Isolation and PBS differentiation of isolates Alternaria spp.

Abstract

Abstract. The purpose of the study. Isolation of Alternaria sp. and their PBS differentiation. The article presents the results of isolation of phytopathogenic fungi of the genus Alternaria spp. from wheat plants and their genetic differentiation using iPBS (Inter Primer Binding Site Polymorphism) analysis. As a result of monitoring studies, it was shown that the fungi Alternaria spp. are the dominant component of the pathocomplex of fungi affecting the embryonic zone of seeds and ears of wheat in the northern regions of Kazakhstan. The pathocomplex of Alternaria is formed by isolates of A. alternata, A. infectoria, and A. tenuissima. Methods. Genetic differentiation of the isolates was performed using iPBS analysis. This method is based on the use of conserved sequences of tRNA binding sites (Primer Binding Sites) as PCR primers. This method is versatile and effective for the direct detection of polymorphism between individuals; therefore, PBS primers can be used in almost any organism, including fungi. Results. Analysis of the PBS primers showed that they all have high resolution in the differentiation of Alternaria spp. The obtained amplification products showed high variability among isolates, both within one species and at the interspecies level. The level of detectable polymorphism varied from 47.43 % to 80.81 %, with an average of 61 %. The size of the amplified PCR fragments ranged from 200 to 3000 bp; on average, amplification was observed from 5 to 15 bands per isolate. Practical significance. This work made it possible to obtain new data on the genetic diversity of Alternaria phytopathogenic fungi for the subsequent development of a strategy for plant protection against Alternaria.