COMBINING ABILITY FOR YIELD, OIL CONTENT, AND PHYSIO-BIOCHEMICAL CHARACTERS OF CANOLA (BRASSICA NAPUS L.) UNDER SALT STRESS CONDITIONS

Abstract

Creating a half-diallel cross succeeded among seven diverse canola genotypes. The obtained 21 F1 hybrids with their seven parents underwent three salinity stress levels exposure—3.91 dsm1 (Normal), 6.24 dsm-1 (S1), and 7.81 dsm-1 (S2) —during the 2020/2021 growing seasons. Salinity treatments significantly reduced days to 50% flowering, plant height, number of primary branches, pods/plant, 1000-seed weight, seed yield/plant, seed oil content, relative water content, calcium, potassium, and the ratio between K+ and Na+ compared with a normal condition. Proline content, osmotic pressure, and Na+ were considerably higher under salinity stress conditions. Highly significant differences showed among the parents and hybrids for all traits across the tested environments. General (GCA) and specific (SCA) combining ability effects were highly significant for all attributes. The parental genotypes Serw4 and Pactol resulted as good general combiners for increased seed oil content (SOC), seed yield/plant (SYPP), and some of its components in research environments. The hybrid combinations H2/S × Serw4 and Serw4 × Serw6 were good specific combiners for days to first flower (DTF), number of primary branches (NPB), number of pods per plant (NP), a thousand seed weight (TSW), seed yield per plant (SYPP), seed oil content (SOC), proline content (ProC), Ca++, and K+/Na+. The SDS-PAGE analysis of seed proteins indicated high levels of genetic variability and revealed some vital biochemical markers for salt tolerance.