节水抗旱稻与高产水稻不同叶位光合特征对土壤水分变化的响应
Responses of photosynthetic characteristics of different leaf positions in water saving drought tolerant rice and high yield rice to soil moisture change

为明确节水灌溉下节水抗旱稻与高产水稻不同叶位光合特征变化规律以及对同化物形成的贡献能力,通过盆栽试验，以节水抗旱稻旱优113（HY113）与高产水稻扬两优6（YLY6）为研究材料，以传统淹灌处理（F:全生育期保持4 cm的水层）为对照，研究湿润处理（S:保持土壤水分处于饱和状态，但不建立水层）和干旱处理（D:返青至水稻成熟期收获前1周，控制土壤水势在-30 kPa左右）下，2个水稻品种在不同生育时期（拔节期、孕穗期、抽穗期、乳熟期）功能叶与孕穗期和乳熟期不同叶位的叶片水势、SPAD值、叶片气体交换、水分利用效率与产量的变化。结果表明：与其他处理相比，S处理下高产水稻YLY6产量显著升高，从产量构成来看，具有较高的有效穗数、每穗粒数与结实率。相关分析表明，乳熟期与成熟期的干物质积累量与产量极显著正相关，并且孕穗期和抽穗开花期的净光合速率与乳熟期及成熟期的干物质量极显著正相关。S处理下YLY6干物质积累量在孕穗期、乳熟期与成熟期显著高于HY113，水分利用效率在抽穗开花期也显著高于HY113；S处理下YLY6在生育后期（乳熟期）不同叶位均维持较高的净光合速率，主要是具有较高的SPAD值、气孔导度、蒸腾速率，使植株维持较高的光合生产潜力 。因此，S处理下YLY6在生育后期（乳熟期）不同叶位均维持较高的光合生产能力，是该处理节水高产的基础。
In order to reveal the change in photosynthetic characteristics and responsive mechanisms of different leaf positions in water saving drought resistant rice and high yield rice under water saving irrigation,water saving and drought resistant rice Hanyou113 (HY113) and high yield rice Yangliangyou 6 (YLY6) were used to conduct a pot experiment in 2015.The effects of traditional flooding (F),saturated treatment (S) and drought treatment (D) on the leaf water potential,SPAD values,leaf gas exchange,instantaneous water use efficiency of function leaf at four important growth stages including jointing stage,booting stage,heading stage and milky stage and yield of rice varieties were studied.The results showed that the yield of YLY6 in S treatment was significantly increased compared with other treatments,contributed by higher effective panicles,grains per panicle and filled grains rate.Correlation analyses showed that there was a significant positive correlation between dry matter accumulation and yield heading stage and milky stage,and a significant positive correlation between net photosynthetic rate at the booting stage and heading stage and the dry matter quality at heading stage and milky stages.The dry matter accumulation of YLY6 at booting stage,heading stage and milky stage under saturated treatment was significantly higher than that of HY113.The instantaneous water use efficiency of YLY6 at heading stage was significantly higher than that of HY113.Under S treatment,YLY6 maintained high net photosynthetic rate with high SPAD value,stomatal conductance,and transpiration rate at the post fertility stage (from milky stage to mature stage) to maintain a high photosynthetic productive potential.Therefore,YLY6 maintains high photosynthetic capacity in different leaf positions at the late growth stage (milky period) under S treatment,which is the basis for water saving and high yield rice