Question

1. Describe the progression of infection with v infestans. Is this organism a true fungus? 2. What is the "Bordeaux mixture"? How was it discovered? 3. Explain why the barberry plant (Berberis) is important to the life cycle of wheat rust. 4. How did chestnut blight make it to North America? Once here - how did it spread? 5. How is the elm bark beetle associated with the spread of Dutch elm disease (DED)? 6. What activities must be included in a successful DED control plan? 7. Describe another fungal pathogen of trees and name its host plants. 8. How could C.purpurea so easily get into the food supply during medieval times? What are the known alkaloids present in ergot & their associated symptoms in animals? 10. What evidence exists that may link ergot to witch trials? 0:51 DNI

please answer these 10 question

Answer 1

1. Phytophthora Infestans responsible for the Late blight in potatoes.Phytophthora infestans produce Sporangia or spores on leaves and stem surfaces of potato / tomato plant which are spread by wind or water to other plants. Human activities also contribute to progression.
Sporangia can germinate within a few hours after landing on potato or tomato foliage if free moisture is present. Germination takes place either indirectly via zoospores or directly via a germ tube that penetrates into foliage, stems, or fruit to initiate infections. Infections are visible as small lesions after three to four days. Lesions enlarge as the pathogen grows through the tissues, and the pathogen can sporulate from older lesions when the environment is favorable. Under dry conditions no sporulation occurs and the lesion has a brown dead center, surrounded by host tissue that has collapsed. Both tomato and potato fruits are vulnerable for infection.

Infestans is an oomycete not true fungus. The cell wall of oomycetes, however, is not composed of chitin, as in the fungi, but is made up of a mix of cellulosic compounds and glycan.

2. Bordeaux mixture is a fungicide  that is composed of copper sulphate and calcium oxide and water.It is used in gardens and Farms to prevent investigation by different Types of fungus. It was discovered by botany professor Pierre-Marie-Alexis Millardet of the University of Bordeaux. He studied the disease in vineyards of the Bordeaux region where he noted that vines closest to the roads did not show mildew, while all other vines were affected. He came to know that those vines had been sprayed with a mixture of CuSO₄ and lime to deter passersby from eating the grapes, since this treatment was both visible and bitter-tasting. So he conducted trials with this treatment.

3. Wheat rust is Caused by puccinia rust fungus . barberry plant is important as it is the alternate host for wheat rust fungus and required to complete its life cycle.

4. Chestnut blight was accidentally introduced in 1904 to North America when Cryphonectria parasitica was introduced into the United States from Japanese nursery stock. It spreads by wind-borne ascospores and conidia which are distributed by rain-splash action.