水稻氮高效品种资源筛选的初步研究 Ⅱ.不同施氮水平下水稻产量性状的品种间差异

A Preliminary Study on Selection of High-nitrogen Utilizable Variety Resources Ⅱ. Differences among Varieties in Rice Yield Character under Different N Application

对不同氮效率类型品种在不同供氮条件下产量性状的变化趋势分析表明:与低氮时相比,氮高效品种在中高氮、高氮高效品种在高氮条件下株高增长幅度较大,单位面积穗数大幅度增加,同时每穗粒数明显增加,高氮时尤其明显,因此,这两种类型品种的单位面积颖花量明显高于其它类型品种,而氮低效品种的表现基本与此相反。低中氮高效品种中多数在中氮到高氮时穗粒数增加的幅度很小,虽然在低中氮时单位面积颖花量较高,而且由低氮到中氮时增加的幅度较大,但由中氮到高氮时增加的幅度明显降低。相关分析结果表明:低中氮时穗数对产量的影响大,而在高氮时穗粒数对产量的作用大。因此,在超级稻育种中,应加强对大穗材料,尤其是高氮时穗粒数增加幅度较大材料的选择。

Changes of rice yield character of different nitrogen use efficiency varieties under different nitrogen application level were analyzed in the study. The results showed that comparing with low nitrogen level, high-nitrogen utilizable varieties under medium-high nitrogen condition, high- nitrogen and high-effect varieties under high nitrogen ,the plant height increased greatly, ears per unit area increased greatly, at the same time, the grains per ear increased obviously, especially when nitrogen was high. So the two kinds of varieties had higher number of flowers per unit area than other kinds of varieties, while low-nitrogen utilizable varieties appeared oppositely. In low medium high- nitrogen utilizable varieties, most of whose grains per ear increased a little when medium nitrogen to high nitrogen. Though the number of flowers per unit area was high, and increased range of flowers was large when it was from low nitrogen to medium nitrogen, whereas increased range of flowers became less when it was from medium to high nitrogen. The analysis of correlation showed that the count of ears influenced yield greatly when at low medium nitrogen, while the function of grains per ear was great to yield when at high nitrogen level. So in the breeding of super rice, materials of big ears, especially those materials which increasing range of grains per ear was big at high nitrogen should be chosen.