Introgression lines (IL) from crosses between elite cultivars and wild species are an important resource for mapping quantitative trait loci (QTLs) for yield. In this study, 25 KMR3-O. rufipogon ILs, from an advanced back cross population, were selected for high grain yield in field trials and characterized in detail for yield and related traits from seed to seed. The aim was to dissect the basis of high yield in the entire life cycle to identify common features in high yielding ILs. This study indicated that each IL has a different strategy or a combination of different yield traits to attain high yield. High yield in these ILs was associated with early flowering, high number of tillers, panicles, grains, seed weight per panicle and seed density. Seed germination rate, leaf SPAD chlorophyll meter value, plant height, panicle length and 100 seed weight did not have much impact on yield. Highest significant positive correlation was observed between number of tillers and number of productive tillers (0.98) as expected. A highest significant negative correlation was observed between seed density and seed compactness (-0.95). The new negative correlation between seed germination rate and leaf SPAD chlorophyll meter value in the top 10 ILs was supported by a non significant negative correlation (-0.17) in BC3F4 IL population and deserves further study. Restricting to a specific ideotype in selection may be counterproductive in rice breeding. These ILs are being used in rice improvement and to identify favorable genes from O. rufipogon for increasing yield.
T. Sudhakar, Madhusmita Panigrahy, M. Lakshmanaik, A. Prasad Babu, C. Surendhar Reddy, K. Anuradha, B.P Mallikarjuna Swamy and N. Sarla, 2012. Variation and Correlation of Phenotypic Traits Contributing to High Yield in KMR3-Oryza rufipogon Introgression Lines. International Journal of Plant Breeding and Genetics, 6: 69-82.