Molecular fingerprinting of highly resistant maize lines to turcicum leaf blight

Abstract

The present study generates information related to the molecular divergence between turcicum leaf blight (TLB)-resistant and -susceptible lines. During molecular diversity studies, a total of 212 alleles were detected at 75 marker loci and ranged from two to five with an average of 2.83 alleles per locus. A direct correlation for the number of alleles and polymorphism information content (PIC) values was ascertained. For instance, marker phi123 produced high number of alleles (5) with PIC values of 0.77. Using the DARwin 6.0 programme, the UPGMA dendrogram grouped 40 maize inbreds into two distinct clusters, cluster-I (36 inbreds) and cluster-II (4 inbreds). Cluster-I contained two subclusters; the first subcluster contained 28 inbreds and the second subcluster contained eight inbreds whereas cluster-II contained four inbreds. This major cluster-II was further classified into two subclusters which contained two inbreds each. Most of the inbred lines except V-25 from cluster-II were highly resistant to TLB disease. These inbred lines can be used in crossing programmes to develop TLB-resistant hybrids by using divergent parents. In this study, allelic diversity and PIC values indicated a good efficiency of markers for studying the polymorphism level available in studied inbred lines. High level of diversity among the inbreds detected with simple sequence repeat markers indicated their suitability for the further breeding programme.