大豆-根瘤菌的固氮作用

报道了我国主要大豆产区根瘤菌和寄主品种固氮资源的分布、主要类型、固氮作用。我国多年连续种植的大豆的田块 ,根瘤菌菌数每克干土一般超过 10 4 个 ,大部分零星隔年种植和不常种植大豆的田块根瘤菌数每克干土低于 10 4 个。多数根瘤菌土著者能与大豆栽培品种有效结瘤 ,但主要是中、低效固氮者。在自然条件下 ,供试的春大豆中高效固氮者占 31.7% ,供试的夏大豆高效者占 6 4.3% ;人工接种根瘤菌 ( 113 - 2 ) ,春豆中高效固氮者占 40 .9% ,夏豆占 5 3.6 %。我国的栽培大豆是较好的耐高氮共生固氮资源 ,评价出 2个在 5mMNO-3 条件下结瘤的品种。

Nodulation and nitrogen-fixation in soybean-rhizobium

This paper reported the distribution, dominant types and nitrogen fixation effect of rhizobia and host nitrogen-fixing resource in Chinese soybean productive region. In general, native-born cell number of rhizobia in most of fields where soybean was planted in frequently was over 104 cells per gram soil. But in most soybean fields where soybean was planted in discontinuous and in scattered, cells numbers were under 104 per gram soil. Most native-born rhizobia could nodulate effectively, but most of them were middling and low-efficiency rhizobia. Chinese soybean cultivars with native-born rhizobia could nodulate effectively. In natural field, high-efficiency cultivars accounted 31.7% of tested spring soybeans, 64.3% in tested summer soybeans. There were nitrate-resistant resources in our soybean and two cultivars that could nodulate with rhizobia in 5mM NO- 3 solution have been identified.