2017-2018 vejetasyon döneminde Ordu ilinin on bir ilçesinden hastalıklı yaprak
lahana (Brassica oleracea var. acephala L.) bitkileri ve onların rizosfer toprağından
toplam elli dört Rhizoctonia spp. izolatı elde edilmiştir. Rhizoctonia spp. izolatlarının
kültürel özellikleri, anastomozis grupları ve patojenisiteleri incelenmiştir. Bu
izolatların %62.96‘sının binükleik (BN) Rhizoctonia spp. (AG-A, AG-E, AG-F, AGK
ve AG-O) ve %37.34‘ünün multinükleik (MN) Rhizoctonia solani (AG 1, AG 2-1,
AG 4 ve AG 5) olduğu tespit edilmiştir. Sörvey yapılan tüm arazilerde en yaygın
izolat, 22 izolat ile BN Rhizoctonia spp. AG-A olarak belirlenmiştir. Geri kalan 32
izolatın 10‘u R. solani AG 4, 6‘sı BN Rhizoctonia spp. AG-K, 4‘ü R. solani AG 2-1,
dördü BN Rhizoctonia spp. AG-F, 3‘ü R. solani AG 5, 1‘er tanesi R. solani AG 1,
BN Rhizoctonia AG-E ve AG-O‘ya aitti. Yaprak lahana fideleri üzerinde tüm
izolatların %53.70‘i kullanılarak yürütülen patojenisite testlerinde, BN ve MN
Rhizoctonia spp. izolatları arasında istatistiksel olarak önemli virülens farkı olduğu
tespit edilmiştir (P<0.05). BN Rhizoctonia spp. izolatlarının hastalık şiddeti skalası
değerlerinin 0.00 ile 2.83 arasında değiştiği, halbuki MN R. solani izolatlarının ise
2.17 ile 3.00 arasında değişmiştir. Dahası, hastalık şiddeti skala değerleri arasında
hiçbir önemli bir fark bulunmayan AG 4, AG 2-1, AG-F, AG-E, AG 1 ve AG 5
izolatları, kontrol bitkileri ile kıyaslandığında bitki büyüme parametleri (bitki boyu,
gövde ve kök yaş ve kuru ağırlıkları ve kök uzunluğu)‘ni önemli ölçüde azaltmıştır
(P<0.05).,A total of fifty four isolates of Rhizoctonia spp. were recovered from diseased kale
(Brassica oleracea var. acephala L.) plants, and their rhizospher soil, collected from
eleven districts of Ordu provinces during the period 2017-2018. The isolates of
Rhizoctonia spp. were examined for their cultural characteristics, anastomosis groups
and pathogenicity. Of these, 62.96% were binucleate (BN) Rhizoctonia spp. (AG-A,
AG-E, AG-F, AG-K, and AG-O) and 37.34% were multinucleate (MN) Rhizoctonia
solani (AG 1, AG 2-1, AG 4, and AG 5). Twenty two of the isolates belonged to AGA
which was the most frequent group (40.74%) in all fields surveyed. Of there
maining 32 isolates, ten belonged to MN R. solani AG 4, six belonged to BN
Rhizoctonia spp. AG-K, five belonged to MN R. solani AG 2-1, four belonged to BN
Rhizoctonia spp. AG-F, three belonged to MN R. solani AG 5, one belonged to MN
R. solani AG 1, one belonged to BN Rhizoctonia spp. AG-E and one belonged to BN
Rhizoctonia spp. AG-O. In the pathogenicity tests carried out using 53.70% of all the
isolates on cabbage seedlings, it was determined that there were statistically
significant virulence differences among BN and MN Rhizoctonia isolates (P<0.05).
The values of disease severity of BN Rhizoctonia isolates ranged from 0.0 to 2.83,
whereas that of MN varied from 2.17 to 3.0. Moreover, the isolates of AG 4, AG 2-1,
AG-F, AG-E, AG 1,and AG 5, which had no significant difference between them in
virulence, significantly reduced on plant growth parameters (plant height, fresh and
dry weights of shoot and root, and root length) when compared to control plants
(P<0.05).
The isolates of
Rhizoctonia spp. were examined for their cultural characteristics, anastomosis groups
and pathogenicity. Of these, 62.96% were binucleate (BN) Rhizoctonia spp. (AG-A,
AG-E, AG-F, AG-K, and AG-O) and 37.34% were multinucleate (MN) Rhizoctonia
solani (AG 1, AG 2-1, AG 4, and AG 5). Twenty two of the isolates belonged to AGA
which was the most frequent group (40.74%) in all fields surveyed. Of there
maining 32 isolates, ten belonged to MN R. solani AG 4, six belonged to BN
Rhizoctonia spp. AG-K, five belonged to MN R. solani AG 2-1, four belonged to BN
Rhizoctonia spp. AG-F, three belonged to MN R. solani AG 5, one belonged to MN
R. solani AG 1, one belonged to BN Rhizoctonia spp. AG-E and one belonged to BN
Rhizoctonia spp. AG-O. In the pathogenicity tests carried out using 53.70% of all the
isolates on cabbage seedlings, it was determined that there were statistically
significant virulence differences among BN and MN Rhizoctonia isolates (P<0.05).
The values of disease severity of BN Rhizoctonia isolates ranged from 0.0 to 2.83,
whereas that of MN varied from 2.17 to 3.0. Moreover, the isolates of AG 4, AG 2-1,
AG-F, AG-E, AG 1,and AG 5, which had no significant difference between them in
virulence, significantly reduced on plant growth parameters (plant height, fresh and
dry weights of shoot and root, and root length) when compared to control plants
(P<0.05).
