芸芥(Eruca sativa Mill.)与芸薹属(Brassica L.)3个油用种的远缘杂交

Intergeneric Crosses between Eruca sativa Mill. and Brassica Species

采用芸芥 (ErucasativaMill.)与芸薹属 3个油用种 (Brassicanapus,Brassicajuncea ,Brassicarapa)进行杂交 ,共授粉15 990朵花 ,获得 12 5 7个角果 ,711粒杂交种子 ,结角率为 7.86 % ,亲和指数 0 .0 4 5。经形态学鉴定 ,无论芸芥作母本还是芸薹属的 3个油用种作母本 ,F1 植株均为偏母植株。杂交所获得角果的角粒数很低 ,许多角果为空角果 ,但在多数角果中可见到许多败育胚的残迹 ,这些败育胚中可能不乏杂种胚。对角果生长发育测量结果表明 ,远缘杂交角果在授粉后 9d左右停止生长 ,据此推断杂种胚的败育时期可能就在授粉后 9d左右。采用苯胺蓝染色法 ,在荧光显微镜下对芸芥与甘蓝型油菜杂交时花粉在柱头上的黏合、萌发及萌发花粉管在柱头和花柱中的生长、伸长情况的观察结果表明 ,异源花粉很难在柱头上黏合和萌发 ,同时在花粉黏合的部位及其附近柱头乳突细胞内产生大量胼胝质 ;萌发的少量花粉粒 ,其花粉管进入柱头也比较困难。表明芸芥与芸薹属杂交 ,存在严重的生殖隔离障碍 ,而且主要是受精前障碍。

Crosses were made between Eruca sativa Mill. and Brassica napus, Brassica juncea and Brassica rapa and the parent materials were selfed. Totally 15 990 stigmas were pollinated and 1 257 pods, 711 pollinated seeds and 675 F 1 plants were obtained. The pods set rate and compatibility index were 7.86%, 0.045 respectively. All the F 1 plants showed the same morphological characters as their female parents, which suggested that F 1 was matroclinous hybrid and the crosses between E. sativa Mill. and B. napus, B. juncea and B. rapa were highly incompatible. The relics of abortive embryos could be found in most of the pods developed from the distant crosses between Brassica and Eruca, and they were possibly the hybrid embryos. The hybrid embryos stopped growth 9 days after pollinated. The pollen-stigma binding, germination of pollen grains and the growth of pollen tubes in the surface of stigma and style were observed under fluorescent microscope. The results showed that the binding degree and germinating rate of pollen grain were weakened when E. sativa Mill. was pollinated with B. napus and the binding degree and germinating rate of pollen grain varied on the cross direction. The pollen of B. napus was hardly ever observed binding to the stigma of E. sativa Mill. which was used as female parent. The callose could be found easily depositing in papillose cells when both B. napus and E. sativa Mill. were used as female parent. It was suggested that the incompatible reaction caused by pollen-stigma interaction could be the one of main barriers of intergeneric crosses between E. sativa Mill. and Brassica crops.