Diagnosis of Ascochyta blight of Pisum sativum Subsp. elatius (M. bieb.) Asch. & Graebn. via molecular techniques

Ascochyta blight or black spot is one of the most devestating disease of the cultivated pea (Pisum sativum L.) and caused by a complex of pathogenic fungi consisting of Ascochyta pinodes, A. pisi, Phoma pinodella, P. koolunga, P. herbarum, P. glomerata and Boerema exigua var. exigua. In the genus Pisum L., P. elatius (M. Bieb.) Asch. & Graebn., annual wild pea species, is a native species to Middle and northwest Asia and the Europe-Mediterranean region including Turkey. It is suffered from ascochyta blight in some sites in Toros Montains, Turkey. Characteristic lesions on leaves of ascochyta blight were collected in Goynuk Canyon (c. 1000 m asl) in Kemer, Antalya, Turkey but its species has been unclear. Therefore, the present study was aimed diagnosing ascochyta blight of P. elatius via molecular techniques. Symptoms on leaves were circular to oval such as ascochyta blight. Samples were placed on PDA plates for 2 to 7 days, and colonies with morphological characteristics typical of pea ascochyta blight were single-spored and transferred to new PDA plates and incubated for 7 to 14 days. DNA was extracted from small pieces of fungus isolates using CTAB method. For molecular characterization, internal transcribed spacer (ITS) regions (ITS-1, 5.8S rDNA subunit, ITS-2) were amplified with PCR primers ITS 5 and ITS 4. Based on BLAST analysis result, the sequence had 99% nucleotide identity with the corresponding sequence in GeneBank for Ascochyta pisi Lib. To our knowledge, this is the first report of ascochyta blight of P. elatius in Turkey. The pathogen is considered to be co-evolved with P. elatius.