氮、磷、钼对木麻黄苗期固氮、生理及生长效应的研究

The Study on the Effects of Nitrogen, Phosphorus, Molybdenum on Crowth, Nitrogen Fixation and Physiological Characters in Casuarina Seedlings

以细枝木麻黄和沿海防护林内的中性沙土为供试材料,采用三因素五水平二次通用旋转设计方案,进行氮、磷、钼施肥试验。结果表明:细枝木麻黄的叶绿素含量、光合作用指标、硝酸还原酶活性、氨基氮含量、结瘤量、固氮酶活性、苗高生长、生物量积累均随磷的增加而提高;苗木结瘤量和结瘤率、固氮酶活性明显受氮肥制约,随施肥的增加而下降。其他生理指标和生长量在0.4gN/pot·范围内较好,超过此限时略有下降趋势或影响不明显;钼在本试验条件下影响不显著。苗木生物量和固氮酶活性与净光合强度、叶绿素含量、呼吸强度、NRA等指标均呈显著正相关。

Casuarina cunninghamiana mig seedlings were raised from seeds and grown in pot culture in which a quadric rotation cut orthogonally design was adopted to arrange the trial including three factors N, P, Mo with five levels which were 0.0, 0.4, 1.0, 1.6, 2.0 gN/pot; 0.0, 0.25, 0.60, 0.95, 1.20 gP/pot; 0.0, 10.0, 26.0, 42.0 52.0mg Mo/ pot. The main results are as follows; 1.With incresing levels of P supply, there were more nodule numbers, higher nitrogen activity of nodule ( NFA)and nitrogen reductase activity ( NRS ), greater height and dry weight of plants, chlorophyll contents, net photosynthesis rate, respiratory rate, 2,Nodule numbers and NFA of nodule decrease with increasing levels of N supply, other items increased withincreasing levels of N supply from 0.0-0.4gN/pot, but, decreased sligtly when at higherleves (< 1.0-2.0gN/ pot). 3. With the increasing levels of molybdenum supply, there were not obvious influence on all trial items in these expriemental soil condition.