Influence of mucilage of Aloe vera (L.) Burm.f, Hibiscus rosa-sinensis (L.), Abelmoschus esculentus (L.) Moench and Neolitsea cassia (L.) Kosterm on seed germination and seedling growth of Vigna radiata (L.)

Abstract

Crop seed germination is one of the fundamental determinants of agricultural productivity and a process influenced by various biotic and abiotic factors. Understanding and optimizing seed germination immensely helps to enhance crop yields and ensure food security via better crop establishment and growth. This study aimed to identify the most effective botanical mucilage extract for enhancing the germination and seedling growth of Vigna radiata among various leaf and pod extracts. Pure leaf mucilage of Aloe vera (T1), Hibiscus rosa-sinensis. (T2), Neolitsea cassia (T3), and mature pod mucilage of Abelmoschus esculentus (T4) were used as the treatments along with uncoated V. radiata seeds as the control (T0). Leaves of T1 – T3 and mature pods of T4 were collected, washed, ground, and the paste was squeezed to obtain pure mucilage extracts. Surfaced sterilized V. radiata seeds were immersed in the T1 – T4 for ten minutes and placed in sterilized petri dishes layered with moistened filter paper. They were incubated at 27 oC under a relative humidity of 83 %. The number of germinated seeds was counted daily and the mean germination rate (MGR), germination time (MGT), germination index (MGI), germination energy (MGE), and coefficient of velocity of germination (MCVG) of V. radiata were calculated. The root and hypocotyl lengths of seedlings were measured during the final data collection. Six replicates were performed for each treatment and control with 120 V. radiata seeds. Based on the number of germinated seeds, T3 was identified as the least active mucilage extraction, and the same experiment was repeated with 1:1 diluted mucilage extraction (T5) under the same conditions. Data were analyzed using one-way ANOVA (at α = 0.05) and PCA in 'R' software. T2 significantly enhanced seed germination recording the highest MGI (19.1 ± 0.88), MCVG (98.3 ± 2.89 %), and lowest MGT (0.7 ± 0.05 days) while T3 reduced both germination and seedling growth (p < 0.05). According to PCA, both A. vera and H. rosa sinensis were identified as the most effective treatments. T3 and T4 were identified as the least effective and moderately effective extracts respectively. The extract of A. vera was 24.31% more effective and the extract of H. rosa-sinensis was 42.25% more effective in promoting the rapid germination of V. radiata seeds compared to the control. The study concluded that H. rosa-sinensis and A. vera can be used to enhance V. radiata seed germination as lowcost alternatives to chemical seed germination enhancers.