两系法亚种间杂交稻氮素营养与物质生产关系的研究

应用~(15)N,~(14)C 示踪技术研究了亚种间杂交组合的氮素营养、光合特性与物质生产的关系.结果表明,亚种间杂交组合P 对氮素的吸收以中期最高(65.91%),前期次之(17.56%),后期最少(16.51%).约1/5来源于当季所施用的肥料氮,约4/5来源于土壤氮.对~(15)N 标记肥料氮的吸收随着生育期的推移而逐渐减少,而对土壤氮的吸收则随着生育期的推移而逐渐增加.氮素在稻株体内的分配,以穗部最高(61.86%),茎叶次之(30.93%),根部最少(7.19%).组合S 与组合P相仿.氮素在稻草中的分配,组合P 高于组合S,而在稻谷中的分配,组合P 则低于组合S.~(14)C 同化物滞留于标记叶(源叶)的量,组合P 显著地高于组合S(4.51%(?)),而转运至穗部的量,组合P 显著地低于组合S(4.87%(?)).干物质在各生育期的积累,两个组合均以中期最高,后期次之,前期最少,且各生育期干物质积累量与氮素积累量呈极显著正相关.

RELATIONSHIP BETWEEN NITROGEN NUTRITION OF TWO-LINE HYBRID RICE SUBSPECIES AND DRY MATTER PRODUCTION

The result of the experiment with ~(15)N and ~(14)C labeling shows that for two-line hybrid rice subspecies P(P),17.56%,65.91% and 16.51% of total absorbed N wasaccumulated in early,midst and late growth stager respectirely;and the total absorbed Nwas 1/5 from fertilizer N and 4/5 from soil N.The rate of N absorbed from fertilizer Ndecreased with growth,while the rate of N absorbed from soil N increased.In addition,therate of N distribution in ears was the highest,amounting to 61.86% of total N absorbed;thesecond was in stems and leaves.30.93%;the least was in roots,only 7.19%.Three-linehybrid rice S(S)showed a similar trend with P about N accumulation.However,N wasdistrbuted more in straws for P than for S.The result also shows that the rate of ~(14)C-assimilates retained in labeled leaves was significantly higher for P than for S.But the rate of~(14)C-assinilates transported to ears was significantly less for P than for S for loth pand S.Drymatter accumulation in both P and S was highest in middle growth stage.Next was latestage and early stage had least accumulation.Highly significant relativity was showedbetween the accumulation of dry matter and that of N in different growth stages.