Phytophthora blight of vegetables caused by Phytophthora capsici causes significant economic losses in production of Solanaceae and Cucurbitaceae crops in Mexico. The development of universal resistant chili pepper cultivars is challenging due to the diverse virulence phenotypes produced by P. capsici. The objective of the study was to characterize the diversity of phenotypic interactions for P. capsici isolates recovered from production fields in Michoacán, Mexico, to facilitate the development of resistant cultivars. Virulence phenotypes were characterized for 12 isolates of P. capsici using 26 Capsicum annuum New Mexico Recombinant Inbred Lines (NMRILs) in greenhouse conditions. Criollo de Morelos CM-334 and California Wonder were used as resistant and susceptible controls, respectively. Seedlings at the four to eight true leaf stage were inoculated with 10,000 zoospores per seedling and disease severity was evaluated at 20 days post-inoculation. Two of the P. capsici isolates did not infect any pepper host even though the isolate was less than a year old. The 10 virulent isolates were designated in 10 virulence phenotypes. The information generated by this study is of utmost importance for efforts of producing resistant cultivars specific for Michoacán producers.

Phytophthora capsici is an oomycete plant pathogen with a wide host range. Worldwide, P. capsici is known for causing the principal disease of chili pepper crops. Our goal was to expand the available genome resources for this diverse pathogen by generating whole-genome sequences for six isolates of P. capsici from Mexico.

<p>The tomato (<em>Solanum lycopersicum</em>) is part of the food basket of Mexicans and is the most consumed vegetable worldwide. Mexico is one of the main producer and exporter countries, the main market to export is the United States of America. The pandemic caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2) seriously affected the economy and consequently the production and distribution of basic foods, including tomatoes. This work summarizes the experiences derived from the production, detection and phytosanitary management of <em>Clavibacter</em> <em>michiganensis</em> subsp. <em>michiganensis</em> during the July–December 2020 season in a tomato crop under macro tunnel located in Copándaro, Michoacán, Mexico. Agriculture, as an essential economic activity in the production of basic foods, must remain active as it is an unconfined productive process, with a low risk of contagion, and it’s a necessary activity for the economic support of agricultural workers.</p>

En Queréndaro, Michoacán, México, el cultivo de chile chilaca (<em>Capsicum annuum</em>) es de importancia económica, social y cultural; sin embargo, los problemas fitosanitarios limitan su producción. En junio de 2017, se observaron plantas enfermas con síntomas de marchitez y necrosis. Con el objetivo de identificar el agente causal de la enfermedad se recolectaron secciones de 10-15 cm de tallo y raíz, se obtuvo consistentemente (30%) un aislado fúngico del género <em>Fusarium</em>. El aislado mostró abundantes clamidosporas terminales de pared lisa, macroconidios con tres a cinco septos y célula apical ligeramente curva, microconidios septados y aseptados, ovales, elipsoides y reniformes. Se realizaron pruebas de patogenicidad bajo condiciones de invernadero, se inocularon 1.2 x 106 conidios/mL-1 de <em>Fusarium</em> en plantas de chile chilaca de 45 días de edad. Veinte días posteriores a la inoculación, se observaron síntomas de marchitez, defoliación, clorosis, y necrosis en el tallo y la raíz. Se re-aisló al patógeno a partir de tejido vegetal enfermo y se amplificó el gen del factor de elongación 1-?. La secuencia obtenida se sometió a un análisis BLAST contra secuencias de las bases de datos de GenBank. De acuerdo con las características morfológicas y moleculares, el agente causal de la marchitez en chile chilaca de Queréndaro, Michoacán es <em>Fusarium solani</em>.

To evaluate the inoculation effect of Arbuscular Mycorrhizal Fungi (AMF) and actinomycetes on promoting plant growth and diminishing wilt in pepper plant (Capsicum annuum L.), a pot experiment was conducted under greenhouse conditions using a factorial design on random blocks. It was evaluated the native Cerro del Metate mycorrhizal consortium, and ABV39 and ABV02 actinomycetes were evaluated against the CH11 stain of Phytophthora capsici. Responses of the variables evaluated were plant height, stem diameter, number of leaves, total fresh and dry biomass, leaf area and radical volume, number of AMF spores, mycorrhizal colonization, roots infected with P. capsici, and severity of wilting utilizing an ordinal qualitative scale. The results showed that mycorrhizal plants and inoculated with ABV39 demonstrated the highest values for plant height, stem diameter, and number of leaves with 26.12 cm, 5.29 mm, and 35.12 leaves, respectively. Co-inoculation of AMF and both actinomycetes significantly promoted (p≤0.001) total fresh and dry biomass and leaf area of the plants without P. capsici. The disease severity of the AMF-inoculated plants diminished against plants without mycorrhization. However, when they were also co-inoculated with ABV39 or ABV02, disease severity was significantly reduced (p≤0.05), up to level 2 of 5 levels on a severity scale. These results show a synergetic effect with co-inoculation of AMF and actinomycetes in vegetal growth promotion and bioprotection against wilting caused by P. capsici in pepper plants.

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<em>Phytophthora capsici</em> es el principal fitopatógeno del cultivo de chile (<em>Capsicum annuum</em>) y de diversas plantas de interés comercial en México. El desconocimiento por parte de los productores sobre la presencia de este patógeno en zonas de cultivo dificulta la prevención y manejo de la enfermedad. El objetivo de este trabajo fue identificar y caracterizar morfológicamente aislados obtenidos de cultivos de cucurbitáceas y solanáceas con síntomas de “marchitez” en Jalisco y Michoacán, México. Los muestreos se realizaron durante 2016 y 2017. Los 41 aislados de <em>P. capsici</em> obtenidos de plantas enfermas se analizaron por morfología comparativa con base a caracteres sexuales y asexuales. Se caracterizaron 33 aislamientos del cultivo de<em> C. annuum</em>, seis de <em>C. pepo</em> y dos de <em>S. lycopersicum</em>. La mayoría de los aislados presentaron características morfológicas típicas de<em> P. capsici</em>. Solo un aislado presentó clamidosporas, globosas y terminales (aislado de Queréndaro, Mich). Se registraron 40 aislados heterotálicos y un aislado homotálico. Se determinó la patogenicidad de siete aislados, asociando a<em> P. capsici</em> como el agente causal de la marchitez para estos aislados y para siete analizados en un estudio previo. Los 27 aislamientos restantes solo se asociaron a la enfermedad. Se sugiere realizar un manejo integrado de este patógeno en las zonas de producción de Jalisco y Michoacán.

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