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Original Research Article
ABSTRACT
For an organized cross breeding program, information on heterotic grouping, perse performance, and commercial heterosis of newly introduced maize lines is required. Therefore, the present study was conducted to determine the heterotic group, commercial heterosis, perse and crosses mean performance of newly introduced from IITA-Nigeria and CIMMYT- Zimbabwe quality protein maize inbred lines. 36F1 progenies generated from the four testers and nine lines, and including four standard checks a total of 40 entries, and thirteen inbred lines were planted by using Alpha lattice design with three replications at Bako National Maize Research Center and Jimma Agricultural Research center in 2019/20 main cropping season. The combined analysis over the two locations showed there were significant differences at (P<0.01) or (P<0.05) between the genotypes in grain yield, and yield contributors of the studied traits. In this study, lines that showed positive SCA when crossed with tester A were assigned to the opposing heterotic group (group B), and vice versa, based on the significance of the SCA effects. This also suggests that these inbred lines could be placed in the same heterotic group as AB. From the study, L5 had the highest yield (3.6 t/ha) of the inbred lines, followed by L2 (3.13t/ha) and L7 (2.53t/ha) respectively were identified. Regarding to the crosses, Eight promising crosses, L2xT4, L3xT4, L4xT4, L5xT2, L6xT3, L7xT2, L9xT1, and L9xT4, with higher yield than the checks, were identified. For grain yield, about twelve crosses nine crosses showed positive and significant advantages over the standard check BH545 with range of (33.3% to-24.2%) were also observed. Multilocation evaluation, tryptophan and lysine content of these genotypes must be re-evaluated to confirm the findings of this study and to use in recurrent breeding program or for directly release of the promised crosses. In general, molecular based heterotic grouping is more effective in clarifying ............
ABSTRACT
Sex determination is a process that leads to the physical separation of male and female gamete-producing structures to different individuals of a species. Sexual reproduction is an ancient feature of eukaryote life, yet the sexes as we currently recognize them are relative late comers in the evolution of sex. Sex determination systems in plants have evolved many times from hermaphroditic ancestors (including monoecious plants with separate male and female flowers on the same individual),and sex chromosome systems have arisen several times in flowering plant evolution. Sex chromosome evolution is intimately connected with Y chromosome degeneration. Most current understanding of how the distinctive properties of Y chromosomes evolved comes from theoretical work on the evolution of genomic regions with low recombination. The identification of sex chromosomes in plants is problematic because most of them do not differ morphologically from autosomes or from one another. For example in some species, such as Actinidia deliciosa var. deliciosa, X and Y chromosomes are too small to support observations of their distinguishing characteristics.) In the majority of plants, male and female organs are formed and developed simultaneously, but only up to a point when the growth of either set of sex organs is inhibited. Inhibition of sexual development can vary in character so that in most cases, sexual development is inhibited by the absence of cell division. In many species of bryophytes, heterothallism (unisexuality) has been correlated with the presence of sex chromosomes. Although the extent of heterothallism and sex chromosomes in the bryophytes has not been assessed systematically, this is the only known group of homosporous plants that uses sex chromosomes in sex determination. To date, studies of bryophyte sex determination have focused on the heterothallic liverwort Marchantia polymorpha. Many dioecious species, including those with well-developed sex chromosomes, ........
Original Research Article
ABSTRACT
A survey was performed in order to characterize the available phytogenetic resources of Chili pepper (Capsicum annun. L.). A sample of one hundred and twenty-six (126) individuals was used in the study. They included 85 traders, 25 producers and 16 seed promotion institutions from Yaounde, (Cameroon) and its supply areas. Respondents described eighteen varieties of pepper by production zones (12.91%) and colours (19.35%), while 65.59% of the respondents have no idea of the varieties marketed. Most of the pepper sold in the market, generally comes from areas such as Foumbot (25.71%), Bangante (13.33%), Okola (8.57%), Mbouda (6.97%), Mfou (5.71%) and unknown origin (21.9 %). The pepper is taken out of their production areas without any varietal identity, due to negligence on the part of producers, who buy 30% of the seedlings from the market, or extract their own seeds (42.5%) without prior identification of the variety. This leads to the loss of the genetic resource, despite the presence of several marketing structures with several well-known varieties. The lack of proper characterization leads to erosion of the pepper plant genetic resources in Yaounde and its supply areas. Added to this is the lack of interest of sellers, the high price of seeds, and the extraction of seeds from fruits after a production season or the use of seeds from the market.
ABSTRACT
Vegetables are considered to be an important part of a balanced diet. Particularly, the brassica vegetables many of them are leafy and green, add significant visual or esthetic attractiveness to a meal. Rapeseed and mustard; most important dicotyledonous, cross pollinated and cool season vegetable crop. Rapeseed oil is considered to have useful influence on human healt. It is suitable for patients suffering from several diseases or to control diseases. Its fatty acid profile along with other components might justify its beneficial impact. The local production of edible oil from all sources could not compete with the growing demand of population. There are many reseasons for low rapeseed production, such as labor and agricultural inputs availability due to the increasing costs. It is grown mainly for root throughout the country. Despite of its wide cultivation the average seed yield is rather low. Limited attention has been paid towards scientific method of good quality root and seed yield.
Original Research Article
ABSTRACT
The on-farm trials were conducted in three districts of west shewa zene, Oromia region, Ethiopia, to compare the performance of Promising hybrids under farmers field and promote one or two hybrids for possible release as commercial variety. Seven hybrids were evaluated using randomized complete block design (RCBD) in 2021 cropping season. The combined analysis of variance for three districts showed highly significant mean squares due to genotypes for all studied traits except ear position. Site*entry interaction showed significant mean variance only for grain yield (GY) indicating that, the performance of these genotypes were not consistent across sites for this trait. Hybrids SXH180174 and 3XH1900432 were the best performing genotypes for grain yield and some yield related traits. The single cross hybrid SXH180174 scored the highest grain yield (10.05 tons/ha) as compared to the checks and showed preferred plant and ear aspects. Accordingly this hybrid was recommended for variety verification trial stage for release as commercial hybrid in highland agro-ecology of the country.
ABSTRACT
Ethiopia is a center of origin and diversity of many cultivated crops and their wild relatives including barley. The richness and range of genetic diversity in Ethiopia, particularly of landraces, is currently subject to serious genetic erosion and irreversible losses due to the changing nature of agricultural production. In this review, the most important factor possibly leading to genetic erosion is the replacement of FV’s by modern cultivars followed by weather variability. Barley, as a food and feed grain, is important to the livelihood of farmers. A number of previous studies have shown higher level of barley diversity in the highland of the country. Traditional barley variety is suffering serious genetic erosion due to displacement by introduced varieties. Knowing the causes of genetic erosion is equally important for devising conservation measures. In conclusion, the use of genetic resources will remain the best way of meeting future food needs and driving the economic and social benefits for the world’s rapidly growing human population.
ABSTRACT
Antibiotic discovery continue to play a critical role in disease containment. Misuse and overuse of these drugs are the main drivers in the development of drug resistant pathogens. The World Health Organisation has declared that Antimicrobial resistance is one of the top 10 global public health threats facing humanity. There is the fears that if nothing is done, it might end the antibiotic era soon. In 2017 alone, over 9000 human deaths were caused by ESBL-producing Enterobacteriaceae in the USA. The ability of bacteria to develop newer strategies to acquire and disseminate resistance, can be traced as far back to 1940s when (R-factor) plasmid mediated antibiotic resistance was observed. They become resistant via the production of 𝛽-Lactamases and ESBLs enzymes which inactivate or modify antibiotics. Extended Spectrum 𝛽-Lactamases are enzymes whose rates of hydrolysis of the extended-spectrum 𝛽-Lactam antibiotics are >10 % than that for benzylpenicillin. Some bacteria may produce multiple ß-lactamases, which may reduce the effectiveness of ß-lactam/ ß-lactamase inhibitor combinations. These enzymes are susceptible to inhibition by 𝛽-Lactam inhibitors such as clavulanic acid, tazobactam, or sulbactam but have no hydrolytic activity against cephamycins and carbapenems. The production of acquired 𝛽-Lactamase and ESBL makes the choice of antibiotic treatment of infections caused by Gram-negative bacteria very limited, these have been the major causes of treatment failures, outbreaks of both community and hospital acquired infections, surgical failures, long hospital stay and huge economic losses, which continue to claim uncountable lives, especially in Nigeria and Africa where the health system are weak. The emergence of drug resistannt strains may be minimized by maintaining high levels of the drug in the tissues to inhibit mutants, administering two drugs that do not give cross-resistance, and by limiting the use of valuable second line ‘reserve drugs’ such .....