01110nam a2200169 a 450000100080000000500110000800800410001910000180006024500980007826000250017652006260020165300170082765300210084465300180086570000290088370000280091216377302013-09-12       1986    bl uuuu     u0uu1 u    #d1 aPASSOS, O. S.  aSelection of nucellar 'Pera' orange, Citrus sinensis (L.) Osbeck regarding to tristeza virus.  aValencia: IOCVc1986  aTwo comparison trials of 'Pera' orange were reviewed and discussed in order to show the need of the preimmunization of seedlings in an improvement program. Tree vigor, fruit quality and yield data were compared to stempitting symptomology of six nucellar clones, which were obtained by crossing with sour orange and from open pollinated flowera. It can be observed a straight relationahip between the behavior of 14-year-old trees and the severity of stem pitting symptoms that permits the clear conclusion about the inclusion of cross-protection as an important step in obtaining useful nucellar clones of 'Pera' orange.  aLate variety  aNucellar budline  aVirus disease1 aCUNHA SOBRINHO, A. P. da1 aSOARES FILHO, W. dos S.