Characterization ofMedicago populations under cold acclimation by morphological traits and microsatellite (SSR) markers

Abstract

The study was carried on 16 accessions of annual Medicago species (M. truncatula Gaertn. M. ciliaris Krocker., M. aculeata Wild. and M. polymorpha L.). Seedlings of different accessions collected from sites of contrasting altitudes (10 to 1170 m) were subjected to different durations of low temperature regimes. Root to shoot ratios of acclimated and non acclimated plants were compared. Among the 16 accessions studied, 12 were used to assess the degree of genetic polymorphism by SSR microsatellites. Results show that accessions that originated from high altitude had a better root to shoot ratios and so had better ability to cold acclimation than accessions that originated from low altitude (lower ability to cold acclimation). Tests differentiation between species by fisher pair indicates that all species were different from each other. Results show the highest level of homozygosity for all species (> 80 %). Moreover, there were differences between populations of the same species of cold acclimation, which will encourage for a study of association between cold acclimation and molecular polymorphism.

Keywords: Cold acclimation, root: shoot ratios, molecular polymorphism, annuals populations, Medicago

African Journal of Biotechnology, Vol 13(27) 2704-2714