Relations entre la chlorose foliaire et des caractères agronomiques chez des lignées de blé, de triticale et des hybrides blé-triticale infectés du virus de la jaunisse nanisante de l’orge

Abstract

To assess the relationships between leaf chlorosis and certain agronomic traits, eight lines of wheat and triticale and their interspecific crosses were experimentally inoculated with BYDV. BYDV infection caused a highly significant reduction in tillering, plant height and biomass in all lines of wheat and triticale irrespective of their degree of tolerance. There was no significant difference between the virus content of the less badly chlorosed and that of the more severely chlorosed plants, indicating that tolerance was the actual mechanism involved in the triticale lines studied. Generally, all phenotypic and genotypic correlations between the extent of chlorosis and tillering, plant height and biomass were negative and highly significant. This suggests that agronomic parameters can be used as selection criteria in a breeding program for resistance to BYDV, through interspecific wheat and triticale hybridization. The severity of leaf chlorosis is recommended as a selection criterion as it does not require the use of a control population. Key words: Barley yellow dwarf virus (BYDV), phenotypic and genotypic correlations, wheat, triticale, interspecific hybridization