Onion (Allium cepa L.) and Drought: Current Situation and Perspectives.

Onions (Allium cepa L.) are the second most commonly produced and consumed vegetable worldwide due to their economic, nutritional, and medicinal benefits. However, drought hinders vegetative growth, lowers yields and bulb quality, reduces photosynthetic activity, and alters the onion plant's metabolism. This review provides a summary of global research on the impact of drought on onions. It specifically seeks to shed light on aspects that remain unclear and generate research avenues. Relevant scientific articles were sourced from the AGORA database, Web of Science (WoS), and search engines such as Google Scholar, Scopus, MEDLINE/PubMed, and SCImago to achieve this objective. A total of 117 scientific articles and documents related to onion and drought were critically examined. The review revealed agromorphological, physiological, biochemical, and genomic studies depicting factors that contribute to drought tolerance in onion genotypes. However, there was little research on the physiological, biochemical, and genetic characteristics of drought tolerance in onions, which need to be deepened to establish its adaptation mechanisms. Understanding the mechanisms of onion response to water stress will contribute to fast-tracking the development of drought-tolerant genotypes and optimize onion production. Future research should be more focused on investigating onion drought tolerance mechanisms and structural and functional genomics and identifying genes responsible for onion drought tolerance.

Diallel analysis of cowpea (Vigna unguiculata (L.) Walp.) genotypes under water deficit stress.

Combining ability is referred to as the hybridization value of the parental genotypes involved in the crossing to develop hybrids. The best parents are selected through combining ability methods and subsequently used to produce high yielding and resistant hybrids. Thus, the objectives of this study were to (i) understand the nature and action of genes controlling water deficit tolerance, and (ii) identify superior genotypes from the genetic breadth provided by hybridization in cowpea. Twenty-four genotypes were subjected to normal irrigation and water deficit condition to examine combining ability, genotypic and phenotypic correlations for traits directly related to water deficit (proline and chlorophylls), grain yield and yield components. The results showed the presence of the action of additive and non-additive genes under both water regime conditions. However, there was the predominance of the action of additive genes for most of the traits studied under both conditions. The parents KVX61-1, IT06K242-3, IT07K-211-1-8, Kpodjiguèguè, IT99K-573-1-1, Tawa and IT97K-206-1-1 were observed to be good general combiners for proline content, chlorophyll content and traits associated with yield, while KVX61-1 × KVX396-18, IT06K242-3 × KVX396-18, IT07K-211-1-1 × KVX396-18, Kpodjiguèguè x KVX396-18, KVX61 -1 × IT97K-206-1-1, IT06K242-3 × IT97K-206-1-1, IT07K-211-1-1 × IT97K-206-1-1 and Kpodjiguèguè x IT97K-206-1-1 were proven to be the best specific combiners for traits directly related to water deficit tolerance and yield. It should be noted that number of days to pod maturity, pod length, number of pods per plant and weight of hundred seeds were highly heritable traits in this study.

Farmers' knowledge, practices and use of sesame genetic resources in the production systems of Benin: case study of agro-ecological zone IV.

Sesame (Sesamum indicum L.) is an important crop cultivated for its grains, which demand is constantly increasing in Africa. In Benin, sesame is produced on a small area despite its high economic potential. The overall objective of this study was to reinforce local knowledge (cultural methods) related to the management of different Sesamum indicum cultivars in Benin's Agro-ecological Zone IV. A total of 273 producers were surveyed using the non-probabilistic snowball method supported by systematic census. The typological analysis consisted of a Multiple Correspondence Analysis (MCA) and a Hierarchical Ascending Classification (HAC) using RGui.4.1.0 software. The result of the MCA revealed four types of sesame production systems based on several variables. The characterization of the producers of each production system according to the townships showed that there was a dependency relationship between the production systems and the townships. 100% of producers in the township of Cobly used the traditional production system (Type IV). 94.7% of producers in Matéri township practiced the modern production system (Type I). The different cultural methods for sesame production varied from one ethnic group to another. The Wama and Mossi ethnic groups practiced the modern semi-intensive production method (Type II). The conservative production system (Type III) was specific to the Ditamari. 61.8% Farmers planted sesame in August and 56.1% farmers harvested in October. Only 0.6% of respondents applied mineral fertilizer for sesame production. The number of cultivars used per village varied from 2 to 4 with an average of 2 over the entire study area. Toucountouna and Matéri had the most diversity with the largest number of cultivars (03) each. Only 1 cultivar was obtained Tanguieta. Sesame processing is low throughout the study area. Sesame cultivation can be intensified because of its low production costs.

Characterization of cultivated pumpkin (Cucurbita moschata Duchesne) landraces for genotypic variance, heritability and agro-morphological traits.

Cucurbita moschata (Pumpkin) is a multipurpose species whose fruits and sometimes oil seeds are used for various purposes. It is low in calories and is a significant source of income. Despite the great potential of the pumpkin production and usage, there is no attention to establish the varieties grown in Benin for proper documentation. Therefore, the present study was carried out to (i) evaluate the agro-morphological variability of pumpkin accessions collected in Benin and (ii) investigate heritability, genetic gain, phenotypic and genotypic variances of the agronomic traits. Six landraces from one hundred and twenty accessions collected in Benin were sown and characterized. The agronomic experiment was laid out in a complete randomized block design with three replicates. Out of the twenty-seven quantitative descriptors measured, fifteen were found to be significant. The 50% emergence time (p = 0.03), the number of female flowers (p = 0.02), the seed width (p = 0.05) and the ratio seed width and length (p = 0.01) were significant. A highly significant difference was observed with the days to 50% flowering and the length of male flower stalks (p = 0.002), the average weight of one hundred seeds (p = 0.009). Fruit set at 50%, length of female flower peduncle, number of male flowers, mean fruit weight, fruit length, fruit diameter, average number of seeds per fruit and seed length were very highly significant (p < 0.001). Fruit color and shape, seed color and leaf color showed phenotypic variability. A positive correlation (r = 0.76; p < 0.05) was observed between average fruit weight and average number of seeds per fruit. Principal component analysis and Hierarchical Ascending Classification revealed three classes. Estimates of the phenotypic coefficient of variation were higher than estimates of the genotypic coefficient of variation for most characters. High heritability was observed for fruit diameter (96.73%), average fruit weight (96.46%) and fruit length (94.64%). High heritability associated with high genetic advance was observed for these traits. In sum, the genetic diversity observed within the landraces of pumpkin shows that there is possibility for further selection.

Genetic diversity and environmental influence on morphological and yield parameters of maize in Benin.

Seeds are the most important input in agricultural production and its quality seed determines the yield of the crop. They contribute to nearly 30% of crop productivity. The present study aims at surveying, collecting and characterizing maize accessions from the North, Centre and South Benin. Thirty-two (32) accessions were collected from 11 townships of Benin. Four experiments (Bassila, Glazoue, N'Dali and Adjohoun sites) were carried out to evaluate the agro-morphological characteristics of the collected 32 accessions. Eighteen (18) quantitative parameters were measured at each site. The accessions were classified into 3 groups by the hierarchical ascending classification showing a very important variability among cultivars with very highly significant (P < 0.001) or highly significant (P < 0.01) differences. The observed diversity among the different cultivars were based on plant height, growth life cycle, ear height, yield and yield components. The collection consisted of 18 intermediate-maturing cultivars showing big corn size with the ears inserted at a great height (Group 1), 8 late-maturing cultivars with the best vegetative and reproductive traits (Group 2) and 6 early-maturing cultivars with the best reproductive growth and best ear and grain yields (Group 3). The phenotypic variability of the cultivars was more related to their agronomic and morphological traits than their origin. These diverse groups of accessions could be used to develop improved maize varieties with high yield potential and adapted to different agro-climatic conditions.

Physiological and agronomical evaluation of elite rice varieties for adaptation to heat stress.

BACKGROUND: The increasing temperatures due to climate change around the world poses a serious threat to sustainable crop production. The growing adverse effects of heat stress are putting global food security at great risk. Crop improvement for adaptation to increased temperatures is therefore of paramount importance. This study aims at assessing the effects of heat stress in relation to agro-morphological and physiological traits of six rice varieties. The study was carried out in the Township of Glazoué, a rice-growing area in Benin. The experiments were laid in randomized complete block design with three replications. Two types of stress were imposed: high-temperature stress in the dry season and optimal temperatures in the rainy season. The calculated mean values of morphological, physiological, and agronomic traits were used to estimate heritability, genetic advance, PCA, and correlation. RESULTS: The results showed that heat stress had a significant (p ≤ 0.01) influence on plant height, leaf length, number of tillers, number of internodes, days to flowering, and days to maturity, 1000-seed weight, and yield per plant. The heat stress had significantly delayed the flowering of all the varieties when compared to the controls. The highest values of 1000-seed weight (34. 67 g) were recorded for BRIZ-8B while the lowest (25.33 g) were recorded for NERICA-L20. The highest values for the genotypic coefficient of variation (43.05%) and phenotypic coefficient of variation (99.13%) were recorded for yield per plant under heat stress. The topmost broad-sense heritability was recorded for grain width (92.72%), followed by days to maturity (69.33%), days to flowering (68.50%), number of grains per panicle (57.35%), and yield (54.55%). CONCLUSIONS: These results showed that BRIZ-8B and BRIZ-10B were the most tolerant to high temperature amongst the six varieties assessed and potentially could be recommended to farmers for production under high temperature and be used in breeding programs to improve heat tolerance in rice.

Influence of the programmed cell death of lymphocytes on the immunity of patients with atopic bronchial asthma.

BACKGROUND: Fairly recent data highlight the role of programmed cell death and autoimmunity, as potentially important factors in the pathogenesis of chronic obstructive airway diseases. The purpose of our research was to determine the influence of apoptotic factors on the immunity of patients with atopic bronchial asthma according to the degree of severity. METHOD: The study was performed on the peripheral blood of patients with atopic bronchial asthma with different severity. The Immunological aspects were determined with ELISA, the fluorimetric method and the method of precipitation with polyethylene glycol. And the quantification of the parameters of the programmed cell death was performed by the method of flow cytometry and electron microscopy method. RESULTS: The data obtained from morphological and biochemical parameters show the deregulation of Programmed Death of lymphocytes of patients with atopic bronchial asthma but individual for each group of patients. This dysfunction might induce the secretion of autoantibodies against DNA. This could explain the accumulation of circulating immune complex with average size considered as the most pathogenic in patients with bronchial asthma especially in the patients of serious severity. It should be noted that Patients with bronchial asthma of mild and severe severity had different way and did not have the same degree of deficiency of the immune system. CONCLUSION: These data suggested that apoptotic factor of lymphocytes may play an important role in controlling immunity of patients with atopic bronchial asthma.