诱导根瘤菌与稻类结瘤共生的探索研究
Studies on Introducing Nodulation and Symbiosis in Rice with Rhizobium
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摘要: 本文研究以植物生长素2,4-D(2,4-二氯苯氧乙酸)处理稻苗(终浓度为1ppm)并接种根瘤菌,诱导根瘤菌与稻苗结瘤共生。自1988年以来,在一些水稻和多种早稻品种上试验,结果表明这种方法可以有效地诱导根瘤菌与稻苗结瘤共生。经多次试验,诱导结瘤的重复性和再现性都很好。不同稻品种的始瘤日期,结瘤率高低以及瘤的大小都有所差异,早稻品种凡289033、福田糯和尤旱三个品种表现结瘤率较高,瘤也较大,接种后4个星期瘤的直径约2-3mm。在10个供试品种中,凡289033的结瘤率最高,达85%。稻根瘤切片经电子显微镜观察表明,瘤组织内有数量众多的根瘤菌菌体,说明根瘤菌可以进入稻根并在瘤内繁殖。本文所揭示的根瘤菌与稻类作物之间新的共生关系,对研究非豆科作物结瘤固氮将是很有意义的。Abstract: Rhizobium was introduced into rice root for nodulation and symbiosis by the addition of synthetic auxin 2,4-D (2,4-Dichlorophenoxyacetic acid) (final concentration was Ippm).A number of upland rice and some lowland rice varieties have been treated since 1988.The results showed that rhizobium can be introduced into rice root to nodulate and symbiosis with rice by this method.The repetition and reappearance of inducing nodulation were very well.The date of the first nodule appearance,nodulation rate and size of nodules vavied with different rice varieties.Upland rice varieties of Fan 289033,Futiannuo and Youhan showed higher nodulation rates with larger nodule size.The diameter of nodules was about 2 to 3 mm four weeks after inoculation.Fan 289033 with highest nodulation rate(reached to 85%)anong 10 varieties tested.Nodule sections of rice were observed under electron microscope.The results showed that there were numerous rhizobia inside the nodule,indicating that rhizobium can enter rice root and propagated in the nodule.The novel association between rhizobium and rice plant revealed here may be important to the research on nodulation and nitroge fixation of non-legume plants.