Expression of high grain number QTL qGN4 1 in genetic backgrounds of different rice varieties

Abstract

Rice is the staple food for the largest number of people on earth, particularly newlinefor the growing Asian population; hence, the utilization of genes for enhancing its newlineyield potential is important for ensuring food security. Green Revolution had led to newlineincreased grain production in 1960s, however no major gain in yield production newlineafterwards has been observed in rice. Earlier, a major quantitative trait loci (QTL) newlinewith high LOD scores of 13, 6.8 and 5.3, explaining 27%, 16% and 12% of newlinephenotypic variation across three years, respectively was mapped for the grain newlinenumber per panicle, qGN4.1, using biparental recombinant inbred line (RIL) newlinepopulations involving a new plant type Indica rice genotype Pusa 1266. Later, three newlineindependent studies have confirmed the presence of a major QTL for spikelet number newlineby three different names (SPIKE, GPS and LSCHL4) in the same chromosomal newlineregion, and have implicated the overexpression of Nal1 gene as the causal factor for newlinehigh spikelet number. newline