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[目的]探索营养生长期高温对水稻生育后期耐冷性的影响,为避免水稻低温冷害提供栽培指导。[方法]以耐冷性品种‘宁粳1号’和冷敏感品种‘扬稻6号’为材料,通过盆栽试验,比较营养生长期高温(日平均温度为32.4℃)处理对水稻在孕穗期、抽穗期低温胁迫下(孕穗期15℃恒温处理5 d;抽穗期17℃恒温处理7 d)叶片抗氧化酶(SOD、POD)活性、膜脂过氧化程度(MDA含量)、细胞膜透性变化(可溶性蛋白含量)以及低温胁迫后的花粉活力、产量及产量结构的影响。[结果]结果表明:营养生长期高温胁迫导致水稻地上部植株含氮量增加,含磷量有降低的趋势;水稻孕穗期和抽穗期低温胁迫下,超氧化物歧化酶、过氧化物酶活性升高,一定程度上抑制丙二醛积累;可溶性蛋白含量升高。相比于冷敏感品种‘扬稻6号’,耐冷性品种‘宁粳1号’叶片中超氧化物歧化酶、过氧化物酶活性和可溶性蛋白的含量更高,丙二醛积累较少。经营养生长期高温处理,水稻在孕穗期、抽穗期低温胁迫后,丙二醛积累增加,上升趋势更加明显;超氧化物歧化酶、过氧化物酶活性降低,可溶性蛋白含量减少,上升趋势减缓;结实率、产量显著降低。[结论]营养生长期高温显著降低了水稻生育后期的抗冷能力,主要表现在丙二醛积累增加,超氧化物歧化酶、过氧化物酶活性降低,可溶性蛋白的含量降低,花粉不育率显著升高,结实率降低,产量显著下降。
[Objective] The research aimed to explore the effect of high temperature in vegetative growth stage on the cold tolerance of late growth period of rice and provide the cultivation guidance to avoid the cold damage of rice. [Method] With cold-tolerant variety ’Ningjing 1’ and cold sensitive variety ’Yangdao 6’ as materials, pot experiments were conducted to compare the effects of high temperature during vegetative growth (daily average temperature of 32.4 ℃) The activity of antioxidant enzymes (SOD, POD), the degree of membrane lipid peroxidation (MDA) and the change of cell membrane permeability under the heading stage at low temperature (15 ℃ booting at 5 ℃ and 17 ℃ at 7 ℃) Soluble protein content) and pollen viability, yield and yield structure under low temperature stress. [Result] The results showed that: the high temperature stress during vegetative growth led to the increase of N content and the decrease of P content in rice plant. Under low temperature stress at heading and heading stage, the activities of superoxide dismutase and peroxidase Increased, to a certain extent, inhibited the accumulation of malondialdehyde; soluble protein content increased. Compared with the cold-sensitive variety Yangdao 6, the content of superoxide dismutase, peroxidase and soluble protein in the cold-tolerant leaves of ’Ningjing 1’ was higher, and malondialdehyde accumulated less. After long-term high temperature treatment, the accumulation of malondialdehyde increased at the booting stage and the heading stage of rice. The increasing tendency was more obvious. The activities of superoxide dismutase and peroxidase decreased, the content of soluble protein decreased, and the upward trend slowed down. Seed setting rate, yield was significantly reduced. [Conclusion] The high temperature during vegetative growth significantly reduced the cold-tolerance ability of rice at the later growth stage, which was mainly manifested by the increase of malondialdehyde accumulation, the decrease of superoxide dismutase and peroxidase activity, the decrease of soluble protein content and the pollen sterility rate Significantly increased, seed setting rate decreased, yield decreased significantly.