Portal de Periódicos da CAPES

Electrophoretic Study of Acid Phosphatase Isoenzymes in the Grass Genus Aegilops L.

1978; Elsevier BV; Volume: 172; Issue: 1-2 Linguagem: Inglês

10.1016/s0015-3796(17)30368-2

0015-3796

Vello Jaaska,

Botany and Plant Ecology Studies

Polyacrylamide gel electrophoresis has been applied to study acid phosphatase (EC 3.1.3.2) isoenzyme (isophosphatase) variation and inheritance in the species of the goatgrass genus Aegilops L. Three genetically independent and electrophoretically distinguishable acid phosphatases of different tissue distribution and activity dynamics during germination were specified. Two of them designated as Ph-1 and Ph-3 to specify acid phosphatases characteristic of the embryo and the leaf tissue, respectively, showed limited electrophoretic variation of no diagnostic value in species comparison. The third one designated as Ph-2 revealed characteristic pattern of inter- and intraspecific variation in Aegilops and has been studied in more detail. In diploid goatgrass species, the Ph-2 locus controls the formation of two electrophoretically separable isophosphatases, the relative activity of which varies depending on the species, the kind and age of seedling tissue. In coleoptile and root tissues of polyploid species, co-dominant expression of the Ph-2 homoeoalleles of the composite genomes was observed. Only in some accessions of the allotetraploid species Ae. biuncialis individuals with only one of the two Ph-2 homoeoalleles active were found along with individuals revealing co-dominant inheritance of both homoeoalleles. In most cases the Ph-2 electrophoretic pattern of the coleoptile tissue of polyploid goatgrass species comprises the sum of isophosphatases characteristic of the contemporary diploid species presumed to be genome donors to the polyploids on the basis of cytogenetic and karyomorphologic evidence. The isophosphatase doublet specific for the diploid Ae. tauschii is observed on the enzymograms of all polyploids of the D genome group, while the isophosphatases characteristic of the diploid Ae. umbellulata are expressed in the polyploids of the Cu genome group. The isophosphatases of the diploid Ae. caudata coincide electrophoretically with those controlled by second genomes of Ae. cylindrica and Ae. triuncialis, but not with those of Ae. kotschyi. The isophosphatases of the diploid Ae. comosa (incl. Ae. heldreichii) correspond electrophoretically to those found in Ae. biuncialis and in a group of accessions of Ae. ovata, but differ distinctly from any characteristic of Ae. crassa. No diploid goatgrass species was found with isophosphatases corresponding to those controlled by second genomes of Ae. crassa and Ae. columnaris. The allotetraploids Ae. cylindrica, Ae. triuncialis, Ae. columnaris and Ae. biuncialis from sympatic natural populations in Transcaucasia always showed characteristic species-specific isophosphatase electrophoretic patterns with no evidence of wide-spread inter-specific introgression of genetic information for the Ph-2 isoenzymes.