Marker assisted selection for drought tolerance in pearl millet (Pennisetum glaucum (L.) R. Br.)
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Date
2014
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Publisher
CCSHAU
Abstract
Pearl millet (Pennisetum glaucum (L.) R. Br.) is the staple cereal of millions of poor rural families in the hottest and driest areas of the tropics and subtropics. Terminal drought stress is a regular occurrence and serious environmental constraint in these regions, making stress tolerance an essential attribute of new pearl millet cultivars. Marker assisted selection is an important molecular tool for improving yield and yield stability of the pearl millet. A number of genomic regions were found to be associated with drought tolerance in terms of both grain yield and its components. A major QTL associated with the drought tolerance of grain yield mapped on linkage group 2 and explained up to 32% of the phenotypic variation. Another QTL were observed on LG 5 with phenotypic variation of 14.8%. During the present investigation, HHB 226 pearl millet hybrid was improved for drought tolerance by marker assisted selection. For this, two crosses were made i.e. HBL 11 x PRLT 2 and HBL 11 x 863 B. PRLT 2 and 863 B were used as donor parent and HBL 11 (male parent of HHB 226) was used as recurrent parent. Eleven SSR primers specific to drought tolerance from LG2 and 5 were used for polymorphism analysis between recurrent and donor parent. Three SSR primers from LG 2 (PSMP2066, PSMP2077, and PSMP2059) and one from LG 5 (PSMP2078) were found polymorphic in both the crosses which were used for further screening. Recurrent and donor parents were crossed to raise the F1 generation. Selected plants were backcrossed with HBL11 three times and in each generation positive plants were selected. Finally, four plants were selected in BC3F1 generation in both crosses which were then used for background selection. 25 and 32 background primers were found polymorphic out of 64 primers in HBL 11 x PRLT 2 and HBL 11 x 863 B cross respectively. About 70 and 80% of the recurrent parent genome was found to be transferred in most of the selected plants in 1st and 2nd cross respectively till BC3F1 generation. During the drought screening test in BC2F1 generation in 1st cross, RWC and 1000 seed weight were found to be enhanced with 27.84% and 15% respectively, in drought tolerant BC2F1 generation plants than drought sensitive. In 2nd cross, RWC and 1000 seed weight were increased with 33.6% and 28% respectively, in drought tolerant plants as compared to drought sensitive.
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Keywords
Selection, Planting, Crossing over, Weather hazards, Millets, Tolerance, Yields, Genetics, Genomes, Hybrids