Examination of dwarf wheats produced by mutation, crossing and physiological procedures

By induced mutations more than 2000 dwarf lines were produced and 1600 were examined in ear-to-row experiments in 1984-85. The new dwarf forms showed a reduction in height of 11-28 per cent as compared to the parental cultivars. By ''cleaning up'' the genetic background euplasmic new dwarf forms can be produced and the productivity of which reaches that of the tall ones, possibly because of the elimination of chromosome and cytoplasm aberrations. Genetic analysis of dwarf wheats verified, that in combining ability for height Mini Mano proved to be the best, reducing the height of its hybrids by more than 7 cm. As Mini Mano has a number of excellent characteristics it seems to be very promising both as a cultivar and as a crossing parent. The internode length of 45 F1 hybrids, along with their parents, was measured in the field. Three of the parents involved (Mv 3, Godollo 1 and Godollo 2) were of mutation origin. The behaviour of Apollo cv. was very favourable. In almost all cross combinations it reduced the length of the first internodes and increased the peduncle length. Using tissue culture methods somaclonal variants in a number of characteristics have been produced. For improving the characteristics of dwarf lines, progenies of their F1, F2 and F3 generations were included in the haploid breeding program. A number of androgenetic doubled haploids have been improved. More than 5.000 gametoclone and/or somaclone lines are under tests in field nurseries. Reduction of the influence of gravitation results as well in a reduction in height. (author). 10 refs, 2 figs, 4 tabs