Development and Evaluation of Primary Introgression Lines of Rice by Advanced Backcross QTL Strategy for Gaozhou Wild Rice (<i>O. rufipogon</i>)

Abstract

Rice ( Oryza sativa L.) is the major cereal crop in China. The modern rice cultivars have narrow genetic base for most of the available traits, wild relatives of rice species contain trait-enhancing genes. The goal of this study was to identify introgression lines that can significantly increase yield in cultivated rice by yield-related traits from an inter-specific advanced backcross population (AB-population) between O.statia×O.rufipogon. AB-population ( O. statia ' Yuexiangzhan'× O. rufipogon ‘G52-9’) has evaluated using statistical methods for 17 agronomic traits pertaining to yield and yield-related components. Our studies indicated that AB-population had higher values for most traits analyzed in comparison to the recurrent parent, Yuexiangzhan. According to the statistical results, about 33.20% of the BC3F1 lines showed better than Yuexiangzhan in some traits. Grain shape and grain weight have selected for QTL mapping as an illustration of AB-QTL analysis. A total of 23 QTLs were identified for grain length (GL), grain width (GW), Grain length/grain width (LW), and grain weight (GWt). Phenotypic variation of each QTL ranged from 3.77%-28.67%. The grain weight of the recurrent ‘Yuexiangzhan’ was improved 15.10%, 28.67%, 26.29%, 24.28% and 12.90% by five main QTLs of GWt (from Gaozhou wild rice). This study confirms that wild progenitor species present potential donor sources for some complex traits and the advanced backcross population provides an efficient source of gene pool for future breeding programs. Therefore, Gaozhou wild rice is an efficient source of gene pool and can further utilize.