Exploring synteny and functions of pearl millet (Pennisetum glaucum (L.) R. Br.) drought tolerance QTL region across rice and perennial ryegrass (Lolium perenne L.)
KrishiKosh
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Title |
Exploring synteny and functions of pearl millet (Pennisetum glaucum (L.) R. Br.) drought tolerance QTL region across rice and perennial ryegrass (Lolium perenne L.)
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Creator |
Richa
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Contributor |
Yadav, R.C.
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Subject |
weather hazards, genes, amino acids, tolerance, millets, planting, enzymes, rice, genomes, drought stress
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Description |
Previous genetic mapping studies in pearl millet [Pennisetum glaucum L. (Br.)] have identified and validated a major QTL of drought tolerance (DT) on linkage group (LG) 2 that enhances yield under drought stress by more than 32%. Recently, this QTL has been fine mapped to a 3 cM region using a high resolution cross and 14 candidate genes based markers were mapped in the fine mapped region as SNP and CISP markers. In the present study, the synteny and functions of these candidate genes across rice, sorghum and ryegrass were explored. Although a broad conservation of gene linkage (macrosynteny) has been reported previously in grass genomes, our results indicate that extensive translocations and duplication events in these grass genomes has disrupted regional synteny. It is clearly evident from our results that DT-QTL region on pearl millet LG 2 shows synteny to >1 linkage groups in rice, sorghum and ryegrass. Most immediate practical application of this work would be future identification of tightly linked markers for marker-assisted selection and map-based isolation of candidate genes in rice, sorghum and ryegrass. The expression patterns of these candidate genes underpinning drought tolerance QTL were also investigated under different water stress treatments at flowering and post-flowering stages. Six candidate genes, protein phosphatase 1 regulatory subunit SDS22, Zn finger CCCH type transcription factor, ubiquitin conjugating enzyme, serine threonine protein kinase, chlorophyll a/b binding protein and dipeptidyl peptidae IV showed either differential expression or fold change among genotypes, H 77/833-2 (drought susceptible), PRLT 2/89-33 (drought tolerant) and DT-QTL NIL ICMR01029 under drought stress conditions which suggests the role of these putative candidate genes under drought stress in pearl millet. The candidate gene strategy shows promising results for bridging the gap between quantitative genetics and molecular genetics approaches to study complex traits like drought tolerance. Once the genes are validated, we can develop CGs-based “functional markers” to enhance the speed, precision and efficiency of introgression of this QTL into farmer-preferred cultivars. Further, metabolome profiling of the pearl millet genotypes contrasting for drought tolerance has also been done by both FIE-MS and GC-MS to see the compositional differences in metabolites under control and drought stress conditions. Compositional differences among the genotypes in different environment conditions may play a key role for the selection of the genotypes for further use in breeding programmes. |
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Date |
2016-02-10T12:07:47Z
2016-02-10T12:07:47Z 2014 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/64272
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Language |
en
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Format |
application/pdf
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Publisher |
CCSHAU
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