II.20. Induced mutagenesis and problem of short culm and lodging resistance in barley.
M. R. Kozachenko. Ukrainian Institute of Plant Industry, Plant Breeding and Genetics, Kharkov, USSR.
A series of barley cultivars have the best productivity when agricultural engineering is ordinary. These cultivars give lower yields than other ones when the agrobackground and moisture levels of the soil are high. Different lodging resistance of cultivars is one of the factors involved. From this point of view the problem of plant breeding of short culm and lodging resistance in barley cultivars seemed to be very important.
Our investigations on radiation and chemical mutagenesis have resulted in spring barley mutants that have higher lodging resistance as compared to parents. Varieties of these mutants are initial (nutans, medicum) or other (erectum, glabrierectum, zeocrithum, palestinicum). A majority of them were induced by radiation treatment (Co60, 5 and 10 kr), minority - by supermutagen N-nitroso-N-ethylurea and N-nitroso-N-methylurea. Obtaining of erectoides (dense ear) gamma-mutants of barley is more probable when the hybrid seeds obtained in the year of crossing were irradiated.
All parts of plant of erectoides barley mutants are shorter than ones of parent cultivars. Their culm lengths were reduced differently: not much- 5-lOcm (varieties erectum, glabrierectum, h=60-70cm), approximately 1/3 or smaller one (varieties palestinicum, zeocrithum, erectum, h=30-40cm). Spike length was decreased too. The most decreased spike length was in mutants with very large ear density. Kernel quantity of ear decreased to lesser extent.
A few erectoides mutants (ert 66, ert 67-4812, ert 67-5361, pal 67 and others) have been crossed with the cultivars that have little lodging resistance. In 1973 individual lines of F5 hybrids were superior to the parents and standard in lodging resistance (3-4 marks for lines F5, 1-2 marks for standard). The results of this study showed the outlook for use of erectoides mutants in plant breeding. Mutants of erectum and glabrierectum varieties with high kernel number of ear are more valuable.
Mutants of medicum and nutans varieties which are superior to the parents and standard in productivity and lodging resistance have some more significance for practical breeding. These are Mutant 67-846 (from Medicum 52-84, 10 kr) with long ear and Mutant 71-6596 (from Donezky 4, 5 kr) with more lodging resistance. In 1973 the former yielded 18% higher than standard Donezky 4.
Thus, induced mutagenesis is the method of obtaining valuable initial material for breeding of cultivars with short culm and higher lodging resistance.
References:
Kozachenko, M. R. 1974. Significance of induced mutants for lodging resistance breeding. In: Materialy seminary selekzionerov "Ustoichivost k poleganiju i korotkostebelnost v selekzii". Kiev. U.S.S.R. (in press).