小麦抗麦双尾蚜研究进展

麦双尾蚜是一种世界性的麦类害虫。本文就小麦抗麦双尾蚜资源筛选、抗性机制、抗性遗传、抗蚜基因染色体定位及分子标记研究进展进行了综述。     

不同稻虾种养模式下水稻中微量元素吸收 与稻米品质的关系研究

为探明不同稻虾种养模式下水稻中微量元素吸收与稻米品质的关系,开展不同龙虾品种和密度的田间试验,设计水稻单作（rice monoculture ,R）、水稻克氏原螯虾低密度共作（rice co-cropping with Procambarus Clarkii in low density,RCL）、水稻克氏原螯虾高密度共作（rice co-cropping with Procambarus Clarkii in high density,RCH）和水稻澳龙共作（rice co-cropping with Cherax quadricarinatus ,RA）4个处理,分析了稻米中微量元素含量、稻米品质、中微量元素与品质的相关性以及经济效益等指标。结果表明：稻虾共作模式提高了稻米中微量元素含量,其中Fe、Ca和Mg含量显著增加,与R处理相比,RCH、RCL和RA处理稻米的Fe含量分别增加52.0%、23.4%和21.4%,Ca含量分别增加45.7%、32.1%和22.8%,Mg含量分别增加45.0%、28.6%和23.3%。稻米中微量元素提升,有利于稻米品质的改善,稻米品质中的蛋白质与Fe、Ca和Mg呈显著（P<0.05）正相关,胶稠度与Fe、Ca和Mg呈极显著（P<0.01）正相关;直链淀粉含量和垩白粒率均与Ca呈极显著（P<0.01）负相关。稻虾共作模式提高了蛋白质含量和胶稠度,降低了稻米的垩白粒率和直链淀粉含量,稻米品质变优,其中RCH处理稻米品质改善效果最好。与R处理相比较,RCH、RCL和RA处理的纯收益分别增加了506%、314%和429%。总体而言,稻虾共作模式能够提高稻米中微量元素含量,改善稻米品质,提高经济效益,因此,在稻虾综合种养模式的选择中,龙虾品种和养殖密度是需要综合考虑的重要因素。     

Phenological and physiological evaluation of first and second cropping periods of sorghum and maize crops

Environmental conditions influence phenology and physiological processes of plants. It is common for maize and sorghum to be sown at two different periods: the first cropping (spring/summer) and the second cropping (autumn/winter). The phenological cycle of these crops varies greatly according to the planting season, and it is necessary to characterize the growth and development to facilitate the selection of the species best adapted to the environment. The aim of this study was to characterize phenological phases and physiological parameters in sorghum and maize plants as a function of environmental conditions from the first cropping and second cropping periods. Two parallel experiments were conducted with both crops. The phenological characterization was based on growth analyses (plant height, leaf area and photoassimilate partitioning) and gas exchange evaluations (net assimilation rate, stomatal conductance, transpiration and water-use efficiency). It was found that the vegetative stage (VS) for sorghum and maize plants was 7 and 21 days, respectively, longer when cultivated during the second cropping. In the first cropping, the plants were taller than in the second cropping, regardless of the crop. The stomatal conductance of sorghum plants fluctuated in the second cropping during the development period, while maize plants showed decreasing linear behaviour. Water-use efficiency in sorghum plants was higher during the second cropping compared with the first cropping. In maize plants, in the second cropping, the water-use efficiency showed a slight variation in relation to the first cropping. It was concluded that the environmental conditions as degree-days, temperature, photoperiod and pluvial precipitation influence the phenology and physiology of both crops during the first and the second cropping periods, specifically cycle duration, plant height, leaf area, net assimilation rate, stomatal conductance and water-use efficiency, indicating that both crops respond differentially to environmental changes during the growing season.     

Establishment of an in vitro method for evaluating whitefly resistance in tomato

An accurate and simple evaluation method is crucial for identifying whitefly resistance in tomato breeding. We developed an in vitro method for evaluating resistance of tomato leaves and tested this on wild and cultivated tomato varieties. We found that young leaves observed for whitefly oviposition after 8 hours provided appropriate comparative conditions. This method effectively distinguished resistance among tomato cultivars and wild species and also demonstrated significant difference in oviposition rates among leaf positions on susceptible cultivars. The in vitro test was as precise as in vivo test using intact plants and had advantages over in vivo test, and can be used for evaluating resistance in large populations.     

不同品种苜蓿在不同生育期总皂苷含量变化的研究

通过分析内蒙古地区种植的紫花苜蓿、黄花苜蓿、草原2号苜蓿在不同生育期总皂苷含量的变化,并利用SPSS11．5统计软件进行方差分析,并采用Duncan法进行均值的多重比较。结果表明,返青期到初花期的植株总皂苷含量为紫花苜蓿〉草原2号苜蓿〉黄花苜蓿,紫花苜蓿的总皂苷含量极显著高于黄花苜蓿（P〈0．01）;在盛花期和结荚期,草原2号苜蓿的总皂苷含量高于其他2个品种;成熟期黄花苜蓿的总皂苷含量最高。紫花苜蓿与草原2号苜蓿在结荚期的植株总皂苷含量显著大于其他生育期（P〈0．05）,黄花苜蓿的总皂苷含量在盛花期达到最大。     

季节对美系杜洛克母猪胴体和肉质性能的影响

本试验测定了不同季节对美系杜洛克的胴体和肉质参数的影响。结果提示:季节对美系杜洛克猪的胴体品质无显著影响。在肉质参数中,秋冬季猪肉的红度(6.47±0.73)显著低于春夏季(8.78±0.85),贮存损失(3.26±0.88)也显著低于春夏季(5.63±0.64)。     

高产奶牛孕检后同期发情程序选择的研究

为了研究适用于高产奶牛的同期发情程序方案,将218头膘情良好、子宫和卵巢发育正常的不同胎次荷斯坦牛随机分成两组,试验1组为106头,试验2组为112头,分别采用两种同期程序(0.5.6.8和0.7.8.9)进行处理,测定情期受胎率,用于评价两种同期程序对高产奶牛的适用性.结果表明,试验2组情期受胎率平均为41.96％,...     

基于B/S结构的家蚕育种与种性维持信息管理系统

对家蚕育种亲本及其新品种性状数据档案实行信息化管理,可在家蚕育种和品种的种性维持过程中自动实现完整的信息采集、计算、调用、选择等功能。开发了一个基于B/S结构的家蚕育种与种性维持信息管理系统,主要包括品种管理、计划任务管理、饲育信息管理、蚕茧信息管理、选种信息管理、选优信息管理等功能模块。选种信息管理模块的运行过程是通过电子天平称量蚕茧质量,然后根据计算模型自动进行数据信息处理与统计分析实施选择。用户可以方便地通过网络访问该系统,实现家蚕新品种选育及种性维持工作的自动化。     

中蜂越夏及秋季繁殖试验

在贵州锦屏进行的中蜂越夏及秋繁试验表明，４框以上的群势越夏较为安全。越夏期间每框足蜂约需补喂白糖１．５公斤。越夏后，蜂群群势约下降１／３左右。蜂群在越夏期间飞逃的主要原因是缺蜜及巢虫危害。当地中蜂在秋季大流蜜初期发生分蜂，分蜂群势均为８框足蜂以上，７框左右不分群。为控制不同起繁群势的蜂群在秋季大流蜜初期正好繁殖到７框左右，不致因分蜂影响秋冬蜜的采集，应分期起步秋繁。根据本试验所建秋季起繁群势（ｘ）与达７框群势所需繁殖天数（ｙ）之间的回归直线方程推算，在起繁群势为１～５框蜂量时，最适的秋繁开始期，１框群为７月３１日，２框群８月１０日……蜂群的基础群势每增加一框，则秋繁开始期应相应推迟１０～１１天。     

新太湖猪选育过程中近交技术的应用及效应分析

利用新太湖猪选育过程中（１９８６～１９９４）６个世代母猪的分娩产仔记录,后备猪生长发育测定资料,分析了近交对繁殖性能和生长发育性状的影响。相关分析表明,近交与产仔数、产活仔数的相关系数分别为－０．１６２５、－０．１５４６。与１８０日龄活重、体高、胸围、及８０ｋｇ时背膘厚度的相关系数分别为－０．１３５,－０．２１１,－０．２１８,－０．２０４。回归分析表明,近交系数每上升１０％,产仔数下降０．３９头,１８０日龄活重下降１．５ｋｇ,背膘厚下降０．０７４８ｃｍ。产仔记录分析表明,母猪近交系数在２０％以下时,产仔数比非近交组下降０．２７头,差异不显著（Ｐ＞０．０５）;近交系数在２０％以上时,下降１．３５头,差异不显著（Ｐ＞０．０５）。生长发育性状表明,近交系数在３０％以上时,１２０日龄活重、１８０日龄活重等性状都显著下降。８０ｋｇ活体背膘厚当个体近交系数上升到２０％以上时,与非近交组相比下降０．１６ｃｍ,差异显著（Ｐ＜０．０５）。