Preliminary Study On Sensitivity For Nutrition Of Rice

It is a very big limitation by "light sensitivity, temperature sensitivity and the basic vegetative phase" as the only theory instruction in hybrid rice seed production. Seedling growing status, nutritional conditions and the cultivation measure have the varying degree influence on the development transformation of hybrid rice parents, promoting or postponing the heading date of the parents.The experiments were conducted to investigate the effects of leaf-age, nutrition condition of the seedlings and the status of the tillers on the heading date of rice. The effects of nutrition condition and age of the seedlings were carried out with four varieties or strains which divided into sowing different densities , sowed the same day and transplanted in turn in field in experiment 1. And the status of tillers of the seedlings on the heading date of rice with Shanyou 63 as material were conducted in the pots in experiments 2 and 3. Moreover, the relation between tillers status of seedlings and the biological output, the effective panicles as well as the number of spikelets were discussed briefly in this paper. The main results are as follows:1. Effect of leaf-age of transplant on the heading dateThe heading date of rice was different of as sowed the same day but transplanted different leaf-age. When transplanted at the leaf-age among 5~7L, the heading date of rice was steady, the discrepancy only 1~2 days. The leaves number of the main stem were few and the days from sowing to heading (DSH) was short. The leaves number of the main stem increased, and the DSH postponed 3~7d when the leaf-age was 7~9L at the transplant. The leaves numbers of main stem decreased and DSH became shorter remarkable as the transplant day delayed as the complement of leaves number was fewer than 6~7 L, and flower date became longer (the extreme date reached 27d).2. Effect of the seedling with different numbers of tillers on heading dateThe tillers numbers of seedlings were different markedly when sowing densities was different. The tillers number of the seedlings in thin sowing were more than that of dense sowing. It can be reflected the...