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为了探明生育后期干旱复水对双季早稻产量补偿效应及其生理机制,选择淦鑫203和淦鑫206为材料,于抽穗期干旱7d,然后复水处理,分析了其结实和产量、剑叶渗透调节物质、丙二醛(MDA)和内源激素含量及保护酶活性等。结果表明,干旱复水处理后供试品种的结实率、千粒重及单株产量均表现出不同程度下降,其中,结实率和单株产量降幅均达显著水平;抽穗期干旱7d复水不存在产量补偿效应;两个品种剑叶可溶性糖(SS)、游离脯氨酸(Pro)、MDA含量以及超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性均表现为干旱处理显著高于CK,以复水0d后相差最大,复水后上述指标均明显下降,但处理与CK之间至复水12d后仍然存在一定差距;总体上,淹水条件下抽穗期两个品种剑叶IAA、GA3含量随生育进程呈现上升趋势,而ABA、ZR含量呈现下降趋势;干旱复水处理下两个品种剑叶ABA、IAA及ZR含量呈持续上升趋势,GA3含量则表现出先降后升趋势。抽穗期干旱处理将启动稻株体内抗衰老机制,复水后将在一定程度上激活稻株体内生长促进因子并抑制生长抑制因子,但其效果十分有限,且与品种产量相关不显著。
In order to find out the compensation effect and physiological mechanism of drought rewatering on the yield of early rice in the second growth stage, Ganxin 203 and Ganxin 206 were selected as the materials, and the seedlings were droughted at heading stage for 7 days and then re-treated with water. Leaf osmotic regulator substances, malondialdehyde (MDA) and endogenous hormone content and protective enzyme activity. The results showed that the seed setting rate, 1000-grain weight and yield per plant all showed different degrees of decline after drought rewatering, in which the seed setting rate and the yield per plant reached the significant level; (SS), free proline (MDA), and activities of superoxide dismutase (SOD) and catalase (CAT) in flag leaves of the two cultivars were all significantly higher than that of drought treatment CK, after rehydration for 0d, the difference was greatest. After rewatering, the above indexes decreased obviously, but there was still a certain gap between rehydration and CK for 12 days. In general, under the condition of flooding, , GA3 content showed an upward trend with the growth process, while ABA, ZR content showed a downward trend; ABA, IAA and ZR content of the flag leaf of two varieties showed a continuous upward trend under drought rehydration treatment, GA3 content showed the trend of first drop and then rise. Drought treatment at heading stage will activate the anti-aging mechanism in rice plants, and rehydration will activate growth-promoting factor and inhibit growth-inhibitory factor in rice plants to a certain extent, but its effect is very limited and it is not significantly related to the yield of rice varieties.