Prospects of genetic modified maize crop in Africa

Genetic modified maize crop increases annually as a result of food insecurity and limited land caused by rapid population increase of over seven billion in the world. Scientists have been playing their role to address this food insecurity problem. The use of genetically modified (GM) maize crop to feed people is one of the proposed ways, because it yields more compared to the conventional varieties. However, there are several contradictions which hinder the adoption of this new technology. Some studies have shown that GM maize is risky to human health, animals and not friendly to environmental conservation, which may lead to the death of other bio-diversities. Generally, other studies have supported the consumption of GM maize. However, after being approved by the scientist in the countries concerned, the GM maize varieties which seem to be hazardous to human health must be prohibited in research centres so as to avoid transportation to other countries. Regarding the new technology of GM maize, the conventional method of breeding is still important to keep maize seeds available in the gene bank. Therefore, researchers should consider this for further research issues on maize improvement.Key words: Bacillus thuringensis-maize, Bacillus thuringensis protein, conventional breeding, environment, food crisis, genetic modified maize, genetic modified organism, health risk, landraces

Genetic diversity of grapevine (Vitis vinifera L.) from Tanzania as revealed by ISSR markers

Research Article published by Journal of Advances in Agriculture Vol .5, No. 1Grapevine (Vitis viniferaL.) is a perennial horticultural crop which is used worldwide for production of wine, table grapes, dried fruits and grape juice. In spite of its importance as a cash crop, the purity of each variety and genetic diversity of this crop has not been identified. The study therefore, was conducted to assess the purity and genetic diversity among and within 10 varieties of grapevines represented by a total of 43 individual plants. By using nine ISSR primers, a total of 56 polymorphic bands were generated. Within variety diversity based on polymorphic bands ranged from 26.79% for Ruby seedless to 73.21% for Alphonce lavallee with a mean of 55.18 %, Nei’s genetic diversity of 0.089–0.308 with a mean of 0.202, Shannon information index of 0.137–0.445 with a mean of 0.302 and analysis of molecular variation (AMOVA) of 76.767% within varieties were detected. With all diversity parameters, the highest diversity was obtained from Regina, Alphonce lavallee, Syrah and Makutupora white varieties, whereas the lowest was from Ruby seedless. AMOVA showed a 23.23% between varieties variability was less than that of within varieties variation. Varieties differentiation with Fixation index (FST) was 0.23. From Jaccard’s pairwise similarity coefficient, Makutupora red and Chancellor were most related varieties exhibiting 0.976 meanwhile Queen of vineyard and Ruby seedless were most distantly related varieties with similarity of 0.408. Alphonce lavallee and Makutupora white varieties exhibited the highest genetic diversity. Therefore, these varieties should be considered for further improvement of this species

Prospects of Biotechnology in Grape Breeding

Research Article published by Journal of Advances in Agriculture Vol .5, No. 1Genetic improvement of grape cultivars to obtain high quality wine and table grape varieties by conventional breeding methods has been difficult and time consuming. The elite grape varieties developed by conventional breeding techniques have less resistance to fungal and bacterial diseases, drought, quality and yield per plant. Breeding programs of grapes are difficult due to lack of true bred from seed and few traits of importance. Though most grapes constitute large number of genes, they have less effect in tolerating biotic and abiotic stresses. Genetic improvement of grapevine (Vitis vinifera L.) through application of biotechnological techniques provide new strategies in grape breeding programs based on rapid selection or induction of desired traits by marker assisted breeding, genetic engineering and plant tissue culture. This review paper therefore, aims to discuss biotechnological techniques proposed for improvement of grape breeding

Screening for resistance of grape varieties to powdery mildew (Erysiphe necator) disease

Research Article published by Journal of Advances in Agriculture Vol. 5, No. 1This study was conducted to evaluate the susceptibility of grapevine varieties to powdery mildew. Powdery mildew is a disease caused by a fungal, Erysiphe necator, and an obligate parasite of grapevine (Vitis vinifera L.). Powdery mildew causes drastic yield losses of 50 to 70%. Commercial grapevines grown in producing countries are susceptible to powdery mildew. Use of fungicides to control the disease is expensive and not environmentally friendly. Therefore, use of grapevine resistant varieties to powdery mildew is cost-effective control method. In this study, ten varieties (Black rose, Regina, Queen of Vineyards, Alphonce lavallee, Makutupora red, Chancellor, Halili belyji, Syrah, Ruby seedless and Makutupora white) were screened for resistance to powdery mildew, using artificial inoculation of spore suspension and dry inoculums. Infected grape leaves were sampled from the field and grounded to obtain powder which was used as dry inoculum. The spore suspension inoculum was made by mixing powder with sterilized distilled water. The inoculation was done in two blocks with concentration of 2x105 spore/ml. Disease severity was evaluated based on a scale of 0 – 5; 0, means immune and 5, high level of disease severity. Results showed significant difference (P<0.05) of disease among grapevine varieties evaluated. It was found that 11.1% were resistant, 33.4% tolerant and 55% susceptible to disease. Grapevine variety Chancellor showed the highest level of resistance, and Black rose the most susceptible. The study demonstrates the effectiveness of using inoculation methods in screening resistance to powdery mildew