粳型杂交稻双单倍体的遗传及其育种意义

INHERITANCE OF DIHAPLOID LINES DERIVED FROM JAPONICA HYBRID RICE AND ITS SIGNIFICANCE IN BREEDING

以六个粳型杂交稻的幼穗为外植体 ,诱导愈伤组织并分化为胚性细胞 ,经秋水仙素处理 ,使胚性细胞染色体加倍为四倍体。共获得 2 43个四倍体株系 ,再由四倍体花药培养成双单倍体。观察到 ,这种四倍体性状稳定 ,但在少数株系中出现二倍体 ,此为无融合生殖的双单倍体。在获得的 86个双单倍体不同株系之间表现遗传的多样性 ,大多数株系性状稳定 ,少数株系有分离。经对性状的考查分析 ,双单倍体的株系中有少数株系产量优势接近或超过原供体亲本 ,且具有许多优良性状。可见由粳型杂交稻培养双单倍体也是改良品种的一种方法。

Young panicles from 6 established japonica hybrid rice lines were cultured to induce calluses. The calluses were then treated with colchicine, and 243 tetraploid lines were regenerated from the calluses. Dihaploid lines were obtained by culturing anthers of the 4n plants. It was observed that the agronomic traits of the tetraploid lines were stable, but in a few tetraploid lines there were some diploids, which may be dihaploids resulting from apomixis. It was showed that genetic diversities existed among 86 dihaploid lines, but most of which were gemetically stable. The yield of a few dihaploid lines with good traits was close to or exceeded that of the original parents, suggesting that the culture of dihaploids derived from japonica hybrid is a rapid and effective method for rice improvement.