Genetic mechanism of heterosis and inbreeding depression for grain physical quality traits in elite rice (Oryza sativa L.) crosses Lingaiah N.1,*, Raju Ch. Surender2, Sarla N.3, Radhika K.4, Venkanna V.5, Reddy D. Vishnu Vardhan6 1Agricultural Research Station (PJTSAU), Kampasagar, Babusaipet Post, Nalgonda-508 207TS 2ICAR-Indian Institute of Rice Research, Rajendranagar, Hyderabad–500 030 3Division of Crop Improvement, ICAR-Indian Institute of Rice Research, Rajendranagar, Hyderabad–500 030 4Department of Seed Science and Technology, Advanced Post Graduate Centre, Lam, Guntur-522 034, Andhra Pradesh 5Agricultural College, Aswaraopet, Kothagudem-Bhadradri (Dist) Telanganan state 507 301 6Jayashankar Telangana State Agricultural University (PJTSAU), Rajendranagar, Hyderabad, India- 500 030 *E-mail: nlrashi80@gmail.com
Online published on 27 December, 2023. Abstract In the present study, heterosis and inbreeding depression were studied to understand the type of gene action and to identify the best crosses for hybrid or varietal development. A lesser amount of heterosis was observed for hulling, milling percentages, and kernel length, the chief reason for the non-expression of heterosis may be due to the complete association of the dominant genes in the parents without any over-dominance. Only three hybrids (WGL-32100 x NH-787, RP-Bio-5478-166 x RP-Bio-5478-176, and RP-Bio-5478-185 x -686) exhibited heterosis w ith insignificant inbreeding depression hence, selection would be effective to improve head rice recovery in these combinations. The best specific crosses with a high amount of heterosis and high per se performance (L/B ratio > 3.5) with no inbreeding depression for kernel L/B ratio are MTU 1010 x WGL-32100, MTU 1010 x RP-Bio-5478-270, MTU 1010 x RP-Bio-5478-166, MTU 1010 x RP-Bio-5478-185 and MTU 1010 x NH-787. In these crosses, selection would be highly effective due to the prevalence of additive gene effects. Top Keywords Rice, Heterosis, Inbreeding depression, Additive gene action. Top |