双季稻区晚稻“籼改粳”品种筛选

【目的】研究双季稻区晚稻季条件下，不同类型水稻品种产量、生育期、温光利用差异及其相互关系，为双季稻区适宜品种的选用提供科学依据与技术支撑。【方法】2010—2013年，在长江中游双季稻地区（江西上高），以杂交粳稻（包括籼粳交偏粳型杂交稻、籼粳交偏籼型杂交稻和粳型杂交稻）、常规粳稻、杂交籼稻3种类型水稻品种为试验材料，采用湿润育秧大苗移栽方式，系统比较双季晚稻不同类型水稻品种产量、生育期、温光利用差异及其相互关系。【结果】双季晚稻不同类型水稻品种产量表现为杂交粳稻＞常规粳稻＞杂交籼稻的趋势，差异显著或极显著。与杂交籼稻相比，4年杂交粳稻的实产增产率为19.20%—28.95%，常规粳稻实产增产率为9.21%—12.17%；通过足量的群体穗数与较大的穗型协调形成足够的总颖花量，并有保持较高的结实率和千粒重，是粳稻综合改良产量结构获得高产的基本途径。杂交粳稻和常规粳稻各生育期均相应推迟，且两者生育期亦延长，其中杂交粳稻生育期平均延长17.1 d，常规粳稻生育期平均延长9.5 d。不同类型品种生育期积温和光照时数及其不同生育阶段温光利用率均表现出杂交粳稻＞常规粳稻＞杂交籼稻的趋势，其中杂交粳稻生育积温和光照时数及其利用率最多，分别为3713.3℃、931.9 h、90.9%、93.5%。【结论】双季晚稻不同类型水稻品种产量、生育期及温光利用的差异大，适宜的粳稻品种可充分利用生育期长优势，提高温光资源利用率，最终提高产量。据此按照全国粳稻生产发展规划的要求，综合考虑双季稻接茬特点与热量条件以及栽培轻简化机械化的需求，筛选出一批适合当地种植的晚粳稻高产品种，供大面积生产选用，即甬优538、甬优8号、甬优2640、甬优1538、甬优1540、长江19、长江21、小叶迟熟、镇稻5108。

Selection of Late Rice Cultivars of Japonica Rice Switched from Indica Rice in Double Cropping Rice Area

【Objective】Under the conditions of late rice of double cropping systems, three different types of rice cultivars were used to investigate the differences and interrelations of yield, growth and utilization of temperature and illumination. The result will provide a scientific basis and technical support for the selection of suitable varieties in double cropping systems.【Method】A field experiment was conducted with japonica hybrid rice (including partial japonica of indica-japonica hybrid rice, partial indica of indica-japonica hybrid rice and pure japonica hybrid rice), japonica conventional rice and indica hybrid rice as materials in double-cropping rice areas (Shanggao of Jiangxi) in the middle reaches of the Yangtze River in 2010-2013. Differences and interrelation of yield, growth and utilization of temperature and illumination of rice cultivars with different types under the late rice of double cropping systems were studied systematically using cultivation with wet nursery and big seedlings transplanting.【Result】The yields of different types of rice cultivars under the late rice of double cropping systems all demonstrated japonica hybrid rice＞japonica conventional rice＞indica hybrid rice significantly or very significantly. Compared with indica hybrid rice, the yields of japonica hybrid rice and japonica conventional rice were increased by 19.20%-28.95% and 9.21%-12.17%, respectively. It was found that building enough total spikelets through adequate panicles and the large spikelets per panicle, and keeping a high seed-setting rate and 1000-grain weight was a basic way to improve yield structure comprehensively and obtain higher yield for japonica rice. Compared with indica hybrid rice, the growth periods of japonica hybrid rice and japonica conventional rice were delayed, and their total growth periods were significantly extended by 17.1 days and 9.5 days, respectively. And the utilization efficiency of temperature and illumination of various types of rice cultivars at different developmental stages showed that japonica hybrid rice＞japonica conventional rice＞indica hybrid rice, and the whole growth period trended similarly among which japonica hybrid rice were 3 713.3℃,924.9 h, 90.9% and 93.5% respectively.【Conclusion】The yield, growth and utilization of temperature and illumination among different types of rice cultivars under the late rice of double cropping systems had big differences. The suitable japonica rice varieties could make good use of longer growth yield with high utilization of temperature and illumination and increase the grain yield. According to the requirements of national japonica rice production development planning, considering the stubbles feature of double-cropping rice and heat conditions as well as the requirement of mechanized and simplified cultivation, a batch of late japonica rice cultivars of high yielding which were suitable for cultivation in the local were selected including Yongyou 538, Yongyou 8, Yongyou 2640, Yongyou 1538, Yongyou 1540, Changjiang 19, Changjiang 21, Xiaoyechishu and Zhendao 5108, in order to provide reference for rice production in large area.