STIMULATION OF GENERATIVE DEVELOPMENT OF WINTER-WHEAT BY THE EXTRACTSFROM INFLORESCENCES OF VARIOUS CROP PLANTS

The influence of extracts from the inflorescence of maize, rape, sunfl ower, cucumber, pumpkin and bean on the generative development of wint er wheat var. Grana was investigated. The embryos of wheat were grown on sterile nutrients containing extracts under conditions suboptimal f or the vernalization of this variety. The growth of partly vernalized seedlings was continued in a glasshouse under conditions excluding the completion of vernalization (temperature 20/17 degrees C day/night, 1 6 hr photoperiod). The generative development of plants was estimated by the number of heading plants or plants with generative shoot apex, as well as by the length of the vegetative phase. The examined extract s stimulated generative development of wheat by the increase in percen tage of heading plants and plants attaining the early generative stage as well as by the acceleration of heading. The non-vernalized embryos were most effectively stimulated by extracts from young maize kernels , female flowers of pumpkin and from the flower buds of rape which ind uced heading in about 76, 47 and 31% of plants, respectively (only 6% in control not treated with extracts), the extracts from maize cobs ac celerated also the heading of plants by as much as 32 days. After 14-d ay vernalization these extracts enabled the heading of all plants, whi le the control plants headed only in 26%. These effects are not of a t rophic character, since all the extracts inhibited the growth of wheat seedlings.