ABSTRACT
Segregation analysis was performed in the progenies obtained in analyzing crosses of hybrids of spring and winter accessions of rye Secale cereale L. and wild S. montanum subsp. anatolicum (Grossh.) Tzvel. (syn. S. strictum (J. Presl) J. Presl). The test genes controlled the brittle stem (bs), the allelic variants of aromatic alcohol dehydrogenase (Aadh 1) and shikimate dehydrogenase (Skdh), and the growth habit (Vrn 1). A linkage was observed in the inheritance of the brittle stem and the aromatic alcohol dehydrogenase and shikimate dehydrogenase alloenzymes. The order of genes was established to be bs-Skdh-Aadh 1, and the genetic distances were estimated to be bs-(9.0%)-Skdh, bs-(10.8%)-Aadh 1, and Skdh-(5.3%)-Aadh 1. The recombination coefficient between the Skdh and Aadh 1 genes varied from 2.2 to 18.2%, averaging 5.3%. The growth habit was inherited independently of the bs-Skdh-Aadh 1 linkage group.
Subject(s)
Chromosome Mapping , Chromosomes, Plant/genetics , Genes, Plant , Genetic Linkage , Secale/genetics , Crosses, GeneticABSTRACT
Diploid species of the genus Triticum L. are its most ancient representatives and have the A genome, which was more recently inherited by all polyploid species. Studies of the phylogenetic relationships among diploid and polyploid wheat species help to identify the donors of elementary genomes and to examine the species specificity of genomes. In this study, molecular analysis of the variable sequences of three nuclear genes (Acc-1, Pgk-1, and Vrn-1) was performed for wild and cultivated wheat species, including both diploids and polyploids. Based on the sequence variations found in the genes, clear differences were observed among elementary genomes, but almost no polymorphism was detected within each genome in polyploids. At the same time, the regions of the three genes proved to be rather heterogeneous in the diploid species Triticum boeoticum Boiss., T. urartu Thum. ex Gandil., and T. monococcum L., thus representing mixed populations. A genome variant identical to the A genome of polyploid species was observed only in T. urartu. Species-specific molecular markers discriminating the diploid species were not found. Analysis of the inheritance of morphological characters also failed to identify a species-specific character for the three diploid wheat species apart from the hairy leaf blade type, described previously.
Subject(s)
Genes, Plant/genetics , Genetic Variation , Phylogeny , Triticum/genetics , Diploidy , Polyploidy , Species SpecificityABSTRACT
The inheritance of several morphological and biochemical traits was studied in diploid (2n = 2x = 14) naked wheat Triticum sinskajae. The electrophoretic pattern of storage proteins (gliadins) of T. sinskajae differed only in two components from the pattern of T. monococcum accession k-20970, in a population of which T. sinskajae had been discovered. Analysis of biochemical polymorphisms revealed a difference between T. monococcum k-20970 and T. sinskajae in a slow 6-phosphogluconate dehydrogenase region but not in the other eight enzyme systems examined. Nucleotide sequence analysis of the nuclear Acc-1 (acetyl-CoA carboxylase) gene revealed a 46-bp deletion from intron 11 in T. monococcum k-20970 but not in T. sinskajae. This difference was not regarded as species-specific in view of the intraspecific polymorphism of the Acc-1 locus in T. monococcum. A monogenic control was demonstrated for the spring growth habit of T. sinskajae, and the monogenic control of the specific T. sinskajae ear shape was verified. The T. sinskajae ear shape is controlled by a recessive gene, while the T. monococcum ear shape is controlled by a dominant gene. The T. sinskajae ear shape, nakedness, soft glume, aristate glume, and the oblique brachium of the outer glume proved to be linked. The set of E. sin-skajae diagnostic characters is determined by a single (possibly, regulatory) gene or a set of closely linked genes. The two other genes specific to T. sinskajae-awnS, determining the awnlessness, and fig, determining the nonfissile inner (flower) glume--are, respectively, 1.35 +/- 0.98 and 3.34 +/- 1.54% of crossing over away from the mom gene, which determines the T. sinskajae ear shape.