This study was carried out to determine the disease severity of Rhizoctonia solani isolates isolated from plant samples collected from bean, sugar beet and potato cultivation areas in Konya in 2020 and the anastomosis groups of the most virulent isolates. A total of 40 R. solani isolates were obtained as a result of the isolations made from 86 plant samples (36 beans, 25 sugar beets and 25 potatoes) showing root rot symptoms in general appearance. The number of R. solani isolates obtained from these plants, respectively; 10 isolates from beans, 15 from potatoes and 15 from sugar beets. Nine of the bean isolates and 14 of the potato and sugar beet isolates were determined as multinucleic. One isolate each isolated from the bean, sugar beet and potato was determined as binucleic. As a result, a total of 37 multinucleate (MN) and 3 binucleate (BN) isolates were obtained from all plants. As a result of pathogenicity tests, 3 R. solani isolates with the highest disease severity for each plant were amplified using ITS1F and ITS4B primers and anastomosis groups were determined. Accordingly, the anastomosis groups of Fa 3.2 (97%), Fa 2.2 (89%) and Fa 1 (86%) in beans were characterized as AG 4HGI. The isolates with the highest disease severity in potatoes (Pa 10, Pa 12.1 and Pa 15.2) were determined as AG 3 group. Disease severity was determined as 50% of Pa 15.2, 44% of Pa 10 and 42% of Pa 12.1. The disease severity of 9 of the isolates obtained from sugar beet was determined as 100%. The anastomosis group of 3 randomly selected isolates from these isolates was characterized as AG 2-2.

This study was carried out to determine the in vitro and in vivo activities of Trichoderma isolates isolated from soil and plants collected from different provinces in 2020-2021 against Rhizoctonia solani, which causes root rot in beans. Using the pathogen as a trap, 61 Trichoderma isolates were obtained from 65 soil samples from 20 provinces. In addition, 8 Trichoderma isolates previously obtained from different plants were included in the experiment. Trichoderma isolates showed very strong (4 Trichoderma isolates), strong (1 Trichoderma isolate), moderate (18 Trichoderma isolates) and low level (18 Trichoderma isolates) hyperparasitic effects against R. solani in in vitro experiments with dual culture method. In comparison, some isolates (28 Trichoderma isolates) were found to be ineffective. As a result of in vivo tests with 10 Trichoderma isolates selected according to the effect results in vitro, it was determined that Trichoderma isolates were 8-89% effective against R. solani. The most effective Trichoderma isolates against R. solani was Trichoderma virens-130 with an 89% effect, followed by Trichoderma-106 and Trichoderma-162.1 with 82% and 75% effect, respectively. According to these results, it was observed that the isolates of Trichoderma, which were moderately and highly effective in vitro, significantly reduced the severity of the disease in vivo.

Macrophomina phaseolina (Tassi) Goid. geniş konukçu aralığına sahip toprak kökenli bir hastalık olup mücadelesi oldukça zordur. Bundan dolayı, çalışmamızda 2021 yılında Konya’nın Çumra ilçesinden alınan fasulye bitkilerinin farklı aksamlarından (çiçek, gövde, kök ve yaprak) ve topraktan elde edilen toplam 71 bakterinin hastalığa karşı in vitro etkinliklerinin belirlenmesi amaçlanmıştır. İkili kültür testlerinde %60 ve üzerinde etki gösteren bakteriler için bazı biyokimyasal testler (Hidrojen siyanid aktivitesi, fosforu çözme yeteneği, siderofor sentez kabiliyeti, indol asetik asit üretebilme yetenekleri ve ACC deaminaz aktivitelerinin belirlenmesi) uygulanmıştır. Deneme sonucunda değerlendirmeler yapılmış ve bu testler puanlandırılarak en yüksek etkiyi gösteren bakteriler daha sonraki çalışmalarda kullanılmak üzere seçilmiştir. Macrophomina phaseolina’ya karşı ikili kültür denemelerinde başarılı olan izolatlar; yapraktan izole edilen Bacillus pumilus DP 25 (%91), rizosferik Bacillus subtilis DP 143.6 (%86) ve rizosferik Bacillus cereus DP 145.1 (%100) olmuştur. Yüksek düzeyde etkili olan bu izolatların fosforu çözme kabiliyetleri, siderofor sentez yetenekleri ve indol asetik asit kabiliyetleri pozitif olarak belirlenmiştir.

Macrophomina phaseolina (Tassi) Goid. is a fungal pathogen causes charcoal rot disease (Sin: Rhizoctonia bataticola) and is responsible for significant yield losses in many plants. In our study, we aimed to evaluate the antagonistic ability of 39 different bacteria, isolated from the fields of sugar beet in 2019, against the pathogen Macrophomina phaseolina isolated from sugar beet, beans and chickpeas. Approximately 31% of the bacteria showed antibiosis effect against the pathogen. It was determined that the effectiveness level of Lelliottia amnigena, Bacillus atrophaeus, B.pumilus and B. cereus (7 isolates) was moderate to high against Macrophomina phaseolina. Bacillus atrophaeus (PTo15-1a) showed the highest efficacy of 80%, 72.94% and 82.35% against Macrophomina phaseolina of chickpea, bean and sugar beet respectively. Lelliottia amnigena (Pto 14-1b) was moderately effective (57.78%) against the chickpea isolate of the pathogen. It was observed that of the seven Bacillus cereus isolates used in the experiment, three isolates (Pto14-1a, Pto12-1b, Pto17-1b) were highly effective against the chickpea pathogen, two (Pto12-1b, Pto14-2b) against bean pathogen, and one (Pto15-1b) against sugar beet isolate. Results have shown varied level of antagonism by different test bacterial against different Macrophomina phaseolina isolates, while the highest level of antibiosis shown by Bacillus atrophaeus against all pathogenic isolates indicated that it can be a potential future bioagent in managing the disease.

Bu çalışma farklı bitkilerin rizosferik toprak bölgesinden izole edilen 38 bakteri izolatının ayçiçeğinde beyaz çürüklük etmenlerinden biri olan Sclerotinia minor Jagger’e karşı antagonistik etkilerini belirlemek amacıyla yapılmıştır. In vitro koşullarda test edilen bakterilerin yaklaşık %37’si orta ya da yüksek düzeyde patojenin misel gelişimini baskılamıştır. In vitro koşullarda patojeni yüksek düzeyde (%80-100) engelleyen bakteriler (Pseudomonas chlororaphis IDV5, Bacillus amyloliquefaciens IEB1, Bacillus cereus IPT3, Stenotrophomonas sp. IGL1, henüz teşhis edilememiş 2 bakteri izolatı (IFG1 ve IFG2)) daha sonra iklim odası koşullarında saksı çalışmaları ile test edilmiştir. Araştırma sonuçlarımıza göre saksı denemelerinde Pseudomonas chlororaphis dışında tüm bakteriler %100 etkili olmuştur. Ayrıca in vitro’da S. minor’e karşı etkisiz olmasına rağmen, daha önce yaptığımız farklı çalışmalarda in vivo koşullarda başarılı olduğunu tespit ettiğimiz Pseudomonas koreensis (IFG4)’de denemeye dahil edilmiş ve in vivo’da etkili bulunmuştur. Bu sonuç bazı rizosferik bakterilerin patojenin baskılanmasında rol oynayan bazı engelleyici özelliklerinin bitki ile bir araya geldiğinde ortaya çıktığını göstermektedir. Sonuç olarak çalışmamız biyolojik mücadelenin ayçiçeğinde toprak patojenlerini kontrol etmenin alternatiflerinden biri olduğunu ve bu antagonistik bakterilerin diğer özellikleri yönünden de araştırıldıktan sonra biyoajan olarak kullanılabileceğini ortaya koymaktadır.