Variability in seed traits, oil content and genetic diversity in local and exotic accessions of Jatropha curcas L. in Senegal

Variability in seed traits, oil content and genetic diversity of Jatropha curcas L. according to rainfall gradient in Senegal are hereby reported and discussed. Seed oil variability ranged from 58.61% in Sudanian zone to 46.94% in Sahelian zone. Seed oil content and seed thickness were correlated to rainfall with a correlation coefficient of 0.62 and 0.48 respectively. However, seed length, breadth and 20 seed-weight were not correlated to rainfall. The random amplification of polymorphic DNA (RAPD) primers used to assess genetic variation showed a clear polymorphism. The mean polymorphism rate was 42.68%. A low variability was observed in the accessions. The genetic diversity was not correlated to geographic position. On the basis of coefficient similarity values, the accessions were genetically diverse. Cluster analysis based on similarity values classified Jatropha curcas L. accessions into three major clusters of which cluster I was the largest group. The lowest genetic distance (0.029) was recorded between Karang and Kaffrine accessions whereas the highest genetic distance (0.274) was observed between Bignona and Karang accessions. Accession from Bignona recorded the highest intra-population variation. Special attention must be accorded to accessions with high oil content, seed weight and high intra-population variation for future selection programs.Keywords: Jatropha curcas L., seed size, oil content, genetic diversity, Senegal.African Journal of Biotechnology Vol. 12(34), pp. 5267-527

Effects of Amendments in Nitrogen, Phosphorus, Potassium, Zinc and Gypsum on the Quality of the Rice Grain, in Salinity Conditions

Abstract : This study is to investigate the effects of the amendments in macronutrients nitrogen-phosphatepotassium (NPK) and microelements zinc and gypsum on physicochemical qualities of rice grain. The design is a split plot with two factors: fertility with 12 levels of fertilizers and variety with 6 rice varieties, repeated in 3 blocks, in two different media, including a salty medium (MS) and a unsalted medium (MNS). Six (6) rice varieties were used, of which four (4) tolerant varieties, and two (2) controls varieties that are moderately sensitive and very sensitive respectively. Results show a total yield milled grain of tolerant varieties, highest in saltwater environments as in unsalted middle, while the opposite effect is observed with susceptible varieties. The highest yields milled total grains were observed in a saltwater medium, with the formula 120-26-50 with or without zinc or Gypsum. In unsalted medium, it is the formula 0-26-50 with or without zinc or gypsum, which gives the best yields total milled grains. Broken grains have best performance in a saltwater environment, whatever variety or combination of fertilizer used. Weight of 100 grains is more efficient in unsalted environment, whatever variety or combination of fertilizer used. Depending on the alkaline spreading value (ASV), varieties can be divided into two groups. Varieties of the first group with low AVS (3 to 4) have a gelatinization temperature (GT) intermediate. Those in the second group, with a middle and higher AVS (5.4 to 6), have low gelatinization temperature. The varieties of this last group with low GT, are more interesting for the market and consumers because they require only a low cooking time

Effect of GammaRay in the Progeny of Trispecific Hybrid [(Gossypium hirsutum x G. raimondii)² x G. sturtianum]

The objective of this study is to analyse the possibilities of fixing in the progeny of the [(Gossypium hirsutum x G. raimondii)² x G. sturtianum] (HRS) trispecies hybrid, the glandless-seed and glanded-plant trait. The expression of the character was analysed in progenies obtained by selfing the HRS BC2S5/9/6/1/51/15 genetic stock. This character is controlled by one or more genes located on introgressed chromosome fragments of G. sturtianum. These foreign DNA fragments seem also carriers of gametes terminators genes on the same chromosome fragments and there would be a possible existence of negative interactions between some of the introgressed G. sturtianum alleles and the G. hirsutum genetic background inducing post-zygotic mortality. In order to break existing lethal links, some of the studied seeds were treated with 15 krad of gamma radiation. The transfer of G. sturtianum chromosome fragments introgressed stocks was assessed using ten mapped SSR markers, carried out on 78 plants HRS ‘BC2S6’. Gamma irradiation used to overcome lethality in HRS hybrid did not give expected results in M2 because of high rate of abortion observed in HRS ‘BC2S6’ seeds. However, gamma ray did not induce the appearance of chimeric tissues in the HRS ‘BC2S5/9/6/1/51/15’ in M1 plants. Moreover, the notable fertility improvement observed for some plants issued from irradiated seeds constitutes a clue of the achievement of favourables recombinations due to the gamma ray treatment. The perspectives opened by the results obtained for the stabilization of the glandless-seed and glanded-plant trait in a G. hirsutum commercial variety are discussed

Genetic diversity of Jatropha curcas L. in Senegal compared with exotic accessions based on microsatellite markers

International audienceSignificant efforts have been undertaken in West Africa to increase biofuel production with the expectation to alleviate the dependency on fossil energies and to reduce rural poverty by diversifying cultivated crops. In this context, Jatropha curcas L., a shrub belonging to Euphorbiaceae family, has gained great interest because of its oil which can be converted to biodiesel. It is also highly adaptable to marginal soils due to its drought-tolerant characteristics. Characterisation of J. curcas germplasm in Senegal could be an important input for its better management and in identifying genotypes that could be used in breeding program. Genetic diversity of 103 accessions including 82 accessions from different agro ecological zones in Senegal and 21 exotic accessions was assessed through 33 microsatellite markers. All the markers gave amplifications at the expected band size. Only one microsatellite marker, JCT17, was polymorphic showing 3 alleles and allows distinguishing 2 accessions from Burkina Faso. The surprisingly low level of genetic variation might be because introduction of J. curcas in Senegal seems to have been done from one or a few origins and the species has not regained genetic diversity since then due to vegetative propagation. Cultivation of J. curcas at large scale may face to vulnerability to pests and require many cautions. They are necessity to widen the genetic base of J. curcas in Senegal via new introductions from its centre of origin

Fonio (Digitaria exilis (Kippist) Stapf): A Socially Embedded Cereal for Food and Nutrition Security in Senegal

International audienceAgricultural diversification with neglected and underutilized species is a viable way to sustainably increase the productivity of agrosystems. Understanding the social, cultural, and ecological roles of these species is crucial for their promotion. White fonio (Digitaria exilis), a neglected cereal endemic to West African Sahelian countries, is recognized as a crop for the future due to its cultural, nutritional, and economic values. In this study, we described fonio farming systems in Senegal through an ethnobotanical approach. As expected in family farming systems, farmers largely practiced diversified subsistence agriculture on small plots and relied on local seed exchange networks. The importance of fonio varied among agroecological zones, ethnic groups, and gender. In the Groundnut Basin, where agriculture is more mechanized, late-maturing landraces of fonio are cultivated as a cash crop rather than a staple crop. However, in southern Senegal, where food shortages are recurrent, fonio is more widespread and the cultivation of both early- and late-maturing landraces contributes to local food security. These differences also reflect the cultural status of fonio: different among ethnic groups and more important for women than for men. Finally, the regressive dynamics of fonio cultivation in most regions emphasizes the need to develop integrated conservation and promotion strategies that take into account the diversity of social and agronomical roles of the plant

Ethnolinguistic and genetic diversity of fonio (<scp><i>Digitaria exilis</i></scp>) in Senegal

International audienceSocietal Impact Statement Fonio (Digitaria exilis-Kippist-Stapf) is a neglected cereal crop that plays a crucial role in the food and nutritional security of sub-Saharan populations. Currently threatened with extinction in many countries, fonio, like other minor species, could help give insights into the history of African agriculture and provide clues to past social interactions. Highlighting and preserving genetic diversity that can be used to develop improved varieties improves food security. By recognizing the role of indigenous people and local communities (IPLCs) in agrobiodiversity creation and management, this study provides support for strengthening the rights of rural communities and promoting their food and seed sovereignty as outlined in the United Nations UNDROP Declaration. center dot Fonio (Digitaria exilis) is a neglected cereal crop that plays a crucial role in the food and nutritional security of sub-Saharan populations. It is an excellent candidate to diversify agricultural and food systems beyond Africa because of its adaptability and hardiness. However, fonio is threatened with extinction and the factors that organize its genetic diversity remain unknown, despite the fact that this knowledge is necessary to define conservation strategies and uses to achieve sustainable agriculture. center dot Here, we combined social anthropology and population genetics analysis of 158 fonio landraces, thereby generating insight into the genetic diversity, population structure and evolutionary history of fonio cultivation in Senegal. center dot We noted a spatial structure of genetic diversity at two embedded levels, with the first corresponding to the genetic differentiation between ethnic groups and the second to the demographic history of the Mande and Atlantic Congo linguistic families. Selection and seed exchange practices have contributed to shaping fonio genetic diversity at the ethnic level, while the migration of Fulani people over the last 500 years has fragmented the Mandinka kingdom, hence leaving a fonio diversity imprint. center dot Our study highlighted that social factors are pivotal in structuring diversity and should be taken into greater consideration in research and conservation projects to dovetail local and regional scales. It also showed that neglected species such as fonio-which are seldom used in breeding and dissemination programmes-are key markers of the history of African agriculture