Theme 12: Forage Breeding and Genetics
Description
A collection of orchardgrass (Dactylis glomerata) was screened under field conditions for resistance to strike leaf blight (SLB) caused by the fungus Scolecotrichum graminis. On the whole, thirty five entries from different countries were studied by sampling ten genotypes from each origin, clonally propagated and transplanted as spaced-plant trial in a randomized design with two replicates. Plants were periodically assessed during 1996 and 1997 by estimating disease severity (percentage of leaf affected). During 1997, disease severity data were used to calculate the area under disease progress curves (AUDPC) as a complementary attribute to screen for resistance to SLB. Important genetic differences were observed among different entries by analyzing the amount of symptoms through disease severity during 1996. Similarly, large differences were detected between entries when analyzed through AUDPC, none of them related to origin of germplasm. Results indicated that there should be good possibilities of selecting resistant genotypes to S. graminis from INTA Pergamino orchardgrass germoplasm collection.
Included in
Breeding for Resistance to Strike Leaf Blight (Scolecotrichum graminis) of Orchardgras in Argentina
A collection of orchardgrass (Dactylis glomerata) was screened under field conditions for resistance to strike leaf blight (SLB) caused by the fungus Scolecotrichum graminis. On the whole, thirty five entries from different countries were studied by sampling ten genotypes from each origin, clonally propagated and transplanted as spaced-plant trial in a randomized design with two replicates. Plants were periodically assessed during 1996 and 1997 by estimating disease severity (percentage of leaf affected). During 1997, disease severity data were used to calculate the area under disease progress curves (AUDPC) as a complementary attribute to screen for resistance to SLB. Important genetic differences were observed among different entries by analyzing the amount of symptoms through disease severity during 1996. Similarly, large differences were detected between entries when analyzed through AUDPC, none of them related to origin of germplasm. Results indicated that there should be good possibilities of selecting resistant genotypes to S. graminis from INTA Pergamino orchardgrass germoplasm collection.
