|Inheritance of short-straw character
Crosses were made between these two varieties and the winter wheats Felix, Manella, Sylvia and the spring wheat Orca. The mean length of the F1-plants appeared to approximate the mid-parent value. The F2 segregated significantly into 1(short) : 2 (intermediate) : 1 (tall). From these observations it is concluded that the short-straw character of the Tom Pouce varieties is conditioned by a single semi-dominant gene.
The present trend of wheat breeding shows that many semi-dwarf varieties are produced. Some of these varieties prove quite productive.
Future varieties may be still shorter than the present one. If so, shortness of straw may be obtained from the Tom Pouce varieties. Besides, its big flag leaf may be important for productivity breeding since that part of the plant appears to play an essential part in grain weight (LUPTON 1966).
These varieties may be of importance as A-lines in hybrid wheat breeding. Because of their shortness a higher percentage of seed set may occur than in taller plants. The F1 plants of avariety carrying the short straw gene of Tom Pouce and a modern variety may give a hybrid variety of a desired length. Its present susceptibility to Septoria is a disadvantage.
Two very short varieties are described. Shortness of straw is conditioned by a single semi-dominant gene. These varieties may prove valuable as a source of shortness of straw and such varieties may be used as parents in the hybrid wheat breeding.
LUPTON, F.G.H. 1966. Translocation of photosynthetic assimilates in wheat. Ann. Appl. Biol. 57 : 355-364.
MARTIN, P. 1960. Personal communication to Dr. J.G. Th. HERMSEN.
N.I.A.B. 1963. Guide to plots of cereals on head-quarters trial ground 1962. National Institute of Agricultural Botany, Cambridge.
ZEVEN, A.C. 1968. Third supplementary list of wheat varieties classified according to their genotype for hybrid necrosis. Euphytica 17 : 46-53.