Note on the efficiency of artificial hybridization in soybean

During a soybean breeding programme, different crossing techniques were applied to several sets of parents belonging to maturity groups 00 to 1. The hypocotyl and flower colour trait was used as a genetic marker in order to distin-guish successful cross-pollinations from selfings. All parental material was grown in the field, female parents were cultivated in pots to allow easier hand-ling of plants during pollination. Around 64 % of pods containing hybrid seeds were obtained when female flowers were emasculated and pollinated using a microscope, whereas only 18 % hybridization was achieved when pollinations were done with the naked eye and without emasculation. Percentage of hybridity decreased from 18 to 6.5 from the first to the second crossing period, which is explained by cleistogamous flowering due to low temperatures during the second crossing period. Key-words: soybean, Glycine max, crossing method. Zur Effizienz unterschiedlicher Kreuzungstechniken bei Sojabohn