Genetic diversity and population structure of wild banana (Musa balbisiana) populations in Sri Lanka

S.L.D. Jayaweera, W.L.G. Samarasinghe
Musa balbisiana, BB, is a wild progenitor of various banana cultivars. Its genetic diversity can be used in crop improvement and conservation programs to strengthen future global food security. Three M. balbisiana populations were surveyed with the objective of assessing genetic diversity. DNA from 23 samples was amplified using 8 simple sequence repeat (SSR) primers. Bands were visualized on 8% polyacrylamide gels, alleles were scored and evaluated using SPSS10 and GenAlEx6 to generate a dendrogram, genetic diversity and population structure information. The molecular diversity of the populations was substantial. Primers generated 3-6 alleles locus-1 and total of 34 alleles. Mb1-113 and MaSSR24 were the best primers for genetic diversity assessments. Three populations were defined based on geographical distribution and showed 96% of mean polymorphic loci percentage. Population 1, 2 and 3 possessed 31, 18 and 5% of population-specific alleles, respectively, and 44% of common alleles. There were two rare alleles found in Population 1. The mean expected heterozygosity (0.497) was higher than the mean observed heterozygosity (0.412). Results indicated moderate values of gene flow values and Fst. Analysis of molecular variance (AMOVA) showed 6% of variance among populations, and 94% of variance within populations. The work articulates a relationship for geographic distances of collection sites. Genetic distances exhibited a location-specific variation irrespective to geographic distances and variation. Sub-populations in Population 1 and 2 should be conserved for both their genetic diversity and their rare and population-specific alleles. Genetic variance among populations was lower than that among individuals within populations. Populations studied possessed a lower level of observed heterozygosity than the expected, favoring inbreeding and increased genetic differentiation. Gene exchanges are proof of moderate gene flow. Further studies on pollinators and seed disseminators will be useful to understand genetic relationships and gene flow between individuals.
Jayaweera, S.L.D. and Samarasinghe, W.L.G. (2016). Genetic diversity and population structure of wild banana (Musa balbisiana) populations in Sri Lanka. Acta Hortic. 1114, 53-60
DOI: 10.17660/ActaHortic.2016.1114.7
'Etikesel', genetic distance, molecular diversity, population genetics, PCR, SSR

Acta Horticulturae