Agro-Morphological Exploration of Some Unexplored Wild Vigna Legumes for Domestication

Abstract

The domestication of novel or hitherto wild food crops is quickly becoming one of the most popular approaches in tackling the challenges associated with sustainable food crop production, especially in this era, where producing more food with fewer resources is the need of the hour. The crop breeding community is not yet completely unanimous regarding the importance of crop neo-domestication. However, exploring the unexplored, refining unrefined traits, cultivating the uncultivated, and popularizing the unpopular remain the most adequate steps proposed by most researchers to achieve the domestication of the undomesticated for food and nutrition security. Therefore, in the same line of thought, this paper explores the agro-morphological characteristics of some wild Vigna legumes from an inquisitive perspective to contribute to their domestication. One hundred and sixty accessions of wild Vigna legumes, obtained from gene banks, were planted, following the augmented block design layout of two agro-ecological zones of Tanzania, during the 2018 and 2019 main cropping seasons for agro-morphological investigations. The generalized linear model procedure (GLM PROC), two-way analysis of variance (two-way ANOVA), agglomerative hierarchical clustering (AHC) and principal component analysis (PCA) were used to analyze the accession, block and block vs. accession effects, as well as the accession × site and accession × season interaction grouping variations among accessions. The results showed that the wild species (Vigna racemosa; Vigna ambacensis; Vigna reticulata; and Vigna vexillata) present a considerable variety of qualitative traits that singularly exist in the three studied checks (cowpea, rice bean, and a landrace of Vigna vexillata). Of the 15 examined quantitative traits, only the days to flowering, pods per plant, hundred seed weight and yield were affected by the growing environment (accession × site effect), while only the number of flowers per raceme and the pods per plant were affected by the cropping season (accession × season effect). All the quantitative traits showed significant differences among accessions for each site and each season. The same result was observed among the checks, except for the seed size trait. The study finally revealed three groups, in a cluster analysis and 59.61% of the best variations among the traits and accessions in PCA. Indications as to the candidate accessions favorable for domestication were also revealed. Such key preliminary information could be of the utmost importance for the domestication, breeding, and improvement of these species, since it also determines their future existence—that is, so long as biodiversity conservation continues to be a challenging concern for humanity.

Vigna Legumes: Exploring Some Biochemical Constituents of the Wild Species for Potential Neo-Domestication Candidates

“…In an earlier study, presence of considerable amounts of Fe, Ca, Na, K and P from wild bean (V. sublobata) was reported 39 . This is in line with speculations earlier suggested and recommended by researchers (Harouna et al, 2020, Harouna et al, 2019. For instance, an accession like TVNu-1792 (0.918 mg/100g) having the highest amount of Cu could satisfy the recommended dietary allowance (RDA) of a male adult just by consuming 100 g of as the recommended dietary requirement is known as 900 µg/d 41 .…”

Crop Wild Relatives: A Valuable Source of Tolerance to Various Abiotic Stresses

“…As wild Vigna relatives are interesting material for the improvement of the cultivated Vigna [ 46 , 122 ], the continuation of the crossing effort is considered critical. Wild cowpea germplasm variation should be more intensively exploited [ 123 ] as it consists of a valuable source of abiotic stresses tolerance [ 124 ].…”

The Trilogy of Wild Crops, Traditional Agronomic Practices, and UN-Sustainable Development Goals

“…Extensive field experiments for understanding the agro-morphological variations in wild crops are also important for selecting elite germplasms. In this way, Harouna and co-workers [25] conducted an extensive field trial of 160 accessions of wild Vigna in Tanzania and studied the variations in the quantitative as well as qualitative traits (15 each) for identifying the superior accessions for breeding and crop improvements. Identifying the most suitable habitats for the large-scale cultivation of wild crops as well as predicting their growth response under futuristic climatic condition is a changing paradigm in wild crop research.…”