Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/3/2010
Publication Date: 12/8/2010
Citation: Emon, R.M., Islam, M.M., Begum, S.N., Jahiruddin, M., Islam, M.A., Hassan, M.M., Haque, M.S., Musket, T., Nguyen, H., Gustafson, J.P. 2010. Molecular marker based characterization and genetic diversity of wheat genotypes in relation to boron efficiency. Euphytica. 70:339-348. Interpretive Summary: Genetic diversity represents the heritable variation within and between populations of all organisms. Knowledge of the genetic diversity and population structure within germplasm collections is an important foundation for any future crop improvement. Progress in plant breeding requires a broad genetic base with a rich and diverse germplasm collection being the backbone of every successful crop improvement program. Recent advances in molecular biology have created new opportunities for evaluating and characterizing germplasm collections beyond the traditional phenotypic limits within a biological species or genus. The use of advanced molecular marker technologies, microsatellites or simple-sequence repeats (SSRs) have become an ideal marker system of choice owning to their abundance in the genomes, co-dominance, high reproducibility, suitable for diversity study particularly in cereals, and appear to be more informative than any other marker system make them one possible approach to understand the diversity within a species. Boron deficiency in wheat is a critical problem for wheat production in Bangladesh and other regions with high rainfall including many areas of the subtropics. The present investigation was designed to evaluate 21 diverse wheat genotypes by 32 SSR markers to identify the most efficient boron genotype, and to assess their diversity at the molecular level so that they can be best utilized in developing boron efficient cultivars for production in Bangladesh and other regions of the world where wheat is being grown on boron problem soils.
Technical Abstract: Boron deficient soils pose a critical problem to wheat production in many areas of the world including Bangladesh and causes significant yield reduction. Therefore, in the present study, 21 diverse wheat (Triticum aestivum L.) genotypes collected from three different countries (Bangladesh, India, and Thailand) were subjected to SSR analysis in order to identify and characterize the most boron efficient variety. In the DNA profiling of the 21 genotypes including two control varieties, Fang 60 (known boron efficient) and SW 41 (known boron inefficient) using 32 SSR loci, a total of 234 alleles were detected. The number of alleles per locus ranged from 3 to 11, with an average of 7.312, and the PIC value ranging from 0.562 to 0.873 with an average of 0.776. The average gene diversity over all SSR loci for the 21 genotypes was 0.804, ranging from 0.637 to 0.884. All the loci were polymorphic among the genotypes and clearly distinguished them. The cluster analysis (NJ tree, UPGMA, PCO) identified a similar pattern of variation. Identification of genetic distances among wheat genotypes should improve their utilization in Bangladesh crop improvement programs. After studying wheat genetic diversity, it was found that INIA 66 and BAW1086 were the most boron efficient genotypes and could be used in any wheat improvement program for developing boron efficient varieties.