Yield stability and economic heterosis analysis in newly bred sunflower hybrids throughout diverse agro-ecological zones

Abstract

Exploration of heterosis is a strategy for enhancing sunflower yield and productivity. In India, the greatest constraints on sunflower production are stagnant and inconsistent yields. By raising them in a variety of ecological conditions, stable per-se performance with the highest yielding potential sunflower hybrids were selected. Sustainable agriculture requires the use of desirable hybrids with high seed yields and oil content too. By making three distinct crossing sets from 32 sunflower genotypes, 11 cytoplasmic male sterility (CMS), and 21 restorer lines, a total of 124 hybrids were developed (comprising both lines and tester). After extensive field evaluation of all hybrids, only eight superior F₁s belonging to all three sets, as well as the three national control hybrids KBSH-53, LSFH-171, and DRSH-1, were selected for stability analysis in four agro-ecological regions of West Bengal, India viz., Nimpith, Baruipur, Bankura, and Berhapore. The genetic stability of several phenotypic characters was assessed using statistical models that examine genotype-environment interaction (G × E) in multi-locational yield trials. In this experiment, the performance of hybrids under various environmental circumstances over two-year periods was measured using regression coefficient (b_i) and deviations from regression (S²d_i). With the exception of genotypes CMS-852A × EC-601751 for volume weight (0.9335) and CMS-302A × EC-623011 for head diameter (0.0905) and volume weight (0.6425), all sunflower genotypes for all concerned traits had extremely minor and negligible deviations from regression (S²d_i), which showed significant values. The genotypes having insignificant values of S²d_i were more stable. The economic heterosis of these novel hybrids was also quantified. CMS-302A × EC-623011 in which seed yield was recorded 20.90, 20.91, 20.95 and 20.90% higher than DRSH-1 at Nimpith, Baruipur, Bankura and PORS (Berhampur), respectively. The research revealed that CMS-302A × EC-623011, CMS-853A × EC-623027 and P-2-7-1A × EC-512682 exhibited good seed production and stability for critical agronomic parameters in addition to oil content. As a result, the current researches enlighten to find out how stable the expression of important economic traits in sunflower hybrids is.

Keywords: Economic heterosis; G × E interaction; Hybrids; Multi-location trials; Seed and oil yield; Stability; Sunflower.