Development of a molecular linkage map of pearl millet integrating DArT and SSR markers uri icon

abstract

  • Pearl millet is an important component offood security in the semi-arid tropics and is assuminggreater importance in the context of changing climate andincreasing demand for highly nutritious food and feed.Molecular tools have been developed and applied for pearlmillet on a limited scale. However, the existing tool kitneeds to be strengthened further for its routine use inapplied breeding programs. Here, we report enrichment ofthe pearl millet molecular linkage map by exploitinglow-cost and high-throughput Diversity Arrays Technology(DArT) markers. Genomic representation from 95 diversegenotypes was used to develop a DArT array with circa7,000 clones following PstI/BanII complexity reduction.This array was used to genotype a set of 24 diverse pearlmillet inbreds and 574 polymorphic DArT markers wereidentified. The genetic relationships among the inbred linesas revealed by DArT genotyping were in complete agreementwith the available pedigree data. Further, a mappingpopulation of 140 F7 Recombinant Inbred Lines (RILs)from cross H 77/833-2 9 PRLT 2/89-33 was genotypedand an improved linkage map was constructed by integratingDArT and SSR marker data. This map contains 321loci (258 DArTs and 63 SSRs) and spans 1148 cM with anaverage adjacent-marker interval length of 3.7 cM. Thelength of individual linkage groups (LGs) ranged from78 cM (LG 3) to 370 cM (LG 2). This better-saturated mapprovides improved genome coverage and will be useful forgenetic analyses of important quantitative traits. This DArTplatform will also permit cost-effective background selectionin marker-assisted backcrossing programs as well asfacilitate comparative genomics and genome organizationstudies once DNA sequences of polymorphic DArT clonesare available

publication date

  • 2011
  • 2011