[A highly efficient system for induction of female flowers in derooted seedlings of Cucumis sativus L. grown on the medium].

This paper reported the synergistic effect of KT and IAA, and the effects of age of seedlings, length of hypocotyls, nitrogen contents and NH(+)(4)-N/TN ratio on the induction of female flowers in derooted seedlings of Cucumis sativus L. for the establishment of an efficient system for the induction of female flowers. When cultured on MS basal medium supplemented with KT 3.0 mg/L and IAA 0.01 mg/L, an induction rate of 28% was obtained for the 7-day-old derooted seedlings with 1/2 hypocotyl, 12% and 26% higher than when cultured with KT 3.0 mg/L alone and IAA 0.01 mg/L alone, respectively, while no female flowers was formed on the control medium, which indicates that KT and IAA have an evident synergistic effect on the induction of female flowers. Experiment was done with N concentration of 60-90 mmol/L or with NH(+)(4)-N/TN ratio of 12.5%-50% (total N kept at 80 mmol/L), with lengths of hypocotyls of 0-4/4, and with different ages of seedlings of 5-8-day-old, the highest induction rate of 40%, 48% and 57% for female flowers was achieved on medium of N 80 mmol/L (NH(+)(4)-N/TN 37.5%), from seedlings with 1/4 hypocotyl and from the treatment using 6-day-old seedlings respectively.