Molecular genetic analysis of some North African barley germplasms

Abstract

Isozyme and RAPD markers were used to characterize 29 barley accessions, which were collected from North Africa. In addition, resistance gene sequences were employed to develop molecular markers using RT-PCR approach. High level of polymorphism was found with both RAPD and isozyme markers, where RAPD showed that 60 % of amplified bands were polymorphic. Peroxidase showed three polymorphic loci (7 allelic bands). Isozymes cluster analysis successfully separated the barley accessions into three geographically distinct groups. RAPD investigation demonstrated that Egyptian accessions were grouped into two obvious groups. Moreover, the Tunisian accessions showed no distinct clustering, while high dissimilarities were revealed by the Algerian accessions. In the RT-PCR, from six primer pairs selected, primer pair AF092524P1P2 successfully amplified two specific amplicons of approximately (340 & 220 bp) and (360 & 270 bp), respectively in two Egyptian barley genotypes (El-Awamah and Awlad-Ali). One primer pair DN988165P1P2 gave only one specific amplicon in both barley genotypes of 250 and 270 bp, respectively. The markers developed could be used in improving barley crop by assisting in breeding selection of resistance genotypes.Key words: RT-PCR; resistance genes; barley; genetic diversity; RAPD IZVLEČEK MOLEKULARNA GENETSKA ANALIZA NEKATERIH SEVERNOAFRIŠKIH GENSKIH VIROV JEČMENA Z izoencimskimi in RAPD markerji je bilo ovrednoteno 29 akcesij ječmena, nabranih v Severni Afriki. Za razvoj molekularnih markerjev na osnovi RT-PCR so bila uporabljena nukleotidna zaporedja genov za odpornost. Ugotovljen je bil velik polimorfizem RAPD in izoencimskih markerjev, kjer je bilo 60 % namnoženih RAPD markerjev polimorfnih. Peroksidaza je pokazala tri polimorfne lokuse (7 alelelov). Z analizo izoencimskih skupin so bile akcesije ječmena uspešno razdeljene v tri razločne geografske skupine. Raziskava RAPD je pokazala, da se egiptovske akcesije razločno povežejo v dve skupini. Tunizijske akcesije niso pokazale razločnega povezovanja, pri alžirskih pa so bile ugotovljene velike razlike. V RT-PCR analizi, je od šestih izbranih začetnih oligonukeltodiov par AF092524P1P2 uspešno namnožil dva specifična amplikona s približno 340 in 220 in 360 in 270 baznih parov pri dveh egiptovskih genotipih ječmena (El-Awamah in Awlad-Ali). Par začetnih oligonukleotidov DN988165P1P2 je pomnožil le en specifični fragment pri obeh genotipih ječmena z 250 in 270 baznimi pari. Razviti markerji se bodo lahko uporabili pri izboru genotipov za izboljšanje ječmena v žlahtnjenju na odpornost.