II. 2 Increase in protein content by partial fertility.
H. Ahokas. Department of Genetics, University of Helsinki, P. Rautatiekatu 13, 00100 Helsinki 10, Finland. "R"
The decrease of fertility appears to raise the protein content (Table 1). The des mutants in cv. Betzes were obtained from Dr. R. T. Ramage. The stocks HA 41, 52, 54, and P-12 are putative des mutants. HA 21 is a mutant with a tendency towards pistillody and with increase of lateral fertility and lateral kernel size. Detailed analytical methods for protein will be presented elsewhere.
Table 1. Protein characteristics of some partial fertiles and their controls
The correlation between protein content and estimated fertility is r = .929* in the stocks with the genetic background of cv. Betzes (Table 1). Thus, the increase in protein content is due to the distribution of an approximately unchanged amount of protein precursors to a lower number of kernels.
One way to profit from des mutants could be producing stable autotetraploids with them. Increase of protein yield by tetraploid barley was evidenced by Gaul & al. (1970). The most serious defect of autotetraploid barley is the mulivalentic pairing at meiosis. In the related genera, the meiotic pairing of homeologues of the polyploid species is restricted by a gene or genes. Actually, those genes could be called asynaptic and desynaptic. Wheat and its relatives are most thoroughly examined of those species. (Sears 1974). Either by a suitable des mutant alone or in combination with other des mutants, a condition may be established which brings about the proper bivalentic pairing in tetraploid barley. The creation of homeology by crossing distant varieties or introducing rearrangements may be necessary. A considerable progress towards diploidized behavior of autotetraploids was reported by the mutation technique (Gaul & Friedt 1976).
Some desynaptic homozygotes and heterozygotes have been subjected to the induction of tetraploids to test the above hypothesis.
The analysis presented in Table 1 were partly carried out with the facilities of Department of Botany and Department of Plant Breeding, Uhiversity of Helsinki.
References:
Gaul, H. & Friedt, W. 1976. Progress in the diploidisation of autotetraploid
barley. Barley Genetics III:378-387.
Gaul, H., Frimmel, G., Fritz, A. & Ulsonka, E. 1970. Combination of yield and protein content in tetraploid barley. Improving Plant Protein by Nuclear Techniques, Proc. IAEA/FAO Symb. 1970:133-145.
Kakade, M. L. & Liener, I. E. 1969. Determination of available lysine in proteins. Anal. Biochem. 27:273-280.
Sears, E. R. 1974. The wheats and their relatives. In King, R. C. (ed.), Handbook of Genetics, vol. 2:59-91.
