Evaluation of Seed Morphometrics, Germination and Oil Content of Collected Castor Landraces

Abstract

Castor (Ricinus communis L.) is a valuable non-edible oilseed crop with industrial and medical applications, known for its high seed oil content (35–65%) and ricinoleic acid (85–90%). This study evaluated seed morphometrics, germination, and oil content of 15 castor landraces collected from six sites in Ilorin, Kwara State, Nigeria. Morphological traits such as stem color, leaf petiole texture, seed color, and size were analyzed, revealing significant variability. Light green stems (73.3%), dark chocolate seeds (66.7%) were predominant, while white, and light brown seeds were rare. Seed size varied, with small seeds (60%) being most common.  Germination parameters showed high variability: germination percentage ranged from 32.67% to 78.00%, with a mean of 55.82%, while mean germination time varied from 3.78 to 8.75 days. Seed oil content ranged from 23.89% to 41.77%, with Samples 15 (41.77%) and 14 (39.72%) exhibiting the highest yields. Morphometric analysis using ImageJ software revealed significant differences in seed traits such as area, perimeter, and circularity, indicating diverse seed shapes and sizes. Correlation analysis showed weak relationships between seed morphometrics and oil content, suggesting that seed size and shape are poor predictors of oil yield. The findings highlight the genetic diversity among castor landraces in Ilorin, with implications for breeding programs aimed at improving oil yield and germination performance. The study underscores the need for integrated approaches combining morphological, biochemical, and genomic data to optimize castor cultivation for industrial applications.