的遗传差异、光温及群体影响机制等生物学规律。     

宁夏主栽苜蓿品种(系)对豌豆蚜的抗性评价

运用蚜量比值法和模糊识别法,对12个宁夏主栽苜蓿品种(系)进行了田间和室内抗蚜评价试验。田间蚜虫种类以豌豆蚜(Acyrthosiphon pisum)为主,占混合种群数量的80%以上。田间和室内结果综合分析表明:供试12个苜蓿品种(品系)中,惊喜、WL343HQ和德宝3个品种为高感品种,其蚜量比值均大于1.25,并与其他品种间差异极显著;柏拉图、中苜3号、甘农4号等3个品种为感蚜品种,其蚜量比值位于0.76~1.25之间;先行者为中抗品种,蚜量比值为0.51,位于0.51~0.75之间;皇冠、三得利、皇后、SR4030和MF40205等5个品种为抗蚜品种,其蚜量比值 0.26~0.50之间。同时,本研究也提出了室内和田间苜蓿抗蚜鉴定方法分别为模糊识别法和蚜量比值法的评价方法和标准。     

Development of Cre–loxP technology in zebrafish to study the regulation of fish reproduction

One cannot seek permission to market transgenic fish mainly because there is no field test or any basic research on technological developments for evaluating their biosafety. Infertility is a necessary adjunct to exploiting transgenic fish unless completely secure land-locked facilities are available. In this study, we report the generation of a Cre transgenic zebrafish line using a cytomegalovirus promoter. We also produced fish carrying the Bax1 and Bax2 plasmids; these genes were separated by two loxP sites under a zona pellucida C promoter or were driven by an anti-Müllerian hormone promoter. We inserted a red fluorescent protein gene between the two loxP sites. After obtaining transgenic lines with the two transgenic fish crossed with each other (Cre transgenic zebrafish x loxP transgenic zebrafish), the floxed DNA was found to be specifically eliminated from the female or male zebrafish, and apoptosis gene expressions caused ovarian and testicular growth cessation and degeneration. Overexpression of the Bax1 and Bax2 genes caused various expression levels of apoptosis-related genes. Accordingly, this transgenic zebrafish model system provides a method to produce infertile fish and may be useful for application to genetically modified fish.