Floral Maturation Indices of African Yam Bean (Sphenostylis stenocarpa Hochst Ex. A. Rich) Harms (Fabaceae)

Abstract

The present investigation aimed at understanding the floral morphology and maturation indices of African yam bean (AYB), knowledge of which is very relevant for the crop's improvement programs. Ten accessions of AYB were grown in rows of ten plants, in three replications. Thirty anthesized flowers were collected from each accession for the study of the floral parts. The progressive development of flowers from buds was additionally investigated. AYB flower is large and complete. The calyx was fused and the corolla has five petals (one standard, two wings and two keels). AYB accessions exhibited racemes and indeterminate form of inflorescence. The mean standard petal length and width were 2.94 cm and 3.59 cm respectively. The androecium which surrounded the carpel consists of ten filaments (nine fused, one free). The gynoecium comprised flattened stigma with hairy edge. The mean length of style and ovary was 1.60 cm and 1.00 cm respectively. A distinct purple line (along the enclosing end of the standard petals) became visible at flower bud stage, when bud length reached 2.2 cm -2.7 cm. Anthesis occurred within 24 hours beyond this stage and petals dropped a day after anthesis. Certification of stigmatic receptivity and pollen fertility may be dependent on the above information. The present study further provides basis for the understanding of pollination mechanism and breeding system within the species.

Morphological characterization and genotypic identity of African yam bean (Sphenostylis stenocarpaHochst ex. A. Rich. Harms) germplasm from diverse ecological zones

“…The IITA AYB descriptor of Adewale and Dumet (2010) was used as a guide for evaluating the 31 qualitative and quantitative traits (online Supplementary Table S4) recorded on randomly selected five plants for each accession. The qualitative characteristics were recorded based on visual observation.…”

Introduction to Africa Yam Bean (Sphenostylis Stenocarpa (Hochst. Ex A. Rich.) Harms)

“…Conventional breeding methods such as hybridization and other breeding techniques have been adopted by few researchers in improving the crop though meaningful results have not been recorded. Little understanding of the crop floral biology and high rate of hand pollination failure are limiting factors in genetic improvement in the crop [37,67]. The reproductive barriers limiting AYB improvement by plant breeders could be overcome by employing tissue culture and micropropagation as it can produce fertile haploid crops.…”

Variations in Phenotypic Characteristics of Vigna Unguiculata (L) Walp. Seeds Sourced From Open Markets in Benin City, Nigeria

“…Cowpea is a staple food in Nigeria and in Africa due to its hardiness, versatility, and popularity. The seed shapes, sizes, colours, texture, pigmentation, and growth patterns of cowpea varieties in Nigeria differ greatly [1][2][3][4][5][6][7][8][9][10]. Unfortunately, the ever-changing environment, volatile global economy, and intensification of low-input agricultural production have resulted in a dramatic increase in soil depletion and nutrient depletion in many Sub-Saharan African regions [11].…”