在抽穗开花期对 2 个超级杂交稻组合‘Y 两优 1 号’和‘两优培九’进行了高温胁迫处理,比较研究了这 2 个超级杂交稻组合对高温胁迫的耐受性。 实验结果显示,经高温胁迫后,‘Y 两优 1 号’和‘两优培九’头季稻的花药开裂系数和花粉可染率均显著下降( P < 0. 05),结实率则分别下降 6. 07% 和 54. 48% ,千粒重分别下降 9. 03% 和9. 98% ,‘两优培九’的各指标降幅均大于‘Y 两优 1 号’。 经高温胁迫后,‘Y 两优 1 号’和‘两优培九’头季稻剑叶中的叶绿素含量较各自的对照分别下降 1. 18% 和 3. 20% ,POD 和 CAT 活性均呈先升高后下降再升高的趋势,MDA含量则呈先下降后升高再下降的趋势,‘Y 两优 1 号’的 POD 和 CAT 活性总体上高于‘两优培九’、MDA 含量总体上低于‘两优培九’。 高温胁迫导致‘Y 两优 1 号’和‘两优培九’再生稻的活芽率、平均芽长以及单茎腋芽数均显著下降,且后者再生稻各指标的降幅大于前者;高温胁迫对‘Y 两优 1 号’和‘两优培九’ 再生稻的再生率和每穗总粒数的影响不明显,但均使再生稻的结实率和千粒重降低,且‘两优培九’再生稻的结实率和千粒重与对照差异显著(P < 0. 05)。 高温胁迫对‘Y 两优 1 号’和‘两优培九’头季稻的热害指数分别为 0. 19 和 0. 56,对再生稻的热害指数分别为0. 04 和0. 13,差异显著(P < 0. 05)。 研究结果表明,在抽穗开花期,‘Y 两优1 号’对高温胁迫的耐受性高于‘两优培九’,且头季稻耐高温有利于再生芽的生长。

Two super hybrid rice combinations ‘ No. 1 of Y liangyou’ and ‘ Liangyoupeijiu’ were subjected to high temperature stress treatment during the period from heading to flowering, and their tolerance were analyzed. The results show that after high temperature stress, the anther dehiscence coefficient and stainable pollen grain percentage of main crop rice of ‘ No. 1 of Y liangyou ’ and ‘Liangyoupeijiu’ decrease significantly (P < 0. 05). The setting rate decreases 6. 07% and 54. 48% , and the 1 000-grain weight falls 9. 03% and 9. 98% , respectively, and ‘ Liangyoupeijiu’ has a bigger decline of each index than ‘No. 1 of Y liangyou’. Compared to the controls, the chlorophyll content in flag leaf of main crop rice of ‘No. 1 of Y liangyou’ and ‘Liangyoupeijiu’ decreases 1. 18% and 3. 20% , respectively. POD and CAT activities of the two combinations increase, then decrease, and increase again, while the MDA content decreases, then increases, and decreases again. On the whole, ‘No. 1 of Y liangyou’ has higher POD and CAT activities and lower MDA content than ‘ Liangyoupeijiu’. High temperature stress leads to significant decrease of living bud rate, average bud length and bud number per stem of ratoon rice of the two combinations, and the ratoon rice of ‘Liangyoupeijiu’ has a bigger decline of each index than the ratoon rice of ‘ No. 1 of Y liangyou’. High temperature stress has no obvious effects on the regeneration rate and grain number per panicle of ratoon rice of the two combinations, but causes decrease of setting rate and 1 000-grain weight, and the setting rate and 1 000-grain weight of ratoon rice of ‘Liangyoupeijiu’ are significantly different with the controls (P < 0. 05). The difference of heat injury index between the two combinations is significant (P < 0. 05), the heat injury index of main crop rice of ‘No. 1 of Y liangyou’ and ‘Liangyoupeijiu’ is 0. 19 and 0. 56, and the heat injury index of ratoon rice is 0. 04 and 0. 13, respectively. It is suggested that during the period from heading to flowering, ‘No. 1 of Y liangyou’ has higher tolerance to high temperature stress than ‘Liangyoupeijiu’, and the heat resisting ability of main crop rice is beneficial to the growth of regeneration bud.