不同杂交水稻吸氮特性与物质生产的关系

RELATION BETWEEN N ABSORPTION CHARACTERISTIC AND DRY MATTER PRODUCTION FOR VARIOUS HYBRID RICE

应用１５Ｎ示踪技术探讨了两系亚种间杂交稻ＰＥ０３７×０２４８和三系杂交组合汕优６３对氮素的吸收特性与物质生产的关系。结果表明，两个组合对氮素的吸收均以中期最高（各占全生育期吸氮总量的６５％左右）、前期次之、后期最少。两者吸氮速率高峰均在移栽后３０ｄ，两系杂交稻为４７２ｋｇＮ·ｈｍ－２·ｄ－１，三系杂交稻为４８０ｋｇＮ·ｈｍ－２·ｄ－１。对１５Ｎ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相反。稻株全生育期吸氮总量，约２０％来源于当季所施用的肥料，８０％来源于土壤。两者氮素在稻株体内的分配比例存在差异，在稻草中的分配比例，两系杂交稻高于三系杂交稻，而在稻谷中的分配比例，两系杂交稻则低于三系杂交稻。各生育期干物质积累量与氮素积累量呈极显著正相关，两系杂交稻相关系数为０９６２１，三系杂交稻为０９４４４。两个组合干物质积累均以中期最高（各占全生育期的６０％左右）、后期次之、前期最少。干物质积累速率的高峰均在移栽后４０ｄ，前者为３９９３０ｋｇ·ｈｍ－２·ｄ－１，后者为３７２９０ｋｇ·ｈｍ－２·ｄ－１。干物质积累总量，两系杂交稻高于三系杂交稻，而稻谷产量两系杂交稻则低于三系杂交稻。

With two line intersubspecific hybrid rice PE037×02428 and ternary hybrid rice Shanyou 63 as experimental material,the relation between nitrogen absorbing characteristic and dry matter prduction was studied.The result are as follows:N absorbed by rice plant at the mid stage(about 65% in total N absorbed)was the most.The high peaks of N absorbing rate were obtained at 30d after transplantation (PE037×02428 was 4 72kg·hm -2 d -1 ,Shanyou 63 was 4 80kg·hm -2 ·d -1 ).N absorbed from 15 N fertilizer by plant decreased with growing time,while N from soil increased with time. About 20% of N absorbed was from fertilizer and 80% from soil at harvest time.However,N absorbed by plant was found more in straw for PE037×02428 than Shanyou 63.The accumulation rate of dry matter and N absorbing rate were highly correlated(r PE037×02428 =0 9621 ** ,r Shanyou 63 =0 9444 ** ).