Existence of genetically diverse ecotypes of Ziziphus nummularia: a wild species of ber from western India

Ziziphus nummularia, a multipurpose under-exploited, wild fruit tree of the arid region, tolerates various abiotic stresses. To improve the genetic resource of Z. nummularia and its sustainable usage, conservation and evaluation of this species is essential. Populations of Z. nummularia from hyper-arid (Jaisalmer), arid (Bikaner), and semi-arid (Godhra) regions of western India were collected and established in the field gene bank at ICAR-CIAH as baseline approach for conservation. Larger leaf, fruit and seed size, lesser number of leaf hairs were observed in Z. nummularia population from semi-arid in comparison to arid and hyper-arid regions. Genomic DNA of these populations was tested with 80 RAPD and 18 ISSR primers. Out of these primers, 26 RAPD and 14 ISSR primers were polymorphic. Phylogenetic analysis showed that populations of Z. nummularia from hyperarid, arid and semi-arid region formed different clusters. The estimated gene flow value (0.697), diversity among populations (0.418), and Fst value (0.419) demonstrated that Z. nummularia has high genetic diversity within the population with limited gene flow between populations suggesting that different ecotypes of Z. nummularia exist in the arid and semi-arid regions.