Pyramiding of qDTY and qDTY into rice mega-variety Samba Mahsuri-Sub1: physiological performance under water deficit conditions.

Unlabelled: Water deficit is a crucial factor causing huge loss to rice productivity. The present study aimed to develop a multiple stress tolerant genotype by pyramiding drought tolerant yield QTLs qDTY and qDTY into high yielding rice variety Samba Mahsuri Sub-1(SMS) through marker assisted pyramiding. To achieve this six introgression lines of SMS carrying qDTY (SAB) were crossed with DRR-50, an Essentially Derived Variety of SMS carrying qDTY. The SAB lines are taller than SMS due to tight linkage between qDTY and wild type SD-1. Therefore, F generation of crosses were screened for recombinants between and qDTY. Phenotyping of 1530 F plants representing three F populations from 35 F hybrids, identified 305 dwarf plants. Three dwarf F plants along with three others carrying qDTY and qDTY. were forwarded to F generation. From the six F (SABD) lines fourteen pyramided progenies were selected and forward to F generation. The six SABD F lines SABD-7, SABD-8, SABD-9, SABD-76, SABD-79 and SABD-80 along with parents were evaluated under moisture stress (MS) for various physiological parameters. Chlorophyll and relative water content were more, while canopy temperature and malonaldehyde (MDA) content were lesser in SABD lines compared to parents indicating tolerance under MS. Variance due to genotypes was highly significant for all the yield related traits except test weight. Based on seed morphology, agronomic characters and physiological parameters six superior lines SABD-9-3, SABD-9-2, SABD-9-6, SABD-9-7, SABD-76-2 and SABD-76-6 performing better under MS were identified, which could be released after multi-location evaluation.

Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01387-5.