8.
Lethal seedling_type.
A chlorophyll‑free lethal seedling type with a
light reddish brown color has been obtained four times in our radiation
studies. One was induced by X‑ray, one by the Bikini bomb radiation,
while the other two may have been either induced or present in the stock.
Intercross tests have shown the two definitely induced ones to be identical
with one of the latter. The fourth one has not yet been intercrossed. The
peculiar color plus the failure of the leaves to unfold under most cultural
conditions give the seedlings an appearance reminiscent of the root‑parasite
Orobanche.
E. E. Dale and E. G. Anderson