GENETIC STUDIES OF α-AMYLASE ISOZYMES IN WHEAT
I. LOCATION OF GENES AND VARIATION IN TETRA- AND HEXAPLOID WHEAT
1971 年 46 巻 5 号 p. 345-353
詳細
1971 年 46 巻 5 号 p. 345-353
For the purpose of showing homoeological relationship between chromosomes at the enzymatic level, α-amylase isozymes of germinated seeds of 27 ditelocentric lines of Chinese Spring wheat were analyzed with disc-isoelectrofocusing.
Two triplicate genetic systems have been proved to specify six α-amylase isozymes out of 15 appeared on the zymogram, namely band 1 was controlled by a gene on the β-arm of chromosome 6D (Amy6D), band 2, band 3, band 11, band 13 and band 15 by a gene on the long arm of chromosome 6A, 6B, 7D, 7A and 7B (Amy6A, Amy6B, Amy7D, Amy7A and Amy7B), respectively. Three genes of each of group 6 and 7 were considered as homoeologous for one another, which might be derived from a gene of the primordial genome by gene mutation.
Forty three varieties or cultivars of hexaploid wheat showed 13 different types of zymogram pattern of α-amylase isozymes and were divided into two clusters according to which of band 3 or band 4' they had, i.e. to Cluster 1 eight types having band 3 belong and to Cluster 2 five types having band 4'. Variation in zymogram patterns was concentrated on group 6 and 7 isozymes. Seven strains having band 10 were European wheat but Asian varieties or cultivars did not possess band 10.
In tetraploid wheat (Emmer and Timopheevi group) band 1 specified by Amy6D and band 11 by Amy7D were absent. It is explainable based on that genome D is not present in tetraploid wheat. Genome A of Timopheevi group was apparently different from that of Emmer and hexaploid wheat in α-amylase isozymes.
Genome specific shift of isoelectric point of α-amylase isozymes was found, i.e. those specified by genes of genome D took position at the most alkaline side, those of genome B at the acidic side and those of genome A between the two. This may have evolutionary significance.
