01726naa a2200253 a 450000100080000000500110000800800410001902200140006010000170007424500920009126000090018352010350019265000110122765000190123865000100125765300190126765300210128665300240130765300120133165300120134370000180135570000450137377300540141816357402000-06-05       1998    bl uuuu     u00u1 u    #d  a0248-12941 aASINS, M. J.  aMolecular markersba continuously growing biotechnology area to help citrus improvement  c1998  aIn order to apply a marker-assssisted selection to the breeding programs, a review related to the application of the molecular marker technique, used to study the citrus genetic resources and the resistance to citrus tristeza virus (CTV), was undertaken. The citrus germplasm bank at Ivia (Valencia, Spain) was studied. Six isoenzymatic systems were assayed. A broad spectrum of heterozygosity values was found in the collection. Two principal groups of Citrus species are clearly defined: the orange-mandarin group and the lime-lemon-citron-pummelo group. Genetic differences between species and genera are in general high, which suggest that adaptation has played an important role during the evolution of the orange subfamily. There is an urgent need to diversify the genetic basis of CTV-resistant rootstocks by developing breeding programs from only CTV-resistant genotypes. Consequently, the first step was to find molecular markers which allow to discard CTV-susceptible genotypes with a minimum error from large progenies.  aCitrus  aplant breeding  aSpain  aGenetic marker  aPest resistances  aPlant biotechnology  aViroses  aVirosis1 aMESTRE, P. F.1 aHERRERO, R. NAVARRO, L. CARBONELL, E. A.  tFruitsgv.53, n.5, p.293-302, Paris, France, 1998