Origin-dependence of variation in seed morphology, mineral composition and germination percentage in Gynandropsis gynandra (L.) Briq. accessions from Africa and Asia

Abstract

Background: Spider plant [Gynandropsis gynandra (L.) Briq.], an economically promising African leafy vegetable, characterized for leaf yield components and nutritive quality, exhibits poor seed germination that hinders a wider expansion of the crop in urban and periurban horticultural systems. So far, there is little information pertaining to seed morphological traits and mineral elements content that may be associated with higher seed germination. This research investigated the hypothesis that spider plants from different geographical areas exhibited differences in seed mineral composition, morphological traits, and germination capacity. To this end, twenty-nine accessions of Gynandropsis gynandra from West and East-Southern Africa, and Asia were screened for variation in seed size (area, perimeter, length, width), 10-seed weight, mean germination time, germination percentage and mineral content variations. The scanning electron microscopy (SEM), light microscopy and energy dispersive spectroscopy (EDS) solution were used to study seed morphology and mineral composition. Results: We show for the first time the external and internal structure of the seeds of Gynandropsis gynandra and measured eight mineral elements, including carbon (C), oxygen (O), magnesium (Mg), aluminium (Al), phosphorus (P), sulphur (S), potassium (K) and calcium (Ca). The accessions differed significantly (p < 0.001) with respect to seed size (area, perimeter, length, width), 10-seed weight, mean germination time and germination percentage. The hierarchical cluster analysis based on fourteen variables grouped the accessions into three distinct clusters, partially dependent on their geographical origin. Asian accessions exhibited smaller seeds and recorded higher values in terms of germination percentage. West African accessions had bigger seeds but with lower germination percentage. Variation in minerals such as potassium, carbon, and calcium content showed different patterns according to geographical origins.(Continued on next page)

Ten Years ofGynandropsis gynandraResearch for Improvement of Nutrient‐Rich Leaf Consumption: Lessons Learnt and Way Forwards

“…Zharare (2012) observed differences in seed dormancy expression between the biotypes of G. gynandra. This was further confirmed by Blalogoe et al (2020) who found that Asian accessions exhibited small seeds with high germination. A possible way to solve the low germination in some accessions would be to select out the genes limiting that trait.…”

“…Further studies integrating more diverse germplasm collections and the use of whole-genome sequences would be helpful to reconstruct the demographic history of the species in the lights of expansion of utilisations (e.g. industrial utilisation of health promoters, establishment of improved seed value chains, leaf processing for consumption) and new scientific endeavours (see Table 2) by Omondi et al (2017b), Sogbohossou et al (2020), andBlalogoe et al (2020).…”

“…Asian accessions exhibited smaller seed size and recorded higher values in terms of germination percentage. West African accessions had bigger seed size but with lower germination percentage(Blalogoe et al, 2020). Those sources of variation can be potentially exploited for accelerated cultivar development.…”

Phenotypic plasticity in Acanthoscelides quadridentatus (Coleoptera: Chrysomelidae) and its effect on the seed fate of Mimosa setosa (Leguminosae: Mimosoideae)

“…Several studies and reviews have shown that larger and heavier seeds germinate faster than smaller and lighter seeds (Ambika et al, 2014; Hojjat, 2011; Mandal et al, 2008; Springfield, 1973), although some few studies have noticed the opposite (Blalogoe et al, 2020; Xu et al, 2017). Indeed, it has been shown that besides germinating better, heavier seeds usually produce larger plants in height, and with a greater number of leaves, stem girth and dry weight (Nagaraju, 2001).…”

The complete chloroplast genome sequence of Gynandropsis gynandra (Cleomaceae)

“…Gynandropsis gynandra (L.) Briquet is a monoecious herb species in the family Cleomaceae. It is widely distributed in many subtropical and tropical regions of the world such as China, India and sub-Saharan Africa (Blalogoe et al 2020 ). As an important commercial crop, its leaves can provide us with vitamin A, vitamin C, flavonoids and essential minerals (calcium and iron) for medicinal uses.…”