Reaction of guava cultivars to Pratylenchus brachyurus.

ABSTRACT The root lesion nematode (Pratylenchus brachyurus) has been found in guava plants; however, there is no information in the literature about whether the crop is a potential host or is damaged due to parasitism by this nematode. The aim of this study was to evaluate, under greenhouse conditions, the development of the guava tree cultivars Paluma, Pedro Sato, Século XXI and Tailandesa inoculated with P. brachyurus. Furthermore, inoculated plants were compared with non-inoculated ones. Evaluations of height, stem diameter, fresh mass of aerial parts, fresh mass of roots, nematode population in the roots, as well as visual aspect, were performed at six and twelve months after inoculation. According to the obtained results, cultivars Pedro Sato, Século XXI and Tailandesa are not good hosts to P. brachyurus; however, Paluma is a good host. Tailandesa presented the best development of stem diameter, fresh weight of aerial parts and fresh weight of roots, relative to the other cultivars. Paluma is susceptible and intolerant to P. brachyurus; Século XXI is resistant and intolerant to P. brachyurus; Pedro Sato is resistant and intolerant to P. brachyurus, and cultivar Tailandesa is resistant and tolerant to P. brachyurus.

摘要 目前虽已在番石榴植株中检出短尾根腐线虫（Pratylenchus brachyurus），但尚无文献明确该作物是否为该线虫的潜在寄主，亦或是否会因该线虫的寄生而遭受为害。本研究旨在温室条件下，评估接种短尾根腐线虫的番石榴品种Paluma、Pedro Sato、Século XXI及Tailandesa的生长状况，并将接种植株与未接种植株进行对比。分别于接种后6个月和12个月，对植株株高、茎粗、地上部鲜重、根系鲜重、根内线虫种群数量及外观长势开展测定。结果表明，Pedro Sato、Século XXI及Tailandesa均不属于短尾根腐线虫的适宜寄主，而Paluma则为适宜寄主。相较于其余三个品种，Tailandesa的茎粗、地上部鲜重及根系鲜重表现最优。Paluma对短尾根腐线虫感病且不耐受；Século XXI对该线虫抗病且不耐受；Pedro Sato对该线虫抗病且不耐受，而Tailandesa品种对该线虫抗病且耐受。