Refinement of the collection of wild peas (Pisum L.) and search for the area of pea domestication with a deletion in the plastidic psbA-trnH spacer

The plastidic psbA-trnH spacer was sequenced in 78 accessions representing the genus Pisum L. A nucleotide substitution C64T in the spacer was found to be specific for Pisum abyssinicum A. Br.; a substitution T75G occurred in five accessions of the wild pea [Pisum sativum L. subsp. elatius (Bieb.) Schmalh.], one from France, three from Greece and one from Turkey, and also in a primitive landrace from Afghanistan with signs of contamination. A 7-bp tandem duplication was found in two P. sativum subsp. elatius accessions, from Turkey and Georgia. All (except for the probably contaminated Afghan accession) of the cultivated subspecies P. sativum L. subsp. sativum had a deletion of one copy of a tandem 8-bp repeat. The same deletion was found in two wild pea (P. sativum subsp. elatius) accessions, from Bulgaria and Georgia, belonging to the same earlier defined lineage B as the cultivated pea. They are supposed to represent the ancestral evolutionary lineage of the cultivated pea. It is noteworthy that accessions from the proposed Core Area of the Near East founder crop domestication in south-eastern Turkey do not have the deletion. Most of wild representatives of lineage B have a scarcely pigmented flower with almost non-opening standard, but those from Transcaucasia have a normal flower. The revealed area of co-existence of the earlier defined wild pea lineages A and B (differing in alleles of three molecular markers from different cellular genomes) was extended from Turkey to include Georgia and probably North Africa. Accessions claimed to represent wild peas were tested for spontaneous pod dehiscing and 14 of them were disproved as such. They are enriched with 'recombinant' marker combinations and most probably resulted from hybridisation of wild and cultivated peas, either in nature or while reproducing in germplasm collections.