| Nowadays, the contradiction between the supply and demand of japonica is very severe in China, so strengthening its development is of greatly need. The northern dominant growing district of Japonica is facing many constraints, like water deficiency, ecological environment protection and so forth. When further improving Japonica yield, hence it’s an important way to popularize the project of japonica rice instead of indica rice to develop japonica in the southern part of China. Hubei Province contributes a lot in southern rice production and it’s a critical part of the project of japonica rice instead of indica rice to develop Japonica. Based on the obvious trend of single-cropping rice instead of double-cropping rice cultivation model in Hubei Province, applying of "japonica rice instead of indica rice in single-cropping rice" project is of increasingly importance, yet so far there has been rare report of it.The objectives of this research are as follows:1) Under the conditions of Hubei province single-cropping rice cultivation model and180kg hm-2nitrogen fertilizer application, we examine the feasibility of applying single-cropping rice in the single-cropping rice instead of double-cropping rice project by comparing the yield and quality of japonica cultivars and the major local indica cultivars;2) To discuss the reasons of the production and quality difference among cultivars by comparing the yield, yield components and dry weight accumulation;3) To discuss the ecological adaptability of japonica cultivars as single-cropping rice cultivated in Hubei Province combining the meteorological data. Via the above research to find out the agricultural characters of single-cropping rice suitable for being cultivated in Hubei Province and expect to supply some theoretical support for Hubei single-cropping rice breeding. The research take11japonica cultivars and two indica cultivars as experimental materials, taking field experiment in Lanjie Village, Huaqiao Town, Wuxue City, Hubei Province between2012-2013to examine the yield, quality and performance of some cultivars among different cultivars. The major consequences are as follows:1. Under the single-cropping rice cultivation model in Hubei Province, the yield of Yongyoul2and Changyou2reached9.98t hm-2and9.60t hm"2respectively, higher13.0%and4.8%than the average yield of indica cultivars. By the same time, the two cultivars both reach the second or even higher levels of nation’s high quality rice. Therefore, these two cultivars are suitable for being cultivated in Hubei Province as high-yield and high-quality ones. 2. All the japonica cultivars have the production potential of9.00t hm-2but the average harvest index can only reaches38.4%,which restricts unearthing of yield potential. The sink potential is the major reason of low harvest index, the spikelet number per panicle positively correlates with the total spikelet number which is the major factor of the sink potential. Thus, the big type panicle maybe the significant target of japonica breeding.3. The growth period CGR of Yongyoul2can reach17g m-2d-1,9.8%higher than the average of indica cultivars, and the green leaves dry weight reaches as high as358.5g m-2in heading, which both demonstrate the distinctively growth vigor of japonica X indica hybrids. The growth period CGR of other japonica cultivars is distinctively lower than indica ones, but their average dry weight accumulation is a little higher than indica cultivars. The reason lies on the longer growth period of japonica cultivars than indica ones and the distinctively positive correlation between growth period and yield. Therefore, in a specific range, choosing the japonica cultivars with long growth period in Huber Province is beneficial for high production.4. Japonica cultivars production is averagely30.1%lower in2013than in2012, that’s because in2013, the frequently high temperature in anthesis period, the distinctively rising of daily maximum temperature and daily mean temperature all lead to the low seed setting rate. In the two years, how much the seed setting rate reduced is distinctively correlates with that of yield (R2=0.97**).Compared with japonica cultivars, indica cultivars has higher temperature tolerance, with yield and seed setting rate reduced by2.0%and7.0%respectively in2013than in2012.Therefore, it’s critical importance to improve japonica high temperature tolerance.5. High-yield and quality cultivars Yongyoul2and Changyou2were all heading in September, which avoid the effect of high temperature heat damage. Therefore, the major growth period avoiding high temperature is the most efficient strategy to save from high temperature heat damage.In brief, the key of single-cropping rice introduction and breeding in Huber province is to avoid the high temperature in July and August via growth period or to improve the cultivars high temperature tolerance. |
