ANASTOMOSIS GROUPS, PATHOGENICITY AND BIOLOGICAL CONTROL OF RHIZOCTONIA SPECIES ISOLATED FROM PEPPER (CAPSICUM ANNUUM L.) PLANTS IN LAKE VAN BASIN


Demirer Durak E.

FRESENIUS ENVIRONMENTAL BULLETIN, cilt.27, ss.4198-4205, 2018 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 27 Konu: 6
  • Basım Tarihi: 2018
  • Dergi Adı: FRESENIUS ENVIRONMENTAL BULLETIN
  • Sayfa Sayıları: ss.4198-4205

Özet

This study was conducted to determine anastomosis groups, pathogenicity and biological control of Rhizoctonia spp. from pepper (Capsicum annuum L.) plants in Lake Van Basin during 2013-2014. Sixty seven isolates of Rhizoctonia spp. were obtained from roots of pepper. Among these isolates, multinucleate anastomosis groups (AG) AG-2, AG 3, AG-4 and AG-5, binucleate AG-K were recorded in the rate of 13,4%, 9%, 62,7%, 4,5% and 10,4%, respectively. In pathogenicity tests on pepper plants, the most virulent group was determined as AG-4, it was followed AG-2, whereas the weak virulent ones were AG-3 and AG-K, isolate of AG-5 was nonpathogenic. A total of 25 isolates of biological control agents belonging to Trichoderma harzianum (44%), T. viride (24%), T. virens (20%) and Gliocladium roseum (12%) were obtained from the roots of pepper plants. The effectiveness of the biological control agents against the most virulent isolate (AG 4 Rs 55) were determined using in vitro and in vivo tests. In vitro tests the most effective isolates were determined as T. harzinum (64,5%), T. viride (58,1%), T virens (57,4%). Whereas G. roseum (35,4%) was the weak inhibition to Rs55. According to the results of in vitro test, isolates showed the highest inhibition against Rs55 were selected, and used in vivo tests. Disease severity and plant growth parameters (plant heigh, shoot and root fresh and dry weights) were evaluated 8 weeks after sowing. According to in vivo test, while T harzianum was found to be the most effective species, T. viride and T virens were moderately, and G. roseum was the least effective genus.