Characterization of Sri Lankan maize accessions using SSR markers associated with insect-resistant traits

Abstract

Maize genetic diversity is utmost to develop new varieties conferred with favorable agronomic traits. Landraces are priceless resources that can serve to strengthen crop breeding programs. Hence, this study aimed to characterize 19 Sri Lankan maize landraces and one elite commercial variety Bhadra using SSR markers linked with insect-resistant traits. Using established procedures, genomic DNA extraction was done from immature maize leaves and PCR was performed utilizing bnlg1017, bnlg339, umc1021, umc1187, bnlg1346, bnlg1588, bnlg1556, umc1178, nc134, umc1688 and umc1045 primers. GenAlex and DARwin software were used for the data analysis. According to the results, a sum of 77 alleles was amplified with the maximum number of observed (13) and effective (11.28) alleles for bnlg1588. The highest gene diversity and PIC values were recorded in bnlg1588 (0.911 and 0.904 respectively), while the lowest was in umc1045 (0.640 and 0.581 respectively). Out of the total SSR primers used, bnlg1588, bnlg339, bnlg1346, and bnlg1017 linked with FAW-resistant traits were found to be more informative based on their genetic diversity parameters. The accessions SEU7, SEU11, SEU16, and SEU20 showed more genetic diversity compared to Bhadra, whereas SEU17 showed the lowest diversity. The dendrogram divided the 20 maize accessions into two main clusters with the mean similarity of 0.752. Similarly, the principle coordinate analysis explained 40.63 % of the genetic variation and grouped the maize accessions into two. Considering the genetic diversity parameters, the accessions SEU6 and SEU7 from cluster I and SEU9, SEU11, SEU16, and SEU20 from cluster II could be utilized for strategic maize breeding programs in Sri Lanka.