Fusarium graminearum is the main causative agent of cereal scab and maize cob rot in China. Two hundred and fifty‐five F. graminearum isolates were obtained from wheat, barley and maize from Hebei, Heilongjiang and Hubei, provinces with distinct climate conditions and cropping systems. The isolates were confirmed to be F. graminearum by polymerase chain reaction (PCR) assay using F. graminearum species‐specific primers Fg16F/Fg16R. Two populations, 7C1 and 6A5, were identified to exist in China. The 6A5 population was predominant in Hubei in central China along the Yangtze River, whereas the 7C1 population was predominant in Heilongjiang and Hebei in northern China. Based on sequences of Tri13 and Tri3, genes involved in the mycotoxin biosynthetic pathway, PCR assays were used to detect 3‐acetyldeoxynivalenol (3‐ADON), 15‐acetyldeoxynivalenol (15‐ADON) and nivalenol (NIV) chemotypes. All three chemotypes of F. graminearum were identified, with 15‐ADON chemotype predominating overall. A greater proportion of 3‐ADON chemotype was found in Hubei, whereas a greater proportion of 15‐ADON was found in Heilongjiang and Hebei.
Blueberry (Vaccinium corymbosum) has developed rapidly in China over the past 20 years because of its perceived health and nutritional benefits. Blueberry stem blight, caused by fungi in the family Botryosphaeriaceae, is the most destructive disease affecting blueberry production and quality worldwide. A field survey of 20 blueberry plantations in eight provinces across China was conducted to determine the occurrence and distribution of Botryosphaeriaceae species. In total, 69 Botryosphaeriaceae isolates associated with blueberry twig dieback and stem blight were identified based on morphological characteristics and analyses of nucleotide sequences of three genomic regions: the internal transcribed spacer region (ITS1-5.8S-ITS2), a partial sequence of the β-tubulin gene, and part of the translation elongation factor 1-α gene (EF1-α). Three species were identified, including: Botryosphaeria dothidea, Neofusicoccum parvum and Lasiodiplodia theobromae. Botryosphaeria dothidea and N. parvum were the most prevalent species and were widely distributed in all blueberry-growing regions. In contrast, L. theobromae was only found in southeastern regions. Koch's postulates showed all three species to be pathogenic when inoculated with mycelial plugs on detached and intact blueberry stems (cv. Bluecrop). Pathogenicity tests showed N. parvum and L. theobromae to be more virulent than B. dothidea. To our knowledge, this study is the first comprehensive description for morphology, phylogenetic analysis, and distribution of Botryosphaeriaceae spp. as causal agents of blueberry stem blight in China.
A real-time quantitative PCR assay using a species-specific primer pair was developed to rapidly and accurately quantify Valsa mali , the causative pathogen of apple Valsa canker (AVC), in crabapple seeds, crabapple seedlings, apple twigs and apple seeds. Surveys were conducted in different regions, and crabapple or apple seeds were collected for V . mali detection by qPCR assay. Our results showed that 12.87% to 49.01% of crabapple seeds collected from different regions were positive for V . mali . The exopleura and endopleura were the two major areas of V . mali infection in crabapple seeds. The presence of V . mali infection in crabapple seeds was also confirmed by a high-throughput sequencing approach. With the growth of crabapple seedlings, the concentration of V . mali gDNA in crabapple seedlings gradually increased until eight or more leaf blades emerged. One-year-old twigs from an apple scion nursery were infected with V . mali , and only apple seeds from infected apple trees showing evident Valsa canker symptoms carried V . mali . In conclusion, this study reports that crabapple seeds and apple seeds carried V . mali as latent inoculum sources. V . mali infected not only apple tissues but also crabapple seedlings, which are the rootstocks of apple trees. This study indicated that the inoculum sources for AVC vary. Application of a novel qPCR assay can potentially improve the accuracy of early diagnosis, and is helpful to reveal the epidemic regularity of AVC.
Six extracts from plant material (Galla chinensis, Potentilla erecta, Rheum rhabarbarum, Salviae officinalis, Sophora flavescens, and Terminalia chebula) were tested for controlling effects against the infection of Phytophthora infestans on detached potato leaves, seedlings, and tuber slices. On detached leaves, G. chinensis (2%), R. rhabarbarum (rhizome, 2%) and S. flavescens (2%) extracts showed a significant control effect, with a control efficacy of 96.67%, G. chinensis was the best. On seedlings R. rhabarbarum (rhizome, 2%) showed the best inhibiting effect, followed by S. flavescens (2%), T. chebula (1%), and G. chinensis (2%). The control efficacies were 91.67%, 75.00%, 70.24%, and 64.29%, respectively on the seventh day after inoculation. However, on potato slices, none of the plant extracts showed effective protection against infection and sporangia pro duction by P. infestans. The reason was analyzed and the potential for developing a natural fungicide based on these plant materials was discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.