普通栽培稻与非洲栽培稻杂交的可交配性研究

Crossability of distant hybridization between O.sativa and O.glaberrima

以二倍体普通栽培稻 (Oryzasativa ,2n =2x =2 4 )为母本 ,以非洲栽培稻 (Oryzaglaberrima ,2n =2x =2 4 )为父本进行远缘杂交配组。研究结果表明 ,二倍体普通栽培稻与非洲栽培稻杂交表现出一定的可交配性 ,但结实率很低 ( 0 32 %～1 97% )。对其杂交结实的胚胎学观察发现 ,非洲栽培稻的花粉能在二倍体普通栽培稻的柱头上萌发 ,萌发率仅为 0 18%～ 0 5 6 % ,花粉管在花柱内的伸长速度比较慢 ,发生的受精频率比较低。以同源四倍体水稻 (Oryzasativa ,2n =4x =4 8)为母本 ,以非洲栽培稻为父本杂交配组。研究结果表明 ,两者间比较容易杂交 ,其结实率达到 5 70 %～ 8 86 %。观察其胚胎学表现 ,非洲栽培稻的花粉在同源四倍体水稻的柱头上萌发频率高达 12 81%～ 14 5 6 % ,花粉管在柱头内伸长速度较快 ,发生的受精频率比较高。利用同源四倍体水稻为桥梁 。

The distant hybridization was made using O.sativa as the female and O.glaberrima as the male.The results showed that there was an obvious crossability, and a lower seed set (0.32%～1.93%). To study the embryological mechanism, the new experiment was made, the results showed that the active pollens from O.glaberrima could germinate on the stigmas of diploid rice after pollination, but the germinating rate of pollens was as low as 0.18%～0.56%. Meanwhile the pollen tubes stretched slowly in the style, resulting in a fertilized frequency, using autotetraploid rice as the female and O.glaberrima as the male, it was easier to cross, and with a higher seed set(5.70%～8.86%),the active pollens from O.glaberrima could germinate better on the stigmas of autotetraploid rice after pollination with a higher germinated rate of 12.81%～14.65%. The pollen tubes stretched fast in the style, resulting in a higher fertilized frequency. Therefore, it is thought that autotetraploid rice shows a great significance in the intergeneric cross of O.sativa with O.glaberrima to make use of favorable genes from O.glaberrima to O.sativa .