两系亚种杂交稻根系活力和磷素分配与籽粒充实度的研究

STUDY ON THE ROOT ACTIVITY, PHOSPHORUS DISTRIBUTION AND GRAIN PLUMPNESS OF TWO LINE INTERSUBSPECIFIC HYBRID RICE

应用放射性３２Ｐ示踪技术对两系亚种间杂交稻根系活力、磷素分配与籽粒充实度进行了研究。结果表明：杂交组合２２６４Ｓ／ＤＴ７１３（Ｆ１）与汕优６３（对照）相比，在抽穗期、灌浆期和成熟期根系吸收３２Ｐ总量较少，各生育期根系吸收３２Ｐ总量下降幅度大，根系活力下降快，根系出现早衰；灌浆期根系吸收的３２Ｐ分配到籽粒的比率较低，滞留于茎鞘和叶的比率较高；库源比高，结实率低，源供应不足，库源流不协调，是该杂交组合籽粒充实度差的原因。相关分析表明：抽穗期和成熟期根系吸收３２Ｐ总量与籽粒中３２Ｐ分配量相关不显著，灌浆期根系吸收３２Ｐ总量显著影响籽粒中３２Ｐ的分配量，ｒ＝０．８８０５。而籽粒中３２Ｐ分配量与籽粒充实度极显著相关，ｒ＝０．９２７１。

The root activity, phosphorus distribution and plumpness of two line intersubspecific hybrid rice were studied with the aid of 32 P tracer technique. The results showed that the total 32 P radioactivity in 2264S/DT713(F 1) cross was less than that in Shanyou 63 ternary hybrid (control) during heading, filling and maturing period.The poor seed plumpness of this cross was due to the sharp decrease of 32 P activity in growing period and the fast degeneracy of its root activity, the low transfer rate of 32 P in grains during filling period, the high ratio of sink to source, the low seed setting rate and insufficient source supply. Correlation analysis revealed that there was no significant correlation between the phosphorus partition in grains and the total radioaitivity in heading and maturing period. However, the amount of 32 P uptake significantly affected the 32 P partition in grain in filling period(r=0.8805 *) and the 32 P in grain remarkably correlated with the plumpness (r= 0.9271 ** ).