节水灌溉对节水抗旱水稻品种产量的影响及生理基础

目的]探明节水抗旱水稻品种在节水灌溉条件下产量形成特点及生理基础.方法] 2个节水抗旱品种旱优113(杂交籼稻)和旱优8号(杂交粳稻)及2个当地高产品种两优培九(两系杂交籼稻)和扬辐粳8号(粳稻)种植于土培池和大田,自移栽后10d至成熟设置常规灌溉和节水灌溉处理.结果]与常规灌溉相比,当地高产品种在节水灌溉条件下产量显著降低,两种灌溉方式间的节水抗旱品种产量无显著差异.节水灌溉显著减少灌溉水量,提高灌溉水生产力(产量/灌溉水量),节水抗旱品种灌溉水生产力增幅大于当地高产品种.与当地高产品种相比较,节水抗旱品种在节水灌溉条件下的相对分蘖数和每穗颖花数(节水灌溉分蘖数或颖花数/常规灌溉分蘖数或颖花数)较多,结实率较高；整个生育期绿叶面积持续期长,抽穗期根重较高,抽穗后根系氧化力、根系和叶片中细胞分裂素(玉米素+玉米素核苷)含量、剑叶光合速率和籽粒中蔗糖合酶和腺苷二磷酸葡萄糖焦磷酸化酶活性、抽穗期至成熟期的干物质积累量、茎中非结构性碳水化合物的运转率和收获指数较高.土培池与大田试验结果趋势一致.结论]在节水灌溉条件下节水抗旱品种比当地高产品种可获得较高的产量和水分利用效率；节水抗旱品种在节水灌溉条件下较好的根系性能和地上部植株较强的生理活性是其高产与水分高效利用的重要生理基础.

Effect of Water-Saving Irrigation on the Grain Yield of Water-Saving and Drought-Resistance Rice and Its Physiological Bases

【Objective】 This study aimed to understand the yield formation characteristics of water-saving and drought-resistance rice cultivars and their physiological bases under water-saving irrigation. 【Method】 Two water-saving and drought-resistance cultivars, Hanyou 113 (an indica hybrid cultivar) and Hanyou 8 (a japonica hybrid cultivar), and two local high-yielding cultivars, Liangyoupeijiu (a two-line indica hybrid cultivar) and Yangfujing 8 (a japonica cultivar), were grown in cement tank and field. Two irrigation regimes, conventional irrigation and water-saving irrigation, were imposed from 10 days after transplanting to maturity. 【Result】 Compared with that under the conventional irrigation, grain yield of local high-yielding cultivars were significantly decreased under the water-saving irrigation, whereas the difference in grain yields of water-saving and drought-resistance cultivars was not significant between the two irrigation regimes. The water-saving irrigation significantly reduced the amount of irrigation water and increased irrigation water productivity (grain yield/amount of irrigation water), with more increase in water-saving and drought-resistance cultivars than in local high-yielding cultivars. In comparison with local high-yielding cultivars, water-saving and drought-resistance cultivars showed higher relative tiller number and spikelet number per panicle (tiller or spikelet number under conventional irrigation/tiller or spikelet number under water-saving irrigation), greater percentage of filled grains, longer leaf area duration during the growing season, higher root weight at heading, and greater or higher root oxidation activity, content of cytokinins (zeatin + zeatin riboside) in roots and leaves, photosynthetic rate of the flag leaf, and activities of sucrose synthase and adenosine diphosphate-glucose pyrophosphorylase in grains after heading, and more dry matter accumulation and more remobilization of non-structural carbohydrate from stems to grains during grain filling, and higher harvest index. Results from the cement tank and field experiments were very similar.【Conclusion】Water-saving and drought-resistance cultivars could obtain a higher grain yield and higher water use efficiency than local high-yielding cultivars under water-saving irrigation. Better root traits and stronger physiological activities of aboveground plants of water-saving and drought-resistance cultivars contribute to their higher grain yield and higher water use efficiency under water-saving irrigation.