Characterization of community structure of culturable endophytic fungi in sweet cherry composite trees and their growth-retarding effect against pathogens

Endophytic fungi have the potential to protect their host plants in stress situations. Characterizing the ecology and complex interaction between these endophytes and their host plants is therefore of great practical importance, particularly in horticultural plants. Among horticultural plants, fruit trees form a special category because of their longevity and because they are composites of rootstock and scion, which often belong to different plant species. Here we present the first characterization of culturable endophytic fungal community of sweet cherry. Samples from the Hungarian cultivar ‘Petrus’ grafted on 11 different rootstocks were collected in autumn and in spring in a bearing orchard and the dependence of colonization rate and endophyte diversity on rootstock, organ and season was analysed. On the basis of their ITS sequences 26 fungal operational taxonomic units were identified at least down to the genus level. The dominant genus, comprising more than 50% of all isolates, was Alternaria, followed by different Fusarium and Epicoccum species. We observed some organ-specificity amongst endophytes, and organs showed more sizeable differences in colonization rates and endophyte diversity than rootstocks. Most dynamic endophyte populations, strongly influenced by environmental conditions and crop management, were observed in leaves. The potential of selected endophytes to confer protection against Monilinia laxa was also analysed and 7 isolates were found to inhibit the growth of this pathogen in vitro

Effect of crop management and cultivar on colonization of Capsicum annuum L. by Endophytic Fungi

Due to their importance as biological control agents, we analysed the colonization of two pepper (Capsicum annuum L.) cultivars by culturable endophytic fungi in natural sandy soil in the open field and under soil-free conditions in the greenhouse, respectively. In natural soil, we observed a significant difference in colonization rates between the cultivars ‘Hó’ and ‘Kápia’. Colonization rates were always lower in the greenhouse than in the open field. Colonization was enhanced towards the end of the growing period and organ-specific differences were also observed. On the basis of colony morphology, 15 separate groups were identified for future sequence-based identification