施氮对香稻某些生理效应的研究

用１个非和时稻品种Ｒａｔｎａ和３个香稻品种ＨＫＲ２２８，Ｂａｓｍａｔｉ３７０及ＣＢⅡ施氮和不施氮处理对比试验结果，施氮可使稻株光合作用，呼吸作用，植株含氮量提高。但是，施氮对光合作用的促进作用未达差异显著水平。对比非香稻品种Ｒａｔｎａ和春稻品种ＨＫＲ２２８，施氮对叶片呼吸作用促进作用前者大于后者。

PHYSIOLOGICAL EFFECT OF NITROGEN APPLICATION ON AROMATIC RICE

A comparison experiment with one non aromatic and three aromatic varieties of rice under no nitrogen and nitrogen application showed that nitrogen application increased photosynthesis and respiration rates and nitrogen content of rice plant. However, the increase of photosynthesis rate was not very significant. In comparison, the promotion of leaf respiration by nitrogen application of Ratna, a non aromatic rice, was significantly larger tnan that of HKR228, an aromatic rice variety. Respiration rate and nitrogen content of rice plant dropped remarkably during panicle initiation and heading periods. After heading the nitrogen contents of various parts of rice plant were arranged as follows: blade>panicle>sheath>culm. Basmati 370 had a small culm and a relatively higher plant height. The increase of plant height of this variety by the application of nitrogen was significantly larger than that of the other three varieties. This was one of the major physiological causes difficult for a further increase of the yield of scented rice of Basmati type.