双季晚粳生产力及相关生态生理特征

于江西鄱阳、上高县，选用代表性晚粳稻品种(武运粳24、南粳44、镇稻11、常优1号、常优5号、甬优8号)在高产栽培条件下以当地代表性晚籼稻品种为对照，系统比较了粳、籼稻间产量、品质和效益的差异，初步阐明了双季晚粳生产力优势，并从温光利用、株型、光合物质生产等方面探讨了其优势形成的生态生理特征。结果表明，3年晚粳平均产量分别为9.6、8.3、9.9 t hm^-2 (2011年上高县甬优8号最高产量田块达10.6 t hm^-2)，极显著高于晚籼，而其产量高的主要原因是每穗粒数、结实率显著或极显著高于籼稻；晚粳加工品质、食味品质优于晚籼(晚粳出糙率、精米率、整精米率显著或极显著高；其直链淀粉、蛋白质含量显著或极显著低，胶稠度显著或极显著长)，外观品质逊于晚籼(粳稻的垩白率、垩白大小、垩白度均显著或极显著高于籼稻)；晚粳效益高于晚籼(3年晚粳的纯收益分别为11 890.6、10 252.1、16 565.9元 hm^-2，分别高23.8%、23.6%、26.7%)。双季晚粳生产力优势形成的相关生理生态特征为，较籼稻全生育期特别是结实期明显延长，抽穗结实期较籼稻适应凉爽气候，增加对温光资源利用，能正常成熟；后期有较高光合生产能力，增大了群体光合物质生产积累量，源库协调性好，库容总充实量高；生育后期在偏低温气候下不早衰，维持较强根系和较大茎鞘强度，具有较强群体抗倒伏能力。

Productivity and Eco-physiological Characteristics of Late Japonica Rice in Double-Cropping Rice System

In the condition of high yield cultivation,a field experiment was conducted with representative japonica rice cultivars (Wuyunjing 24, Nanjing 44, Zhendao 11, Changyou 1, Changyou 5, Yongyou 8) and the typical local late indica rice cultivars in double-cropping areas (Poyang and Shanggao in Jiangxi Province). Differences of grain yield, quality and net income between japonica and indica were studied systematically. The productivity advantages and its mechanism of late japonica rice were explained from the effects of temperature and light, plant type, and photosynthesis. Results showed that the average yield of late japonica rice in three years was 9.6, 8.3, and 9.9 t ha^-1 respectively, which was higher than that of indica rice significantly. The highest yield of Yongyou 8 in 2011 was 10.6 t ha^-1. The grain number per panicle, seed-setting rate of japonica rice were higher than those of indica rice, which was the reason of higher yield of japonica rice. Milling quality, cooking and eating quality of japonica rice were also better than those of indica rice significantly, while appearance quality showed an opposite tendency. The brown rice rate, milled rice rate, and head rice rate of japonica rice were significantly higher than thoseof indica rice while the amylose content, protein content of japonica rice were significantly lower than thaose of indica rice. And the gel consistency of japonica rice was also longer. The appearance quality including chalky grain rate, chalkiness area and degree of japonicawere significantly higher than those of indica rice. The benefits of late japonica rice were significantly higher than those of indica rice, with the net income of 11890.6, 10252.1, 16565.9 Yuan ha^-1 in these years, respectively, which were higher than those of indica rice by 23.8%, 23.6%, and 26.7% respectively. The physiological and ecological characteristics of productive advantages of late japonica rice in double-cropping rice area were as follows. Firstly, growth duration of japonica rice was longer than that of indica rice significantly and japonica rice was more adapted to grow in cool weather at the later period of grain filling, increasing utilization of temperature and solar radiation and ensuring maturity safely. Secondly, strong photosynthetic capacity of japonica rice at the later period increased dry matter accumulation and total grain filling. Thirdly, japonica rice improved resistances to cold, premature senescence, and lodging due to strong root, stem and sheath.