Saikai Kanan, MacGuidwin Ann E
Plant Pathology Department, University of Wisconsin-Madison, 491 Russell Laboratories, 1630 Linden Dr., Madison, WI, 53706.
J Nematol. 2020 Aug 25;52. doi: 10.21307/jofnem-2020-090. eCollection 2020.
induce necrotic lesions, the hallmark symptom for the genus, soon after infection. The objective of our study was to characterize and quantify gender differences in lesion development. Independent experiments were conducted for three hosts; pea ( L. cv. Early Alaskan), dill ( cv. Long Island Mammoth), and alfalfa ( cv. Vernal). Each experimental unit was an excised radical placed on water agar in a Petri dish and inoculated with either 40 adult males or 40 fourth-stage juvenile females. Length, size, and number of lesions were recorded during the experiment and the radicals were harvested 14 days after introducing nematodes. Lesions were first observed on pea after two days for female-inoculated roots, and 24 hr after introducing both genders to dill and alfalfa. Lesions expanded either by multiple lesions coalescing or individual lesions expanding over time. Males made fewer, smaller lesions with less discoloration for all three hosts. There was no difference among genders for the total number of nematodes recovered per Petri dish or the number of endoparasitic nematodes after 14 days. The survival rate of males and females at harvest was not different, indicating that the difference in lesion formation was not related to nematode population densities. This study verified and quantified the observation that lesions induced by males are less extensive and in smaller numbers than lesions by females.
感染后不久便会诱发坏死性病变，这是该属的标志性症状。我们研究的目的是描述和量化病变发展过程中的性别差异。针对三种寄主进行了独立实验，分别是豌豆（品种为早阿拉斯加）、莳萝（品种为长岛猛犸象）和苜蓿（品种为弗纳尔）。每个实验单元是置于培养皿中含琼脂的水上的一段切下的胚根，接种40只成年雄虫或40只第四阶段的雌虫幼虫。在实验过程中记录病变的长度、大小和数量，并在接入线虫14天后收获胚根。接种雌虫的豌豆胚根在两天后首次观察到病变，接入雌雄虫的莳萝和苜蓿胚根在24小时后首次观察到病变。病变通过多个病变融合或单个病变随时间扩展而扩大。对于所有三种寄主，雄虫造成的病变数量更少、更小，变色也更少。每个培养皿中回收的线虫总数或14天后内寄生线虫的数量在不同性别之间没有差异。收获时雄虫和雌虫的存活率没有差异，这表明病变形成的差异与线虫种群密度无关。本研究证实并量化了以下观察结果：雄虫诱发的病变比雌虫诱发的病变范围更小、数量更少。
