Correlation and path coefficient analysis of grain yield and its components in toraja land-race aromatic rice mutants induced by heavy ion beam

Background and Objective: The development of local aromatic rice cultivars has become a distinct segment market for plant breeders and producers. This study aimed to identify the Genotypic Coefficient of Variation (GCV), Phenotypic Coefficient of Variation (PCV), heritability (h²bs), a close relationship between traits and the direct and indirect effect of aromatic rice lines based on traits among the population observed. Materials and Methods: The field experiment was conducted in Enrekang Regency, South Sulawesi, Indonesia (650 m above sea level), from May-October, 2018. Toraja Local Aromatic Rice "Pare Bau" were irradiated with 300 keV µmG¹ (10 Gy) Argon ion at RIKEN Nishina Center, Wako-shi, Saitama, Japan. Eighteen aromatic rice lines from M₃ generation and one control (non-irradiated) were transplanted in the paddy field. Results: Results showed that the traits observed had a coefficient of variation of moderate to high. All the lines tested showed high heritability associated with the genetic advance as percent of mean (GAM) for all traits, indicating that these traits could be useful to be selected. Based on correlation analysis, the traits that support high yield were the number of panicles, grain weight per panicle and percentage of fertile grain. Moreover, path analysis showed two essential and useful selection traits for grain yield improvement in aromatic rice mutant lines of third generations (M₃), i.e., number of panicles and percentage of fertile grain. In the brief of lines, G₄ is the highest yield per plant. Conclusion: It can be concluded that variability observed among lines associated with high yield could be exploited in rice breeding, especially mutant aromatic rice.