Investigation on Genetics Controlling the High Head Rice Recovery under High-Temperature Conditions

Abstract

The global rise in temperatures is negatively impacting head rice recovery (HRR), which is crucial for food security. To address this, a study was conducted during rabi (high temperature) 2023-24, using Six basic generations (P1, P2, F1, F2, BC1P1 and BC1P2) of the cross RNR 25842 × SVIN 301 were raised at Rice Research Unit, ARI. The results of the scaling tests (A, B, C, D) showed that scales B, C and D were significant while scale A was non-significant. The significance of three out of four scales clearly indicates that the additive–dominance model is inadequate and that epistasis plays an important role in the inheritance of the head rice recovery. The six-parameter model further partitioned the generation means into mean effect (m), additive (d), dominance (h) and epistatic components (i, j, l) and revealed that all the genetic components (m, d, h, i, j, l) were highly significant and confirming the presence of epistasis in the inheritance of head rice recovery, particularly duplicate epistasis, play a key role in head rice recovery inheritance, complicating breeding efforts. These findings highlight the complex genetic basis of head rice recovery and the need for targeted breeding strategies to improve head rice recovery under changing climate conditions.