Physiological studies of isolates of Colletotrichum spp.

Abstract

In the physiological studies were included 20 isolates of Colletotrichum spp. originating from pear, apple, sour cherry and tomato fruits, as well as reference strains of C. acutatum (CBS 294.67) and C. gloeosporioides (CBS 516.97). The results indicated that five different culture media (PDA, CA, OA, MEA, CDA), seven different pH (3, 4, 5, 6, 7, 8, 9), and temperatures (5º, 10º, 15º, 20º, 25º, 30º, 35ºC) have significant influence on growth and sporulation of isolates of Colletotrichum spp. All tested media, except CDA, were suitable for pathogens development. Five morphological groups of colonies on PDA were observed, confirming the great phenotypic variability of isolates. The best media pH for pathogens growth and sporulation were pH 6 and 7. The optimum temperature for colonies development was 25˚C, and temperatures of 20° and 25ºC were the most favorable for sporulation of isolates of Colletotrichum spp.

U fiziološka ispitivanja su uključena 20 izolata Colletotrichum spp. poreklom sa plodova kruške, jabuke, višnje i paradajza, kao i referentni sojevi C. acutatum (CBS 294.67) i C. gloeosporioides (CBS 516.97). Rezultati ukazuju da pet različitih hranljivih podloga (PDA, CA, OA, MEA, CDA) sedam različitih pH (3, 4, 5, 6, 7, 8, 9) i temperatura (5º, 10º, 15º, 20º, 25º, 30º, 35ºC) imaju značajan uticaj na razvoj i sporulaciju izolata Colletotrichum spp. Sve testirane podloge, izuzev CDA su pogodne za razvoj patogena. Na podlozi PDA moguće je razlikovati pet morfoloških grupa kolonija, što potvrđuje fenotipsku varijabilnost proučavanih kultura. Podloge pH 6 i 7 su najbolje za porast i sporulaciju patogena. Optimalna temperatura za razvoj ispitivanih kolonija je 25°C, a temperature od 20° i 25°C su najpovoljnije za sporulaciju izolata Colletotrichum spp.