1. A study of the enzymatic relationships in some parasitic organisms. 2. Observations on the occurrence and spread of the ring spot or anthracnose disease of lettuce caused by mars-sonina panattoniana
Author(s)
Stevenson., Greta B.
Type
Thesis
Abstract
1. A study of the enzymatic relationships in some parasitic organisms: (A comparison was made of two organisms, Botrytis clnerea and Bacillus carotovorus, both of which cause a soft rot in the tissue which they parasitise. Enzymic extracts capable of producing a soft rot were prepared from both organisms. The physiological behaviour of the extracts was examined and also their enzymic constitution. It was found that soft rotting enzymes of considerably different constitution had the same effect of causing a soft rot of a piece of potato tissue.) 2. Observations on the occurrence and spread of the ring spot or anthracnose disease of lettuce caused by mars-sonina panattoniana: (Outbreaks of the disease were first observed in the field on a number of market gardens. Information was collected concerning the variety of lettuce attacked, the source of the seed, conditions favouring attack, the extent of previous attacks and whether lettuce or diseased lettuce had been grown on the same ground before. Seed was raised from clean and infected plants and some in succeeding seasons. It was found that seed from infected plants produced infected seedlings while the clean seed produced clean seedlings. Experiments were run to see if the disease carried over in the soil; the indications from these were that infection lasted a short time in the soil but that after longer periods it was not present.)
Version
Open Access
Date Awarded
1938
Publisher Department
Department of Life Sciences
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)