籼粳野杂交后代田间苗期耐寒性初步分析

Cold tolerance analysis on filial generation of Indica, Japonica and common wild rice at seedling stage in field

【目的】获得可供育种利用的耐冷材料,为耐冷育种提供种质资源。【方法】分别对亲本材料籼稻品种9311、普通野生稻DP10、粳稻品种白R54和日本晴及其杂交后代进行田间耐冷性鉴定,在自然低温冷害严重条件下观察其在田间自然栽培条件下的苗期耐寒性表现。【结果】获得可供育种利用的农艺性状优良、耐冷性强的材料39份,其中33份材料粳稻遗传成分为87.5%,6份材料籼稻遗传成分为75.0%,60份耐寒材料中野生稻遗传成分高达50.0%,但农艺性状较差。在所有不耐寒的材料中,籼稻遗传成分高达87.5%。【结论】不同水稻品种杂交后代中,含有较多粳稻和野生稻遗传成分的材料表现出较好的耐寒性;粳稻和普通野生稻是籼稻耐寒育种改良中重要的耐冷资源,导入野生稻或粳稻的遗传成分能够明显提高籼稻的耐寒性。

[ Objective ]The present research was carried out to obtain rice germplasm resources on rice cold tolerance breeding, and preliminarily determine the strategy for rice cold tolerance breeding. [ Method ]Cold tolerance characters of four parents （Indica rice 9311, Japonica rice Bai R54, Nippon bare, and common wild rice DP10 ） and their filial gener- ations were investigated at seedling stage under natural cultivation conditions in field. All materials grouped 6 to observe their cold damage performance on Mar. 22. [ Result ] Under natural low temperature condition, 39 accessions with strong cold tolerance and excellent comprehensive agronomic traits were screened out for rice breeding. Out of which, 33 accessions had 87.5% Japonica genetic constitution, 6 accessions had 75.0% [ndica genetic constitution. Moreover, the 60 cold tolerant accessions had 50.0% wild rice genetic constitution with worse comprehensive agronomic traits. All the cold sensi- tive rice accessions had a high Indica rice genetic constitution of 87.5%. [Conclusion]Among all the filial generations of four parents, those with more genetic constitution of Japonica and common wide rice showed stronger cold tolerance. Japonica and common wild rice are important germplasm resources in cold tolerance breeding, the cold tolerance level of Indica rice could be enhanced by introducing genetic constitution of Japonica or common wide rice .