Endosperm Type Effects on Biomass Production and on Stalk and Root Quality in Sweet Corn
In maize (Zea mays L.), a strong reproductive (grain) sink has been associated with increased stalk and root lodging. A weak reproductive sink may result in reduced production of photosynthate. Endosperm mutants sugary1 (su1) and shrunken2 (sh2) reduce the strength of the reproductive sink. Our objective was to examine stalk and root quality, biomass production, and reproductive sink size using su1 and sh2 in near-isogenic backgrounds. In 1989 and 1990, seed of two half-diallels made from six inbreds was planted. The same inbreds were used; however, one diallel used su1 versions of the inbreds and the other, sh2 versions. Each diallel was planted twice; in one planting the su1 and sh2 diallels were pollinated with su1 pollen and in the other, they were pollinated with sh2 pollen. This resulted in four sets of hybrids that varied only for endosperm type. Stalk and root quality and biomass and partitioning traits were measured. Percentage root lodging, root pull resistance, stalk diameter, stalk section weight, and grain yield differed significantly between starchy and sh2 endosperm types. Hybrids with sh2 had less grain yield and root lodging, higher root pull resistance and stalk section weight. Starchy types had a slightly higher harvest index than the su1 endosperm types. There were no significant differences in biomass among the four groups. The significant reduction in reproductive sink caused by the sh2 endosperm was not associated with decreased biomass.
Copyright © 1994.