Diversity Analysis of Seed Characters and Seedling Performance of Selected Accessions of Psophocarpus tetragonolobus (L.) DC

Abstract

Background: Winged bean (Psophocarpus tetragonolobus) is an underutilised legume with high protein content, edible parts, and nitrogen-fixing ability, but its potential is hindered by limited research, anti-nutritional factors, and lack of breeding advancements. Assessing genetic diversity and seedling performance can help identify elite genotypes for crop improvement. Aims: The aim of this study was to investigate the diversity within twenty-five (25) accessions of winged bean obtained from IITA, Ibadan, Nigeria and to identify genotypes with better performance for the enhancement of the winged bean germplasm. Study Design: This experiment was laid out in a Randomised Complete Block Design (RCBD) with five replications. Place and Duration of Study: Seeds of twenty-five accessions of Psophocarpus tetragonolobus plant were obtained from International Institute of Tropical Agriculture (IITA), Ibadan, Oyo State, Nigeria in August 2023. The sowing and analysis of quantitative parameters such as seed length, seed width and seed weight were carried out at the Department of Botany, Faculty of Science, Obafemi Awolowo University, Ile-Ife (N 07 ᵒ31.15’; E 04 ᵒ31.58’) between August 2023 and December 2023. The seed performance evaluation was investigated at the Seed Science Laboratory of the Department of Crop Production and Protection, Faculty of Agriculture, Obafemi Awolowo University, Ife (N 07ᵒ31. 19’; E 04ᵒ31.33’) between January 2024 and March 2024 Methodology: Seed morphometric parameters and seedling performance were documented and analysed for twenty-five accessions of winged bean obtained from IITA, Ibadan. The quantitative traits were measured instrumentally, while the germination and seedling parameters were determined over 14 days following ISTA guidelines. Data were analysed using ANOVA, with mean separation by LSD at P ≤ 0.05. Results: The analysis of variance revealed that there were significant differences in the seed and seedling performances of the selected winged bean accessions studied with respect to seed length, seed breadth, seed weight, germination percentage, germination index, germination rate index, shoot length, number of leaves, fresh shoot weight, dry shoot weight and vigour index. Genotypes such as TPt-12, TPt-15 and TPt-43 with the highest seed length; TPt-15 with the highest seed breadth; TPt-53 with the highest seed weight                              and germination percentage; TPt-42 with the highest germination index; TPt-53 with the lowest germination rate index; TPt-48 with the highest number of leaves; TPt-2 with the highest dry shoot weight and                 TPt-53 with the highest vigour were identified for breeders to explore in further enhancement of the plant studied. Conclusion: The 25 winged bean accessions studied demonstrated remarkable genetic diversity for seed morphometric traits (seed length, breadth, and weight) and seed performance traits (germination percentage, germination index, germination rate index, vigour index, shoot length, number of leaves, and shoot weight). Genotypes such as TPt-2, TPt-10, TPt-12, TPt-15, TPt-42, TPt-43, TPt-48, and TPt-53 identified in this study as having superior performance could serve as promising materials for direct varietal development and as parental materials for breeding vigorous winged bean cultivars.