01742naa a2200313 a 450000100080000000500110000800800410001910000190006024501150007926000090019452009410020365000180114465000160116265000140117865000260119265000120121865000150123065000140124565000140125965000170127365000140129065300090130465300120131365300140132565300090133965300180134870000150136677300470138111345062018-05-10       2001    bl uuuu     u00u1 u    #d1 aMELO, N. F. de  aKaryotypic stability in asparagus (Asparagus officinalis L.) cultivars revealed by rDNA in situ Hybridization.  c2001  aFour asparagus cultivars were cytologically studied by conventional staining and in situ hybridization, in order to evaluate both the variability among cultivars and the distribution pattern of 18S-25S rRNA genes. lhe mitotic and meiotic analysis with conventional chromosome staining did not show heteromorphisms or differences between cultivars. In situ hybridization with 18S and 25S rONA probes showed 6 chromosomes with 18S-25S rONA sites in the 4 studied genotypes. lhe New Jersey, Waltam Washington and G4X 14 cultivars presented 4 chromosomes with larger subterminal sites and 2 with interstitial sites of smaller size. In the Oeco cultivar, heteromorphism was verified in the size of the rONA sites, which were larger and subterminal in 3 chromosomes, and small and interstitial in 3 other chromosomes. lhe results suggest that asparagus cultivars may present only small differences in the number and distribution of rONA loci,  ahybridization  avariability  avarieties  aAsparagus Officinalis  aAspargo  aCruzamento  aGenética  aGenótipo  aHibridação  aVariedade  aDNAr  aGenetic  aGenotypes  arDNA  aVariabilidade1 aGUERRA, M.  tCytologia, Tokyogv. 66, p. 127-131, 2001.