Morphological characterization of strong culm traits and their association with yield performance in rice (Oryza sativa L.)

Lodging resistance is an important characteristic for enhancing the productivity and stability of rice (Oryza sativa). This study assessed the genetic variability of 81 rice germplasm lines from southern India, focusing on 12 traits contributing for culm structure and yield. A field experiment was conducted in a randomized block design, and the recorded phenotypic data were analysed employing descriptive statistics, variability estimates, correlation analysis, and Principal Component Analysis. The findings revealed high genotypic coefficient of variation and phenotypic coefficient of variation, along with high heritability and genetic advance for culm length of fourth internode, section modulus of fourth internode, and single plant yield. These results indicate strong genetic control and the potential for effective selection for culm traits. Additionally, SPY showed strong positive correlations with the number of productive tillers and hundred seed weight. Plant height, culm length, and culm thickness also exhibited strong correlations with section modulus of fourth internode, highlighting their importance in lodging resistance. The PCA identified three major components that explained 56.16% of the total variability, with culm related traits and yield traits being key contributors. These findings highlight the significance of culm morphology traits in breeding programs and provide valuable insights for parental line selection to enhance rice productivity and develop non-lodging cultivars.