[Chromosomal localization of aromatic alcohol dehydrogenase fast-migrating isoenzyme Aadh1F (CAD1-F) gene in Triticum aestivum L. bread wheat].

Differences in isoenzyme pattern of aromatic alcohol dehydrogenase, NADP-AADH or CAD, were found in the Triticum aestivum L. winter bread wheat cultivars by the method of electrophoresis in the starch gel. A standard three-component spectrum is present in the cv. Zitnica (former Yugoslavia); additional fact-migrating isoenzymes appear in the cv. Novosibirskaya 9 (Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Russia). The presence of fast-migrating CAD isoenzymes is designated as FF phenotype; their absence, as 00 phenotype. Hybridological analysis was carried out; the excess of "null" genotypes was found in F2 progenies. Hybridization with nulli-tetrasomic lines of the chromosomes of the fifth homeologous group was conducted for the gene localization. The segregation analysis demonstrated the most probable localization of the CAD1-F gene in the chromosome 5A. The plants with FF and 00 genotypes differed in a number of chemical and anatomical traits, as well as in grain productivity. The results obtained are discussed in connection with the function of this enzyme in the wheat plant tissues.

[Inheritance and phenotype expression of functional and null alleles of aromatic alcohol dehydrogenase (CAD) in diploid wheats].

Functional F and null 0 alleles of the CAD1 (Aadh1) gene, which controls the biosynthesis of aromatic alcohol dehydrogenase, were studied in hybrids of the diploid wheat T. monococcum L. and Triticum sinskajae A.Filat. et Kurk. The gene CAD1 is located in chromosome 5A and is linked with the awnless gene awnS (La) with a recombination frequency of about 32%. Plants with genotypes FF, F0, and 00 were significantly different in the height and mechanical strength of the stalk (culm). The elastic limit of the culm tissues of plants FF was considerably higher than in 00 plants. F0 heterozygotes had intermediate values. The thickness of the wall of the sclerenchyma was thinner in plants with genotype 00. The chemical structure of lignin of plants with the functional CAD allele contained units of a phloroglucinol series missing in the mutant plants. The CAD genotypes had no effect on the relative content of cellulose and lignin in stalks ofdiploid wheat and insignificantly influenced the ratio of H :G : S units in the lignin structure, as well as some components of extractives.