烤烟主要农艺性状对产量的遗传贡献率分析

为了研究烤烟主要农艺性状对产量的贡献,以14个品种(系)及其配制的41个杂交组合为材料,利用估算条件方差分量和预测条件遗传效应值的统计方法对多点实验数据进行了分析。结果表明,株高对产量的加性遗传方差贡献率最高,腰叶长对产量的显性遗传方差贡献率最高,各农艺性状对产量的加性×环境互作遗传方差、显性×环境互作遗传方差的贡献率均较小。对产量加性效应贡献最大的农艺性状因不同亲本而异,表明各亲本具有其独特的遗传和发育特性。多数杂交组合产量的显性效应主要受腰叶长影响,因此腰叶长可作为间接选择组合产量显性效应的指标。

基于遗传贡献率的陆地棉营养品质性状动态发育研究

为研究陆地棉的三个营养品质性状(油分指数,蛋白质指数和赖氨酸指数)的动态发育过程,以三种品种和五个材料的实验数据,利用估算的遗传方差和遗传贡献率进行分析.分析结果表明,在整个发育过程中,蛋白质指数对油分指数的母体效应遗传变异检测到有较大的贡献.在发育的四个阶段,对于细胞质效应遗传变异,赖氨酸指数对油分指数和蛋白质指数的贡献未检测到,而对母体效应遗传变异却检测到有较大的贡献.环境影响了油分指数与蛋白质指数之间,赖氨酸指数与蛋白质指数之间的遗传贡献,这对于指导陆地棉的遗传育种有重要的意义.

Optimization of Grease Properties to Prolong the Life of Lubricating Greases

Grease life refers to the time it takes for the grease to lose its ability to keep the lubrication due to grease degradation. As grease life is generally shorter than fatigue life of bearing, the service life of grease-lubricated rolling bearings is often dominated by grease life. When designing a bearing systemolecular weightith grease lubrication, it is necessary to define the operating conditions limits of the bearing, for which grease life becomes a determining factor. Prolongation of grease life becomes an especially important challenge when the bearing is to be operated trader high-speed, high-temperature, and other severe conditions. Selecting a number of commercially sold greases composed of varying base oils, the author evaluated their properties and analyzed how each property affected the grease life by performing a multiple regression analysis. The optimum grease composition to best exploit each property was also examined. The results revealed among others that one would need to first determine the base oil type and then maximize ultimate bleeding while minimizing the evaporation rate.