普通小麦-滨麦-簇毛麦三属杂交后代的细胞遗传学研究

Studies on cytogenetics of the progenies of trigeneric hybridization involving Triticum aestivum,Leymus mollis and Haynaldia villosa

对普通小麦 -滨麦 -簇毛麦三属杂交后代进行了细胞遗传学研究。结果表明 :三属杂种杂交结实率较低 ,平均为 14 .0 3%。 F1 自交结实率极低 ,平均为 0 .7% ;F1 形态兼具普通小麦、滨麦、簇毛麦特性 ,F2 、F3出现严重分离 ;F1 染色体平均构型为 2 n=12 .32 +2 1.0 2 +0 .13 +0 .0 9 +0 .0 6 +0 .0 5 ,F1 出现较多多价体 ,说明来自滨麦的 J染色体组和来自簇毛麦的 V染色体组能形成不紧密的配对 ;PMC MI后期 有落后染色体排列在赤道板上 ,末期 和末期 出现大量的二分孢子、四分孢子带微核和畸形孢子现象。这是三属杂种 F1 育性极低的原因。

The progenies of trigeneric hybridization involving Triticum,Leymus and Haynaldia were created by crossing between amphidiploids Triti leymus and Triti villosa .The cytogenetics and fertility of the progenies were studied.The main results of the study are as followings:(1) The rate of hybrid fertility was very low (averaged only 14.03%).The self fertility of F 1 plant was also rather low (averaged only 0.8% ).(2) The average chromosome configuration of F 1 at MI in PMC was 12.32Ⅰ+21.02Ⅱ+0.13Ⅲ+ 0.09Ⅳ +0.06Ⅴ+0.05Ⅵ,the chromosome number of univalent was less than the theoretical number 14,and the number of multivalents was very high.This indicates that the chromosome set of J (from L.mollis ) and V (from Ha.villosa ) can untightly pair.(3) At telophase Ⅰ in PMC,there were some laggard chromosomes ranked on the equatorial plate,and at telophase Ⅰ,telophase Ⅱ,these chromosomes didnt often distribute to two poles equally.It appeared a large number of bispore or tetraspore with micronucleus and abnormal spores.Consequently,a great number of abortive pollen was formed and it made the self fertility of F 1 plant rather low.