人工诱导根瘤菌(ORS-571)与高粱结瘤共生固氮研究

STUDIES ON SORGHUM FOR NODULATION AND SYMBIOTIC NITROGEN FIXATION WITH RHIZOBIA INDUCED BY 2,4-D

以植物激素2，4－D（2，4－D二氯苯氧乙酸）（终浓度3mg／L），处理高粱（甜杂1号Sorghumvulgars），并接种ORS－571根瘤菌；诱导根瘤菌与高粱共生。结果表明，这种方法可以诱导高粱根系结瘤并与结瘤组织共生，表现固氮活性。高粱在移苗后5～7天进行处理，效果较好，一般结瘤率都超过50％，最高可达80％。接种后4期周瘤的直径约2－3mm，制片显微镜观察；瘤组织内有大量的根据瘤菌菌体，说明根瘤菌可以进入高粱根系，并在瘤组织内繁殖。结瘤植株经气相色谱仪乙炔还原法测定，能表达一定程度的固氮活性。本研究实验的重复性和再现性都很好。

Sorghum (Sorghum vulgare) was induced to produce nudules by a trcatment of2,4-D in 3ppm final concentration, and thizobia (ORS-571) was inoculated into root of sorghum forming symbiotic association and exprassing activity of nitrogen.The tests have been mademany times since 1993, and the results can be repeated, 5-7 days after induction, the nodulationrate of the treated sorghum was more than 50%, the highest reaching 80%. The diameter of thenodules was about 2-3mm 4 weeks after inoculation. The numerous rhizobia in the nodules wereobserved under microscope. It was shown that the rhizobia had entered the tissue of the rootnodules and multiplied. Also the results from an analysis by acetylene reduction method with gaschromatograph (CG) showed that the nodules plants have certain activity of nitrogen fixafion.The new symbiosis of rhizobia with sorghum revealed here may be important to the research on nodulation and nitrogen of non-legume plant.