Genetic analysis and pyramiding of two gall midge resistance genes (Gm-2 and Gm-6t) in rice (Oryza sativa L.)
Genetic analysis and pyramiding of two gall midge resistance genes (Gm-2 and Gm-6t) in rice (Oryza sativa L.)
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DOI：
10.1023/a:1012965915812
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发表时间：
2001-01-01
期刊：
影响因子：
1.9
通讯作者：
Bennett, J
中科院分区：
文献类型：
--
作者：
Katiyar, S;Verulkar, S;Bennett, J
亚洲稻瘿蚊（Orseolia）是南亚和东南亚大部分地区的主要害虫。这种害虫的遗传多样性和许多瘿蚊生物型已知存在于每个国家。在过去的三十年里，寄主植物的抗性被证明是控制亚洲稻飞虱的最有效的机制。在水稻（Oryza sativa）中已经鉴定了7个调节对瘿蚊幼虫的抗性的基因，并正在用于品种改良计划。然而，其中一些基因因新的瘿蚊生物型而变得无效。增加对遗传学、遗传、等位基因关系和连锁的理解对于通过这些基因的重复来最大化主基因抗性的持久性是必要的。已知这两个基因Gm-2和Gm-6（t）分别在印度和中国赋予对许多生物型的抗性。在中国广东对来自多抗#1（Gm-6（t）的供体）和Phalguna（Gm-2的供体）之间的杂交的F-3群体进行抗中华瘿蚊生物型4的筛选，在印度Raipur对来自印度瘿蚊生物型1的筛选。在每一个地方，分别有一个基因控制着抗性。在两个地点的两个生物型的417个F-3后代的平行分离揭示了两个基因之间发生了重组，确定这两个基因不是等位基因。然而，发现两个基因Gm-2和Gm-6（t）以近似16.3cM的距离连锁。鉴定并选择了许多在一个基因座上纯合而在另一个基因座上分离的品系。将这些品系自交以获得在两个基因座（两个基因座金字塔）上的有利等位基因纯合的品系。这是第一次利用传统的寄主-害虫互作方法来检测两个位置相近但效应不同的抗Gm基因座。部署这些金字塔内和跨越国界的影响，参照流行的瘿蚊种群进行了讨论。
Asian rice gall midge ( Orseolia oryzae) is a major pest across much of south and southeast Asia. This pest is genetically diverse and many gall midge biotypes are known to exist in each country. During the last three decades, host plant resistance has proved to be the most effective mechanism of controlling the Asian rice gall midge. Seven genes conditioning resistance to gall midge larvae have been identified in rice (Oryza sativa) and are being used in cultivar improvement programs. However, some of these genes are rendered ineffective by new gall midge biotypes. Increased understanding of genetics, inheritance, allelic relationships and linkage is necessary to maximise the durability of major gene resistance by the pyramiding of these genes. The two genes, Gm-2 and Gm-6(t), are known to confer resistance against a number of biotypes in India and China, respectively. An F-3 population derived from a cross between Duokang #1 (donor of Gm-6(t)) and Phalguna (donor of Gm-2) was screened against Chinese gall midge biotype 4 at Guangdong, China, and Indian gall midge biotype 1 at Raipur, India. At each location, separately, a single gene governed resistance. The parallel segregation of 417 F-3 progenies for both biotypes at two locations revealed that recombination had occurred between the two genes, establishing that the two genes are not allelic. However, the two genes Gm-2 and Gm-6(t), were found to be linked with a distance of similar to 16.3 cM. A number of lines homozygous at one locus and segregating for the other locus were identified and selected. These lines were selfed to obtain lines homozygous for the favourable alleles at both loci (two locus pyramids). This is the first report on use of conventional host-pest interaction method for pyramiding two closely located Gm-resistance loci of dissimilar effects. The implications of deployment of these pyramids within and across country borders, with reference to the prevailing gall midge populations are discussed.