Natural range, habitats and populations of wild peas ( Pisum L.)

The natural distributional ranges of pea crop wild relatives, confined to Pisum sativum L. subsp. elatius (M. Bieb.) Asch. & Graebn. sensu lato (alternatively Lathyrus oleraceus Lamarck subsp. biflorus (Rafin.) H. Schaefer, Coulot & Rabaute) and Pisum fulvum Sm. (alternatively Lathyrus fulvus (Sm.) Kosterin) are reconstructed as precise as possible from multiple regional floristic literature and internet resources. P. sativum subsp. elatius occupies the Mediterranean area in a broad sense and extends to Normandie and Moldova in the north, Kopet-Dagh Mts in the east and Djanet Oasis of Sahara in the south. P. fulvum is an East Mediterranean species ranging in Peloponnese, Crete, the East Aegean Islands, Cyprus, western and southern Anatolia, Lebanon, Syria, Jordan, Israel and Sinai Peninsula. Wild peas from North Africa, Greece and Iran are strongly underrepresented in germplasm collections. The ranges of both wild pea species were predicted to shrink in future because of the current climate change. P. sativum subsp . elatius in most of its range is confined to different versions of open oak or juniper forests or their derivatives in calcareous habitats but ecotypes confined to grassland and volcanic soils, as well as weedy ecotypes occurring in fields and plantations, are added in Levant and Turkey. P. fulvum prefers half-shaded woody, often stony habitats. Populations of P. sativum subsp. elatius are very small, dozens to hundreds of individuals, sparse to very rare, and occupy tiny areas . P. fulvum usually has larger populations and areas occupied by them. Both species exhibit seed dormancy, so that most individuals exist as seed bank in soil and litter. Because of their patchy nature, wild pea populations are quite homogeneous genetically, with scarce gene flow between them, making possible great inter-population diversity. At the same time, counter the common notion of the pea as a selfer, both wild pea taxa show high level of cross-pollination. Both species, but more P. sativum subsp. elatius , strongly suffer from ruminant grazing, and the latter taxon also from pea weevil. In situ protection of wild peas and investigation of their underestimated genetic diversity is of utmost importance. Special efforts are welcome to locate and investigate the enigmatic wild peas in Djanet Oasis in Sahara Desert (which could be the main reservoir of the genus still some 10,000 years ago), in subalpine communities of Georgia, and throughout Greece. Their search in the Asir Mts in Yemen would also be of some sense with respect to the problem of the origin of the cultivated taxon Pisum abyssinicum A. Braun (alternatively Lathyrus schaeferi Kosterin).