Determination of antagonistic traits of bacterial isolates obtained from apricot against green fruit rot disease agent Sclerotinia sclerotiorum

M. Kara, S. Soylu, Ş. Kurt, E.M. Soylu, A. Uysal
Blossom and fruit diseases occur widely and pose serious impacts on apricot (Prunus armeniaca L.) production in Turkey. Green fruit rot disease occurs during the jacket stage when remnants of the flower parts are still attached to the immature fruit. The disease are usually common on apricot trees growing in high humidity orchards and causes a brown discoloration on the fruit under the jacket (shuck). The young fruit withers and falls off the tree within a few weeks. In this study, 12 endophytic bacterial isolates were isolated from healthy and diseased immature fruits of apricot and identified by MALDI-TOF. Antagonistic efficiency and mechanisms of these bacterial isolates were determined against jacket rot of apricot disease agent Sclerotinia sclerotiorum in vitro conditions. Among the bacterial isolates, 4 isolates showed antagonistic activities on mycelial growth and sclerot formation in dual culture petri plates. Among the bacterial isolates, the highest mycelial growth inhibition was caused by the most efficient isolate Bacillus vallismortis AB13 (69.4%) followed by Bacillus mojavensis (68.3%) and Bacillus subtilis (59.4%) respectively. Bacterial isolates belonging the Pseudomonas sp., Serratia sp. and Pantoae spp. were not found effective for inhibitions in mycelial growth and sclerotia formation. Antagonistic and plant growth-promoting activities, such as production of siderophore, synthesize extracellular enzymes (protease) and solubilization of inorganic phosphorous, were tested for each of these bacterial isolates in vitro conditions. Siderophore and protease activity were determined as major antagonistic mechanisms for suppression of mycelial growth and sclerotial formations. Although further studies are needed, these endophytes might have great potential in the field of biocontrol and plant growth promoting for sustainable agricultural practices.
Kara, M., Soylu, S., Kurt, Ş., Soylu, E.M. and Uysal, A. (2020). Determination of antagonistic traits of bacterial isolates obtained from apricot against green fruit rot disease agent Sclerotinia sclerotiorum. Acta Hortic. 1290, 135-142
DOI: 10.17660/ActaHortic.2020.1290.25
https://doi.org/10.17660/ActaHortic.2020.1290.25
apricot, antagonist, biological control, Sclerotinia
English

Acta Horticulturae