EFFECTS OF TEMPERATURE AND MOISTURE ON INDUCTION OF GENETIC CHANGES IN SEEDS OF BARLEY BROAD BEANS AND PEAS DURING STORAGE

Seeds were 'aged' by treatments with various combinations of temperature and moisture content so that viability was reduced to about 50 per cent. It was shown that such treatments induced non-heritable morphological abnormalities in about 10 per cent of the bean plants and 5 per cent of the pea plants; but no non-heritable morphological abnormalities were observed in the barley plants. In all species there was an increased frequency of pollen abortion in the plants produced from 'aged' seeds. From the examination of second and third selfed generations it was shown that single-recessive and double-recessive chlorophyll-deficiency mutations of various types were usually induced in sectors of about 1-3 per cent of the plants grown from treated seeds.The evidence from pollen-abortion supports previous cytological evidence that, under most storage conditions, for a given loss of viability, a predictable amount of chromosome damage is found in the surviving seeds, irrespective of how fast viability was lost or which environmental factor was mainly instrumental in the loss of viability. A comparison of the frequency of chlorophyll mutations produced under different storage treatments was not as quantitatively precise, but this evidence also is at least compatible with the thesis that loss of seed viability is associated with chromosome damage which is reflected in gene mutation. It is concluded, therefore, that percentage seed viability is a good index of the loss of genetic purity resulting from mutations which accumulate during storage. © 1969 OXFORD UNIVERSITY PRESS.