4. Tryptophane and niacin in sugary endosperms.
Endosperms from TB‑4a x su assayed for tryptophane and niacin showed the same relationship as su and Su on segregating ears or in comparable lines i.e both substances were present in greater amounts in su (deficient) seeds than in phenotypically Su (hyperploid) seeds. Thus in the case of the su gene the quantity of both substances in the endosperm is a function of the genetic constitution of the endosperm itself. The embryo genotype apparently plays no part in the quantity of tryptophane or niacin storage by the endosperm.
H. J. Teas and Anna C. Newton