Department of Plant Pathology, University of California-Davis, Kearney Agricultural Research and Extension Center, Parlier, CA 93648.
University of California - Cooperative Extension, Colusa/Sutter/Yuba Counties, Yuba City, CA 95991.
Plant Dis. 2019 Sep;103(9):2374-2384. doi: 10.1094/PDIS-11-18-1963-RE. Epub 2019 Jul 12.
The Botryosphaeriaceae family is considered a fungal family that includes pathogens causing latent infection of woody plants, and a number of species were identified as causal pathogens of canker and shoot blight diseases. To better understand the process of latent infection of major canker-causing pathogens in woody tissues in different tree crops important in California, shoot and bud samples were randomly collected from four tree crops: almond, dried plum, pistachio, and walnut. The previously developed DNA primers and quantitative real-time PCR (qPCR) assay systems were applied to detect six canker-causing pathogen groups, including , and species of , , , , and The concepts of molecular severity (MS) and latent infection index (LII) were introduced and applied to quantify the latent infection levels for these samples. Variation in incidence of latent infection among pathogen groups was observed, whereas the incidences were relatively low among species of and High incidences of spp. were observed in two dried plum (prune) orchards. Most orchards showed high incidences of and spp. and moderate incidences of spp. Variations in MS were observed among samples of the studied orchards, ranging from 4 to 8. The overall results of LII demonstrated that species of and were less important in population development of canker-causing pathogens at the latent phase. spp. were the most aggressive and had been well developed in populations among the studied tree crops. spp. became predominant in two of the three dried plum orchards, whereas and spp. showed trends of increase in incidence across various tree crops. This study also demonstrated the usefulness of this sensitive qPCR approach in providing evidence of the latent phase of major canker-causing pathogens of stone fruit and nut crops at an early stage of latent infection in woody plant tissues.
该 Botryosphaeriaceae 家族被认为是一个真菌家族，其中包括引起木本植物潜伏感染的病原体，并且已经鉴定出一些物种是溃疡和梢枯病的病原菌。为了更好地了解加利福尼亚州重要的几种木本作物中主要溃疡病原菌在木质组织中潜伏感染的过程，从杏仁、李干、开心果和核桃这四种树木作物中随机采集了芽和芽样本。先前开发的 DNA 引物和定量实时 PCR（qPCR）检测系统被应用于检测六个引起溃疡的病原体组，包括、、、、和。引入了分子严重度（MS）和潜伏感染指数（LII）的概念，并应用于量化这些样本的潜伏感染水平。观察到病原体组之间潜伏感染发生率的变化，而在和种中相对较低。在两个李干（prune）果园中观察到高比例的 spp.。大多数果园表现出高比例的 spp. 和 spp.，中比例的 spp.。在所研究的果园样本中观察到 MS 的变化，范围从 4 到 8。总体 LII 结果表明，在溃疡病原菌潜伏阶段，和种在种群发展中不太重要。 spp. 是最具侵略性的，在研究的树木作物中种群已经很好地发展。在两个李干果园中的两个果园中，spp. 成为主要种，而在各种树木作物中，spp. 和 spp. 的发病率呈上升趋势。本研究还证明了这种敏感的 qPCR 方法在提供早期木质组织中石果和坚果园主要溃疡病原菌潜伏阶段证据方面的有用性。
