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STUDIES IN BACTERIOSIS: XXI. AN INVESTIGATION OF MARSH SPOT OF PEAS: WITH A NOTE ON THE MORPHOLOGICAL STRUCTURE
Author(s) -
LACEY MARGARET S.,
GRIEVE BRIAN J.
Publication year - 1934
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1934.tb07465.x
Subject(s) - germination , biology , seedling , leaf spot , marsh , cotyledon , inoculation , horticulture , shoot , spots , bacillus subtilis , botany , bacteria , ecology , wetland , genetics
Summary. A bacterial examination was made of the cotyledon lesions of 200 dried and 200 fresh green‐pea seeds. Cultures made from 60 per cent, of the dried and 80 per cent. of the fresh peas were sterile; the remainder yielded growths of micro‐organisms of which the two predominating species were a sporing bacillus of the B. subtilis or B. mesentericus type and a minute yellow rod, probably B. herbicola aureum . These two types are often present on the outside of pea seeds, and were isolated in a few cases from the centres of the cotyledons of healthy peas. Further proof of the saprophytic nature of these two types, and of the other organisms isolated in the cultural tests. was afforded by numerous inoculation experiments, which all gave negative results. Tests on the germination of marsh‐spot seeds show that badly diseased seeds fail to germinate, while in less severe cases the primary shoot is frequently dead or dies soon after germination, the growth being continued by lateral development. After the seedling stage in most seasons no difference can be detected between plants grown from marsh‐spot or healthy seeds. No evidence was obtained of any increase of marsh spot in the progeny from diseased seeds as compared with that from healthy seeds grown under the same conditions. Pot‐culture experiments on the effect of soil and of excessive watering on the development of marsh spot gave entirely negative results. Pot cultures are apparently unsuitable for the development of marsh spot.