3株联合固氮菌对甘蔗的促生作用

【目的】探讨3株联合固氮菌单株或组合接种对甘蔗组培苗的促生效应。【方法】采用室内盆栽试验，分别设单菌株（11-31， 07-98和08-200）及其4个不同菌株组合共7个接菌处理接种新台糖22号（ROC22）组培苗，设1个不接菌处理为对照，接种86 d后比较不同处理对甘蔗生物量、株高、氮磷含量和根系活力等生理生化性状的影响。【结果】7个接菌处理对甘蔗植株的生物量、株高、氮磷含量和根系活力等生理生化性状均有不同程度的提高，其中处理Ⅶ的促生效应最为显著，该处理的植株株高和生物量分别比对照增长25.23%和60.79%；植株总氮含量最高的是处理Ⅳ，比对照增长45.79%；含磷量增长最显著的是处理Ⅶ，比对照增长76.29%。【结论】联合固氮菌单株或组合接种对甘蔗生长、氮磷元素的累积和生理生化性状都有不同程度的促进作用，但不同处理对甘蔗的促生效应有显著差异；多菌株混合接种的促生效应不一定会比单菌株接种高，具体效果因固氮菌种类和组合而异。

Growth-promoting effect by nitrogen-fixing inoculating 3 strains of associative bacteria in sugarcane

【Objective】The present study was conducted to investigate the growth-promoting effect of sugarcane plantlets by inoculating with three associative nitrogen-fixing bacteria strains. 【Method】Eight treatments, viz., control, 3 single strain treatments （strains 11-31, 07-98 and 08-200） and their 4 combination treatments were designed to investigate the effects of their inoculums on sugarcane cultivar ROC22 using pot test. The growth and physiological-biochemical characteristics of plants were assessed in 86 days after inoculation. 【Result】Statistic analysis revealed that all of the 7 inoculate treatments resulted in significant increase in biomass, plant height, total nitrogen and phosphorus contents and root activity of sugarcane plants. The best promoting effect was showed by the treatment Ⅳ, compared with none inoculated control, its’biomass, plant height, and phosphorus content increased by 60.79%, 25.23% and 76.29%, and total nitrogen also increased 45.79%. 【Conclusion】This study indicated that the 3 associative nitrogen-fixing bacteria strains can be used as potential inoculants of sugarcane, and different inoculated methods show significant differences on growth-promoting effect, which depends on species of nitrogen-fixing bacteria and combination methods. It will be significant for further studies on the applications of nitrogen-fixing bacteria as biofertilizer.