Ibn Al-Haitham J. for Pure & Appl. Sci. Vol. 28 (3) 2015 Genetic Diversity of Iraqi Barley Species Differing in Their Tolerance to Drought by RAPD Analysis

Abstract

The genetic diversity was studied in sixteen barley Hordeum vulgar L. species cultivated inIraq , which are differ in their ability to drought stress tolerance by using random amplifiedpolymorphic DNA polymerase chain reaction (RAPD - PCR ) .Barley species was evaluatedto drought stress after treatment the plant seedling at germination stages to differentconcentration of polyethylene glycol (PEDG6000) . The results showed that the Broaq andArefat species have the highest tolerance to drought stress in contrast the rest of Barly specieslike Alkhair, Alwarkaa, Ebaa99, Shoaa, Alrafidain,Sameer Rehana 3 , forat9 , jazeral ,andebaa7 revealed sensitivity to drought stress .The primes which used RAPD technique for all the studied species were produced 203bands . The percentage of monomorphic bands is 10.39 % , while the polymorphic bandsscored 89.70% raning from 71.4 % for OP-B11 primer to 100% for OP-C16 primer .Someprimers produced specific or distinguished bands for some Barley species , such as primerOP-N13 which produced band with 450 bp molecular weight. and this band was appeared insensitive drought stress species only like Forat 9 ,Jazera 1 and Ebaa7. Primer P27 producedband with 2000 bp molecular weight and this band was appeared in highest tolerance BoraqBarley species .This band maybe associated with drought tolerant. Cluster analyses by usingjaccard scale for genetic similarity revealed a dendogram with three major groups with 75%similarity degree .The first and second sub group of group one included the tolerant andmoderately tolerant species excluding Alkhair and Alwarkaa species which they are separatedaccording to their genetic origin with one of the parents (Arefat) . The second and the thirdgroups with the third sub group of group one included the sensitive species. The results ofRAPD markers indicated the presence of high percentage of genetic diversity within thestudies Barley species cultivated in Iraq .Moreover .these result enable the researches toseparate the samples which differ in their ability to drought stress tolerance by using fewnumbers of genetic sites