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本文通过两种土壤、两种不同基因型小麦的盆栽模拟试验,对与土壤氮素转化有关的根际细菌及酶活性等进行了动态研究。结果表明:两种不同基因型的小麦根系对氨化细菌和反硝化细菌均有明显的根际效应,但对自生固氮细菌则为负效应;亚硝酸细菌差异不明显。两合土中菌数大于红砂土;在红砂土中未发现自生固氮细菌。小麦根际土中菌数以宝丰7228大于郑引Ⅰ号;根际的优势细菌以革兰氏阴性杆菌为主,常见的科、属有Enterobacteriaceae、Pseudomonas和Acinetobacter;此外,还有Bacillus。小麦根际土壤中硝酸还原酶活性以郑引Ⅰ号>宝丰7228;还原NO_3~-为N_2O的酶活性在不同基因型间没有差异;而根际、根外土壤间存在一定差异。就土壤类型而言,还原NO_3~-为N_2O的酶活性以两合土>红砂土。在小麦扬花期前,宝丰7228根际的脲酶活性>根外土壤;郑引Ⅰ号则相反;在成熟期均以根外脲酶活性>根际土壤。两种不同基因型小麦根际土壤的硝化作用强度无差异。
In this paper, two kinds of soil, two different genotypes of wheat pot experiment to study soil rhizosphere bacteria and enzyme activities related to soil nitrogen transformation. The results showed that two wheat genotypes had obvious rhizosphere effect on ammonification bacteria and denitrifying bacteria, but negative effect on autotrophic nitrogenous bacteria. Nitrite bacteria had no obvious difference. The number of bacteria in the two combined soils was greater than that of red sandy soil; no autotrophic nitrogenous bacteria were found in the red sandy soil. The number of bacteria in rhizosphere soil of wheat is more abundant than that of Zheng-Yin-Ⅰ in Baofeng 7228. The predominant rhizosphere bacteria are Gram-negative bacilli. Common families are Enterobacteriaceae, Pseudomonas and Acinetobacter, and Bacillus. Nitrate reductase activity in rhizosphere soil of wheat was the same as that of Zheng-Yin-Ⅰ> Baofeng-7228. There was no difference in the enzyme activity of NO_3 ~ - -N_2O between different genotypes, but there was a certain difference in rhizosphere soil and rhizosphere soil. In terms of soil type, the enzyme activity of reducing NO_3 ~ - as N_2O is as follows: red soil> red sandy soil. Before the flowering stage of wheat, the urease activity in the root of Baofeng 7228 was higher than that in the soil outside the root, the opposite in Zheng 引 Ⅰ, and the activity of rhizosphere soil urease> rhizosphere soil in the mature stage. There was no difference in the nitrification intensity of soil rhizosphere soil between the two genotypes.