The relationship between panicle architecture traits with the grain count per panicle and yield per plant of upland black rice from East Nusa Tenggara

Abstract The panicle is a critical trait for rice productivity, serving as the foundation for grain development and comprising key components such as the main axis, primary branches, secondary branches, and tertiary branches. This study aimed to evaluate the relationships between various panicle architecture traits, grain count per panicle, and grain yield per plant. The research was conducted in Lasiana Village, Kelapa Lima District, Kupang City, from July to December 2019, using twelve accessions of upland black rice from East Nusa Tenggara in a randomized treatment design with three replications. The results showed that panicle architecture traits significantly influenced grain count per panicle, with the number of secondary branches exhibiting the strongest positive correlation (r = 0.83). Secondary branches accounted for 68% of the variation in grain count per panicle. However, increased grain count did not translate into higher grain yield per plant, likely due to reduced grain-filling capacity in compact panicle structures. These findings offer valuable insights for breeding programs focused on enhancing the yield potential of upland black rice by selecting for favorable panicle traits.