土壤中大豆根瘤菌之间竞争结瘤的研究——Ⅲ.接种菌量对大豆生长的影响

STUDIES ON COMPETITION FOR NODULATION BETWEEN SOYBEAN RHIZOBIA IN SOIL III EFFECT OF INOCULATION RATE ON SOYBEAN GROWTH

本文研究了大豆根瘸菌PRC005的接菌量对大豆生长的影响。田间试验结果表明:接菌量在播种后40天和60天没有显著增加根瘤数、根瘤干重、地上部植株干重和植株含氮量。施氮肥处理和较高接菌量处理之间的大豆种子产量差异不显著,与不接菌对照处理相比,施氮肥和较高接菌量两个处理的种子产量显著增加。施氮肥处理没有使植株含氮量增加,并且还妨碍了大豆的结瘸作用。室内盆栽试验结果表明:只有当接菌量高于土著菌数1200倍时,才能显著地提高大豆的结瘤数和植株干重。

To study the effect of Bradyrhizobium japonicum strain PRC005 inoculation rate on growth of soybean (Glycine max L. Merr.), field experiment was conducted in the University farm soil containing a large quantity of indigenous soybean-nodulating rhizobia, and pot experiment was carried out with the same soil. Number and dry weight of nodules, dry weight and total nitrogen content of plant tops, and seed yield were determined. Neither number and dry weight of nodules nor dry weight and total nitrogen content of plato tops were significantly increased by different inoculation rates of soybean grown in the field for both 40 days and 60 days after planting. There was no significant difference in soybean yields between higer inoculation rate and nitrogen fertilization, but they significantly increased soybean yield, as compared with no inoculation cheak. Nitrogen treatreent lind not increase nitrogen content of plant, and decreased the number and dry weight of nodules. The results of the pot experiment indicated that only when an inoculation rate of 1200 times the indigenous population was used at planting, could the number of nodules and plant dry weight be incresed significantly.