籼粳双单倍体的诱导及其性状遗传

INDUCTION OF DIHAPLOID FROM INDICA/JAPONICA HYBRIDS AND THE INHERITANCE OF CHARACTERS

本研究用秋光/水源290,8411/mudgo和日本晴/mudgo三个组合的粳/籼杂种体(F_1)的茎、鞘或幼穗离体培养诱导成四倍体无性系植株,再用其花药培养获得双单倍体。这种再生植株(4n-R_1)的花药培养力和同组合的二倍体的花药培养力类同。双单倍体的诱导频率因基因型而有差异。这种来自粳/籼四倍体杂种的双单倍体育性和结实率明显不同于粳籼杂种(F_1)及后代(F_2)和杂种体细胞再生植株(R_1),这种双单倍体的育性、结实率百分之六十以上的植株是正常的。各株系的性状类型多样,出现了具有粳/籼杂种超亲优努株系。实践证明:由籼粳杂种经组织培养加倍成四倍体,再经花药培养诱导出双单倍体是研究籼粳杂交遗传规律及育种的一条新途径,加倍后的籼粳杂种比没有加倍的具有更有利的遗传背景,分解成的双单倍体能藉以克服粳籼杂交的许多障碍,在育种上有相当的潜在价值。

The rice tetraploids (4nR_1) were obtained by means of tissue culture of stems, leaf sheathes and young panicles of Japonica/Indica hybrids then the dihaploids (DH_1) were got through anther culture of 4nR_2. The anther culture ability of the tetraploids was the same as that of diploids. The induction frequencies of dihaplolds from different genotypes showed difference. The dihaploids from Japonica/Indica hybrids were obviously different from F_1, F_2 and R_2 regenrated plants from somatic tissue culture of Japonica/Indica in pollen fertility and spikelet fertilty. The proportion of dihaploid plants with normal pollen and spikelet fertility were over 60％. The characters and types of dihaploids were rich and varied, and some over-parent dihaploid lines have been found.The research showed that the means of getting tetraploids by tissue culture of Japonica/Indica hybrids and then obtaining dihaploids by anther culture is a new way of research on genetic law and breeding application of Indica-Japonica crosses. The tetraploids obtained by doubling the Japonica/Indica hybrids had more advantageous genetic background than the diploids. The dihaploids got through anther culture of above tetraploids could be used to overcome some obstructions in Indica-Japonica erosses, and therefore had great potential value in rice breeding.