Preliminary Screening Of High Efficient Soybean Rhizobia Strains In Sichuan Province

The production potentiality and utilization potentiality of rhizobia inoculant in Sichuan is large. Screen the high efficient and best matched with the mainly planted soybean cultivar in Sichuan province and make it into bacteria agent instead of part of the use of nitrogen fertilizer. It can increase soybean yield and decrease the pollution of the environment. This experiment use the research method of natural selection. In order to select nodular ability strong, nitrogen-fixing efficient strains,first of all, we isolated stains from nodules which were collected from sampling points and made them through hydroponic experiment, pot experiment and field experiment. Here is the main result.(1) Isolated85rhizobia strains in nodules which were collected from21cities (24sampling points)in Sichuan.(2) The preliminary screening by hydroponic experiments resultes that the nodules number was0.67-32No./strain,16.5%of the strains of nodules number are more than20, S20and S81of nodules number are more than30. The plant dry weights was0.32-0.70g/strain and48.8%strains are higher than CK(0.48g/strain). The plant dry weights of10.5%strains is significantly higher than CK. Integrated plant dry weight and nodule number, S8,S20,S22,S36,S39,S46,S50,S55,S65,S81had been screened for pot experiment.(3)The results of pot experiment at full bloom stage of the above10strains vaccinatied with Nandou No.12is that the nodules number is in the range of232～485. There are eight processing of nodules number are higher than CK in the range of8.7%～69.0%.S8of nodules number reached significant level with CK. S46、S81of nodules number increased than CK by more than60%.The plant dry weight of all processing are higher than CK (17.55g/plant) in the range of1.88%-63.5%.The plant dry weight of S8and S65are significant differences with CK. Comprehensive indicators,the effective of inoculation of S8,S65are better.(4)Finally, we make S8and S65, the most potential strains, into rhizobia inoculant and use it in the Field trials to improve its nitrogen fixing capacity and compatibility with "Gongxuan No.1".Coated data shows that the plant dry weight、production and the nodule number of S65were higher than CK10.8%、29.6%、17.8%respectively. The full pod number of S65reached significant level with CK. The plant dry weight,production and full pod number of S8were similar to CK. It is thus clear that S65increase production mainly by improving the full pod numberThus,the S65rhizobial strains are selected out with best matching"Gongxuan No.1"and "Nandou No.12" though by hydroponic experiment, potting experiment and field plot experiment. S65preliminary has the production potential of microbial fertilizer in Sichuan.