Panicle Architecture in Enhancing Grain Yield in Rice (Oryza sativa L.)

Abstract

The architecture of the rice panicle is a crucial focus in breeding for both high yield and quality. It stands as a significant agronomic trait that influences the number of grains per panicle, playing a direct role in contributing to the overall yield of rice grains. Unravelling the genetic basis of panicle architecture is crucial for improving the grain yield in rice. In this study, the panicle architecture traits were meticulously dissected into five distinct components viz., number of primary rachis, number of secondary rachis, grain number on primary rachis, grain number on secondary rachis and total grain number. These components were systematically phenotyped in F2 and F3 population derived from a cross between DRR Dhan 48 and Maudamani. ‘DRR Dhan 48’ is a biofortified elite fine grain medium slender grain type cultivar with high zinc (22 ppm in polished rice) and low glycemic index (51.1). It has resistance to bacterial blight with the incorporation of xa5, xa13 and Xa21 in the background of Improved Samba Mahsuri. ‘Maudamani’ is a high yielding cultivar with high grain number and short bold grain type. Analysis of variance, histograms and boxplots revealed highly significant variation for the studied traits. Grain number in F2 population ranged from 29 to 333 grain with a mean of 162.72 whereas in F3, its varied from 49 to 368 with a mean of 184.17. Correlation analysis revealed significant correlation among the studied traits. The continuous variation observed in the population for panicle traits indicates that genetic control is governed by multiple minor loci. The presence of superior transgressive segregants highlights a complementary gene action influencing panicle architecture traits. The present investigation on panicle architecture offers scope for improving rice varieties and creating new germplasm resources and provides valuable information for further unravelling the genetic basis determining rice panicle architecture.