Osmotic potential of Zinnia elegans plant material affects the yield and morphology of tracheary elements produced in vitro

The Zinnia elegans cell suspension culture is excellent for xylogenesis studies at the cellular and molecular level, due to the high and synchronous in vitro differentiation of tracheary elements (TEs). The percentage TE differentiation (%TE) in the culture is, however, influenced by a number of factors before and during cell differentiation. One of the factors that is potentially important but has not gotten much attention is the initial osmolarity of the plant material. To examine whether the growth conditions that determine leaf osmolarity (LO) affect the final %TE, we used three light intensities (50, 70 and 100 mu mol.m(-2)s(-1)) and three electrical conductivity (EC) levels (EC 2, 4 and 6 dS.m(-1)) in hydroponic systems to induce different osmolarities in leaf materials from two cultivars (cvs) of Z. elegans, Envy and Purple Prince. The isolated leaf mesophyll cells were subsequently cultured in a liquid medium (300 mOsm extracellular osmolarity) containing alpha-naphthalene acetic acid (NAA) (1 mg.l(-1)) and benzylaminopurine (BA) (1 mg.l(-1)). The LO increased in both Zinnia cvs with increasing light intensity and increasing EC during growth. Mesophyll cell size correlated negatively with EC, but the correlation was positive with light intensity in both Zinnia cvs. There was an overall positive correlation between % TE and LO although the degree of % TE change versus LO differed between light and EC treatments and also between the two Zinnia cvs. Envy cv is the best known Z. elegans cv for establishing xylogenic cultures. However, it turned out that by subjecting the plants to different growth conditions, the Purple Prince cv produces a higher % TE as compared to the Envy cv. At EC4 the TE differentiation for the Purple Prince cv was 75%, a level that is 25 to 60% higher than those earlier reported. We conclude that light intensity and EC of the root environment affect the LO of Z. elegans which in turn influences the development and therefore dimensions of TEs in an in vitro xylogenic culture. Thus, proper optimization of the growth conditions for the Zinnia plants prior to establishment of xylogenic cultures leads to enhancement of in vitro TE formation

Effect of 2,4-D, explants type and cultivar on the callogenesis expression of cassava (Manihot esculenta Crantz) in Ghana

Modern biotechnological applications in breeding programmes for economically-important crops like cassava begins with successful establishment of stable and active callus cultures for somatic embryos which can be genetically manipulated and induced into planting materials. We have investigated the effects of explants (leaves, stem petiole and axillary buds), auxin (2, 4-D) concentrations (8, 12 and 15 mg/l) and cultivar in the induction of callus cultures from local cassava varieties in Ghana - Tuaka, Afisiafi, Afebankye and Doku. Callus formation was successfully induced in all explants (leaf, petiole and auxiliary buds) from the four cassava cultivars. Generally, there were no significant differences in callogenesis of the different explants at the three different 2,4-D concentrations (p < 0.05) producing 75% callus for explants. The stem petiole or stem bark produced the least percentage of callus per cultivar at all the auxin concentrations. However, the leaf explants were superior in callus formation in all the cassava varieties. Although, statistically insignificant, the 8 mg/l 2,4-D concentration was visually the best in callus formation from explants both within and across the cassava cultivars. This study had shown that different cassava explants respond differently to tissue culture conditions established for callus culture formation.Key words: Auxin, callogenesis, callus induction media, cassava Manihot esculenta Crantz, 2,4- dichlorophenoxyacetic acid (2,4-D), somatic embryogenesis

Genetic relationships between some released and elite Ghanaian cassava cultivars based on distance matrices

Eleven (11) released and two local Ghanaian cassava cultivars were fingerprinted to estimate the genetic diversity among them using 35 SSR markers. Genomic DNA of thirteen cassava cultivars (UCC, IFAD, Agelifiaa, Nyerikobga, Nkabom, Essam Bankye, Akosua Tumtum, Debor, Filindiakong, Afisiafi, Doku Duade, Bankye Hemaa and Bankye Botan) were isolated and used as template for PCR amplification involving 35 SSR markers. The recorded gel bands (163 polymorphic bands) were subjected to NTSYSpc Version 2.1 software for cluster analysis and development of dendrogram to show the corresponding similarity coefficients. Genetic relationships between Bankye Hemaa and Filindiakoh and that between Bankye Hemaa and Afisiafi recorded 1.2% similarity coefficients respectively. The local cultivars, Debor and Akosua Tumtum were distantly related at 52.31% similarity. Filindiakoh was found to be the closest relative to Akosua Tumtum and Debor at 17.9 and 29.1% similarity, respectively. Bankye Botan and Bankye Hemaa, however, were distantly related to most of the cultivars, including the local varieties. Bankye Hemaa was found to be closest relative of Filindiakoh and Afisiafi (1.2 and 1.1% similarity, respectively) and suggesting that they could serve as very good candidates in breeding programs in Ghana. Bankye Botan and Bankye Hemaa are distant relatives to most of the cultivars, including the local varieties which could however make these cultivars also very useful in breeding.Key words: Maninhot esculenta, cassava, molecular diversity, fingerprint, selection of genotype, DNA, SSR markers

Osmotic potential of Zinnia elegans plant material affects the yield and morphology of tracheary elements produced in vitro

The Zinnia elegans cell suspension culture is excellent for xylogenesis studies at the cellular and molecular level, due to the high and synchronous in vitro differentiation of tracheary elements (TEs).The percentage TE differentiation (%TE) in the culture is, however, influenced by a number of factors before and during cell differentiation. One of the factors that is potentially important but has not gotten much attention is the initial osmolarity of the plant material. To examine whether the growth conditions that determine leaf osmolarity (LO) affect the final %TE, we used three light intensities (50, 70 and 100 μmol.m-2s-1) and three electrical conductivity (EC) levels (EC 2, 4 and 6 dS.m-1 ) in hydroponic systems to induce different osmolarities in leaf materials from two cultivars (cvs) of Z. elegans, Envy and Purple Prince. The isolated leaf mesophyll cells were subsequently cultured in a liquid medium (300 mOsm extracellular osmolarity) containing α-naphthalene acetic acid (NAA) (1 mg.l-1) and benzylaminopurine (BA) (1 mg.l-1). The LO increased in both Zinnia cvs with increasing light intensity and increasing EC during growth. Mesophyll cell size correlated negatively with EC, but the correlation was positive with light intensity in both Zinnia cvs. There was an overall positive correlation between %TE and LO although the degree of %TE change versus LO differed between light and EC treatments and also between the two Zinnia cvs. Envy cv is the best known Z. elegans cv for establishing xylogenic cultures. However, it turned out that by subjecting the plants to different growth conditions, the Purple Prince cv produces a higher %TE as compared to the Envy cv. At EC4 the TE differentiation for the Purple Prince cv was 75%, a level that is 25 to 60% higher than those earlier reported. We conclude that light intensity and EC of the root environment affect the LO of Z. elegans which in turn influences the development and therefore dimensions of TEs in an in vitro xylogenic culture. Thus, proper optimization of the growth conditions for the Zinnia plants prior to establishment of xylogenic cultures leads to enhancement of in vitro TE formation.Keywords: Electrical conductivity, in vitro culture, leaf osmolarity, light intensity, osmotic potential, tracheary element, xylogenesis, Zinnia elegans

Genetic relationships revealed by simple sequence repeat (SSR) markers among Ghanaian cassava cultivars released by different research groups

Cassava (Manihot esculenta) is an important staple crop in Ghana and it is widely cultivated.The crop has diverse industrial applications. Knowledge about the state of cassava genetic structure in Ghana is paramount in any cultivar improvement especially through breeding for superior qualities. The objectives of the study were to assess the SSR allele polymorphism, and the estimation of inter- and intra-population genetic diversity among released cassava cultivars. The results showed high diversity among the studied cultivars with an average of seven alleles per locus. Polymorphic loci varied from 68.6 per cent to 100 per cent with an average of 88.58 per cent. Genetic diversity was observed within populations (HS = 0.552) and, therefore, suggesting a low rate of inter-population gene flow among the individuals constituting the populations

Agronomic potentials of quality protein maize hybrids developed in Ghana

A quality protein maize (QPM) hybrid programme was started in 1991 to develop and promote high and stableyielding QPM hybrids to increase production of nutritionally superior maize varieties in Ghana. Six 3- way QPM hybrids developed from inbred lines originating from germplasm of the International Centre for Maize and Wheat Improvement (CIMMYT) were evaluated on research stations and in farmers\' fields in Ghana from 1995 to 1996. In the on-station evaluations, grain yields across 10 sites in both years averaged 6.0 ton ha-1 for the three hybrids (GH132-28, GH110-5 and GH2328-88), 5.22 ton ha-1 for Obatanpa, and 3.60 ton ha-1 for the local maize variety. In farmers\' fields, data from over 50 farm sites in 1995 and 1996 showed mean yields of 4.95 ton ha-1 for the three hybrids, and 4.28 ton ha-1 for Obatanpa compared to 3.59 ton ha-1 for farmers\' varieties. On the average, the hybrids were similar to Obatanpa in days to 50 per cent silking, but were shorter in plant height and ear placement. Consumer preference tests showed that the three hybrids were rated similar to the local variety in popular traditional food preparations such as ‘kenkey\' and ‘tuo zafi\'. In 1997, the National Variety Release Committee approved the release of GH132-28, GH110-5, and GH2328-88 under the local names Dadaba, Mamaba, and CIDA-ba, respectively. These hybrids are recommended for planting in all the major agro-ecologies to boost maize production in Ghana.Les variétés de maïs hybride (Zea mays L.) dont les plus sésirées que les variétés de pollinisation libre à cause de leur uniformté et leurs potentiels de rendement plus élevés. Pour augmenter la production de variétés de maïs nutritionnellement supérieures au Ghana, I\'Institut de Recherche de Cultures a mis en place un programme hybrid de maïs protéique de qualité (MPQ) en 1991 pour développer et promouvoir des hybrides de MPQ de rendement élevés et stable. Six hybrids en trois de MPQ développés d\'issu de la même souch provenant de germeplasmes de CIMMYT (Centre International pour I\'amélioration de maïs et de blé) étaient évalués aux stations de recherches et aux champs d\'agriculteurs au Ghana de 1995 à 1996. Dans les évaluations sur place, les rendements de grain à travers 10 sites dans les deux années ont atteint la moyenne de 6.0 ton ha-1 pour les trois hybrids (GH132-28, GH110-5 et GH2328-88), 5.22 ton ha-1 pour \'Obatanpa\' et 3.60 ton ha-1 pour la variétés de maïs local. Sur les champs d\'agriculteurs des données de plus que 50 sites de champs en 1995 et 1996 montraient les rendements moyens de 4.95 ton ha-1 pour les trois hybrids et 4.28 ton ha-1 pour les \'Obatanpa\' comparées à 3.59 ton ha-1 pour les variétés d\'agriculteurs. En moyenne, les hybrides étaient semblables à \'Obatanpa\' en jours jusqu à 50% d\'apparition de soie maïs étaient plus courtes en taille de plante et en placement d\'épi. Les essais de préférence de consommateur montraient que les trios hybrides étaient évalués semblables à la variété locale dans les préparations de nouriture traditionnelle populaire telle que \'kenkey\' et \'tuo zafi\'. En 1997, le comité pour la mise en vente de Variété Nationale a approuvé la mise en vente de GH132-28, GH110-5 et GH2328-88 sous les noms locaux respectifs de Dadaba, Mamaba, et CIDA-ba. Ce hybrides sont recommandés pour la popultion dans toutes les agroéclogies majeures pour stimuler la production de maïs au Ghana. Ghana Journal of Agricultural Science Vol. 40 (1) 2007: pp. 81-8

Effects of water stress during growth of xylem anatomy, xylem functioning and vase life in three Zinnia elegans cultivars

In cut flowers, hydraulic properties and dimensions of xylem vessels in the stem directly influence vase-life and thus post-harvest quality. Xylem hydraulic conductance as well as recovery from air embolisms at the start of vase life strongly depends on number, diameter and length of xylem vessels in the base of the cut flower stems. In this research we employed different water availability levels (high and low water content) in the growing medium of Zinnia elegans plants of three cultivars ('Envy', 'Purple Prince' and 'Scarlet Flame') to modify xylem anatomy and post-harvest xylem functioning and vase life of cut flowers from these plants. Vase-life was longer among fresh-cut Zinnia flowers in all three cultivars grown under low water content in the root medium. Zinnia flowers of all cultivars grown at high water content were not able to sufficiently restore water uptake at the start of their vase life. Shoot hydraulic conductivity was lower in water-stressed plants but it was not different among the three Zinnia cultivars within the same treatment. Anatomical analysis showed smaller xylem vessel diameters but no differences in xylem number and length, with the exception that in cultivar Purple Prince vessels were longer in well-watered plants. We conclude from these results that within these three Zinnia elegans cultivars water stress conditions in the root environment significantly affected xylem anatomy and functioning which correlates well with a longer vase life. Differences in xylem properties between the three cultivars due to pre-harvest watering treatments were limite

MAPPING FIRE SEVERITY FROM RECENT CALIFORNIA WILDFIRES USING SATELLITE IMAGERY

Urban sprawl has become a huge concern for cities like Los Angeles, New York, and Chicago in recent years. As urban sprawl pushes urbanization into city suburbs and outskirts, forest fragmentation becomes evidently prevalent and exposes forests to high temperatures, pollution, pests, and fires that threaten forest health. A 2021 report titled Rebuilding for a Resilient Recovery affirmed that the frequency and damage potential of wildfires have been exacerbated by climate change and urban sprawl especially in California. Globally, these fires can be attributed to both natural and anthropogenic drivers such as deforestation, agriculture, mining, and industrialization. Future projections predict that these incidences of fires will only worsen as the planet continues to warm further, with emphasis on the spread and intensities of the annual California wildfires over the decade. Quantifying the consequences of these fires on global climate change has become crucial and with the emergence of advanced GIS mapping tools, focus, visualization, and interpretation of fire and burn severity has become easier. However, knowledge and understanding of wildfire dynamics is limited especially in terms of fuel load, impacts on vegetation health, aerosol release and associated movement in the atmosphere. It is therefore important to address these gaps to make better and informed actions towards forest use, protection, management, and policies and broadly towards ambitious climate goals such as the UN’s Carbon Neutral goal by 2050. This study uses Sentinel 2A data from the Copernicus fleet between 2018 and 2022 to identify and assess the burn severity of affected areas in Sonoma County, California. The aim of the study is to understand the impacts of fires of fire on vegetation health and the post-fire recovery process. The Normalized Burn Ration Index (NBRI) was used to identify and measure the extent of the burnt areas within the county and their severity and Normalized Difference Vegetation Index (NDVI) was used as a measure of forest heath. The results show that Sonoma County has become a high burn severity area with a major decrease in unburned areas between 2018 and 2022. NDVI values recorded all decrease from January to December for all the years because of pre-fire season drought. The wildfire season begins in May and before then there are seasonal droughts that occur hence accounting for the initial decline in NDVI. The least values recorded were between 0.5 and 0.57 for September, indicating sparse and unhealthy vegetation because of sharp declines during the fire season

ANALYZING THE IMPACT OF SEA LEVEL RISE ON COASTAL FLOODING AND SHORELINE CHANGES ALONG THE COAST OF LOUISIANA USING REMOTE SENSORY IMAGERY

Sea level rise poses risks to coastal areas which is increasingly rendering such areas susceptible to flood and shoreline retreat. Notably, coastal areas like Southern Louisiana located along the Gulf of Mexico has experienced endangering events of land subsidence due to flood inundations resulting from incessant distribution of hurricanes and tropical storms. This research therefore employed remote sensing data to analyze the impacts of sea level rise on coastal flooding and shoreline retreat along the coast of Louisiana. That is, by assessing Sentinel-2 imagery data to evaluate flood prone and flood extent areas particularly during the Louisiana floods and Hurricane Harvey. Based on this, the results show most of the inland parishes in coastal Louisiana such as Assumption, St. James, Livingston, Lafourche and Terrebonne were within high flood risk zones of about 9.3. These parishes also suffered severe damage in terms of affected croplands, potentially flooded areas and affected urban areas. On the other hand, most of the parishes in close proximity to the waterbodies such as the Gulf of Mexico were interestingly within low flood risk zones of about 6.1 suggesting proximity to waterbodies not being the only indicating factor of a flood prone area. This research also highlights that Louisiana's shorelines are rapidly receding at a rate that could result in the loss of one million acres of the state’s land in the next four decades. Hence, the results from this research are anticipated to contribute to sustainable shoreline setback plans and mitigative strategies to protect Louisiana's coast

THE INTEGRATION OF REMOTE SENSING AND GEOGRAPHIC INFORMATION SYSTEM (GIS) IN MANAGING URBAN ECOSYSTEMS

Urban ecosystems face numerous challenges due to rapid urbanization and population growth. Effective management of these ecosystems is crucial to ensure their sustainability and the well-being of urban residents. Remote sensing (RS) and Geographic Information Systems (GIS) have emerged as valuable tools for understanding and managing urban ecosystems. The integration of remote sensing and GIS technologies facilitate the monitoring and assessment of urban biodiversity, aiding in the conservation and restoration of ecological habitats. With this mind, the objective of this study was to investigate the integration of remote sensing and GIS technologies for real-time monitoring and assessment of environmental parameters in urban ecosystems, and their role in supporting sustainable urban ecosystem conservation efforts. Landsat 8 Operational Land Imager (OLI) images were acquired between January 2nd and April 5th 2020 to assess and monitor the dynamics in urban ecosystems in Abidjan, Accra, and Lagos. The Normalized Difference Built-up index was used to detect areas covered with concrete structures and impervious surfaces, while the Normalized Difference Vegetation Index and Normalized Difference Water Index were used to detect areas covered with vegetation and water bodies, respectively. Results of the study show that Abidjan, Accra, and Lagos experienced increased built-up areas at the expense of other land uses such as forests. Remote Sensing and GIS technologies provide valuable insights into the spatial and temporal dynamics of urban environments, supporting evidence-based decision-making and sustainable urban planning and development