小麦与长穗偃麦草、中间偃麦草杂种及其衍生后代的细胞遗传学研究──Ⅲ．小麦和偃麦草基因重组的遗传基础浅析

Cytogenetic Research on Hybrids of Triticum with both Thinopyrum ponticum and Th. intermedium as well as Their Derivatives Ⅲ.Primary Detection of Genetic Base for Introgression of Useful Genes from the Two Alien Species to Wheat

十倍体长穗偃麦草和六倍体中间偃麦草均含有一些基因促使部分同源的染色体之间发生配对，这些基因分布于不同的染色体组中，并具很强的传递力。小麦与长穗偃麦草杂种回交后代的部分植株在减数分裂后期出现多条染色体同时断裂现象，使不同染色体通过断口联结形成新的易位成为可能。上述二因素可能是造成小麦和偃麦草基因重组的主要原因之一。

Th.ponticum and Th.intermedium have genes promoting homoeolgous chromosomes to pair.These genes locate in several different genomes of the wheatgrasses.They have strong transmission ability to the selfing and backcrossing progeny.Breakage of a number of chromosomes at metaphase of meiosis in some BC1 individuals makes translocation possible by misreunine of the breakaged chromosomes.The two factors make gene introgression relatively easier from wheatgrass than from other species with chromosomes not homologous with hexaploid wheat.