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Synthetic fungicides are used to control anthracnose caused by Colletotrichum gloeosporioides; however, their frequent application increases the risk of pathogen resistance, environmental damage, and health concerns. It has been reported that caprylic acid (CA) inhibits the in vitro development of C. gloeosporioides; however, its antifungal mechanism and in vivo antifungal potential are still unknown. Therefore, the present work aims to analyse the effect of a CA‐enriched sub‐fraction (CAES) extracted from Vitex mollis fruit on the fungal microstructure by confocal fluorescence microscopy and morphometric analysis. Moreover, the effect of CAES on anthracnose development and quality parameters in papaya fruit was evaluated. The confocal microscopy images confirmed that CAES damaged the cell wall of conidia, given their decreased width. The increased fluorescence intensity in the CAES and CA‐treated mycelium suggested they were attached to the plasma membrane. These treatments produced structural alterations of the vacuoles and septa in mycelium, while in the fungicide thiabendazole (TBZ) treatment, apoptotic bodies appeared. CAES at 1.0 g L−1 had the best effect against anthracnose incidence and severity in papaya fruit, whereas TBZ was only effective on anthracnose severity. None of the applied treatments affected the fruit quality parameters. Therefore, CAES may be develop as an effective option to suppress anthracnose on papaya fruit. [ABSTRACT FROM AUTHOR]

Objective: To quantify the heterosis in physical and physiological characteristics in seeds of simple and trilinear crosses of the HAZUL 10E corn hybrid. Methodology: Seeds of the genotypes conforming to the HAZUL 10E corn hybrid (endogamic lines and simple and trilinear crosses) were used. The experimental design was completely randomized with three repetitions. Physical (weight, width, thickness, length, volume, density, and the width/length and thickness/length ratios) and physiological (normal and abnormal seedlings, death seeds, and lengths and dry matter of plumule, radicle, and total) characteristics of the seeds were evaluated. Heterosis and heterobeltiosis were determined, and the differences between both crosses were statistically tested with Student's t-test. Results: Heterosis and heterobeltiosis were higher in the single cross than in the trilinear one. In the single cross, the highest values of both heterosis corresponded to the plumule, radicle, and total dry matter; followed by weight and volume seed. In the trilinear, the highest values corresponded to normal seedlings, radicle length, and biomass total. The variables corresponding to shape seed, normal seedlings formation, and radicle elongation, responded better to hybridization in the trilinear cross. Study limitations: None presented. Conclusions: In the single cross, heterosis increased the seed size and accumulated biomass in seedlings; while in the trilinear cross, it affected the shape of the seeds and the produced seedlings. [ABSTRACT FROM AUTHOR]

Fusarium species belonging to the Fusarium fujikuroi species complex ( FFSC) are associated with maize in northern Mexico and cause Fusarium ear and root rot. In order to assess the diversity of FFSC fungal species involved in this destructive disease in Sinaloa, Mexico, a collection of 108 fungal isolates was obtained from maize plants in 2007-2011. DNA sequence analysis of the calmodulin and elongation factor 1α genes identified four species: Fusarium verticillioides, F. nygamai, F. andiyazi and F. thapsinum (comprising 79, 23, 4 and 2 isolates, respectively). Differential distribution of Fusarium species in maize organs was observed, that is F. verticillioides was the most frequently isolated species from maize seeds, while F. nygamai predominated on maize roots. Mixed infections with F. verticillioides/F. thapsinum and F. verticillioides/F. nygamai were detected in maize seeds and roots, respectively. Pathogenicity assay demonstrated the ability of the four species to infect maize seedlings and induce different levels of disease severity, reflecting variation in aggressiveness, plant height and root biomass. Isolates of F. verticillioides and F. nygamai were the most aggressive. These species were able to colonize all root tissues, from the epidermis to the vascular vessels, while infection by F. andiyazi and F. thapsinum was restricted to the epidermis and adjacent cortical cells. This is the first report of F. nygamai, F. andiyazi and F. thapsinum infecting maize in Mexico and co-infecting with F. verticillioides. Mixed infections should be taken into consideration due to the production and/or accumulation of diverse mycotoxins in maize grain. [ABSTRACT FROM AUTHOR]