Mundo-Ocampo M, Baldwin J G
J Nematol. 1983 Oct;15(4):544-54.
Host responses to Meloidodera floridensis Chitwood et al., 1956, M. charis Hooper, 1960, and M. belli Wouts, 1973 were examined on loblolly pine, peony, and sage, respectively, with light, scanning, and transmission electron microscopy. In each case the nematodes induce a single uninucleate giant cell. The giant cell is initiated in the pericycle and expands as it matures. The mature giant cell induced by M. floridensis is surrounded by vascular parenchyma, whereas that caused by M. charts and M. belli coutacts xylem and phloem. The cell wall of giant cells induced by all three Meloidodera spp. is generally thicker than that of surrounding cells, with the thickest part adjacent to the lip region of the nematode. The thinner portion of the wall includes numerous pit fields with plasmodesmata, but wall ingrowths were not detected in a thorough examination of the entire wall. The nucleus of a giant cell induced by M. goridensis is highly irregular in shape with deep invaginations, whereas those caused by M. charis and M. belli include a cluster of apparently interconnected nuclear units. Organelles, including mitochondria, endoplasmic reticulum, and plastids of giant cells caused by Meloidodera, are typical of those reported in host responses of other Heteroderidae. The formation of a single uninucleate giant cell by Meloidodera, Cryphodera, Hylonerna, and Sarisodera, but a syncytium by Atalodera and Heterodera sensu lato, might be considered in conjunction with additional characters to determine the most parsimonious pattern of phylogeny of Heteroderidae.
分别利用光学显微镜、扫描电子显微镜和透射电子显微镜，研究了寄主对1956年奇伍德等人发现的佛罗里达根结线虫、1960年胡珀发现的查里斯根结线虫以及1973年沃茨发现的贝利根结线虫的反应。在每种情况下，线虫都会诱导形成一个单核巨细胞。巨细胞在中柱鞘中起始，并随着成熟而扩展。佛罗里达根结线虫诱导形成的成熟巨细胞被维管束薄壁组织包围，而查里斯根结线虫和贝利根结线虫诱导形成的巨细胞则与木质部和韧皮部接触。所有这三种根结线虫诱导形成的巨细胞的细胞壁通常比周围细胞的细胞壁厚，最厚的部分靠近线虫的唇部区域。细胞壁较薄的部分包括许多具胞间连丝的纹孔场，但在对整个细胞壁进行全面检查时未检测到细胞壁内突。佛罗里达根结线虫诱导形成的巨细胞的细胞核形状高度不规则，有深陷的内陷，而查里斯根结线虫和贝利根结线虫诱导形成的巨细胞则包括一组明显相互连接的核单位。根结线虫诱导形成的巨细胞中的细胞器，包括线粒体、内质网和质体，是其他异皮科寄主反应中报道的典型细胞器。根结线虫、隐根结线虫、湿根结线虫和萨里斯根结线虫诱导形成单个单核巨细胞，但阿托根结线虫和广义异皮线虫诱导形成多核细胞团，这一点可能需要结合其他特征来考虑，以确定异皮科最简约的系统发育模式。
