Premium
Assessment of Repetitive DNA Variation among Accessions of Hexaploid and Tetraploid Wheat
Author(s) -
Talbert Luther E.,
Moylan Susan L.,
Hansen LeRoy J.
Publication year - 1992
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1992.0011183x003200020018x
Subject(s) - biology , genetics , repeated sequence , restriction enzyme , germplasm , genome , southern blot , chromosome , genomic dna , restriction fragment , dna sequencing , dna , gene , botany
Genetic evidence has suggested that only a few coding genes separate varietal groups within the wheat species Triticum aestivum L. emend. Thell and T. turgidum L. emend. Morris & Sears. However, reduced chromosome pairing is often observed in wheat intraspecific hybrids. Most of the DNA in higher plants is noncoding repetitive DNA, and this type of DNA has been hypothesized to influence chromosome pairing. Our objective was to determine whether this genomic component varies among wheat accessions. Thus, we cloned representatives of six repetitive DNA families found primarily in the wheat A or B genomes. These cloned sequences were used to address the possibility of variation for either restriction fragments or sequence abundance among a diverse set of wheat germplasm. Southern blot analysis of genomic DNA from 33 accessions digested with eight restriction enzymes revealed no restriction site variation for any of the six repetitive sequences. This suggests a lack of sequence divergence for the repetitive DNA families among the accessions. However, dot blot analysis showed that one B genome sequence varied significantly (P < 0.01) in copy number among 10 diverse accessions of T. aestivum These results suggest that copy number variation for repetitive DNA families may exist among accessions of wheat, although sequences of the families as indicated by restriction fragment analysis are conserved.