Genetic diversity of Tribolium castaneum (Herbst) population in storage infrastructures and agro ecological zones in Senegal

In Senegal, millet is the most exploited cereal and the second most one consumed after rice. It is cultivated in most agroecological zones whose more or less arid climatic characteristics favor the development of several insect pests, among which Sitophilus Zeamais, a beetle of the Curculionidae. This insect causes a lot of losses of millet stocks, mainly in four agro-ecological zones: NBA , SBA , SOHC and BMC . Our study aims to highlight a possible genetic structuring of Sitophilus Zeamais subservient to millet according to these agroecological zones. The advantage of the existence of a genetic differentiation between agroecological zones is to be able to detect after the degree of genetic homogeneity of each one of them and consequently their impacts on the survival or the extinction of the insect, because the genetic diversity of populations influences their adaptive potentials. To achieve this goal, we sampled Sitophilus Zeamais insects subservient to millet in each agroecological zone. 43 individuals were harvested in total. The exploitation of the sequences of the cytochrome b gene corresponding to these individuals has highlighted a genetic structuration of Sitophilus Zeamais subservient to millet according to the 4 agroecological zones, attested by the values of genetic distance, Fst ones and corroborated by the results of the test. AMOVA. KEYWORDS : Sitophilus Zeamais, cytochrome b, millet, genetic structuring.

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Genetic diversity of aflatoxin-producing Aspergillus flavus isolated from groundnuts in selected agro-ecological zones of Uganda

10.21203/rs.2.13266/v1 ◽

2019 ◽

Author(s):

Amos Acur ◽

Renée S. Arias ◽

Steven Odongo ◽

Samuel Tuhaise ◽

Joseph Ssekandi ◽

...

Keyword(s):

Genetic Diversity ◽

Aspergillus Flavus ◽

Lake Victoria ◽

Farming System ◽

Aspergillus Species ◽

Lake Victoria Basin ◽

West Nile ◽

Ecological Zones ◽

Post Harvest ◽

Agro Ecological Zones

Abstract Background Aspergillus is the main fungal genus causing pre- and post-harvest contamination of groundnuts. Aspergillus flavus belongs to section Flavi, a group consisting of both the aflatoxigenic species (A. flavus, A. parasiticus and A. nomius) and non-aflatoxigenic species (A. oryzae, A. sojae and A. tamarii). Aflatoxins are food-borne toxic secondary metabolites produced by Aspergillus species, causing hepatic carcinoma and stunting in children and are the most toxic carcinogenic mycotoxins ever identified. Despite the well-known public health problems associated with aflatoxicosis in Uganda, information about the genetic diversity of the main aflatoxin causing fungus, Aspergillus flavus in this country is still limited. Results A cross-sectional survey was therefore carried out in three main groundnut-growing agro-ecological zones (AEZs) of Uganda; West Nile farming system, Lake Kyoga basin mixed farming system and Lake Victoria basin farming system. This was to assess the genetic diversity of A. flavus and to establish the contamination rates of groundnuts with Aspergillus species at pre- and post-harvest stages. Out of the 213 A. flavus isolates identified in this study, 96 representative isolates were fingerprinted using 16 insertion/deletion microsatellite markers. Data from fingerprinting were analyzed through Neighbor Joining while polymorphism was determined using Arlequin v 3.5. The pre- and post-harvest contamination rates were; 2.5% and 50.0% (West Nile farming system), 55.0% and 35.0% (Lake Kyoga basin mixed farming system) and 32.5% and 32.5% (Lake Victoria basin farming system) respectively. The Chi-square test showed no significant differences between pre- and post-harvest contamination rates among AEZs (p = 0.199). Only 67 out of 96 isolates produced suitable allele scores for genotypic analysis. Analysis of genetic diversity showed higher variation within populations than among populations. Two major clusters (aflatoxigenic and non-aflatoxigenic isolates) were identified as colonizing groundnuts at pre- and post-harvest stages. Conclusions These findings provide a first insight on the existence of non-aflatoxigenic strains of A. flavus in Uganda. These strains are potential candidates for developing local Aspergillus bio-control agent.

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Effect of agro-ecological zones and contiguous basin crops of groundnut (Arachis hypogaea) on the structuring and genetic diversity of Caryedon serratus (Coleoptera: Chrysomelidae, Bruchinae) in the sub-region of West Africa

Journal of Asia-Pacific Entomology ◽

10.1016/j.aspen.2013.01.004 ◽

2013 ◽

Vol 16 (3) ◽

pp. 209-217 ◽

Cited By ~ 3

Author(s):

Toffène Diome ◽

Assane Ndong ◽

Khadim Kébé ◽

Cheikh Thiaw ◽

Awa Ndiaye ◽

...

Keyword(s):

Genetic Diversity ◽

West Africa ◽

Arachis Hypogaea ◽

Ecological Zones ◽

Caryedon Serratus ◽

Agro Ecological Zones

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Genetic diversity assessment of neem (Azadirachta indica A. Juss) in northern Nigeria

10.1101/2021.11.22.469531 ◽

2021 ◽

Author(s):

Barka Peter MSHELMBULA ◽

Geoffrey Obinna Anoliefo ◽

Beckley Ikhajiagbe ◽

Boniface Edegbai

Keyword(s):

Genetic Diversity ◽

Germplasm Conservation ◽

Western Hemisphere ◽

Northern Nigeria ◽

Important Species ◽

Tropical Regions ◽

Ecological Zones ◽

Diversity Assessment ◽

Wide Range ◽

Agro Ecological Zones

Neem is a tropical tree that can adapt to a wide range of places and particularly to semi- arid conditions. As at present, it is grown in many Asian countries and also in the tropical regions of the western hemisphere. Genetic variability and diversity are a major requirement needed for both immediate results and the one ones thereafter adaptation of plant types in their original domain. The evaluation of genetic diversity of any species is extremely crucial for their sustainability, continuity, survival and gene manipulation. Major breakthroughs in the field of molecular biology was able to develop several tools for the investigation of genetic diversity at the genome level to determine phylogenetic relationships among inter or intra-species. The advent of molecular markers for the detection and exploitation of DNA polymorphism is one of the major breakthroughs in the world of molecular genetics. The importance of genetic diversity in plant germplasm conservation, especially in economically important species such as Azadirachtaindica, is enormous, particularly in Nigeria. The question is whether A. indica from different Agro-ecological zones have genetic variations or similarities. This was the bane of the current study, which used RAPD to look atgenetic diversity of 27 randomly selected neem trees within the agro-ecological zones in Northern Nigeria. A total of 9 primers were employed out of which only 5 were responsive (OPA-02, OPA-03, OPA-15 and OPA-19). These primers showed dissimilarities in the visible DNA bands among the various tree samples. There was evidence of genetic dissimilarities among the trees sampled. Differences in percentage polymorphism was reported, where it was reportedly highest among the Borno State tree samples (97.44%), compared to those in Yobe State with no polymorphism.

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