水稻披垂叶突变体及其杂交后代耐冷性的鉴定与评价

在云南高海拔冷凉自然条件下对两个粳型水稻披垂叶突变体品系（MR304、MR312）及其与常规品种的杂交后代（F1、F2）进行了苗期耐冷性鉴定，在抽穗期对突变体及其杂交后代的花粉育性类型进行了分析，并在成熟期进行了相关经济学性状和生物学性状的考察。结果表明，在苗期的耐冷性鉴定中，突变体及杂交亲本均为抗型(R)；杂交后代F1中南40/MR312、滇粳优5号/MR304、Ansanbyeo/MR304为中抗型（MR），滇粳优5号/MR312为感型（S），其余均为抗型（R）。抽穗期亲本银光花粉可育率最高，为88.9%；杂交后代F1组合中只有银光/MR304的花粉可育率最高，为94.5%，超过对照（92.5%），组合Ansanbyeo/MR304的花粉可育率最低。亲本银光的结实率超过对照（70.9%），达到82.4%，突变体MR304、MR312的结实率低，分别为26.2%和5.0%；F1中两组合（银光/MR304、银光/MR312）的结实率均超过对照或亲本。该研究揭示了利用水稻披垂叶突变体产生的F1杂种优势可以增强杂交稻在高海拔冷凉条件下的耐冷性优势；抽穗期的花粉育性大小是鉴定杂交后代（F1）植株耐冷性强弱的重要指标。

Characterization and Evaluation of Cold Tolerance in the Drooping Leaf Rice Mutants and Its Progenies

This experiment investigated the cold-tolerance in two japonica drooping leaf mutants(MR304、MR312) and its crossing progenies (F1 and F2) at seedling stage under the high elevation cold area in Yunnan, analyzed the pollen fertility between the mutants and their crosses at heading stage, and measured the correlated economical and biological traits at maturity stage. The results showed that: mutants and parents were resistance (R); the Nan29/MR312, Dianjingyou5/MR304, Ansanbyeo/MR304 were medium resistance (MR), the Dianjingyou5/MR312 was sensitivity (S), others were resistance (R) in F1 The pollen fertility of Yinguang at the heading stage were highest, which was up to 88.9%; the Yinguang/MR304 surpassed the contrast (92.5%) were the highest in F1 of nine combinations, to 94.5%, and Ansanbyeo/MR304 were the lowest. The seed-set rate of Yinguang surpassed the contrast (70.9%), to 82.4%, and seed-set rate of MR304 and MR312 were lower, 26.2%and 5.0%, respectively, and the seed-set rate of two combinations (Yinguang/MR304 and Yinguang/MR312) in F₁ surpassed the contrast. The study revealed that we could utilize the F1 heterosis derived from the cross of drooping leaf mutants and conventional varieties to enhance the superiority of cold tolerance in the high elevation cold area, and the pollen fertility at the heading stage was the important index to evaluate the cold tolerance in crossing progenies F₁.