Évaluation des caractéristiques des stomates chez le palmier à huile (Elaeis guineensis Jacq.)

Objectif: l’objectif principal de cette étude est de déterminer les paramètres caractéristiques des stomates chez Elaeis guineensis Jacq actuel.Méthodologie et résultats: Les paramètres comme la densité, la longueur et la largeur des stomates ont été évalués en observant l’épiderme des feuilles au microscope. Ainsi, le matériel adulte (dura, pisifera et, tenera) en champ et le matériel jeune (plants de tenera en pépinière et plants de tenera en pré pépinière) ont été considérés. Les résultats ont montré que, sur la face inférieure des feuilles, la densité stomatique est plus importante chez le matériel adulte 50,32 stomates par mm2 que chez le matériel jeune 23,88 stomates par mm2 et, sur la face supérieure des feuilles, cette situation s’inverse 4,77 stomates par mm2 contre 9,21 stomates par mm2. Les stomates sur la face supérieure des feuilles sont plus longs et larges que ceux observés sur la face inférieure des feuilles pour tous les matériels. Les stomates du matériel adulte sont aussi plus longs que ceux du matériel jeune. Pour tous les paramètres étudiés, la face inférieure apparaît la plus indiquée pour caractériser des stomates chez le palmier à huile.Conclusion et application des résultats: cette présente étude montre l’importance des stomates dans la caractérisation du niveau de ploïdie du palmier à huile. Ainsi, les résultats obtenus peuvent s’appliquer dans les recherches des plantes ayant une fertilité plus intéressante en s’appuyant sur la polyploïdisation.Mots clés: Elaeis guineensis, stomates, caractéristiquesEnglish AbstractObjective: To determine the characteristics of stomata parameters in Elaeis guineensis Jacq. Current.Methodology and results: Parameters such as the density, the length and with of stomata were evaluated by observing the leaf epidermis microscopically. Thus, adult material (dura, pisifera and tenera) field and the young material (tenera nursery plant and prenursery tenera plant) were considered. The results showed that on  the underside of leaves, stomata density was greater in adult material 50.32 stomata per mm2 than in younger material 23.88 stomata per mm2 on the upper leaf surface this reverses stomata per mm2 4.77 against 9.21 stomata per mm2. Stomata on the upper leaf surface are longer and wider than those seen on the underside of leaves for all materials. Stomata adult materials are also longer than those of young material. For all the parameters studied, the underside of leaves appears most indicated to characteristerize the stomata in the oil palm.Conclusion and application of results: this present study shows the importance of stomata in the characterization of the ploidy level of the oil palm. So, results can be applied in the research of plant with a more interesting fertility based on the polyploidization.Keywords: Elaeis guineensis, stomata, characteristic

Integrating genetic markers and adiabatic quantum machine learning to improve disease resistance-based marker assisted plant selection

The goal of this research was to create a more accurate and efficient method for selecting plants with disease resistance using a combination of genetic markers and advanced machine learning algorithms. A multi-disciplinary approach incorporating genomic data, machine learning algorithms and high-performance computing was employed. First, genetic markers highly associated with disease resistance were identified using next-generation sequencing data and statistical analysis. Then, an adiabatic quantum machine learning algorithm was developed to integrate these markers into a single predictor of disease susceptibility. The results demonstrate that the integrative use of genetic markers and adiabatic quantum machine learning significantly improved the accuracy and efficiency of disease resistance-based marker-assisted plant selection. By leveraging the power of adiabatic quantum computing and genetic markers, more effective and efficient strategies for disease resistance-based marker-assisted plant selection can be developed

Evaluation of maize (Zea mays L.) accessions using line x tester analysis for aluminum and manganese tolerance

Soil acidity is a limiting factor severely affecting the growth and yield of maize. The present study aimed at estimating the breeding value of inbred lines and to assess the test-cross performance of the hybrid maize under acid soil conditions. A line x tester analysis involving 63 test-crosses generated by crossing 20 maize inbred lines with 3 testers and between testers themselves, and 1 standard check was investigated during the cropping season 2012 in two contrasted regions with aluminum and manganese toxicity in Cameroon. Both treatments, acid soil and non-acid soil, using dolomitic lime were conducted in a randomized complete block design with 3 replications. Seven hybrids producing high grain yield (4.27 to 9.88t/ha), with high specific combining ability (SCA) and slow rate of yield loss were discovered such as tolerant for both types of acidic soils. Likewise, four inbred lines (ATP-46, 87036, and Cam Inb gp117, C4SRRA7) with high general combining ability (GCA) were retained as good progenitors. The GCA and SCA effects showed that the tolerance to aluminum toxicity was controlled by additive effects of genes while on acid soil with manganese toxicity, the contribution of non-additive effects of genes was dominant.Keywords: Inbred lines, hybrids, acid soil, GCA, SCA, humid forest zone

Galaxy Zoo: dust and molecular gas in early-type galaxies with prominent dust lanes

We study dust and associated molecular gas in 352 nearby early-type galaxies (ETGs) with prominent dust lanes. 65% of these `dusty ETGs' (D-ETGs) are morphologically disturbed, suggesting a merger origin. This is consistent with the D-ETGs residing in lower density environments compared to the controls drawn from the general ETG population. 80% of D-ETGs inhabit the field (compared to 60% of the controls) and <2% inhabit clusters (compared to 10% of the controls). Compared to the controls, D-ETGs exhibit bluer UV-optical colours (indicating enhanced star formation) and an AGN fraction that is more than an order of magnitude greater (indicating higher incidence of nuclear activity). The clumpy dust mass residing in large-scale features is estimated, using the SDSS r-band images, to be 10^{4.5}-10^{6.5} MSun. A comparison to the total (clumpy + diffuse) dust masses- calculated using the far-IR fluxes of 15% of the D-ETGs that are detected by the IRAS- indicates that only ~20% of the dust resides in these large-scale features. The dust masses are several times larger than the maximum value expected from stellar mass loss, ruling out an internal origin. The dust content shows no correlation with the blue luminosity, indicating that it is not related to a galactic scale cooling flow. No correlation is found with the age of the recent starburst, suggesting that the dust is accreted directly in the merger rather than being produced in situ by the triggered star formation. Using molecular gas-to-dust ratios of ETGs in the literature we estimate that the median current and initial molecular gas fraction are ~1.3% and ~4%, respectively. Recent work suggests that the merger activity in nearby ETGs largely involves minor mergers (mass ratios between 1:10 and 1:4). If the IRAS-detected D-ETGs form via this channel, then the original gas fractions of the accreted satellites are 20%-44%. [Abridged]Comment: 11 pages, 18 figures, 1 table, MNRAS (Accepted for publication- 2012 March 19

Metallicity in the merger Seyfert galaxy NGC 6240

We have calculated the physical conditions throughout the NLR of the merger Seyfert galaxy NGC 6240 by modelling the observed optical and infrared line ratios. We have found that the optical spectra are emitted by clouds photoionised by the power-law radiation flux from the AGN (or AGNs), and heated mainly by the shock accompanying the propagation of the clouds outwards. The infrared line ratios are emitted from clouds ejected from a starburst which photoionises the gas by the black-body radiation flux corresponding to a stellar colour temperature of about 50,000 K. Both the flux from the AGN and the ionization parameters are low. The most characteristic physical parameters are the relatively high shock velocities (>400 km/s) and low preshock densities (about 40-60 cm-3) of the gas. The C/H, N/H, O/H relative abundances are higher than solar by a factor lower or about 1.5. We suggest that those high relative abundances indicate trapping of H into H2 molecules rather than high metallicities. Adopting an initial grain radius of 1 micron, the dust temperatures calculated in the clouds reached by the power-law radiation flux and by the black-body radiation flux are 81 K and 68 K, respectively.Comment: 14 pages, 5 figures, accepted for publication in MNRA

Family Farming Systems in Northern Central Cameroon: Challenges and Prospects for Food Security

If family farming is supported, it can serve as a foundation for growth and food security. One of Cameroon's biggest development challenges is still food insecurity. Therefore, the purpose of this study was to investigate the situation and key determinants of food security in the northern forest-savanna transition zone of the Central Cameroon Region. To do this, 180 family farmers from Mbangassina, Ntui, Batchenga, and Obala participated in a survey and field observations (January-March 2020; March-May 2021, and July-September 2021). According to this survey and these findings, the useful agricultural area is 4.55 ± 0.21 hectares. Cocoa, yam, cassava, maize, plantain, sweet potato, and peanut are the principal crops mentioned. With a mixed workforce, the vast majority of agricultural work is performed manually (machetes, daba, etc). (Family and external). Seven significant challenges face family farming in these areas: poor market organization, bad road/track conditions, a lack of inputs, seasonal uncertainties/rainfall deficits, challenging access to irrigation, unstable land tenure, challenging access to credit, and challenging access to agricultural equipment. Each community faces unique challenges. The family agricultural industry, which these people rely on for their food security, needs to be saved to overcome these obstacles. According to the findings, expanding access to financial and commercial services will help agricultural operations in the study area increase food security. This will be in line with initiatives made by both governmental and non-governmental organizations to advance agricultural technologies as a way to address the issue of food insecurity

Family Farming Systems in Northern Central Cameroon: Challenges and Prospects for Food Security

If family farming is supported, it can serve as a foundation for growth and food security. One of Cameroon's biggest development challenges is still food insecurity. Therefore, the purpose of this study was to investigate the situation and key determinants of food security in the northern forest-savanna transition zone of the Central Cameroon Region. To do this, 180 family farmers from Mbangassina, Ntui, Batchenga, and Obala participated in a survey and field observations (January-March 2020; March-May 2021, and July-September 2021). According to this survey and these findings, the useful agricultural area is 4.55 ± 0.21 hectares. Cocoa, yam, cassava, maize, plantain, sweet potato, and peanut are the principal crops mentioned. With a mixed workforce, the vast majority of agricultural work is performed manually (machetes, daba, etc). (Family and external). Seven significant challenges face family farming in these areas: poor market organization, bad road/track conditions, a lack of inputs, seasonal uncertainties/rainfall deficits, challenging access to irrigation, unstable land tenure, challenging access to credit, and challenging access to agricultural equipment. Each community faces unique challenges. The family agricultural industry, which these people rely on for their food security, needs to be saved to overcome these obstacles. According to the findings, expanding access to financial and commercial services will help agricultural operations in the study area increase food security. This will be in line with initiatives made by both governmental and non-governmental organizations to advance agricultural technologies as a way to address the issue of food insecurity

Family Farming Systems in Northern Central Cameroon: Challenges and Prospects for Food Security

If family farming is supported, it can serve as a foundation for growth and food security. One of Cameroon's biggest development challenges is still food insecurity. Therefore, the purpose of this study was to investigate the situation and key determinants of food security in the northern forest-savanna transition zone of the Central Cameroon Region. To do this, 180 family farmers from Mbangassina, Ntui, Batchenga, and Obala participated in a survey and field observations (January-March 2020; March-May 2021, and July-September 2021). According to this survey and these findings, the useful agricultural area is 4.55 ± 0.21 hectares. Cocoa, yam, cassava, maize, plantain, sweet potato, and peanut are the principal crops mentioned. With a mixed workforce, the vast majority of agricultural work is performed manually (machetes, daba, etc). (Family and external). Seven significant challenges face family farming in these areas: poor market organization, bad road/track conditions, a lack of inputs, seasonal uncertainties/rainfall deficits, challenging access to irrigation, unstable land tenure, challenging access to credit, and challenging access to agricultural equipment. Each community faces unique challenges. The family agricultural industry, which these people rely on for their food security, needs to be saved to overcome these obstacles. According to the findings, expanding access to financial and commercial services will help agricultural operations in the study area increase food security. This will be in line with initiatives made by both governmental and non-governmental organizations to advance agricultural technologies as a way to address the issue of food insecurity

Family Farming Systems in Northern Central Cameroon: Challenges and Prospects for Food Security

If family farming is supported, it can serve as a foundation for growth and food security. One of Cameroon's biggest development challenges is still food insecurity. Therefore, the purpose of this study was to investigate the situation and key determinants of food security in the northern forest-savanna transition zone of the Central Cameroon Region. To do this, 180 family farmers from Mbangassina, Ntui, Batchenga, and Obala participated in a survey and field observations (January-March 2020; March-May 2021, and July-September 2021). According to this survey and these findings, the useful agricultural area is 4.55 ± 0.21 hectares. Cocoa, yam, cassava, maize, plantain, sweet potato, and peanut are the principal crops mentioned. With a mixed workforce, the vast majority of agricultural work is performed manually (machetes, daba, etc). (Family and external). Seven significant challenges face family farming in these areas: poor market organization, bad road/track conditions, a lack of inputs, seasonal uncertainties/rainfall deficits, challenging access to irrigation, unstable land tenure, challenging access to credit, and challenging access to agricultural equipment. Each community faces unique challenges. The family agricultural industry, which these people rely on for their food security, needs to be saved to overcome these obstacles. According to the findings, expanding access to financial and commercial services will help agricultural operations in the study area increase food security. This will be in line with initiatives made by both governmental and non-governmental organizations to advance agricultural technologies as a way to address the issue of food insecurity