水稻抗褐飞虱基因Bph14和Bph15的分子标记辅助选择

【研究目的】褐飞虱是危害水稻的三大病虫害之一，利用品种自身的抗性是目前防治褐飞虱最经济有效的方法之一。为了选育抗虫品种，【方法】本研究以携带有抗褐飞虱主效基因Bph14和Bph15的抗虫品系B5为抗源，以优良杂交稻亲本9311和1826为受体材料，通过复交和回交，分别利用与Bph14和Bph15紧密连锁的SSR标记MRG2329和MS5在分离群体中进行分子标记辅助选择，【结果】最终获得一系列目标基因纯合且农艺性状优良的稳定株系。采用苗期群体鉴定技术，对其中的38份重要材料进行了抗虫鉴定，在26份Bph14单基因纯合株系中，92.31%的材料抗性水平在中抗以上，6份Bph15单基因纯合株系全为抗或高抗，聚合有Bph14和Bph15双基因的6份株系抗性都达到了高抗水平。【结论】说明在育种进程中利用与Bph14和Bph15紧密连锁的分子标记开展抗褐飞虱分子标记辅助育种是一种有效的途径。     

野生稻高产基因及其分子标记辅助育种研究

传统遗传育种方法在挖掘和利用水稻栽培品种的遗传资源方面日趋饱和,进一步提高杂交水稻产量潜力必须考虑利用水稻野生近缘种的有利基因库.随着分子生物学技术的发展,分子标记辅助选择在定向导入远缘有利基因方面的研究日益活跃.介绍了马来西亚普通野生稻的2个高产QTLs(即yld1.1和yld2.1)的发现及其分子标记辅助育种的进展,并展望了这一领域的研究前景.     

共显性分子标记与显性基因数量性状

对以正交表形式表现的共显性动物分子标记资料根据显性基因控制的数量性状遗传模型配合了动物分子标记回归方程。结果表明，在一定的条件下，对以正交表形式表现的显性基因共显性分子标记资料配合的分子标记回归方程，可以对显性基因的相对作用加以估计，并可作为育种的依据。运用此方法亦可以实现从基因到性状的翻译。     

Identification of molecular markers linked with crown rust (Puccinia coronata f. sp. lolii) resistance in perennial ryegrass (Lolium perenne) using AFLP markers and a bulked segregant approach

Crown rust resistance is an important selection criterion in ryegrass breeding. The fungal disease caused by P. coronata causes yield loss and a reduced quality of the fodder crop. Molecular markers were used to unravel the genomic organization of crown rust resistance in a segregating L. perenne population. Two genomic regions involved in crown rust resistance were identified that together explained 35% of the phenotypic variance present. Bulked segregant analysis in combination with AFLP markers was a suitable method to identify DNA markers associated with genomic regions of major effect. One cluster of AFLP markers explained 6.1% of the variance and mapped to linkage group 2, a genomic region known to contain crown rust resistance genes. A second cluster of AFLP markers detected a novel genomic region of major effect that explained 27.7% of the phenotypic variance in crown rust resistance. This cluster was unlinked to the cluster on linkage group 2. Divergent selections performed within the segregating F₁ population on the basis of genotype and phenotype revealed that the markers associated with crown rust resistance identified in this study have potential for marker assisted selection. Selection of plants on the basis of markers was more straightforward than the selection on the basis of phenotype.     

水稻不同生态型品种间直链淀粉含量的变异及其遗传分析

以250个代表性水稻品种和一个籼粳交（巴利拉/南京11）DH群体为材料，研究了直链淀粉含量在不同生态型品种间的变异，以及不同品种Wx基因座不同基因型与直链淀粉含量之间的关系。结果表明，在供试的250个水稻品种中直链淀粉含量存在着明显差异，分布在9.2%~29.2%之间；用AccⅠ-PCR标记对这些品种和DH群体Wx位点基因型的检测表     

A Co-Dominant Marker BoE332 Applied to Marker-Assisted Selection of Homozygous Male-Sterile Plants in Cabbage (Brassica oleracea var. capitata L.)

The dominant genic male sterility (DGMS) gene CDMs399-3 derived from a spontaneous mutation in the line 79-399-3 of spring cabbage (Brassica oleracea var. capitata L.), has been successfully applied in hybrid seed production of several cabbage cultivars in China. During the development of dominant male sterility lines in cabbage, the conventional identification of homozygous male-sterile plants (CDMs399-3/CDMs399-3) is a laborious and time-consuming process. For marker-assisted selection (MAS) of the gene CDMs399-3 transferred into key spring cabbage line 397, expressed sequence tag-simple sequence repeats (EST-SSR) and SSR technology were used to identify markers that were linked to CDMs399-3 based on method of bulked segregant analysis (BSA). By screening a set of 978 EST-SSRs and 395 SSRs, a marker BoE332 linked to the CDMs399-3 at a distance of 3.6 cM in the genetic background of cabbage line 397 were identified. 7 homozygous male-sterile plants in population P1170 with 20 plants were obtained finally via MAS of BoE332. Thus, BoE332 will greatly facilitate the transferring of the gene CDMs399-3 into the key spring cabbage line 397 and improve the application of DGMS in cabbage hybrid breeding.     

抗稻瘟病多基因聚合对川恢907田间抗性的影响

通过杂交、回交以及分子标记辅助选择技术,将稻瘟病广谱抗病基因Pi-1、Pi-2和Pi-33聚合到川恢907中。稻瘟病田间抗性鉴定显示,其稻瘟病叶瘟发病率、病情指数从36.31%和15.57分别下降到10.65%～13.88%以及4.2～5.27;穗颈瘟发病率、病情指数从36.53%和12.77分别下降到7.13%～10.22%以及1.51～5.02,显著提高了川恢907的稻瘟病田间抗性。     

分子标记辅助选择在林木育种中的应用

历史上,数量遗传学被认为是指导林木育种的唯一有效工具,这有两个方面的原因：第一,在林木上具有重要经济价值的性状,如树干材积生长、木材纤维长度及适应性等,均是以数量方式遗传的性状,并且控制这些性状的每一个过程是假设受微效多基因所控制的;第二,林木具有很长的世代间隔,很高的遗传杂合性和很高的遗传负荷,这些特性限制了一些经典的遗传材料,如近交系,突变体及特异类型的产生。然而,传统的数量遗传学方法用于指导林木育种的实践并不是完美无缺的。林木个体高大,占地面积大,且大多栽植在非农用耕地上,这样的环境异质性在很大程度上影响性状遗传力的提高,有些林木树种人工杂交比较困难,很难获得足够大的家系,从而产生不平衡的交配设计。Ｎａｍｋｏｏｎｇ 和Ｒｏｂｅｒｄｓ（１９７６） 认为,不平衡的交配设计很难获得准确的遗传参数估计。到目前为止,大多数成功的林木育种方案往往都是基于对表型的简单选择。这种表型选择不能利用林木固有的非加性效应,以及对异质环境的反应潜能,因而育种效果是极为有限的。分子标记技术为现代数量遗传学的发展提供了新的方向。通过利用中性标记与影响数量性状的位点（ＱＴＬ） 之间的连锁关系,人们已经提出了一套统计方法用来鉴定重要的Ｑ     

家畜分子育种研究进展

本文综述了家畜（猪）的主效数量性状基因座育种和转基因育种的研究进展。主要包括构建基因图谱，并据此定位主效数量性状基因座或与之连锁的DNA标记；通过转基因技术来改良家畜重要经济性状或生产生化制剂或进行器官移植的研究。