|Venu, R. C.|
|Sreerekha, M. V.|
Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/27/2011
Publication Date: 8/6/2011
Citation: Venu, R., Jia, Y., Liu, G., Jia, M.H., Nobuta, K., Sreerekha, M., Moldenhauer, K., Pellegrini, M., Jacobsen, S., McClung, A.M., Meyers, B., Wang, G. 2011. Molecular mapping of yield related traits in a recombinant inbred line population of a Nipponbare x 93-11 cross and identification of candidate genes associated with heterosis in rice [abstract]. American Society of Plant Biologists Annual Meeting, Minneapoli, Minnesota. Abstract P15068. Interpretive Summary:
Technical Abstract: Rice (Oryza sativa) is a model cereal crop as well as a staple food for about 50% of the world’s population. Although rice is a self-pollinated crop, over the last 20 years rice hybrids have been commercialized extensively in China, India, and the USA. Heterosis is a complex biological phenomenon where hybrid offspring show better performance compared to the inbred parents. To better understand the genetic and molecular mechanisms underlying heterosis, a linkage map was constructed using 131 polymorphic Simple Sequence Repeat (SSR) markers with 259 recombinant inbred lines (RILs) (F8) derived from a cross between Nipponbare and 93-11. Quantitative trait loci (QTL) mapping was performed for days to heading, days to harvest, plant height, tiller angle, tiller number, awn length, seedling vigor, panicle length, number of primary branches per panicle, number of seeds per panicle, kernel weight, and grain yield per plant. We observed transgressive variation among the RILs for the yield related traits. To understand the molecular mechanism of heterosis, massively parallel signature sequencing (MPSS) libraries were constructed from leaves, roots and meristem tissues harvested from the two parents and their F1 hybrid. One to 3 million signatures were obtained from each library. MPSS analysis showed that many highly expressed genes were located in QTL regions for yield related traits identified in the RILs. Using cluster analysis, commonly and specifically expressed genes in Nipponbare, 93-11 and their F1 hybrid were identified in all three tissues. The Gramene and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were used to identify many important putative transcription factor genes and regulatory genes belonging to photosynthesis and energy metabolism in these QTL regions. Identification of these candidate genes in the Nipponbare x 93-11 hybrid provides the starting genomic materials to elucidate the molecular basis of heterosis in rice.