Estimation of the Genetic Parameters Associated with High-yielding and Early Harvesting in Rice

Climate change is threatening global food security, particularly rice production. This makes it crucial to identify rice cultivars that are both high-yielding and suitable for early harvesting. This study evaluated combining ability and estimated genetic parameters of F1 seeds from crosses among nine rice genotypes.

The study was conducted at the Greenhouse of the Faculty of Agriculture, Universitas Gadjah Mada, Yogyakarta, Indonesia, from September 2022 to March 2024. The study employed a North Carolina II (NC II) mating design and was arranged in an augmented randomized block design (ARAB) with three rows and six columns. Genotype was the fixed effect and block was the random effect.

The results showed that 100-seed weight exhibited considerable General Combining Ability (GCA) and rice female genotype G4 had the most beneficial additive effect. Estimation of genetic parameters revealed that most were influenced by non-additive gene action. 100-seed weight showed the most significant additive variation and narrow-sense heritability, making it a good candidate for early-generation selection. Assessment of Specific Combining Ability (SCA), genotype performance and hierarchical clustering indicated that G4/GB was the most advantageous rice line, combining high yield and early harvest. These findings establish a strong foundation for developing high-quality rice that is resilient to climate change.