Showing papers by "Jitendra P. Khurana published in 1987"

Role of Catecholamines in Promotion of Flowering in a Short-Day Duckweed, Lemna paucicostata 6746.

Abstract: l-Epinephrine, l-norepinephrine, and l-isoproterenol substantially promote flowering under a photoperiodic regime of 8 hours light and 16 hours darkness in Lemna paucicostata 6746 when grown on the modified Bonner-Devirian medium devoid of ethylenediaminetetraacetic acid. If catecholamines are provided to plants at 10−4 molar level prior to transferring them to the short-day regime, they not only induce more floral primordia but also significantly improve flower development and sustain the flowers for a longer period. Propranolol (10−4 molar), a β-adrenergic blocking agent, partially suppresses flowering and the inhibition of flowering is relieved by catecholamines.

Obligate Requirement of Salicylic Acid for Short-Day Induction of Flowering in a New Duckweed, Wolffiella hyalina 7378

Abstract: Wolffiella hyalina 7378, a member of the Lemnaceae, does not flower in the basal media of Bonner-Devirian, Hoagland, Hutner (½ strength), M medium of Hillman or Pirson-Seidel under either long or short day photoperiodic regimes. Well-known chelating agents, such as EDTA, EDDHA and 8-hydroxyquinoline, which have been shown to significantly influence flowering in other members of the Lemnaceae, also do not show any effect in this strain. It is, however, noteworthy that W. hyalina 7378 flowers profusely under a short-day photoperiodic schedule of 8 h light and 16 h darkness provided that 10 -5 m salicylic acid is supplemented to modified Bonner and Devirian medium. The critical daylength of W. hyalina 7378 is 13 h. Further, at least two inductive photocycles are required for initiation of flowering. As to the mechanism of SA action, it appears that SA effect on flowering is hormonal in nature rather than due to chelation of metal ions.