四个品种烟草内生微生物的分布特征

Distribution characteristic of endophytic microbes in four different tobacco species

对4个常规优质烟草品种(K326、G-80、红花大金元、净叶黄)的种子、根、茎、叶进行了内生菌的分离计数、初步分类与拮抗筛选研究。结果表明:烟草中有大量的内生菌分布,以细菌最多,放线菌次之,真菌最少,与土壤中的分布规律一致。烟草不同器官中内生菌的分布表现为根和种子中数量相当,茎次之,叶最少的规律。不同烟草品种间的分布为:种子中是K326和红花大金元内生菌分布较多,净叶黄次之,G-80最少;苗期植株中4个品种的内生菌数没有明显差别;大田期是净叶黄烟草的内生菌数量最少。烟草中内生细菌以革兰氏阴性菌为主,而种子中内生细菌的芽胞菌数量要明显多于植株中的。通过对大肠杆菌和金黄色葡萄球菌的抑菌实验,从红花大金元品种中筛选到有抑菌活性的菌株5株,从净叶黄和K326中分别筛选到1株,体现出了4个品种的抗病性与拮抗菌之间的一定相关性。

In order to understand the distribution character and the relationship of plant diseases with endophytes,studies on the quantity,classification and antagonism of endophytes from seeds,stems and leaves were conducted on four species of high-quality tobaccos. The tobaccos studied were K326,G-80,Hong Hua Da Jing Yuan and Jing Ye Huang. The results showed that the endophytic microorganisms existed widely in tobaccos. Bacteria were the most abundant followed by actinomycetes,then fungi. This reflects microbial distribution in soil. However,endophytes are not equally distributed in each organ. The root and seed contain the most,followed by stem with leaf containing the least. Among different species of tobaccos the distribution of endophytes is also variable. Endophyte distribution in the seed of K326 and Hong Hua Da Jing Yuan is the highest,with Jing Ye Huang next and G-80 containing the least. During the seedling period no obvious distinction was observed among the four species. During gruthduration after transplant Jing Ye Huang contains the least endophytes. Gram-negative bacteria are the most abundant in the all four species of tobacco and the quantity of spore bacteriain seeds is apparently higher than that of whole plants. Through antagonistic experiments of Escherichia coli and Staphylococcus aureus,we isolated five strains from Hong Hua Da Jing Yuan and one each from Jing Ye Huang and K326.The results indicated antagonistic characteristics of the four species is related to the antibacterium to some extent.