[Nucleotide sequence organization of nuclear DNA of wheat embryos]

The kinetic component composition of wheat embryo nuclear DNA was studied. It was shown that 32% of the genome consist of highly repetitive sequences. Intermediate repetitive sequences with repetitive frequency 1300 per genome constitute the bulk (52%) of the wheat embryo nuclear genome. The unique sequences constitute 12% of wheat embryo DNA. The individual families of intermediate repetitive and unique sequences were isolated; their reassociation kinetics were investigated and their kinetic complexity and repetition frequency were evaluated. Intermediate repetitive sequences 600-800 nucleotides in length were interspersed with unique sequences 800-1000 nucleotides long in the nuclear genome of wheat embryos. The linear relationship between the fragment length and the increasing amount of the zero-time binding DNA implies that 4% of the wheat embryos genome consists of palindromic sequences, which are clustered into groups.