摘要
应用限制性片段长度多态性（ＲＦＬＰ）分析了高秆野生稻（Ｏｒｙｚａ ａｌｔａ Ｓｗ ａｌｌｅｎ）与栽培稻（Ｏ．ｓａｔｉｖａ Ｌ．）之间的多态性差异，以及二者杂交后通过胚挽救获得的后代植株的染色体大致组成情况。结果表明，高杆野生稻基因组与栽培稻基因组差别极大，经胚挽救获得的杂种后代植株大部分为三倍体，不育；两个部分不育的植株中发生了染色体丢失，基因组趋向栽培稻的基因组。结果还表明，在野生稻与栽培稻杂交获得后代的过程中，可能存在一种非传统的遗传重组机制导致野生稻染色体片段向栽培稻基因组的“渗入”
Oryza alta Swallen is a species of allotetraploid wild rice (CCDD,2n=48) with high biomass production and resistant to several insects and diseases.The high polymorphism (RFLP)between O.alta and O.sativa L.(average 90%)reveals the long phylogenical distance between these two species which may impede the crossing. The chromosome constitutions of several progeny from O.alta × O.sativa were analyzed with 22 mapped rice RFLP markers.The results showed that almost all triploid sterile plants which had 36 chromosomes were,as expected,composed of the chromosomes from two parents.But the two partial fertile regenerated plants from 02428(O.sativa)× WHS601 2(O.alta) which had only 24 and 25 chromosomes respectively,in most cases,had RFLP patterns similiar to their O.sativa parent. Therefore the chromosomes constituted their genomes were mainly from O.sativa or have high homology with the chromosomes of O.sativa. It seems evident that chromosome elimination had occurred during the wide hybridization as O.alta RFLP patterns could be found in them.Furthermore, that the introgression of O.alta chromosome fragment into that of O.sativa in an F 2 plant was indicative that some kind of recombination also occurred.Regarding the rare chromosome pairing in PMCs,the probability of the existence of a non conventional mechanism for the wild rice chromosomes (chromosome fragments )to introgressing into cultivated rice genomes in a relatively short time was discussed.
基金
美国洛克菲勒水稻生物技术基金
