Cotton, cowpea and sesame are alternative crops to cucurbits in soils naturally infested with Monosporascus cannonballus

[EN] Monosporascus cannonballus is an important cucurbit root pathogen, which has been reported in the main production areas of melon and watermelon in Brazil and worldwide and potentially capable to colonize roots of different species. Crop rotation is considered an effective management strategy to prevent this disease. The aim of this study was to evaluate the response of different crops, pumpkin, cotton, cowpea, sesame, watermelon, melon, corn, cucumber, sorghum and tomato, to the infection of this pathogen. Seedlings were transplanted into plastic containers with an inoculum concentration of 20 colony-forming units (CFU) g(-1) of M.cannonballus. Fifty days after transplanting, the variables analysed were the degree of disease severity on the root system and the frequency of reisolation. On cucurbits, the results demonstrated different degrees of susceptibility among crops and cultivars, being melon and watermelon the most sensitive species. In contrast, Cucurbita cultivars were the most tolerant. Regarding non-cucurbit crops, maize, sorghum and tomato presented root discoloration and M.cannonballus was reisolated from roots. Cotton, cowpea and sesame cultivars were not affected by the pathogen, so they can be considered as alternative crops to be cultivated, or in rotation with cucurbits, in M.cannonballus infested soils.We are thankful to Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq for the research fellowships granted to Rui Sales Junior e Erika Valente de Medeiros.Sales, R.; Días Balbino, DA.; Mitsa Paiva Negreiros, A.; Da Silva Barboza, H.; Valente De Medeiros, E.; Armengol Fortí, J. (2018). Cotton, cowpea and sesame are alternative crops to cucurbits in soils naturally infested with Monosporascus cannonballus. Journal of Phytopathology. 166(6):396-402. https://doi.org/10.1111/jph.12698S396402166

Genic SNP markers and legume synteny reveal candidate genes underlying QTL for Macrophomina phaseolina resistance and maturity in cowpea [Vigna unguiculata (L) Walp.]

<p>Abstract</p> <p>Background</p> <p><it>Macrophomina phaseolina </it>is an emerging and devastating fungal pathogen that causes significant losses in crop production under high temperatures and drought stress. An increasing number of disease incidence reports highlight the wide prevalence of the pathogen around the world and its contribution toward crop yield suppression. In cowpea [<it>Vigna unguiculata </it>(L) Walp.], limited sources of low-level host resistance have been identified, the genetic basis of which is unknown. In this study we report on the identification of strong sources of host resistance to <it>M. phaseolina </it>and the genetic mapping of putative resistance loci on a cowpea genetic map comprised of gene-derived single nucleotide polymorphisms (SNPs) and amplified fragment length polymorphisms (AFLPs).</p> <p>Results</p> <p>Nine quantitative trait loci (QTLs), accounting for between 6.1 and 40.0% of the phenotypic variance (R²), were identified using plant mortality data taken over three years in field experiments and disease severity scores taken from two greenhouse experiments. Based on annotated genic SNPs as well as synteny with soybean (<it>Glycine max</it>) and <it>Medicago truncatula</it>, candidate resistance genes were found within mapped QTL intervals. QTL <it>Mac-2 </it>explained the largest percent R²and was identified in three field and one greenhouse experiments where the QTL peak co-located with a SNP marker derived from a pectin esterase inhibitor encoding gene. Maturity effects on the expression of resistance were indicated by the co-location of <it>Mac-6 </it>and <it>Mac-7 </it>QTLs with maturity-related senescence QTLs <it>Mat-2 </it>and <it>Mat-1</it>, respectively. Homologs of the <it>ELF4 </it>and <it>FLK </it>flowering genes were found in corresponding syntenic soybean regions. Only three <it>Macrophomina </it>resistance QTLs co-located with delayed drought-induced premature senescence QTLs previously mapped in the same population, suggesting that largely different genetic mechanisms mediate cowpea response to drought stress and <it>Macrophomina </it>infection.</p> <p>Conclusion</p> <p>Effective sources of host resistance were identified in this study. QTL mapping and synteny analysis identified genomic loci harboring resistance factors and revealed candidate genes with potential for further functional genomics analysis.</p

Powdery Mildew of Strawberries

Powdery mildew occurs in most areas of the world where strawberries are grown, infecting leaves, flowers, and fruit. Infected transplants are normally the primary source of inoculum for fruiting fields in Florida, but even disease-free fields can become infected by conidia blown in from neighboring fields. Fields with susceptible cultivars should be surveyed regularly for powdery mildew, especially early in the season. Usually, controlling foliar infection helps to prevent fruit infection. This 4-page fact sheet was written by N. A. Peres and J. C. Mertely, and published by the UF Department of Plant Pathology, May 2013.&#x0D; http://edis.ifas.ufl.edu/pp129</jats:p

Powdery Mildew of Strawberries

Powdery mildew, caused by Sphaerotheca macularis, occurs in most areas of the world where strawberries are grown. This is document PP-208 a publication of the Plant Pathology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL. Publication date: March 2005. PP-208/PP129: Powdery Mildew of Strawberries (ufl.edu

Root Necrosis of Strawberries Caused by Colletotrichum acutatum

Colletotrichum acutatum is widely known as a fruit rot pathogen, but also infects other strawberry tissues, including the roots. Root necrosis has been observed in Florida since 2000.  This document is PP-211, one of a series of the Plant Pathology Department, UF/IFAS Extension. Original publication date August 2005. PP-211/PP128: Root Necrosis of Strawberry Caused by Colletotrichum acutatum (ufl.edu

Botrytis Fruit Rot or Gray Mold of Strawberry

PP-230, a 4-page illustrated fact sheet by J. C. Mertely and N. A. Peres, describes the symptoms, disease development, and control of one of the most important diseases of strawberry worldwide. Includes table of fungicides used to control Botrytis fruit rot of strawberry in Florida. Published by the UF Department of Plant Pathology, July 2006. PP230/PP152: Botrytis Fruit Rot or Gray Mold of Strawberry (ufl.edu

Root Necrosis of Strawberries Caused by Colletotrichum acutatum

Colletotrichum acutatum is widely known as a fruit rot pathogen, but also infects other strawberry tissues, including the roots. Root necrosis has been observed in Florida since 2000.  This document is PP-211, one of a series of the Plant Pathology Department, UF/IFAS Extension. Original publication date August 2005.&#x0D; PP-211/PP128: Root Necrosis of Strawberry Caused by Colletotrichum acutatum (ufl.edu)</jats:p