Comparative Research On Regenerative Characteristic Of Japonica And Indica Rice Varieties

Ratoon rice is a second harvest, originating from the previously main crop stubble. At the moment, indica rice varieties are being served as the most important cultivars of ratoon rice. The rice quality of japonica is better than indica rice, but it is seldom used as ratoon rice widely. Hubei province is the interlaced zone of indica and japonica rice, it is proposed to expand japonica rice area which is in recent years conducive to high yield and efficiency of rice cultivation. With the development of economy and improvement of people s living standards, japonica rice gains more popularity and has far greater market prospects than indica rice in the northern and large-medium coastal cities. The demand for japonica rice is increasing due to its strong starch viscosity.It is necessary to introduce some weakly photosensitive japonica rice varieties for ratooning cultivation; so that it would provide direction and theoretical basis on japonica ratoon rice production and rice quality improvement for Hubei province. In this study, five japonica and three indica rice varieties were tested and grown in a field under zero (T1) and high (T2) bud fertilizer conditions. The following results were obtained:1. In five japonica and three indica rice varieties, the growth period of main crop plummeted in between123days and181days. The growth period of NG43and JD263were less than147days and matured before November5th.2. The ratoon yield response of japonica rice to bud fertilizer was more sensitive. It required enough bud fertilizer to accomplish high yield for ratoon rice. Significant increase in yield of ratoon rice was mainly due to the noteworthy enhancement of effective panicles per unit area and number of spikelets per panicle. Bud fertilizer was no considerable effect on yield of main crop. With plenty of bud fertilizer, japonica rice has the higher yield of ratooning than indica rice, but total yield of was slightly lower than indica rice due to its lower yield of main crop.3. Among investigated varieties there was significant genetic variation in terms of bud regenerative ability. The foremost regeneration position of japonica rice was at the base node, which contributed more than75%of the yield of ratoon rice. It belonged to the regeneration type of the lower node. Conversely, the main regeneration position of indica rice was at the2th and3th node from top, which contributed more than85%of yield of ratoon. It belonged to the type of regeneration of an upper node. The lower regeneration node of japonica had the effect on prolonging growth duration of ratooning, while it increased grain yield of ratoon rice to a certain degree.4. Rice s quality of ratoon rice was superior to main crop. For rice processing quality, head rice rate of ratoon of japonica and indica rice varieties was significantly higher than main crop, especially in japonica rice. For rice exterior quality, rice chalkiness and chalkiness degree of all varieties were significantly lower than main crop.