The predictive value of quantitative genetic parameters in autogamous crops: Bias caused by intergenotypic competition. 2. F∞-variance

Summary Quantitative genetic theory for autogamous crops enables the estimation of the parameters m (F-mean) and D (F-variance) in the F₃-generation. With these estimated m and D a prediction can be made of the probability of finding superior inbred lines in the F-offspring of the cross. The accuracy of this procedure is influenced by the correctness of the genetic model, by the magnitude of the error variance, and by the bias caused by intergenotypic competition, which is present in the environment in which the F₃ is grown and absent in the monoculture environment at which the selection is aimed, especially in a cereal crop like wheat. The influence of the latter was investigated by a special method of simulating segregating populations. In this method genotypes in the offspring of a cross are represented by varieties and segregating populations are composed by mixing the appropriate varieties according to the proper segregation frequencies. Growing the simulated population enables the estimation of m and D in the normal selection environment, while simultaneously growing the varieties in a large monoculture trial enables the calculation of true values of m and D in the monoculture environment. Hence, a comparison is possible.The second of this set of two papers presents the investigations on the influence of intergenotypic competition on the estimation of the parameter D. The correlation between the estimates from the selection environment and the calculated true values from the monoculture environment was low. On the average the true values were overestimated, however in a few cases the monoculture values were significantly underestimated. Using the estimated m's and D's to rank crosses may lead to rather erroneous results.     

琯溪蜜柚和度尾蜜柚自交和互交亲和性观察

用荧光显微技术对王官溪蜜柚 (Citrusgrandis cv.Guanximiyou)和度尾蜜柚 (Citrusgrandiscv.Duweimiyou)自交和互交亲和性进行了观察 .发现两品种自交和互交花粉在柱头上都萌发正常 .自交花粉管进入柱头组织后 ,大部分在伸长过程出现破裂 ,伴随有内容物渗出 ,在花柱道内缘有胼胝质出现 ,但仍有部分花粉管能正常生长进入子房 ,并从胚柄处进入胚珠 ,在珠心组织里 ,观察到胼胝质的积累 ,其中大多数王官溪蜜柚和少数度尾蜜柚胚珠的胚囊位置出现强烈的荧光亮点 .而互交的胚珠中没有观察到这些现象 .由此可见 ,两品种的自交组合在花粉管进入柱头组织 ,直至进入子房、胚珠的整个伸长过程中 ,存在一系列不亲和反应     

鹤望兰的自花与异花授粉研究

珍稀名贵花卉鹤望兰是典型的鸟媒植物，引种到我国栽培，由于没有蜂鸟，必须人工授粉才能结实.为了研究人工授粉的效果，提高鹤望兰的授粉成功几率，对授粉的时间、同一花序的不同花朵、自花、异花等进行比较试验.结果表明①在厦门地区，4～7月、9～11月进行人工授粉效果最好；②异花授粉的结果率明显高于自花授粉，异花授粉的结果率平均为91.75%，自花授粉仅为40.76%；③异花授粉的单果种子数为24.5个、自花授粉为10.4个，两者存在明显差异；④同一花序的各花朵间异花授粉结果率无差异，而进行自花授粉各花朵间存在明显差异；⑤同一花序的不同花朵间授粉结实的单果种子数无差异.     

鹤望兰的自花与异花授粉研究

珍稀名贵花卉鹤望兰是典型的鸟媒植物 ,引种到我国栽培 ,由于没有蜂鸟 ,必须人工授粉才能结实 .为了研究人工授粉的效果 ,提高鹤望兰的授粉成功几率 ,对授粉的时间、同一花序的不同花朵、自花、异花等进行比较试验 .结果表明 :①在厦门地区 ,4～ 7月、9～ 11月进行人工授粉效果最好 ;②异花授粉的结果率明显高于自花授粉 ,异花授粉的结果率平均为 91 75 % ,自花授粉仅为 40 76 % ;③异花授粉的单果种子数为 2 4 5个、自花授粉为 10 4个 ,两者存在明显差异 ;④同一花序的各花朵间异花授粉结果率无差异 ,而进行自花授粉各花朵间存在明显差异 ;⑤同一花序的不同花朵间授粉结实的单果种子数无差异     

安徽红籽瓜及其自交一代粗脂肪含量分析

对安徽红籽瓜及其自交一代进行了分析比较,结果表明:①安徽红籽瓜种仁粗脂肪含量丰富.②含山、凤阳、合肥红籽瓜自交一代粗脂肪含量并没有显著差异;但是含山和凤阳的红籽瓜自交一代与黑籽瓜自交一代之间存在显著差异.③变异系数的比较显示含山的红籽瓜自交一代更有希望选育出优良自交系.④由相关回归分析可知,粗脂肪含量与种子长×宽、千粒重、种子长呈正相关,其回归方程分别为:y=27.215x1+22.398,y=0.115x2+33.746和y=12.858x23+27.427,(y为粗脂肪含量%;x1为种子长宽乘积mm2;x2为种子千粒重g;x3为种子长mm.)     

我校研究生学位论文网络数据库建设方案初探

在高校开发自有资源网络数据库的工作中，学位论文是一种重要的文献资源。本文以南京农业大学研究生学位论文网络数据库的建设为例，阐述了研究生学位论文开发利用的意义和利用方正德赛自有资源管理系统进行学位论文网络数据库建设的思路与方法。     

基于李雅普诺夫直接法的自适应预测电流控制算法

针对预测电流控制算法忽略线阻且未考虑干扰信号的缺点,提出了一种适用于光伏并网逆变器的自适应控制算法。该算法基于李雅普诺夫稳定性定理进行设计,在达到控制目标和保证系统稳定的前提下,实现了根据实时采样数据对电路未知参数进行自适应调节,避免因对电压或电流的假设和忽略负载电阻的影响而造成误差,使系统对干扰信号具有更强的抗干扰性,提高控制器对噪声的抑制能力。最后,通过仿真和试验验证了该算法的有效性。     

A parallel cluster algorithm for self adaptive particle swarm optimization

Full scale data mining, such as in cluster problems, requires large numbers of computations. A parallel cluster algorithm for self adaptive particle swarm optimization was proposed to deal with this problem. The proposed parallel particle swarm optimization algorithm reduced the impact of the initial conditions via parallel searches of the globally best position amongst a varied population. Task parallelization and partially asynchronous communication of the algorithm were employed to decrease computing time. Furthermore, if combined with the characteristics of self adaptive and dynamical optimization parameters of the parallel particle swarm algorithm, the problems of particle mobility loss and the end of evolution could be dealt with successfully. When modified thusly, the algorithm maintains individual diversity and restrains degeneration. The simulation experiments indicate the algorithm helps increase computing speed and improve cluster quality.     

浅析《印度之行》中殖民主义者的身份危机

《印度之行》是研究殖民主义背景下宗主国和殖民地关系的经典文本。小说围绕两个初到印度的英国女性与思想单纯,热情好客的印度人阿齐兹的交往,展开了殖民地背景下的两种英印关系。对于印度这一他者,善良友好的摩尔夫人和在印度从事教育的菲尔丁体现出的人道主义和自由主义思想与小说中具有殖民主义意识的众多在印度的英国人形成鲜明对比。小说中另一个中心人物,到印度准备与当地执法官朗尼结婚的阿德拉·奎斯蒂德小姐在受阿齐兹的邀请游览马拉巴山洞时,陷入阿齐兹企图强奸她的“幻觉”之中,使她从阿齐兹的“客人”变成控告他“强奸罪”的“敌人”。山洞里究竟发生了什么？印度如何从“友好神秘的他者”变成“暴力和野蛮的他者”？本文从心理学的“自我”和“他者”的角度,运用赛义德的“东方主义”理论中西方殖民者对负面的东方形象的建构,透视阿德拉在“身份认同”危机中表现出的两种对他者态度的矛盾,揭示隐藏在殖民主义心理深处的“自我身份”的危机。     

Dynamic Performance Analysis of Prestress Self balanced Cable Truss

As a new kind of supporting member, a prestress self balanced cable truss has been widely applied in point supported glass curtain walls. The free and forced vibration behaviors were analysed. Taking the temperature effect and geometric nonlinearity into consideration, the nonlinear vibration equation was derived with continua theory for prestress self balanced cable truss support system in point supported glass curtain wall. By the Galerkin method, the partial differential equation was transformed into ordinary differential equation and then solved with L P method and KBM method. With the case study, the effects of temperature, amplitude, and exterior excitation on the nonlinear vibration were discussed. And it was found that the frequency would decrease with increase of temperature and the nonlinear vibration showed the characteristics of hard spring.