Transgenic canola plants over-expressing bacterial catalase exhibit enhanced resistance to Peronospora parasitica and Erysiphe polygoni

Transgenic canola [Brassica napus.L] plants expressing the bacterial catalase katE in the chloroplasts were obtained by the Agrobacterium-mediated transformation method. Resistance and susceptibility of the transgenic canola plants were evaluated against the airborne pathogenic fungi, Peronospora parasitica causing downy mildew and Erysiphe polygon causing powdery mildew under artificial infection in the greenhouse. The bioassays of the transgenic plants demonstrated that the growth of both fungi and the development of disease incidence were significantly inhibited in the leaves of the transgenic canola plants compared to controls. Chemical analyses of the transgenic plants revealed constitutive expression of the enzymes catalase, peroxidase and polyphenoloxidase as well as higher levels of free polyamines i. e. putrescine, spermidine and spermine compared with the control plants. Together, these data indicate an enhanced resistance of the transgenic canola plants expressing the bacterial catalase to the downy mildew and powdery mildew pathogens

Genetic markers for cultivar identification in potato in relation to insect tolerance as reveald by RAPD analysis

In Egypt losses of agricultural products by mole cricket are abundant. However the genetic information on tolerance to mole cricket is limited. Therefore, in the present study the yield of four potato cultivars [Alfa, Scort, Desrea and Diamond] were compared under natural mole cricket infestation. The tuber yield decreased by this insect infestation, and the reduction differed significantly among cultivars. The cultivar Alfa prooved to be the one of choice under the soil that has infection with mole cricket. The infestation of potato by mole cricket reduced the carbohydrate concentration in the infected compared to the non-infected tubers. For RAPD analysis, seven arbitrary 10-mer primers were used. A total of 62 scoreable bands was detected of which 30 bands Were polymorphic[48.4%]. Based on the data obtained by RAPD analysis, it was possible to discriminate between the four potatoes genotypes used in the present study. The genotype-specific Marker indicates that six markers distinguish the cultivar Alfa [OPB-09-800, OPB-09-650, OPD-04-1970, OPD-04-475, OPD-04-317,OPE-13-890], three markers distinguish Diamond [OPA-06-1250, OPD-04-1000, OPD-04-600] one marker for Scort [OPD-04-580] and one marker for Desrea [OPA-15-2190]. The cultivar-specific markers represented 17. 7% of the total markers and 36.6 of the polymorphic markers. These markers can help in marker-assisted selection breeding Programs for improving mole cricket tolerance in potato plants