PAG-II Plant Genome II Conference

Town & Country Conference Center, San Diego, CA, January, 1994.


PG-II: LOCATING QTL FOR CARBON METABOLISM AND EARLY GROWTH IN MAIZE, USING CANDIDATE GENE APPROACH

LOCATING QTL FOR CARBON METABOLISM AND EARLY GROWTH IN MAIZE, USING CANDIDATE GENE APPROACH.

M. Causse 1, J.P. Rocher 2, J.L. Prioul 2 and D. de Vienne 1, 1 Station de Genetique Vegetale, INRA, CNRS-URA 1492, UPS, Ferme du Moulon, 91190 Gif s/Yvette, France. 2 Structure et Metabolisme des Plantes, Institut de Recherche sur les Plantes, CNRS-URA 1129, Bat 430, Universite Paris XI 91405 Orsay, France


Relationships between physiological traits and early growth in maize has been studied in a population of recombinant inbred lines using the QTL/RFLP methodology. The population has been characterized for more than 100 RFLP marker loci in order to detect marker-trait associations. A wide range of variation has been found for growth traits as well as for the concentration of carbohydrates and the activities of four key-enzymes of carbon metabolism in leaves (sucrose phosphate synthase, ADP-glucose pyrophosphorylase, invertase and sucrose synthase). Strong correlations were found between growth rate and invertase activity, which reflects sink organ strength. QTLS, located on thirteen chromosomal regions, were detected for every trait. Each region frequently concerned more than one trait. Common location of QTLs for growth traits and activity of enzymes, such as invertase and ADP-glucose pyrophosphorylase were consistent with physiological data. Some of the structural genes of the key-enzymes appeared located close to or on the QTL for the activity of the enzyme, emphasizing the role of these candidate genes in physiological processes. Furthermore, these loci were found to be involved in epistatic interactions, suggesting their implication in regulation networks.


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