Assessment of Somaclonal Variation for Growth, Yield, and Grain Traits in Second-Generation Rice Somaclones Derived from the Aromatic Landrace Ranisalute

Abstract

Somaclonal variation is considered an effective technique to introduce genetic variability in crop plants and selecting superior genotypes with desirable agronomic traits. A field experiment was conducted to evaluate twenty-eight (28) rice somaclones (2nd generation) developed from Ranisalute, a popular aromatic landrace of the Khulna district, during Aman season (August-January, 2022) at Professor Dr. Purnendu Gain Field Laboratory of Agrotechnology Discipline, Khulna University following a Randomized Complete Block Design (RCBD) with three replications. The objective was to identify morphological variations among the somaclones and to select promising yield contributing somaclone/s compared to the parental genotype. Analysis of variance revealed that variations exist in different parameters except for secondary branches hill-1 , and panicle length among the somaclones. But in comparison with control using Dunnett test, most of the somaclones were statistically similar for all the parameters. Among the evaluated genotypes, RSC-2021-16 showed maximum number of total tillers hill-1 and effective tillers hill⁻¹, maximum grain length, highest 1000- grain weight and maximum grain weight hill⁻¹. RSC-2021-17 recorded the highest number of grain panicle-1 , filled grains panicle⁻¹ and maximum leaf area. RSC-2021-27 produced the lowest grain breadth. Cluster analysis grouped the genotypes into four major clusters, where Cluster II and Cluster IV exhibited the highest inter-cluster distance, indicating greater genetic divergence and potential for heterosis and transgressive segregation. Correlation analysis revealed strong positive associations of effective tillers hill⁻¹, grain length, and 1000-grain weight with grain weight hill⁻¹ and harvest index, suggesting their usefulness as indirect selection criteria for yield improvement. The study recommends further investigation of the selected somaclones from Cluster II and Cluster IV, along with superior genotype RSC-2021-16 from Cluster I in the third generation, including their evaluation of genetic stability and quality-related traits.