Abstract:

A pot experiment was carried out to study the character of carbon nutrition of effective and ineffective tiller byusing rice variety Zhe 8619 as materials. When the leaf-index of main stem was in the range of from 84. 5% to 91. 6%, the dryweight of ineffective culms almost did not increase in this period. As a result the largest critical dry weight of the ineffectivetillers was taken as the critical individual dry weight of effective tillers and the period was called dry weight stagnating increase stage. The dry weight stagnating increase stage could be taken as the index for direct diagnosis of turn stage from ineffective tillers to effective tillers. The results also showed the carbon nutrition characteristics of ineffective tillers: The abilityof ineffective tillers accepting nutrition was no less than that of other tillers in the early growing stage I Since the tillers stagnated growth the total amount of ¹⁴C-glucose accumulated in the tillers was distinctly lower because the assimilation productwhich main stems exported to tillers was reduced. During the turn stage, the photosynthetic ability distinctly became less andthe accumulation of photosynthetic products was reduced. When the ineffective tillers were dying there were a few assimilation products exporting from ineffective tillers. The poorer the ineffective tillers were, the less the assimilation products exported.

Key words: rice, tiller, effectiveness, carbon nutrition, dry matter accumulation, diagnosis criterion

摘要： 以水稻品种浙8619为材料进行盆栽试验研究了有效茎和无效茎的碳素营养特性。当主茎叶龄指数在84.5%～91.6%时，无效茎出现干重滞增期，其最大干重乃为该品种有效茎的临界个体重，故可将干重滞增期作为该分蘖的有效、无效转折期的直接诊断指标。并阐明了无效分蘖的碳素营养特性：出生初期接纳养分的能力并不弱，后来由于生长停滞，来自母茎的同化物输入减少，致使¹⁴C葡萄糖的积累高峰提前，积累总量明显偏低；进入转折期后，光合能力明显降低，光合产物积累减少；在濒临死亡时，可能有一定量的同化物输出，但其输出总量并不大，且越是受光条件和生长基础差的无效分蘖，输出总量越少。还就无效分蘖对产量的贡献以及高产栽培对策进行了讨论。

关键词: 水稻, 分蘖, 有效性, 碳素营养, 干物质积累