Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: December 1, 2002
Publication Date: January 1, 2003
Citation: Kim, M., Lee, B., Wang, R., Waldron, B.L. 2003. Genome relationships among three kochia species based on gish. Plant and Animal Genome Abstracts. Technical Abstract: Forage kochia (K. prostrata ssp. virescent cv. 'Immigrant') is native to the arid and semiarid regions of Central Eurasia. It was introduced into U.S. in 1966 as PI 314929 and released as a perennial forage shrub in 1984. Kochia americana is a perennial native to U.S., whereas K. scorparia is an introduced annual species that became a weed. To assess both the breeding potential and the possibility of genetic contamination, genome relationships among the three species were analyzed using the genomic in situ hybridization (GISH) technique. Somatic chromosomes in root-tip cells were probed with biotin-labeled genomic DNA of each of three species and blocked by unlabeled genomic DNA of one or both of the other species. In situ hybridization was detected by FITC green fluorescence and reddish PI staining under fluorescence microscopy. Chromosomes of one species fluoresced in green only when they were probed by genomic DNA of the same species. Cross-hybridization by genomic DNA of another species was not observed. These results lead to the conclusion that genomes in K. americana, K. prostrata, and K. scoparia are not closely-related. This conclusion is congruent with that drawn from data of RAPD analyses. Genomic contamination among the three studied Kochia species would be an extremely rare occurrence.