Browsing by Author "Harouna, Difo Voukang"

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Agro-Morphological Exploration of Some Unexplored Wild Vigna Legumes for Domestication
(MDPI, 2020-01-13) Harouna, Difo Voukang; Venkataramana, Pavithravani; Matemu, Athanasia; Ndakidemi, Patrick
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
Assessment of Water Absorption Capacity and Cooking Time of Wild Under-Exploited Vigna Species towards their Domestication
(MDPI, 2019-09-04) Harouna, Difo Voukang; Venkataramana, Pavithravani; Matemu, Athanasia; Ndakidemi, Patrick
Some phenotypic traits from wild legumes are relatively less examined and exploited towards their domestication and improvement. Cooking time for instance, is one of the most central factors that direct a consumer’s choice for a food legume. However, such characters, together with seed water absorption capacity are less examined by scientists, especially in wild legumes. Therefore, this study explores the cooking time and the water absorption capacity upon soaking on 84 accessions of wild Vigna legumes and establishes a relationship between their cooking time and water absorbed during soaking for the very first time. The accessions were grown in two agro-ecological zones and used in this study. The Mattson cooker apparatus was used to determine the cooking time of each accession and 24 h soaking was performed to evaluate water absorbed by each accession. The two-way analysis of variance revealed that there is no interaction between the water absorption capacity and cooking time of the wild Vigna accessions with their locations or growing environments. The study revealed that there is no environment × genotype interaction with respect to cooking time and water absorption capacity as phenotypic traits while genotype interactions were noted for both traits within location studied. Furthermore, 11 wild genotypes of Vigna accessions showed no interaction between the cooking time and the water absorption capacity when tested. However, a strong negative correlation was observed in some of the wild Vigna species which present phenotypic similarities and clusters with domesticated varieties. The study could also help to speculate on some candidates for domestication among the wild Vigna species. Such key preliminary information could be of vital consideration in breeding, improvement, and domestication of wild Vigna legumes to make them useful for human benefit as far as cooking time is concerned.
Biochemical and agro-morphological characterization of wild, under-exploited vigna species and their utilization
(NM-AIST, 2020-05) Harouna, Difo Voukang
According to the Food and Agriculture Organization (FAO) of the United Nations recent report, the immense challenge of achieving the Zero Hunger target by 2030 is still persistent. Therefore, the search for alternative food and feed sources for human and animal nutrition to feed the exponentially growing human population is a daunting task. It is imperative that 70% more food is needed to cover the gap between suppy and demand of food. Exploring the new, innovative methods of crop production remains the most viable and sustainable option available to most researchers to achieve food and nutrition security. This study explored the biochemical, agro-morphological, cooking cookability and farmers‘ preference of 160 accessions of four wild unexplored Vigna species in order to reveal information leading to their future domestication and utilization. The agro-morphological study was conducted in two agro-ecological zones in Tanzania, namely: The mid-altitude agro-ecological zone (Kisongo, Arusha region) and the high altitude agro-ecological zone (Lyamungo, Kilimanjaro region). The augmented block design study was used. An explorative survey and a focus group discussion (FGD) were performed to assess the farmers‘ preferences, perception and prospective use of the wild Vigna legumes while the Mattson Bean Cooker was used to evaluate the cooking characteristics of the legumes. Standard procedures and methods approved by the Association of Official Analytical Chemists (AOAC) were used in carrying out the biochemical characteristics tests of the wild Vigna legumes. The study revealed that the wild Vigna legumes are less known by many farmers but can be accepted as food, feed, cover crop or organic fertilizer although thre is need for improvement. Furthermore, it was demonstrated that the wild Vigna species possesses a large variation range of agromorphological, biochemical and consumption characteristics which could be exploited in the improvement and/or domestication of species. It was also found that some individual wild accessions have higher nutrient, mineral content and best cooking time as compared with domesticated ones which could be advantageous for bio-fortification or domestication. Indications relating to the candidate accessions favorable for domestication, based on the agro-morphological, socio-cultural practice, cooking and biochemical characteristics were revealed. The study concluded that the genus Vigna (wild and domesticated species) presents a considerably high diversity in terms of agro-morphological, socio-cultural practice, cooking and biochemical characteristics. However, despite their under-exploitation for human benefits, the wild Vigna legumes demonstrated important agro-morphological, socio-cultural practice, cooking and biochemical characteristics comparable with the domesticated ones that attracted some farmers‘ preferences. Therefore, the evaluat ion of other important agro morphological traits, biochemical characteristics, socio-economic implication of wild Vigna utilization, toxicity studies and prospects of a patent/prototype establishment for promising accessions are among other recommendations for further studies.
Under-exploited wild Vigna species potentials in human and animal nutrition: A review
(Elsevier, 2018-09) Harouna, Difo Voukang; Venkataramana, Pavithravani; Ndakidemi, Patrick; Matemu, Athanasia
Food insecurity, protein-energy malnutrition, and food-feed competition have motivated the search for alternative food and feed sources for human and animal nutrition. According to the FAO, only four crop species provide half of the plant-based calories in the human diet. This review, with an inquisitive focus on investigating alternative potential food and feed sources, has revealed that the Vigna genus (an important group of legumes) possesses more than a 100 species from which only 10 have been domesticated and are being given better attention. Thus, more than 90 species are still under-exploited despite their probable huge potential to alleviate food insecurity either by adding food varieties (domestication) or by providing information for breeding purposes. The review further demonstrates that the utilization of the wild Vigna species for both human food and animal feed is still very limited because of the unawareness of their potentials over some improved varieties which are facing challenges. An increased scientific effort towards exploring the potentials of wild legumes is recommended in planning the future food strategies.
Wild Vigna Legumes: Farmers’ Perceptions, Preferences, and Prospective Uses for Human Exploitation
(MDPI, 2019-05-31) Harouna, Difo Voukang; Venkataramana, Pavithravani; Matemu, Athanasia; Ndakidemi, Patrick
The insu cient food supply due to low agricultural productivity and quality standards is one of the major modern challenges of global agricultural food production. Advances in conventional breeding and crop domestication have begun to mitigate this issue by increasing varieties and generation of stress-resistant traits. Yet, very few species of legumes have been domesticated and perceived as usable food/feed material, while various wild species remain unknown and underexploited despite the critical global food demand. Besides the existence of a few domesticated species, there is a bottleneck challenge of product acceptability by both farmers and consumers. Therefore, this paper explores farmers’ perceptions, preferences, and the possible utilization of some wild Vigna species of legumes toward their domestication and exploitation. Quantitative and qualitative surveys were conducted in a mid-altitude agro-ecological zone (Arusha region) and a high altitude agro-ecological zone (Kilimanjaro region) in Tanzania to obtain the opinions of 150 farmers regarding wild legumes and their uses. The study showed that very few farmers in the Arusha (28%) and Kilimanjaro (26%) regions were aware of wild legumes and their uses. The study further revealed through binary logistic regression analysis that the prior knowledge of wild legumes depended mainly on farmers’ location and not on their gender, age groups, education level, or farming experience. From the experimental plot with 160 accessions of wild Vigna legumes planted and grown up to near complete maturity, 74 accessions of wild Vigna legumes attracted the interest of farmers who proposed various uses for each wild accession. A X2 test (likelihood ratio test) revealed that the selection of preferred accessions depended on the farmers’ gender, location, and farming experience. Based on their morphological characteristics (leaves, pods, seeds, and general appearance), farmers perceived wild Vigna legumes as potentially useful resources that need the attention of researchers. Specifically, wild Vigna legumes were perceived as human food, animal feed, medicinal plants, soil enrichment material, and soil erosion-preventing materials. Therefore, it is necessary for the scientific community to consider these lines of farmers’ suggestions before carrying out further research on agronomic and nutritional characteristics toward the domestication of these alien species for human exploitation and decision settings.