Sugary enhancer1 and Endosperm Carbohydrate Composition in Near-Isogenic Germplasm; Genetic and Physiological Effects.

When combined with sugary1 (su1), the sugary enhancer1 (se1) allele, results in maize endosperm with elevated sugar levels and high levels of water-soluble polysaccharides resulting in excellent sweet corn quality. The wild type Se1 allele has been sequenced, but its function is unknown. The commercially used allele (se1) is a deletion. Two experiments were preformed in order to determine the effect of the se1 allele on endosperm carbohydrate composition and rate of sugar accumulation and conversion to polysaccharides. Experiment 1 used four pairs of lines near isogenic for se1 and their reciprocal crosses. The reciprocal crosses were used to determine if se1 has a dosage effect in the triploid endosperm. Experiment 2 used five se1 inbreds, five non-se1 inbreds, five se1 hybrids and five non-se1 hybrids. This material was used to determine the rate of sucrose accumulation and conversion to polysaccharides. The experimental details were identical for both studies. All materials were planted at the University of Wisconsin West Madison Agricultural Research Station with two planting dates and two replications at each environment in a randomized complete block design. Ears were self or cross-pollinated and harvested over four seven-day intervals starting at 14 days after pollination.  Endosperm carbohydrate composition, specifically sugar and polysaccharides, was determined using enzymatic assays. Preliminary results will be discussed.