【摘要】 在群体水培条件下,以汕优63为供试材料,于生育前、中、后期设计不同氮素供应水平（18个处理）,研究其对根原基分化数、不定根数、根重及其根系活力的影响。结果表明:（1）生育前期的单株根重随着氮素供应水平的提高而增加,10、13、14、15叶龄期的单株根重与不定根数均呈极显著正相关,与每条不定根重无显著相关,（2）主茎第10叶节的根原基分化数与10叶期的植株含氮率呈正相关(r=0.978^**),第10叶节根原基的发根率与13叶期的植株含氮率呈负相关(r=-0.969^**),与可溶性糖、非可溶性糖均呈正相关(r=0.784^NS,r=0.946^**),（3）生育中期短期（12日）内增加氮素供应水平可提高根重,处理时间过长（21日以上）则使根重尤其是上层根重下降;但增加氮素供应水平可提高单位根重的活力;（4）生育后期氮素供应水平对单株根重影响很小,且因稻体内含氮水平不同而异。生育中期供氮水平低或适宜时,生育后期适量施氮则可明显提高根系活力,生育中期供氮水平过高时,生育后期施氮则不能提高根系活力。更多还原

【Abstract】 Effects of nitrogen supplying levels and timings in solution culture on the number of root primordia, number of adventitious roots, root weight and activity of hybrid indica rice Shanyou 63 was investigated. Results showed: (1). Root weight per plant was increased with higher nitrogen supplying level in early growth period, and positive correlation was found between root weight and number of adventitious roots. (2). The number of root primordia differentiated on the 10th leaf node of main culm was significantly correlated with the nitrogen content of the plant at leaf-age 10, with correlation coefficient of 0. 978. The emerged rate of the root primordia differentiated on the 10 th leaf node was negatively correlated with the nitrogen con tent of the plant at leaf-age 13, and positively correlated with the content of soluble and insoluble carbohydrates at that time, with correlation coefficients of-0. 969, 0. 784, 0. 946, respectively. (3). Raising the nitrogen supplying level for a short term (12 days) in middle growth period, would result in higher root weight, but a longer treatment (21 days or longer) would induce root weight decrement, especially for the superficial root weight, yet the activity was higher. (4). The root weight was less respondent to nitrogen levels in late growth period. However, the late nitrogen application would induce a higher root activity, if nitrogen supplied was at a lower or optimum levels in middle growth period.更多还原