抽穗期干旱对水稻生理性状和产量的影响

Effects of Drought Stress on Rice Physiological Traits and Grain Yield at Heading Stage

以籼型常规稻黄华占(HHZ)、籼型三系杂交稻珞优8号(LY8)和冈优527(GY527)、粳稻WDR129等4个水稻品种为材料,研究了抽穗期干旱胁迫对水稻生理性状(光合速率、蒸腾速率、叶片水势、气叶温差等)和产量的影响。结果表明,抽穗期干旱胁迫导致水稻产量严重下降,产量下降的主要原因在于结实率和千粒重的下降;干旱胁迫使叶片的水势下降,叶片温度升高,气叶温差减小,气孔导度降低,叶片气孔关闭,蒸腾速率下降,最终导致光合能力下降;一定程度干旱胁迫下光合能力的下降不是导致水稻产量降低的主导因子,花后干物质积累与分配有待进一步研究;在常规淹水灌溉和抽穗期干旱胁迫下,籼稻LY8、HHZ、GY27的产量无显著差异,但都显著高于粳稻WDR129。

In order to investigate the drought stress influence on physiological traits and grain yield of rice during the heading stage, a field experiment was conducted with four rice genotypes： indica inbred rice-Huanghuazhan,three-line indica hybrid rice-Luoyou 8,Gangyou 527 and japonica rice WDR129. The results showed that the yield was significantly decreased by 16%~22% under drought treatment（DS）compared with CK. The key reasons for the significant reduction of yield are the reduction of seed setting rate and 1000-grain weight; photosynthetic rate, transpiration rate, leaf water potential, air-leaf temperature gap were significantly decreased under drought stress compared to CK, whereas the reduction in photosynthetic is not the dominant factor account for yield reduction.So it is necessary to make further research on dry matter accumulation and distribution after flowering; the yield of indica rice is significant higher than japonica rice under both flooding and drought stress treatments in this experiment.