小麦接种联合固氮菌增产原因分析

Analysis on High Yield Reason of Wheat Inoculated with Associative Nitrogen -fixing Bacteria

在自然条件下,小麦接种联合固氮菌(土生克雷伯氏菌)43菌株、获得了显著增产效果.本研究结果表明.其增产的主要原因是菌株与小麦根系结合.在根毛细胞、表皮细胞、皮层细胞的间隙及输导组织中存在大量的菌体细胞.在小麦抽穗期固氮酶活性达到148.8n mol C_2H_4株^(-1)h(-1),^(15)N稀释法测定固氮量占植株总氮量的15.3%～22.1%.由于菌株产酸,在砂培条件下,速效磷增加16.1%～39.7%.提高了植株磷素营养水平.同时菌株代谢物中存在生长素、赤霉素和细胞分裂素,可刺激植株生长发育.显然,小麦接种43菌株增产是因菌株固氮、解磷和产生多种激素综合作用的结果.

The wheat inoculated with strain 43 of associative nitroge -fixing bacteria (Kleb-siella terrigena)had significantly shown high -yield result under natural conditions.The research results indicated that the reason of yield increace was the combination of the strain with the wheat root system and the presence of the bacteria cells in spaces of the roothair cells,epidermal cells an within the transportation tissues. In the heading period the nitroge-nase activity was as high as 148. 8 nmol C2H4·plant-1 ·h-1 ,and the fixed nitrogen amount was 15. 3-22. 1 % of the total nitrogen amount in the plant. Since the strain might release acides , the activate phosphorus content could increase by 16. 1-39. 7% under sand culture condition, so that the phosphorus nutrition status of the plant could be improved. In addition some hormones such as auxin,gibberellin and cytokinin existing in metabolic products of the strain could stimulate the plant to grow. It is quite evident that the reason why the wheat inoculated with the strain increases the yield is that the strain can fixe nitrogen,resolve phosphorus and produce many sorts of hormons.