Genetic Parameters and Selection Indices of Grain Yield trait and Its Components for Genotypes of Rice

Abstract

This study was conducted at rice research station in Al-Mashkhab/Najaf, Iraq, to determine the best rice genotypes based on grain yield and selection index. Seven genotypes were planted using a three-replicates in randomized complete block design (RCBD) in 2021 and 2022. Mean squares of genotypes were significant for all traits at 1% probability in both seasons. FA1 and Furat1 outperformed the other seven genotypes in tiller number and grain yield. Heritability broad sense (H²_BS) and predicted genetic improvement were high for most traits except plant height and panicle length, which were low. FA1 and AF2 genotypes had the greatest selection indices in both seasons. The genetic and phenotypic path coefficient analyses demonstrated a substantial direct influence of tillers on grain yield owing to the genetic and phenotypic link between grain production and its components. Furat genotype had the lowest grain yield and tiller coefficient of variation. m^-2, although genotype (FA1) had somewhat higher coefficient of variation than Furat. Thus, rice breeding programmers should use tillers and grains as selection indicators. Future experiments might assess the effectiveness of these improved genotypes under diverse conditions.