Genetic Analysis of Backcross Derived Lines for Yield and Yield-f Attributing Traits in Rice (Oryza Sativa L.)

Rice production faces challenges due to biotic stresses influenced by climate fluctuations. Brown
plant hopper (BPH), being a major biotic stress in rice, significantly impacts yield. It is a major
insect pest that causes 10%–30% annual yield loss in Asia by direct phloem feeding and
transmitting viral diseases like rice ragged stunt virus (RRSV) and rice grassy stunt virus
(RGSV). With an objective of BPH resistance integrated with yield, two cross derivatives in
BC 2 F 1 generation were developed by crossing susceptible, high-yielding, slender grain rice
variety, Telangana Sona (TS), with two resistant parent’s viz., 10-3 and M229. These
backcrosses were studied to investigate genetic variability, correlation, and principal component
analysis for yield and yield-related traits. Both crosses exhibited high GCV, PCV, and high
heritability coupled with high genetic advance for productive tillers per plant and single plant
yield, indicating a preponderance of additive gene action. Correlation analysis demonstrated a
significant positive association of single plant yield with plant height, productive tillers per plant,
and filled grains per panicle in both crosses. PCA revealed a cumulative variance of of94.72%
and 77.23% from plant height, productive tillers per plant, kernel breadth, days to 50 %
flowering, days to maturity, kernel length, and filled grains per panicle in TS X 10-3 and filled
grains per panicle, 1000 seed weight, kernel breadth, days to 50 % flowering, days to maturity,
kernel length/breadth ratio and panicle length in TS X M229 respectively, indicating their
substantial contribution to variability. Consequently, the selection of backcross-derived lines
based on these traits would be the most appropriate strategy for yield improvement.