1/9/05 12:26

Genetic analysis of dry matter and nitrogen accumulation and protein composition in wheat kernels

En el presente trabajo se informa un análisis genético de los parámetros de llenado del grano y de la composición proteica final, usando una progenie recombinante de un cruzamiento entre dos variedades francesas. En el mismo se identificaron 5 QTLs asociados a la cinética de acumulación de materia seca y nitrógeno en el grano. Un QTL permitió explicar más del 70 % de la variación total en el contenido de gluteninas de alto peso molecular de los genotipos en estudio.

G Charmet, N Robert, G Branlard, L Linossier, P Martre and E. Triboi 
Theor Appl Genet (2005), 111: 540-550

The maximum rate and duration for grain dry matter (DM) and nitrogen (N) accumulation were evaluated in 194 recombinant inbred lines (RILs) from a cross between the two French wheat cultivars Récital and Renan. These cultivars were previously identified as having contrasting kinetics of grain DM and N accumulation. Grain protein composition was analysed by capillary electrophoresis (CE), which enabled quantification of the different storage protein fractions ( -gliadins, -gliadins, LMW glutenins, HMW glutenins, and each of their subunits). Correlation analyses revealed that DM and N accumulation rates were closely correlated and repeatable over several years, which was not the case for DM and N accumulation durations, and that protein composition was primarily influenced by the N accumulation rate. This was particularly true for the LMW-glutenins and the -gliadins, the most abundant protein fractions. A genetic map of 254 molecular markers covering nearly 80% of the wheat genome was used for quantitative trait loci (QTL) analysis. A total of seven QTLs were found. Five QTLs were significantly associated with the kinetics of DM and N accumulation, and two of them also influenced protein composition. Two QTLs affected only the protein composition. One major QTL explained more than 70% of the total variation in HMW-GS Glu1B-x content.