“Genetic Architecture and Line × Tester Analysis for thermotolerance and Yield in Indian Mustard (Brassica juncea L.)”

Abstract

The present study focused on the general combining ability (GCA), specific combining ability (SCA), standard heterosis (SH), and per se performance of mustard genotypes for various physio-morphological-quality traits. The best general combiners identified based on GCA and individual performance were NRC-DR-2 (SLW at 30 DAS, CC at 60 DAS, LAI at 30 DAS), RH-30 (SLW at 60 DAS, PB/Pl), Rajendra Sufalam (SLW at 60 DAS, 1000 SW), NDRE-7 (Early DFFO & DPM), TPM-1 (SS), and RAURD-78 (PB/Pl). Among the studied hybrids, the top yielders were RH-30/RAURD-78, Rajendra Sufalam/NDRE-7, PM-25/RAURD-78, and RH-8814/TPM-1, based on SCA, SH, and per se performance. The RH-30/RAURD-78 cross, which involved two good general combiners, is a promising candidate for heterosis breeding. Additionally, the Rajendra Sufalam/NDRE-7 and PM-25/RAURD-78 crosses, which involved HxL or LxH general combiners, may generate desirable segregants suitable for transgressive breeding programs. The four best economic crosses for seed yield per plant (SY/pl)—RH-30/RAURD-78, Rajendra Sufalam/NDRE-7, PM-25/RAURD-78, and RH-8814/TPM-1—showed superior heterosis for key traits such as SLW (60 DAS), CGR, PH (60 DAS), PB/Pl, and SB/Pl. These superior F₁ hybrids demonstrated significantly higher yield potential along with desirable morpho-physiological and quality traits, making them valuable for future breeding endeavours aimed at enhancing mustard productivity and resilience