镰孢属几种植物病原真菌分子核型的研究*

利用脉冲电场凝胶电泳（ｐｕｌｓｅｄ－ｆｉｅｌｄｇｅｌｅｌｅｃｔｒｏｐｈｏｒｅｓｉｓ，ＰＦＧＥ），研究了４株串珠镰孢（Ｆｕｓａｒｉｕｍ　ｍｏｎｉｌｉｆｏｒｍｅ）、１株尖镰孢（F．ｏｘｙｓｐｏｒｕｍ）、１株茄镰孢（Ｆ．ｓｏｌａｎｉ）和１株Ｆｕｓａｒｉｕｍｓｐ．的分子核型以及不同地域和寄主来源的串珠镰孢种内菌株间的分子核型差异。以凝胶包埋法（不破除分生孢子细胞壁）制备供试菌株电泳样本，采用３组条件组合进行电泳，分离出供试串珠镰孢完整染色体ＤＮＡ１０～１３条，分子量分布范围０．７Ｍｂ～６．９Ｍｂ，基因组大小为４２．２６Ｍｂ～４７．７５Ｍｂ；尖镰孢８条，分子量分布范围１．２Ｍｂ～６．７Ｍｂ，基因组大小为３２．２５Ｍｂ；茄镰孢６条，分子量分布范围２．４Ｍｂ～６．３Ｍｂ，基因组大小为２５．２Ｍｂ；Ｆｕｓａｒｉｕｍｓｐ．９条，分子量分布范围０．８Ｍｂ～６．８Ｍｂ，基因组大小为３６．４５Ｍｂ。结果表明，供试４种镰孢菌染色体数目、ＤＮＡ分子量及基因组大小都有较大不同，分子核型差异较大。不同来源的串珠镰孢种内菌株间分子核型亦有明显差异。

MOLECULAR KARYOTYPES OF PHYTOPATHOGENICFUNGI OF FUSARIUM SPP.

Molecular karyotypes of four Fusarium species were obtained by usingPulsed--field gel electrophoresis (PFGE). Numbers of chromosomes, sizes ofchromosomal DNAs and genome sizes of Fusarium spp. represented by the isolatestested were estimated as follows: Fusarium moniliforme: 10~ 13, 0.7Mb-- 6.9Mb,42.26Mb~ 47.75Mb; F. oxysporum: 8, 1.2Mb-- 6.7Mb, 32.25Mb; F. solani: 6,2.4Mb~6.3Mb, 25.2Mb; Fusarium sp.: 9, 0.8Mb~6.8Mb, 36.4Mb. The variation innumber of chromosomes, sizes of chromosome DNAs and genome sizes indicatedextensive molecular karyotypic differences among those fusarium spp. tested. Theisolates tested of F. moniliforme, regardless of their hosts and localities, did not sharelarger chromosomal DNAs, except a smaller one, suggesting that F moniliforme wasa heterogenous species.