Aloe Vera Leaf Extract as a Biopriming Agent to Improve Germination Performance in Bitter Gourd (Momordica charantia) Seeds

Abstract

Bitter gourd (Momordica charantia L.), locally known as “Karela,” is an important summer vegetable in Pakistan belonging to the Cucurbitaceae family. Its cultivation is often constrained by a thick seed coat that restricts water uptake and gas exchange, leading to poor germination. Seed priming has emerged as an effective strategy to overcome this limitation and improve early seedling vigor. In this study, Aloe vera leaf extract (AVE), containing bioactive compounds such as vitamins, salicylic acid, enzymes, and amino acids, was evaluated as a biological priming agent. A Completely Randomized Design (CRD) was employed with treatments including non-primed control, hydropriming, and osmopriming with AVE (0.5 and 2.5%) for 24 and 48 hours. Germination parameters such as emergence speed, germination percentage, germination rate index, mean germination time, vigor index, root length, root-to-shoot ratio, and total biomass were recorded. Results showed that seed priming substantially enhanced germination and seedling growth. The most effective treatment was soaking seeds in 2.5% ascorbic acid for 48 hours, which achieved 90% germination energy, 88.15% seed moisture, and significantly higher root growth compared to untreated seeds. Shorter priming durations or lower concentrations (0.5% AVE or hydropriming for 24 hours) also improved results, but less consistently. Overall, priming with 2.5% ascorbic acid for 48 hours was identified as the most effective approach for improving bitter gourd seed germination and vigor, offering a practical method for growers to enhance crop establishment.