Lesley, J.W., Margaret M. Lesley, and F. M. Turrell.
This mutant, which occurred in R2, is easily distinguished in field cultures, but is not so easy to identify in the greenhouse. In the field the plant is small with rather uneven leaf surfaces and differs from the normal in its blue-green color. Many small fruits are produced and seed production is good. In the greenhouse, although the plant is shorter than normal, the leaves are less rough than they are in the field and there is less color difference. The newer leaves tend to wilt. Blue-green behaves as a simple recessive. The F1 blue-green x normal had 12 pairs of chromosomes, one of which was often weakly joined at MI. At pachytene, pairing was normal except for one half of one bivalent. An occasional bridge and small fragment were found at AI. One blue-green F2 plant that was less fruitful than usual had some dyads, triads, and pentads. It is believed that an inversion is present in the blue-green mutant.
Field-grown blue-green plants contained from 18 to 134 per cent more total chlorophyll than normal plants, but, unexpectedly, the ratio chlorophyll a/b was slightly higher in the normal. In greenhouse-grown plants there was little difference in total chlorophyll content or in the chlorophyll a/b ratio. In high light intensity the mutant is able either to inhibit the destruction of chlorophylls a and b or to accelerate their formation. Ripe fruit color was similar in field-grown plants, but in small samples from greenhouse-grown plants, blue-green contained more total carotene and lycopene. The absorption ratio (r = E4875A/E4375) was lower in blue-green, indicating the presence of carotenes other than beta-carotene.