In a study conducted in 2016, internal transcribed spacer (ITS) amplicon sequencing was used to investigate fungal endophytic communities in one-year-old apple shoots of cultivars highly susceptible (Gala, Braeburn) and relatively resistant (Grenadier, Golden Delicious) to N. ditissima due to their capacity to colonise apple tissues prior to wound formation and thus prevent pathogen entry. Endophytes could be especially effective the in control of N. According to Schulz and Boyle, the majority of aboveground fungal endophytes in trees are non-systemic with a broad host range (Class III endophytes), implying that a single strain could colonise a range of host species and cultivars. It is therefore possible that endophytic communities play a role in host susceptibility. Recent reports suggest that apple endophyte communities vary due to host genotype and susceptibility to European apple canker. Endophytes have been shown to contribute to host disease resistance and also other agronomic traits such as growth promotion and abiotic stress tolerance. The presence of particular endophytes and differences in endophyte community composition can affect plant properties more than genetic variation intrinsic to the host. Their efficacy in field conditions, however, has not been tested. Recent research used a systematic approach to screen over 500 fungal strains stepwise to identify four Clonostachys rosea isolates with high efficacy in detached branch tests and with commercially relevant cold, drought, and UV tolerance. So far, no commercially available biocontrol agents have been found to be effective against N. Rainfall during high wound availability periods (such as picking and leaf fall) can further increase disease risk by increasing N. Chemical protection is hampered by recent dose reductions and bans of effective plant protection products such as carbendazim and copper oxychloride. Removal of inoculum (infected tissue) is effective but also very expensive, time and labour-intensive and therefore seldom implemented in commercial apple production. Breeding resistant varieties may be possible, but it is a long process given the polygenic nature of resistance against N. Most commercial apple cultivars are highly susceptible to N. ditissima control is difficult to achieve. ditissima in commercial apple production.Įffective N. nigrum B14-1 did not cause detrimental effects on apple foliage, buds, fruit, or growth and could therefore present a new biocontrol agent to manage N. 1.5×, but this returned to control levels after one year. nigrum abundance in apple tissues at 10–20 days post-inoculation by ca. Autumn application of B14-1 conidia increased E. ditissima infections of leaf scars by 46.6% and pruning wounds by 5.3% in field conditions at leaf fall. ditissima in vitro and reduced the incidence of N. Epicoccum nigrum B14-1, isolated from healthy apple trees, antagonised N. This study used cues from a previous apple endophyte community analysis to isolate and test fungal endophytes belonging to the genus Epicoccum as potential endophytic biocontrol agents. ditissima is difficult to control removal of inoculum (cankers) is expensive and therefore seldom practiced, whilst effective chemical products are being banned and no biocontrol products have been found to be effective against N. Infected wood develops canker lesions which girdle branches and main stems causing reduced yield and tree death. ditissima infects through natural and artificial wounds. Tul.) Samuels and Rossman, is a major disease of apples ( Malus domestica) worldwide. Apple canker, caused by Neonectria ditissima (Tul.
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