Bambara groundnut (Vigna subterranea) seed quality in response to water stress on maternal plants

Abstract

Farmers who still cultivate bambara groundnut (Vigna subterranea) rely on landraces and seed retained from previous harvests. Given that the crop is typically cultivated in semi-arid regions, seed quality of farmers' retained seed might be compromised due to water stress experienced by maternal plants during production. The aim of this study was to determine the effect of water stress on maternal plants on subsequent seed quality of bambara groundnut. A single bambara groundnut landrace was characterised into four distinct selections based on seed coat and speckling colour. Initial seed quality (viability and vigour) was evaluated prior to planting seed in a field trial under irrigated and rainfed conditions. Final yield and yield components were determined at harvest. Thereafter, seed quality (viability and vigour) of progeny of different landrace selections was evaluated. Yield was lower under rainfed than irrigated conditions. Overall, subsequent seed quality showed improvement from initial seed quality of the original seedlot. Seed viability was higher in seeds produced under irrigated than rainfed conditions. Seed quality of bambara groundnut may be reduced underwater-limited production conditions. Seed enhancement practices such as priming may assist farmers to achieve better emergence. In the long term, seed production should be done under optimum conditions in order to achieve high-seed quality.

Natural Genotypic Variation Underpins Root System Response to Drought Stress in Bambara Groundnut [Vigna subterranea (L.) Verdc.]

“…This research builds on a prior study by Mateva et al (2020) , which identified the presence of RSA variation in eight non-stressed bambara groundnut core parental lines, i.e., single genotypes derived from landraces from various agroecologies. These findings corroborated prior physiological evaluation ( Mwale et al, 2007 ; Jørgensen et al, 2010 , 2012 ; Berchie et al, 2012 ; Mabhaudhi and Modi, 2013 ; Mayes et al, 2013 ; Al Shareef et al, 2014 ; Chibarabada et al, 2015a , b ; Chai et al, 2016b ; Nautiyal et al, 2017 ) which had been largely limited to aboveground phenotyping. The present results show strong genotype-specific differences in root morphology in response to DS within the eight bambara groundnut core parental lines.…”

“…Progress in drought phenotyping in bambara groundnut for the past 30 years has been elucidated by above ground shoot traits ( Collinson et al, 1997 , 1999 ; Jørgensen et al, 2010 ; Sesay et al, 2010 ; Vurayai et al, 2011a , b ; Mabhaudhi and Modi, 2013 ; Chibarabada et al, 2015a , b ; Chai et al, 2016a , b ; Muhammad et al, 2016 ). This has proved fruitful, revealing the potential in selecting individual lines with improved drought resistance.…”

Spectrophotometric Quantification of Phytic Acid During Embryogenesis in Bambara groundnut (Vigna subterranea L.) Through Phosphomolybdenum Complex Formation

“…Oxidative stress is a common abiotic related problem that affects seeds in maturation phase when seed tissues undergo dehydration and viability. Chibarabada et al (2015) reported higher levels of phenolics and drought tolerance in dark coloured Bambara groundnut seeds compared to light coloured seeds. However, the results were limited to phenolics and are therefore not representative of phytic acid which has a novel role in seed protection against oxidative stress (Pilu et al, 2005).…”

Root Foraging Capacity in Bambara Groundnut (Vigna Subterranea (L.) Verdc.) Core Parental Lines Depends on the Root System Architecture during the Pre-Flowering Stage

“…Considering the increasing shortage of agricultural water and that no single shoot trait has yet been identified for its unique and dominant contribution to drought resistance [8][9][10][11][12][13][14][15][16][17][18][19], current bambara groundnut breeding efforts could investigate root system function and its manipulation in order to improve water and nutrient capture [20][21][22]. Bambara groundnut genotypes, such as S19-3 (from Namibia) are promising candidates for investigating and expanding plant ideotypes suited for dry environments [11,23].…”