低温对杂交水稻及其亲本三系始穗期旗叶光合作用的影响

研究了低温对5套杂交水稻组合的影响。始穗期旗叶光合作用的最大速率和表观量子效率受低温抑制的程度表明:其耐冷顺序为粳稻型的“秀优57”>“釉稻型的青优早”>“汕优63”、“汕优64”与“威优64”。杂交水稻 F_1的耐冷水平与母本近似,与父本关系不大,保持系的耐冷性相似于不育系。杂交水稻幼苗经低温处理后的存活率亦表现出同样的规律。证明所试5套杂交水稻的生育后期与苗期对低温的反应是一致的。本文对该结果在杂交水稻抗冷性选育种中的意义进行了讨论。

EFFECT OF CHILLING ON PHOTOSYNTHESIS IN FLAG LEAVES AT PRIMARY HEADING STAGE OF F_1 HYBRID RICE CULTIVARS AND THEIR PARENTAL LINES(THREE LINES)

With the purpose of selecting and breeding cold stress tolerance of hybrid rice cultivars, the effect of chilling on five hybrid rice combinations was investigated. The results indicated that the cold tolerance of different hybrid rice varieties were dif- ferent.The order of the cold tolerance as the degrees of inhibition of maximum photosynthetic rate and of apparent quantum yield of flag leaves at primary heading stage by chilling was as follows:The cold tolerance of Japanica type Xiuyou-57 was the highest then Indica type Qing-Youzao followed by Shangyou-63,Shangyou-64 and Weiyou-64.The cold tolerance of F_1 hybrid rice was similar to that of the maternal lines and not similar to the paternal lines.The cold tolerance of maintainer lines was similar to that of the male sterile lines.The tests on the survival rate of hybrid rice seedlings after chilling treatment also showed a similar re- gular patterns.These indicated that the responses by the chilling temperature in these five hybrid combinations were exactly the same in the seedling stage as well as in the late grow- ing stage. The results of these experiments on the impact of selecting and breeding cold tolerance in hybrid rice were discussed.