不同供氮水平下稗草营养元素(N)的生育期分配研究

Reproductive Allocation of Nutrient Element N in Echinochloa crusglli( L.) Beauv under Different Nitrogen Levels

采用盆栽试验方法测定了5个供氮条件下的稗草(Echinochloa crusglli(L.)beauv.)3个生长时期各器官的氮含量,分析了营养元素(N)生殖分配的特点。结果表明:(1)随生育期的延长,各处理的根、茎的氮含量、氮分配由分蘖期到盛花期增大、盛花期到结实期减小,叶和叶鞘逐渐减少,生殖器官显著增加,结实期果的氮素分配比例最大。(2)随施氮量的增加,各器官的氮含量大致呈增加趋势;花和果器官的氮单位含量处理间差异不显著,叶鞘的氮单位含量分蘖期和盛花期在高浓度(N4)时最大;花器官的氮元素分配中浓度(N2)处理显著高于其他处理,果器官氮元素分配低浓度(N0)处理显著低于其他处理。

Five nitrogen treatments were given to Echinochloa crusglli （ L.） beauv .The nitrogen contents in its various organs were determinated in three periods .Then the characteristics of the reproductive allocation of the element N.The results indicated that：（1）With the extension of the growing stage ,from tillering to flower-ing ,each organ ’ s nitrogen content and nitrogen element allocation to root and stem increased;from flowering to ripening ,each organ ’ s nitrogen content and nitrogen element allocation to root and stem decreased;that to leaf decreased ,that to genitals increased significantly ,the nitrogen element allocation of fruit was the largest in the ripening stage.（2）With the amount of nitrogen application increased ,each organ’s nitrogen content increased;the unit nitrogen contents of flower and fruit organs did not show significant differences among the treatments , the unit nitrogen content of leaf sheath was the largest under high concentrations （N4） at the tillering and flow-ering stages;the nitrogen element allocation of flower organ was significantly higher than that of other treat-ments under the condition of N 2 ,that of fruit organ was significantly lower than that of other treatments under the condition of N 0 .