Morphological And Molecular Characterization Of Eggplant Lines For Resistant To Phomopsis Blight And Fruit Rot

The F4 lines of eggplant derived from the crosses of Dohazari G x BAU Begun-1 and Laffa S x BAU Begun-1 were evaluated for resistance to phomopsis blight and fruit rot under confined field conditions. The inoculated plants exhibited differential disease reactions. Among the parents, BAU Begun-1 was resistant whereas Dohazari G and Laffa S were susceptible to Phomopsis vexans. All the phenotypes of F4 progenies showed resistant reaction to the disease. Significant differences were observed among the phenotypes in all the yield components. High genotypic and phenotypic coefficient of variation, heritability and per cent genetic advance were estimated for number of fruits per plant, number of secondary branch per plant, fruit length and fruit breadth. Significant positive correlation was observed between yield contributing characters. Random amplified polymorphic DNA technique was used for assessing genetic variation and relationship among parent cultivars and their F4 progenies of eggplant. Amplification with five decamer primers generated 69.0% polymorphic bands. Comparatively higher genetic distance was observed between Laffa S vs. green globose (Dohazari G x BAU Begun-1). The dendogram constructed from Neis genetic distance produced two main clusters, the parent cultivars and six F4 lines formed cluster 1 and one line in cluster 2. F4 lines of the tested phenotypes showed similar disease reaction and divided into same sub cluster. The parent cultivars were different in case of disease reaction and finally divided into two groups, susceptible cultivars Laffa S and Dohazari G belonged to group 1 and the resistant parent BAU Begun-1 formed another group. Int. J. Agril. Res. Innov. & Tech. 3 (1): 35-46, June, 2013 DOI: http://dx.doi.org/10.3329/ijarit.v3i1.1605

Gamma Radiated Wheat for Combating Devastating Blast Disease (Magnaporthe Oryzae Triticum) In Bangladesh

Wheat is a global food security crop, providing 20 percent of protein and calories consumed worldwide and up to 50 percent in developing countries. It is the second most important cereal next to rice in Bangladesh and playing an important role in attaining food security. But wheat is very susceptible to diseases that often place major biological constraints on production. In 2016, a new wheat disease called “blast” was identified by wheat scientists for the first time in Bangladesh. Wheat blast disease caused by Magnaporthe oryzae triticum is causing enormous yield loss worldwide. At present, control of blast disease is a great challenge due to frequently introduction of new races of the pathogen. The present investigation focused on screening M2 population of gamma radiated wheat where four doses of radiations viz. 150 Gy, 200 Gy, 250 Gy, and 300 Gy were applied to the seeds of three wheat varieties viz. BARI Gom-25, BARI Gom-29 and BARI Gom-30 from a Cobalt 60 source (Gamma Chamber 5000). The irradiated seeds were sown in farmers’ fields of a wheat blast disease-prone area Chandbil, Meherpur Sadar. All the doses of irradiation showed a significant effect on incidence and severity of wheat blast disease in all three varieties. Among the treatments 200 Gy and 250 Gy reduced the disease effectively. Molecular detection of Magnaporthe oryzae triticum was also done using specific primer. The size of the band (350 bp) confirms the infection of M2 families by Magnaporthe oryzae triticum. Development of wheat blast resistant variety through irradiation could be a potential substitute to replace the available chemical control methods and it is described as eco-friendly, sustainable and nonhazardous strategy to reduce wheat yield loss due to blast disease

Determination of Economic Threshold Level (ETL) of Tobacco Mosaic and Leaf Curl Viruses

Experiments were conducted for the determination of economic threshold of Tobacco Mosaic and Leaf Curl viruses of tobacco. Infection of tobacco plants occurred naturally in the field. Mean values of yield were obtained after curing of tobacco leaves which varied significantly with incidence of disease. Yield loss assessment of tobacco caused by Tobacco Mosaic Virus and Tobacco Leaf Curl Virus was considered first. Grade index values of tobacco that influence market value and support price of flue-cured tobacco were also considered. Economic threshold values were determined from economic analysis and regression analysis and those were found to be at 4.5% and 4% disease incidence in NC 95 and K326 for Tobacco mosaic Virus and 4% and 4.5% for Tobacco Leaf Curl Virus respectively

MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF EGGPLANT LINES FOR RESISTANT TO PHOMOPSIS BLIGHT AND FRUIT ROT

The F4 lines of eggplant derived from the crosses of Dohazari G x BAU Begun-1 and Laffa S x BAU Begun-1 were evaluated for resistance to phomopsis blight and fruit rot under confined field conditions. The inoculated plants exhibited differential disease reactions. Among the parents, BAU Begun-1 was resistant whereas Dohazari G and Laffa S were susceptible to Phomopsis vexans. All the phenotypes of F4 progenies showed resistant reaction to the disease. Significant differences were observed among the phenotypes in all the yield components. High genotypic and phenotypic coefficient of variation, heritability and per cent genetic advance were estimated for number of fruits per plant, number of secondary branch per plant, fruit length and fruit breadth. Significant positive correlation was observed between yield contributing characters. Random amplified polymorphic DNA technique was used for assessing genetic variation and relationship among parent cultivars and their F4 progenies of eggplant. Amplification with five decamer primers generated 69.0% polymorphic bands. Comparatively higher genetic distance was observed between Laffa S vs. green globose (Dohazari G x BAU Begun-1). The dendogram constructed from Nei’s genetic distance produced two main clusters, the parent cultivars and six F4 lines formed cluster 1 and one line in cluster 2. F4 lines of the tested phenotypes showed similar disease reaction and divided into same sub cluster. The parent cultivars were different in case of disease reaction and finally divided into two groups, susceptible cultivars Laffa S and Dohazari G belonged to group 1 and the resistant parent BAU Begun-1 formed another group

Native <i>Trichoderma</i> strains isolated from Bangladesh with broad spectrum antifungal action against fungal phytopathogens

<p>Nineteen <i>Trichoderma</i> isolates, collected from different locations in Bangladesh, were characterised through phenotypic, biochemical and molecular means. Besides, they were assessed for their antifungal action <i>in vitro</i>. The isolates were divided into three groups: <i>T. asperellum</i>, <i>T. virens</i> and <i>T. harzianum</i>. A dual culture assay and a culture filtrate assay against 6 phytopathogens revealed that 9 of the 19 isolates showed significant antifungal activities. The isolate <i>T. harzianum</i> TR05 showed the highest inhibition against <i>Fusarium oxysporum</i>, <i>Rhizoctonia solani</i>, <i>Fusarium circinatum and Phomopsis vexans</i>, followed by <i>T. asperellum</i> TR08 and <i>T. virens</i> TR06. TR08 had the highest inhibition against <i>Sclerotium rolfsii</i> and <i>Pythium aphanidermatum</i>, followed by TR05 and TR06. These findings were in agreement with their activities of extracellular hydrolytic enzymes, including chitinase, β-1,3-glucanase, and proteinase. Our results suggest that isolates TR05, TR06 and TR08 have the potential to be effective biocontrol agents against the phytopathogenic fungi.</p