开花期寒露风对江西晚稻功能叶生理特性及产量的影响

Effect of Autumn Low Temperature During Flowering Stage on Physiological Property and Yield of Late Rice in Jiangxi Province

以晚稻品种‘268’为试材,于2013年8-10月(晚稻开花期)采用人工气候箱模拟江西寒露风发生的气象模式,试验温度设定为22℃/17℃(昼/夜),处理时间分别为3、6、9、12和15d,以外界环境条件32℃/25℃(昼/夜)为对照(CK),对各处理晚稻叶片保护酶活性、光合色素、光合参数、荧光参数以及晚稻产量及构成进行测定。结果表明:(1)叶片过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量随着低温胁迫时间延长逐渐增加,低温处理15d后细胞受到严重损伤。(2)与CK相比,处理15d后叶片的最大光合速率及最大羧化速率分别下降65.99%和67.44%,同时叶片光化学淬灭(qP)、最大光化学效率(Fv/Fm)及光电子传递速率(ETR)依次减少了19.50%、10.25%及42.77%,而非光化学淬灭(qN)略有上升。(3)低温影响下,光合色素合成受到抑制,叶片叶绿素a、叶绿素b和类胡萝卜素含量显著降低。(4)在产量及产量构成方面,开花期低温处理的穗长、有效分蘖数、一次枝梗及二次枝梗数、结实率及千粒重均显著低于CK,从而导致产量显著下降,处理15d后产量下降幅度达48.42%。可见,晚稻开花期若遇寒露风可明显抑制功能叶的生理活性并导致产量显著下降。

To study the impact of autumn low temperature of Jiangxi province on rice leaf physiological characteristics and yield function during the flowering stage,five artificial environmental control experiments and one basis experiment were designed in artificial climate chamber in Nanjing University of Information Science ＆ Technology from August to October in 2013.The processing time of control experiments were 3d,6d,9d,12d and 15d（denoted as T3d,T6d,T9d,T12d and T15d）,respectively,with test temperature of 22℃/17℃ （day/night）,and the basis experiment was set at 25 ℃.The results showed that,（1） peroxidase （POD）,superoxide dismutase （SOD） and catalase （CAT） activity and malondialdehyde（MDA） content gradually increased with prolonged low temperature,and cells would suffer serious damage after 15d of low temperature processing.（2） Compared with CK,the maximum photosynthetic rate and maximum carboxylation rate of T15d fell by 65.99% and 67.44%,respectively,at the same time the blade photochemical quenching （qP）,maximal photochemical efficiency （Fv/Fm） and photoelectronic transfer rate （ETR） also reduced by 19.50%,10.25% and 42.77%,rather than the photochemical quenching （qN） increased slightly.（3） Under the influence of low temperature,photosynthetic pigment synthesis had been restrained,so the chlorophyll a,chlorophyll b and carotenoid content decreased significantly.（4）With low temperature treatment during flowering period,ear length,effective tillers,seed setting rate and grain weight etc significantly were much lower than CK,which resulted in a significant decline in production,and T15d declined up to 48.42% as example.Therefore,autumn low temperature of late rice at flowering stage could obviously inhibit the function of physiological activity of rice leaf,which leaded to a significant reduction in the production,and the results of this study would provide a scientific basis for early warning and disaster assessment of autumn low temperature.