Genetic Variability, Heritability, and Clustering Pattern Exploration of Bambara Groundnut (Vigna subterranea L. Verdc) Accessions for the Perfection of Yield and Yield-Related Traits

Abstract

Bambara groundnut (Vigna subterranea L. Verdc.) is considered an emerging crop for the future and known as a crop for the new millennium. The core intention of this research work was to estimate the variation of landraces of Bambara groundnut considering their 14 qualitative and 27 numerical traits, to discover the best genotype fitted in Malaysia. The findings of the ANOVA observed a highly significant variation ( p ≤ 0.01 ) for all the traits evaluated. There was a substantial variation (7.27 to 41.21%) coefficient value, and 14 out of the 27 numerical traits noted coefficient of variation CV ≥ 20 % . Yield (kg/ha) disclosed positively strong to perfect high significant correlation ( r = 0.75 to 1.00; p ≤ 0.001 ) with traits like fresh pod weight, dry pod weight, and dry seed weight. The topmost PCV and GCV values were estimated for biomass dry (41.09%) and fresh (40.53%) weight with high heritability (Hb) and genetic advance (GA) Hb = 95.19 %, GA = 80.57 % and Hb = 98.52 %, GA = 82.86 %, respectively. The topmost heritability was recorded for fresh pod weight (99.89%) followed by yield (99.75%) with genetic advance 67.95% and 62.03%, respectively. The traits with Hb ≥ 60 % and G A ≥ 20 % suggested the least influenced by the environment as well as governed by the additive genes and direct selection for improvement of such traits can be beneficial. To estimate the genetic variability among accessions, the valuation of variance components, coefficients of variation, heritability, and genetic advance were calculated. To authenticate the genetic inequality, an unweighted pair group produced with arithmetic mean (UPGMA) and principal component analysis was executed based on their measurable traits that could be a steadfast method for judging the degree of diversity. Based on the UPGMA cluster analysis, constructed five distinct clusters and 44 accessions from clusters II and IV consider an elite type of genotypes that produce more than one ton yield per hectare land with desirable traits. This study exposed an extensive disparity among the landraces and the evidence on genetic relatives will be imperative in using the existing germplasm for Bambara groundnut varietal improvement. Moreover, this finding will be beneficial for breeders to choose the desirable numerical traits of V. subterranea in their future breeding program.

Genetic Analysis and Selection Criteria in Bambara Groundnut Accessions Based Yield Performance

“…However, low GCV and high PCV were registered for the other traits (Table 6). Similar findings were also reported for most of the characteristics of the estimates of genetic parameters in Bambara groundnut, the variation in the pod yield characteristics, and the heritability estimates in some cultivars of Bambara groundnut by [7,17]. Note: σ 2 g = genotypic variance, σ 2 s = seed weight variance, σ 2 e = error of variance, σ 2 p = phenotypic variance, PCV = phenotypic coefficient of variation, GCV = genotypic coefficient of variation, h 2 B = broad-sense heritability, GA = genetic advance.…”

Bambara Groundnut (Vigna subterranea L. Verdc): A Crop for the New Millennium, Its Genetic Diversity, and Improvements to Mitigate Future Food and Nutritional Challenges

“…Loosening and earthing up the soil had a positive effect on pod formation and pod growth under and above the soil surface after successful fertilization and the peg goes into the soil. The pod is usually 17.96-53.54 nm long and contains one or two seeds, 7.54-22.48 nm long [37]. Plant population density should be held between 6 and 29 plants•m −2 for optimal growth and development, and it requires mild temperatures, bright sunlight, and evenly distributed precipitation.…”

“…During germplasm screening in Ghana and Tanzania, it was reported that Bambara groundnut production varied from below 10 kg ha −1 to above 800 kg ha −1 [42]. In tropical regions such as Malaysia, the yield of Bambara groundnut was recorded as 380.48 to 1635.29 kg ha −1 [37], with an average of 1180 kg ha −1 [53]. To evaluate the yield potentiality of Bambara groundnut in African regions, Azam-Ali et al [41] applied computer-based analytical tools (CBATs), especially crop simulation models (CSM) and geographic information systems (GIS).…”

“…The resulting qualitative (Figures 8 and 9) criteria were taken as guidelines: growth habits; the shape of the terminal leaflet; hairiness of stem; entirely prolonged terminal leaflet color; petiole pigmentation; pod size, shape, texture, and color; and seed color, shape, and pattern. Aliyu et al [39] and Khan et al [37] summarized the findings of several researchers on Bambara groundnut landrace accumulation and investigation as well as highlighted the prominent distinct phenotypic characteristics in Table 4. To date, there have been little or no studies on qualitative traits such as photoperiodic reaction, banner and wing coloration, or stem hairiness, owing to the lack of an accepted procedure for photoperiodic response and large-scale phenotyping.…”

“…Reported major qualitative trait variation in Bambara groundnut races (adopted from Aliyu et al[39] and Khan et al[37]). …”