Genetics of alpha-amylases in hexaploid oat species.

The inheritance of alpha-amylases was studied in six F2 populations of hexaploid oats (Avena sativa, A. byzantina, A. fatua, A. sterillis) using polyacrylamide gel electrophoresis. A total of 22 loci was identified and described. Three main linkages of four or five loci each and an additional two pairs of linked loci were detected. It seems likely that the three main linkage groups represent homeologous chromosomes. Matching of alpha-amylase profiles of hexaploid (AACCDD), tetraploid (AACC), and diploid (AA) species was made to assign the linkage groups to particular subgenomes in the hexaploid oat. It was proposed that Linkage 1 (Amy12-Amy10-1-Amy4-Amy13-Amy11) belongs to the D-subgenome; Linkage 2 (Amy10-2, Amy9-Amy8-Amy6) belongs to the A-subgenome; and Linkage 3 (Amy7-Amy3-Amy5-Amy2) belongs to the C-subgenome of the hexaploid oat. The "malt" and "green" alpha-amylases in hexaploid and tetraploid oats have been identified. Isozymes of "green" alpha-amylase were lower in electrophoretic mobility than other isozymes and were governed by loci assigned to the A- and D-subgenomes.

Inheritance and linkage relationships of seed peroxidase loci in hexaploid oat (Avena sativa L.).

Polyacrylamide gel electrophoresis has been used to investigate the inheritance and linkage relationships between anodal (PXA) and cathodal (PXC) seed peroxidases in hexaploid oat (Avena sativa L.). A total of 12 seed peroxidase loci (5 loci of PXA and 7 loci of PXC) were identified in three crosses. Only two Pxc loci (Pxc5 and Pxc7) were not linked to any peroxidase loci; the others were scored in three linkage groups. The order of the three loci assigned to one of the linkage groups was Pxc1-Pxa5-Pxc2. The order of loci in the other two linkages were Pxc4-Pxa1-Pxa3 and Pxc3-Pxa4-Pxa2. Also, the Pxc6 locus was shown to be linked to the Pxc3 locus. Considering that A. sativa is an allohexaploid, it can be proposed that the three peroxidase linkages represent homoeologous chromosomes.