II. 27. Inheritance of cu4 for curly 4 (spiral neck) mutant in barley(1)
T. Tsuchiya, Department of Agronomy, Colorado State University, Fort Collins, Colorado 80523 U.S.A.
(1) Supported by USDA-CSU Cooperative Research Grant 58-9AHZ-2-265 and CSU Hatch Project.
The mutant curly 4 or spiral neck (cu4) was induced by x-ray irradiation (15 kr) to dormant seeds of a two-rowed, spring type cultivar Asahi No. 5 (Tsuchiya, unpublished). Seedling roots grow curled instead of straight (Tsuchiya, 1974), seedling leaves do not grow straight, leaves often show wrinkles at the margins or portion of a leaf, culm nodes bend in many cases, awns are waved. The most striking trait of this mutant is the spiral neck which was proved by taking a movie with time-lapse method (unpublished). This gene was considered to be a simple Mendelian recessive (Tsuchiya, unpublished; Furst, 1983).
However, A.B. Brown of the University of Georgia, Athens, GA expressed question regarding the inheritance of this mutant gene (A. R. Brown, personal communication). Brown (1984) also reported his results on the genetic studies of cu4 (spn) without showing pictures of the plants.
The present author repeated his previous experiments (Tsuchiya, unpublished) with the following results:
Two F2 populations of 57 and 41 plants each were studied. The segregations were a simple Mendelian fashion as shown above and the genetic nature of this mutant gene cu4 is obviously Mendelian recessive.
In agreement with the F2 results, F1 plants did not show any sign of its dominant or even incomplete dominant nature.
These results are in agreement with previous results of the present author (Tsuchiya, unpublished) and Furst (1983).
References:
Brown, A.R. 1984. 1983 Barley Newsletter 28 (In press).
Furst, E. 1983. Primary trisomic analysis of three mutant genes in barley. M.S. Thesis, Colorado State University, Fort Collins, C0, 71 pp.
Tsuchiya, T. 1974. Root character of curly mutants in barley. BGN 4:88-89.
