II.39 Viability of or (orange seedling) homozygotes.
T. Tsuchiya, Agronomy Department, Colorado State University, Fort Collins, Colorado 80521, U.S.A.
Orange seedling (or) has been considered to be lethal. The homozygote for the or gene has yellow leaves and stems throughout its whole life from the first foliage leaf to near maturity. Under usual growing conditions in the field the or or plants cannot survive beyond several leafed stages. Therefore, the stock has been kept in the heterozygous condition.
A homozygote for the or gene was planted in a pot in the greenhouse
in May, 1970 and grown under usual care of other barley materials. The
plant was healthy with typical yellow leaves and continued to grow. At
the beginning of June one tiller started to develop a culm and produced
a spike on June 20, 1970. The fertility of the spike was complete. This
finding is important because: (1) it is now clear that we can use the or
gene in the homozygous condition for crossing and (2) it may be possible
to find other color mutants which have been considered to be lethal to
actually be viable in homozygous condition.
Reports II.29 (P. 58) through II.39 (P. 66) by T. Tsuchiya and coworkers are based on the results of researches supported partly by NSF Research Grant GB 4482 X.