灌溉稻田水稻旱作法研究——水稻的生育与生理特性

 以亚种间杂交稻两优培九（两系）及协优9308（三系）为材料，比较研究灌溉稻田旱作法与常规灌溉法水稻的生育与生理持性。结果表明，两杂交组合不因旱作改变全生育总叶片数，但播种至齐穗期因旱作缩短4～8 d，幼穗发育（拔节期）未见明显差别，说明旱作水稻生殖生长期相对缩短。旱作法水稻单丛叶面积大于常规灌溉稻，叶面积指数小于常规灌溉稻。水稻根系单丛干重因旱作比常规灌溉法水稻有明显增加，并营造了比常规灌溉法水稻根重根深的土壤环境。结果还表明,水稻旱作法有益于构建由大个体构成的高生物产量的群体，抽穗后生物产量占全生育期生物产量近40%；但是，旱作法对水稻也有诸多不利的生理影响，其一是比常规灌溉法水稻根系生理活性下降，表现在单茎根系伤流量、根系伤流液中玉米素含量、根系呼吸强度均较低；其二是灌浆-成熟期稻株剑叶光合速率低于常规灌溉法水稻，叶片气孔阻抗高于常规灌溉法水稻。因此，进一步提高灌溉稻田水稻旱作法的产量水平，其技术的主攻方向似应为提高稻株籽粒灌浆期间的生理素质，以提高成熟期的光合生产能力。

Study on Non-flooding Farming Technique in Irrigated Paddy Field--Physiological and Developmental Characteristics of Rice

Sub-species hybrid rice Liangyoupeijiu (two-line hybrid rice) and Xieyou-9308 (three-line hybrid rice) were selected as testing materials. The physiological characteristics of rice growth and development were studied by comparing the conventional flooding rice farming CFRF)with non-flooding rice farming ( NFRF). Results of the experiment showed that there were no differences as total leaf number and panicle initial development were concerned. At the same time, the period from sowing to heading was 4-8 days less of the NFRF than the CIRF, showing that the NFRF had comparative shorter reproductive duration. Larger total leaf area per hill, leaf area index and heavier root dry weight were observed on the NFRF. At the same time, the NFRF facilitates heavier and deeper root system. However, the NFRF is access to form a high biomass colony by large individual plant, and the dry matter accumulated after heading accounted for 40% of the total dry matter. Several disadvantages were also observed on the NFRF technique: (1) Less amount of root exude with lower zeatin content, and a lower respiration rate. (2) The flag leaf photosynthesis rate from filling stage to ripening stage decreased, and stomatal resistance increased as compared to traditional flooding irrigation. Some possible ways for increasing photosynthesis rate by improving physiological activity of plant during filling stage were also discussed.