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Search Results: 1 - 10 of 223774 matches for " R Akromah "
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What we should know about genetically modified foods
R Akromah
Journal of Science and Technology (Ghana) , 2004,
Abstract: Most of us know very little about the way our food plants are grown and are far removed from the factories where they are processed. All we care about is that our food should be wholesome, nutritious and tasty. Critics of crop biotechnology are of the opinion that potential ecological and food safety disasters are looming on the horizon because genetically modified (GM) crops have entered the food chain. Alarmists have introduced emotionally charged terms into the debate and speak of ‘frankenfoods' and ‘genetic pollution'. Issues of food safety and food sufficiency are extremely important to the general public and all need to be adequately informed to be able to take decisions on whether or not to allow GM foods into the food chain. In this paper, I present basic facts for the general public and invite other opinions on the topic and suggestions for the Way Forward in a developing country like Ghana. Journal of Science and Technology Vol.24(2) 2004: 8-12
Evaluation of tomato genotypes for resistance to root-knot nematodes
F Jaiteh, C Kwoseh, R. Akromah
African Crop Science Journal , 2012,
Abstract: Tomato (Solanum lycopersicum) is one of the most popular vegetable crops worldwide, owing to its high nutritive value and diversified use. Tomato production in Ghana is threatened by plant parasitic nematodes, especially the root knot nematodes (Meloidogyne spp.), which are responsible for huge economic yield losses. The losses, however, can be averted through use of resistant varieties. A study was conducted to evaluate tomato genotypes reaction to root-knot nematodes. Five inoculum levels, 100, 500, 1000, 1500 and 2000 root-knot nematode eggs per 1.6 litres of soil per pot were inoculated on tomato seedlings. A total of 33 genotypes were screened for resistance to Meloidogyne spp. Nine tomato genotypes were collected from Burkina Faso, eight from Vietnam, seven from the United States of America, three genotypes from South Africa, and six from local agro-dealers and farmers in Ghana. The genotypes were screened in pots and the field for host resistance to Meloidogyne spp. The 1500 eggs per plant inoculation level resulted in the highest number of eggs, juveniles and fresh root weight. Among the 33 genotypes screened, Tomato Mongal T-11 and Tomato Beef Master were found to be highly resistant to Meloidogyne spp. and also recorded the lowest reproductive factors of 0.71 and 0.53, respectively.
Genetic variation and trait correlations in a birdresistant pearl millet landrace population
R Akromah, D Afribeh, MS Abdulai
African Journal of Biotechnology , 2008,
Abstract: Genetic variation and correlations among traits within a Ghanaian bird-resistant pearl millet landrace population were investigated by evaluating S1 plants derived from the population, at two locations and for two years in Ghana. The objectives were to study genetic variation and correlations among traits in the population, determine the feasibility of selection and to suggest appropriate selection methods and selection indices for effective improvement. There was significant genetic variation for grain yield and most yield component traits, indicating that selection within the population would be feasible. Genetic variation was, however not significant for the percent incidence of downy mildew, implying that selection for improving resistance to the disease would not be effective. Heritabilities ranged from moderate to high (0.4- 0.73) for most traits, in view of which the use of recurrent selection methods, with progeny testing, could be effective for improvement of the population. Grain yield was observed to have significant phenotypic and genotypic correlations with days to 50% blooming and with earhead length, indicating that those two traits could be relied upon as selection indices for selection to improve grain yield. However, significant positive correlations were also observed between earhead length and plant height, which is undesirable, as plants with tall height tend to have a low harvest index and are also prone to lodging. In view of this, caution would be needed during selection, in order to achieve an improved population with good grain yielding ability and not very tall plant height.
Identification of Near-Isogenic lines Resistance to Rice Yellow Mottle Virus
A Jaw, MN Ndjionndjop, R Akromah, Y Sere
African Crop Science Journal , 2012,
Abstract: Rice yellow mottle virus (RYMV) is a serious disease in rice production in the lowland and irrigated ecologies. A study was conducted to examine the resistance of rice (Oryza sp.) lines RYMV. One hundred near-isogenic lines (NILs) from BC2F7 population derived from cross combination: Gigante (Oryza indica cv.) x IR64, Gigante x FK28 and Gigante x IR47 were evaluated. Twenty NILs were identified to be resistant to RYMV BF27 isolate from phenotypic screening. Enzyme-Linked-immunosorbent assay (ELISA) test revealed 36 lines to be resistant to RYMV with low virus content. Foreground selection using the gene marker, revealed 22 lines showed introgression of rymv1-2 allele. On the average, 71% of the markers used in the evaluation showed polymorphism. The highest proportion of recurrent parental contribution was obtained from the cross Gigante x IR64; and the lowest from Gigante x IR47. Individuals from Gigante x FK28 had the highest percentage of the donor parent (70%) and Gigante x IR64 had the lowest value but showed the highest genomic proportion of the recurrent parent (57%) was showed by Gigante x IR64.
Is there Avocado sunblotch Viroid in Ghana?
AK Acheampong, R Akromah, FA Ofori, JF Takrama, M Zeidan
African Journal of Biotechnology , 2008,
Abstract: The prevalence of Avocado sunblotch Viroid (ASBVd) among Ghanaian accessions was investigated. One hundred and eighty five (185) symptomatic and symptomless avocado trees were tested by DIGdot blot hybridization for the presence of ASBVd. One (0.01%) accession tested positive, 158 (85.8%) tested negative, while the results of the remaining 26 (14.1%) were inconclusive (herein referred to as “possible carriers”). Only one true symptomless carrier of the viroid was identified. The viroid showed no geographical or topographical preferences. The positive and ”possible carriers” were evenly distributed around the country. The incidence of the disease in Ghana was found to be very low and hence steps must be taken to eradicate it and maintain a clean industry.
Inheritance Of Spikelet Fertilty in two Rice Crosses
M D Asante, R Akromah, P K Darty, J Ofori
Journal of Science and Technology (Ghana) , 2006,
Abstract: Spikelet sterility is the greatest barrier to rice hybridization. Two crosses IDSA 85/NERICA 1 and IDSA 85/JASMINE 85 were made to study the inheritance of spikelet fertility. Percent Spikelet fertility was obtained by calculating the number of filled spikelets as a percentage of the total number of spikelets. F2 spikelet fertility was then ranked into “low fertility class” plants and “normal fertility class” plants based on the fertility range of the less fertile parent. Any plant that fell into a fertility class similar to the range of fertility classes that the less fertile parent fell into was regarded as having a normal fertility and those that did not fall into this range were regarded as having a low fertility. There were significant differences (p<0.001) in mean fertility amongst the various populations in both crosses. Parents had significantly higher mean percent fertilities than F1 and F2 populations for both crosses. Mean percent fertility in F2 was significantly higher than F1 for the IDSA 85/NERICA 1 cross but there was no difference in F1 and F2 for the IDSA 85/JASMINE 85 cross. The F2 of the two crosses made in this study were found to have segregated into 9 low fertility plants: 7 normal fertility plants. This indicates that spikelet fertility in both crosses displayed duplicate recessive epistasis. Journal of Science and Technology Vol. 26 (3) 2003: pp. 40-45
Host Plant Resistance to Phytophthora Pod Rot in Cacao (Theobroma cacao L.): The Role of Epicuticular Wax on Pod and Leaf Surfaces
D. Nyadanu,R. Akromah,B. Adomako,C. Kwoseh
International Journal of Botany , 2012,
Abstract: Black pod disease caused by P. palmivora and P. megakarya in Ghana is one of the major causes of yield loss in cocoa. Several defense mechanisms are required to counter attack the pathogen. To investigate the role of epicuticular wax in resistance of cocoa to Phytophthora pod rot, 12 cocoa genotypes with and without epicuticular wax on pod were inoculated with P. palmivora and P. megakarya. The wax layers were removed by washing the surfaces of leaf and pod in chloroform for 30 sec. The level of resistance of cocoa genotypes was higher in leaves and pods with wax layer than in chloroform washed leaves and pods (wax removed). Cocoa genotypes with higher amount of wax were more resistant than cocoa genotypes with lesser amount of wax. These results suggest that epicuticular wax layer provide an extra defense against Phytophthora species. There was a significant difference in lesion number and lesion size of cocoa genotypes after removal of their waxes suggesting that other factors are also involved in the resistance of cocoa to Phytophthora species. Cocoa genotypes with higher amount of cuticular waxes on the surfaces of their leaves and pods retained smaller amount of water and take shorter time for moisture to evaporate from their surfaces than cocoa genotypes with lesser amount of wax. Water retention and time to drying of water varied significantly among the cocoa genotypes with intact wax layers. However, there were no significant differences among cocoa genotypes for moisture retention and time to drying of water from leaf and pod surfaces after washing leaves and pods in chloroform. This indicates hydrophobicity of epicuticular waxes on leaf and pod surfaces of cocoa. The implications of these findings in breeding for black pod disease resistance are discussed.
Evaluation of nutritional quality of groundnut (Arachis Hypogaea L.) from Ghana.
J Asibuo, R Akromah, HK Adu-Dapaah, O Safo-Kantanka
African Journal of Food, Agriculture, Nutrition and Development , 2008,
Abstract: Groundnut is the most important legume in Ghana. The crop is grown in all the agroecologies in the country; from the dry savannah regions to the moist forest areas. Several food preparations incorporate groundnut to improve the protein level, taste and flavour. Despite the importance of the crop, the chemical compositions of the varieties grown by farmers have not been analyzed according to their nutritional quality. Oil, fatty acids, protein, oleic/linoleic (O/L) acid ratio, iodine value and free soluble sugars were studied in 20 groundnut varieties grown in Ghana to determine their nutritional quality and to inform endusers which variety to choose for maximum benefit. Results indicated a significant difference (p<0.05) in oil content among the varieties. Oil content ranged from 33.60 to 54.95%. Mean oil content of the subspecies hypogaea (49.7%) was higher than in subspecies fastigiata (47.3%). The major fatty acids were oleic and linoleic which accounted for 77.89% of the total fatty acids. The subspecies hypogaea had significantly higher (p<0.01) content of oleic acid (55.9%) than the subspecies fastigiata (43.3%). The sum of three fatty acids oleic, linoleic and palmitic acid constitute 89.35% of the total fatty acids of the seeds. The mean O/L ratio ranged from 1.14 to 3.66; the mean for subspecies hypogaea was 2.59 as compared to 1.28 for subspecies fastigiata. There was high correlation between oleic and O/L acid ratio (r2=0.983) and negative correlation between oleic acid and linoleic acid (r2=-0.996). The iodine value ranged from 85.77 to 98.43% and total soluble sugars from 9.20 to 13.30%. Protein of defatted portion ranged from 39.65 to 53.45%. Subspecies fastigiata had higher mean protein content than subspecies hypogaea. Generally, there were significant variations in the parameters measured in the groundnut varieties. Five varieties with O/L ratio more than 2.0 were identified and their oils would be further tested for their stability.
Chemical composition of groundnut, Arachis hypogaea (L) landraces
JY Asibuo, R Akromah, Osei Safo-Kantanka, HK Adu-Dapaah, S Ohemeng-Dapaah, A Agyeman
African Journal of Biotechnology , 2008,
Abstract: Groundnut production and utilization in Ghana has tripled in the last decade due to its high nutritive value and the number of uses it can be put into. The chemical quality of seeds of Ghanaian groundnut are different from those of other countries, however, no previous studies has been done. This study was initiated to examine the nutritional quality of 20 groundnut varieties grown in Ghana. Dry samples were examined for oil content, crude protein, total carbohydrate, calcium, potassium, magnesium, sodium, zinc, copper, iron and manganese. Results from these analyses showed significant variation between the parameters measured. Virginia cultivars which belong to subspecies hypogaea had higher oil content (49.7%) than the Spanish and Valencia market types, which belong to subspecies fastigiata (47.3%). The mean protein content of subspecies fastigiata was however higher (25.69%) than subspecies hypogaea (22.78%). The mineral elements examined were substantial in reducing malnutrition especially in young and growing children. Broni fufuo, a Spanish market type had the highest crude protein content (30.53%) and the least oil content (33.60%) and is idea for products which require more protein and less oil. Substantial genetic variability exists for chemical composition and nutritional traits which could be utilised for various food preparations and selection for breeding purpose.
Genetic diversity within Ghanaian cowpea germplasm based on SDS-page of seed proteins
EYR Oppong-Konadu, HK Akromah, Adu Dapaah, E Okai
African Crop Science Journal , 2005,
Abstract:
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