Evaluation of Resistance of Different Kiwifruit Varieties (Lines) to Canker Disease and Brown Spot Disease

Kiwifruit canker and brown spot are significant diseases affecting kiwis,caused by Pseudomonas syringae patho-genic variations(Pseudomonas syringae pv.Actinidiae(Psa))and Corynesporapolytica(Corynespora cassiicola).At present,the research on canker disease and brown spot disease mainly focuses on the isolation and identification of pathogenic bacteria,drug control,resistance gene mining and functional verification.Practice has proved that breeding disease resistant varieties are an effective method to control canker disease and brown spot disease.However,most existing cultivars lack genes for canker and brown spot resistance.Wild kiwifruit resources in nat-ure exhibit extensive genetic diversity due to prolonged natural selection,containing numerous resistance genes.But,due to insufficient understanding of the resistance of most kiwifruit varieties(lines)to canker disease and brown spot disease,some high-quality resources have not been fully utilized.The incidence of canker and brown spot of 18 kiwifruit cultivars(lines)was measured by inoculating isolated branches and leaves,and their resistance to canker and brown spot was analyzed according to the length,disease index,mean diameter,and systematic clustering.The results were as follows:Among 18 different kiwifruit varieties(lines)for canker disease,there were two highly resistant materials,eight disease-resistant materials,four disease-susceptible materials,and two highly susceptible materials.Moreover,regarding brown spot disease,there were one highly resistant material,five dis-ease-resistant materials,four susceptible materials,and three highly susceptible materials.Furthermore,four resources were resistant to both diseases.The outcomes provided a theoretical basis for breeding kiwifruit against canker and brown spot.

Histopathological Observation of Goose Escherichia coli Disease

[ Objective] This study aimed to provide reliable basis for in-depth understanding of histopathological changes in geese suffering from Escherichia coli disease and accurate diagnosis of goose E. coli disease. [ Method] By using paraffin embedding, section slicing and HE staining, histopathological changes in the heart, liver, spleen, lung, kidney and small intestine tissues of three diseased geese were observed. [ Result] The liver generated protein fiber membranes, showing liver cell degeneration, increasing number of red blood cells in sinusoids and liver congestion; the kidney had relatively serious lesions, including renal tubular epithelial cell degeneration, necrosis and shedding from the basement membrane and hyaline degeneration of glomerulars. The lung showed epithelial cell degeneration and necrosis and was filled with a large number of red blood cells and shedded epithelial cells, showing typical red hepatization; a large number of red blood ceils were aggregated in pulmonary blood vessels, resulting in lung congestion. Epithelial ceils of various digestive tubes all showed varying degrees of minor shed- ding and local infiltration of inflammatory ceils, thereby leading to death of geese due to substance metabolism, electrolyte and acid-base balance disorders and metabolic acidosis. [ Conclusion] Based on epidemiology survey, clinical symptom observation, pathological necropsy and laboratory diagnosis, the diseased geese were confirmed to be suffering from E. coli disease.