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A new disease on greenhouse pepper (Capsicum annuum L.) plants in Culiacan, Mexico with symptoms of chlorosis, wilting and vascular necrosis was observed in 2014. Sixty diseased pepper plants were collected from three different areas of the Culiacan Valley to determine the causal agent of the disease and analyse the potential risk presented by this disease in this region. Fusarium oxysporum was recovered consistently (88% of samples collected) and identified based on cultural, morphological and pathogenicity tests, as well as by PCR amplification and DNA sequencing of the TEF-1α gene. Two pathogenicity tests with 10 monoconidial isolates of F. oxysporum, which were selected randomly from diseased tissues, produced disease symptoms similar to those observed on pepper plants in the greenhouses. Symptoms were different from the typical root rot, wilting and necrosis caused by F. solani and F. oxysporum f. sp. radicis-capsici and instead matched those reported for F. oxysporum f. sp. capsici causing pepper wilt. The results suggest that the causal agent of pepper wilt in the samples analysed was F. oxysporum. This is the first report of pepper wilt caused by this fungus in Mexico, and this disease is a potential threat for pepper production in this region. [ABSTRACT FROM AUTHOR]

Pepper huasteco yellow vein virus (PHYVV) is a major disease in pepper (Capsicum annuum) that causes quantitative and qualitative losses to the crop in Central America and part of North America. To date, no resistant cultivars are available, and breeding is hampered by the lack of knowledge of the inheritance of this trait. Sources of resistance to PHYVV have been identified in the wild peppers of Mexico. The objectives of this study were to determine the grade of dominance, to analyze the maternal influence, and to estimate the number of genes involved in this resistant trait to PHYVV in the resistant wild pepper accession UAS12. Three susceptible parent lines-'Anaheim' (Ana), 'Ancho Gigante' (AG), and 'Yolo Wonder' (YW)-were crossed with resistant UAS12 accession to develop F1 (reciprocal), F2, and BC1 progenies in three families. Plants from this study were inoculated with PHYVV through Bemisia tabaci, evaluated phenotypically, and the segregation of disease scores was studied. A single recessive gene was found to control resistance to PHYVV in the resistant UAS12 accession, although segregation patterns suggested that other minor genes could participate in the expression of this resistant trait. No proof was found for maternal inheritance of PHYVV resistance. The gene symbol phv is proposed for PHYVV resistance in UAS12 accession in pepper. These results provide useful information for the design of pepper breeding programs in the introgression of this trait into commercial pepper backgrounds. [ABSTRACT FROM AUTHOR]