Variation in seed protein concentration and seed size affects soybean crop growth and development.

LUCAS BORRÁS; LUCAS BORRÁS; JOSE L. ROTUNDO; JOSE L. ROTUNDO; FLORENCIA POETA; FLORENCIA POETA

CROP SCIENCE

CROP SCIENCE SOC AMER

Lugar: Baltimore; Año: 2016 vol. 56 p. 3196 - 3208

0011-183X

Developing high protein (HP) cultivars is oftenprecluded by the inverse relationship betweenprotein and yield. We hypothesized that attainingHP concentration based on contrasting seedsize impacts crop growth and development differently.We screened 97 soybean genotypesand found lines with HP concentration (~450 gkg−1) associated with (i) increased protein content(mg seed−1) in large seed genotypes, and (ii)reduced oil and carbohydrate contents in smallseed ones. Then, we evaluated different growthtraits in a subset of three HP large and threeHP small seed genotypes, as well as in threehigh-yielding genotypes with average seed sizeand protein concentration. High-yielding genotypesshowed higher leaf area duration and harvestindex when compared with HP genotypes,regardless of seed size. High protein large seedwas associated with more assimilate availabilityper seed during seed filling, while HP small seedshowed higher leaf area at the beginning ofseed fill, more canopy biomass production, andvery low levels of assimilate per seed. Resultsshow that selecting for seed protein concentrationcan impact crop growth and developmentdifferently, depending on the strategy used forselection in terms of seed size. These findings,if utilized for parental selection, might contributeto eliminating negative correlations betweenseed protein and yield, since these strategiesmay be under different genetic control and/ordetermine different biophysical constraints.