Assessment of Genetic Variability, Character Association and Path Analysis of Sweet Potato (Ipomoea batatas L. Lam.) Accessions Using Morphological Characters

Abstract

The present study was conducted on 100 distinct sweet potato accessions during Rabi season 2022 - 23 to address the limited understanding of genetic variability and trait associations among the underutilized accessions influencing yield efficiency in sweet potato, a nutritionally important crop with significant potential for food security. An augmented block design with four blocks and two check varieties was utilized to assess twelve quantitative characters. Analysis of variance revealed significant differences among treatments and checks for most traits, indicating substantial genetic variability. Phenotypic coefficient of variation (PCV) values was marginally higher than genotypic coefficient of variation (GCV), suggesting limited environmental influence on trait expression. High heritability coupled with high genetic advance was observed for traits such as tuber girth, number of tubers per plant, average tuber weight, sugar content, dry matter and tuber yield per plant, highlighting their suitability for early generation selection. Correlation and path analysis identified tuber length, tuber girth, number of tubers per plant and average tuber weight as significantly and positively associated with tuber yield. Path coefficient analysis further revealed that average tuber weight and number of tubers per plant had the strongest direct effects on yield, while tuber length, tuber girth and mature leaf size exerted notable indirect effects. The findings highlight substantial genetic diversity among accessions and provide valuable insights for breeding programs aimed at improving yield and ensuring food and nutritional security.