To the question about origin of compound leaf of soybean Glycine max (L.) Merrill. (Fabaceae lindl.)

During the period 2000-2003 morphological researches of trifoliate compound leaf as well as leaf shape with increased and decreased quantity of leaflets of soybean Glycine max (L.) Merrill were conducted. It is determined that the quantity of leaflets on compound leaf of soy- bean depends on concentration of endogenous cytokinins. Their excess is caused the further complication of trifoliate leaf and lack of it is caused his reduction to secondary simple leaf. It is determined that formation of lateral and additional leaflets occurs by means of isolating of lower couple of lateral veins of central blades and lower out ward vein of lateral leaflet. The suggestion based on conducted researches is in following: formation of trifoliate leaf of soybean in phylogenesis could occur by isolating of lower lateral veins of blades, but not by reduction of unabrupty pinnate compound leaf, as it was supposed early. For the first time morphologically new type of compound soybean leaf was explored and described, having got the name ‘pseudodigitate compound’ leaf.