Molecular Evidence for Two Domestication Events in the Pea Crop

Abstract

Pea, one of the founder crops from the Near East, has two wild species: Pisum sativum subsp. elatius, with a wide distribution centered in the Mediterranean, and P. fulvum, which is restricted to Syria, Lebanon, Israel, Palestine and Jordan. Using genome wide analysis of 11,343 polymorphic single nucleotide polymorphisms (SNPs) on a set of wild P. elatius (134) and P. fulvum (20) and 74 domesticated accessions (64 P. sativum landraces and 10 P. abyssinicum), we demonstrated that domesticated P. sativum and the Ethiopian pea (P. abyssinicum) were derived from different P. elatius genepools. Therefore, pea has at least two domestication events. The analysis does not support a hybrid origin of P. abyssinicum, which was likely introduced into Ethiopia and Yemen followed by eco-geographic adaptation. Both P. sativum and P. abyssinicum share traits that are typical of domestication, such as non-dormant seeds. Non-dormant seeds were also found in several wild P. elatius accessions which could be the result of crop to wild introgression or natural variation that may have been present during pea domestication. A sub-group of P. elatius overlaps with P. sativum landraces. This may be a consequence of bidirectional gene-flow or may suggest that this group of P. elatius is the closest extant wild relative of P. sativum.

Potential and limits of exploitation of crop wild relatives for pea, lentil, and chickpea improvement

“…A secondary gene pool (crosses with less success and lower fertility) extends to the other species in the genus, P. fulvum and P. abyssinicum . P. abyssinicum has never been found in the wild but has a distinct diversity and karyotype (Trněný et al, 2018; Weeden, 2018). The tertiary gene pool (with strong reproductive barriers between crop and CWR) currently consists of Vavilovia formosa (Stev.)…”

Release of Medicago truncatula Gaertn. and Pisum sativum subsp. elatius (M. Bieb.) Asch. et Graebn. Seed Dormancy Tested in Soil Conditions

“…Seed dormancy release in both species varied among accessions and this could potentially act as a mechanism that favors the persistence of the seed in the soil and helps to distribute genetic diversity through time [35,40,41]. In wild pea, three accessions (IG52518, IG52520, IG52442) with the least PY dormancy after exhumation might be genetically closest to the cultivated pea or even represent some escapes from early pea cultivation ( Figure 2) [31,42] and the results agree with Hradilová et al [30]. However, it seems that the instantaneous soil conditions (water availability) to a greater extent influence the PY dormancy release in both species, whereas arid soil conditions reduce the potential for germination.…”

DNA Fingerprinting and Species Identification Uncovers the Genetic Diversity of Katsouni Pea in the Greek Islands Amorgos and Schinoussa

“…elatius ancestor [10] followed by a migration to Abyssinia, possibly through ancient human trading routes [11], indicating at least two domestication events independent of P. sativum subsp. sativum [9,12]. The alternative hypothesis about the origins of P. abyssinicum suggests that it derived from a hybridization event between P. fulvum and P. sativum subsp.…”

“…elatius, which occurred in the western half region of the Fertile Crescent [13] and then a small sample was introduced to north-eastern Africa, where it evolved into the modern P. abyssinicum [14]. The very low genetic diversity in the Abyssinian pea suggests that the taxon has recently experienced a severe bottleneck or is a relatively young taxon [10] and the hybridization event has most likely occurred about 4000 years bp [15].The Pisum genus is very diverse, showing the gamut of relatedness that reflect taxonomic identifiers, eco-geography and breeding gene pools [8,12,16,17]. Several phenotypic classification studies on pea germplasm are based on agronomical characteristics and morphological descriptors [18][19][20][21], which are unreliable for the evaluation of pea genetic resources and the identification of different cultivars in the Fabaceae family [22], especially considering the environmental effects on the expression of the genotype.…”

“…The Pisum genus is very diverse, showing the gamut of relatedness that reflect taxonomic identifiers, eco-geography and breeding gene pools [8,12,16,17]. Several phenotypic classification studies on pea germplasm are based on agronomical characteristics and morphological descriptors [18][19][20][21], which are unreliable for the evaluation of pea genetic resources and the identification of different cultivars in the Fabaceae family [22], especially considering the environmental effects on the expression of the genotype.…”