Brito J, Powers T O, Mullin P G, Inserra R N, Dickson D W
J Nematol. 2004 Sep;36(3):232-40.
The discovery of Meloidogyne mayaguensis is confirmed in Florida; this is the first report for the continental United States. Meloidogyne mayaguensis is a virulent species that can reproduce on host cultivars bred for nematode resistance. The perineal patterns of M. mayaguensis isolates from Florida show morphological variability and often are similar to M. incognita. Useful morphological characters for the separation of M. mayaguensis from M. incognita from Florida are the male stylet length values (smaller for M. mayaguensis than M. incognita) and J2 tail length values (greater for M. mayaguensis than M. incognita). Meloidogyne mayaguensis values for these characters overlap with those of M. arenaria and M. javanica from Florida. Enzyme analyses of Florida M. mayaguensis isolates show two major bands (VS1-S1 phenotype) of esterase activity, and one strong malate dehydrogenase band (Rm 1.4) plus two additional weak bands that migrated close together. Their detection requires larger amounts of homogenates from several females. Amplification of two separate regions of mitochondrial DNA resulted in products of a unique size. PCR primers embedded in the COII and 16S genes produced a product size of 705 bp, and amplification of the 63-bp repeat region resulted in a single product of 322 bp. Nucleotide sequence comparison of these mitochondrial products together with sequence from 18S rDNA and ITS1 from the nuclear genome were nearly identical with the corresponding regions from a M. mayaguensis isolate from Mayaguez, Puerto Rico, the type locality of the species. Meloidogyne mayaguensis reproduced on cotton, pepper, tobacco, and watermelon but not on peanut. Preliminary results indicate the M. mayaguensis isolates from Florida can reproduce on tomato containing the Mi gene. Molecular techniques for the identification of M. mayaguensis will be particularly useful in cases of M. mayaguensis populations mixed with M. arenaria, M. incognita, and M. javanica, which are the most economically important root-knot nematode species in Florida, and especially when low (<25) numbers of specimens of these species are recovered from the soil.
在佛罗里达州已证实发现了马亚圭斯根结线虫；这是美国大陆的首次报道。马亚圭斯根结线虫是一种毒性很强的物种，能够在为抗线虫而培育的寄主品种上繁殖。来自佛罗里达州的马亚圭斯根结线虫分离物的会阴花纹表现出形态变异性，且常常与南方根结线虫相似。将佛罗里达州的马亚圭斯根结线虫与南方根结线虫区分开来的有用形态特征是雄虫口针长度值（马亚圭斯根结线虫比南方根结线虫小）和J2幼虫尾部长度值（马亚圭斯根结线虫比南方根结线虫长）。这些特征的马亚圭斯根结线虫值与来自佛罗里达州的花生根结线虫和爪哇根结线虫的值重叠。对佛罗里达州的马亚圭斯根结线虫分离物进行的酶分析显示出酯酶活性的两条主要条带（VS1 - S1表型），以及一条强苹果酸脱氢酶条带（迁移率1.4）加上另外两条紧密迁移在一起的弱条带。检测它们需要来自几只雌虫的大量匀浆。线粒体DNA两个不同区域的扩增产生了独特大小的产物。嵌入COII和16S基因的PCR引物产生了705 bp的产物大小，63 bp重复区域的扩增产生了322 bp的单一产物。这些线粒体产物的核苷酸序列比较以及来自核基因组的18S rDNA和ITS1序列与来自波多黎各马亚圭斯的马亚圭斯根结线虫分离物的相应区域几乎相同，马亚圭斯是该物种的模式产地。马亚圭斯根结线虫能在棉花、辣椒、烟草和西瓜上繁殖，但不能在花生上繁殖。初步结果表明，来自佛罗里达州的马亚圭斯根结线虫分离物能在含有Mi基因的番茄上繁殖。在马亚圭斯根结线虫种群与花生根结线虫、南方根结线虫和爪哇根结线虫混合的情况下，马亚圭斯根结线虫的分子鉴定技术将特别有用，花生根结线虫、南方根结线虫和爪哇根结线虫是佛罗里达州经济上最重要的根结线虫物种，尤其是当从土壤中回收的这些物种的标本数量较少（<25）时。
