II. 14. Genetic analysis of spike characters of barley mutants.
M. Gaj and M. Maluszynski (l), Department of Genetics, Silesian University, Katowice, Jagiellonska 28, Poland.
(1)Present address: Joint FAO/IAEA Division, A-1400 Vienna, P.O. Box 100, Austria.
After MNH treatment of Aramir and Georgia two-row, spring barley varieties, a large collection of different morphological mutants was obtained. Among forms which differ in morphology of spike more than 20 mutants have "zoocrithon" phenotype, 5 are six-row forms, for example. There are "hooded" and "elongated glume" mutants as well. Four mutants exhibiting six-row, which were used for genetic analysis are different in other morphological characters as well. Two of them are semi-dwarf and two normal height, one of the high forms has additionally black coloured spikes. Plants of the F1 generation from crosses of these four mutants with the parent variety Aramir have intermedium type of spike. In F2 segregation ratios 9:3:3:1, intermedium : normal two-row : six-row sessile : six-row pediceled, respectively were observed. This result indicated that the analysed character is determined by 2 interdependently segregated genes.
All four six-row mutations are allelic to six-row "vv" marker from the Svalof collection which is located on chromosome 2 (Gymer, 1978), which was pointed out after crosses with marker stock. The genotype "vvII" for all mutants and "vvii" for the parent variety Aramir were established on the basis of presented results.
The F1 generation obtained after crosses of two erectoid mutants with parent variety Georgia has normal spikes and segregated in F2 progeny, in ratio 3:1, normal to erectum type, respectively. Results of crosses of these mutants with “ert-c” erectoid marker from Svalof located on chromosome 3, indicated allelism.
The single recessive gene is responsible for mutant phenotype "elongated glume" with length of awn 14 cm, which was found on the basis of segregation ratio in F2 progeny with parent variety Georgia. The cross between this mutant and "elongated glume" marker stock from Svalof revealed that both phenotypes are determined by allelic genes located on chromosome 2.
The hooded, calcaroides-type spike of mutant from variety Georgia is recessive to normal spike. The allelic relations were found after cross with hooded marker. The F1 plants from this cross segregated in F2 in ratio 9:3:4, hooded as marker calcaroides : normal, respectively. The calcaroides phenotype is determined by 2 genes located in independent loci, as indicated on the basis of above results. A similar type of inheritance of different types of hood was found by Woodward and Rasmussen (1957).
References:
Gymer, P.T., 1978. The genetics of the six-row/two-row character. BGN 8:44-46.
Woodward and Rasmussen, 1957. Hood and awn development in barley. Agron.
J. 49:92-94.