1. Seed Biology, Dep. of Crop and Soil SciencesCornell Univ. Agricultural Experiment Station, Cornell Univ.617 Bradfield HallIthacaNY14853‐1901
2. Siedlce Univ. of Natural Sciences and HumanitiesFaculty of Natural Sciences, Dep. of Plant Physiology and GeneticsPrusa 12, 08‐110SiedlcePoland
3. Dep. of Plant Breeding and GeneticsCornell Univ. Agricultural Experiment Station, Cornell Univ.IthacaNY14853‐1901