Herbal
Parissa Jonoubi; Masoumeh Arang
Abstract
Introduction: Plant growth regulators exert significant effects on the anatomical structure, differentiation of floral primordia, and development of reproductive organs in plants. This experiment investigated the impacts of auxin and gibberellin on the vegetative and reproductive development of cucumber ...
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Introduction: Plant growth regulators exert significant effects on the anatomical structure, differentiation of floral primordia, and development of reproductive organs in plants. This experiment investigated the impacts of auxin and gibberellin on the vegetative and reproductive development of cucumber (Cucumis sativus L. cv. Supernia F1). Materials and methods: A factorial experiment was conducted as the basis of a randomized complete block design with three replications. The treatments included naphthalene acetic acid at concentrations of 0, 50, and 100 mg l-1, and gibberellic acid at concentrations of 0, 25, and 50 mg l-1, which were sprayed on the plants every ten days until the end of flowering. Results and discussion: Anatomical studies had significant impacts on the thickness of the cortex layers, the phloem and xylem regions, the diameter of the xylem opening of the root, stem, and leaf, the thickness of the petiole and pith of the stem and leaf trichome at various hormonal levels. The investigation of male reproductive organs revealed that at high concentrations of both hormones, earlier nuclear division occurred during the microspore mother cell and tetrad stages. Additionally, callose walls were observed not only surrounding the tetrad cells and microspores but also around the mature pollen grains, exhibiting high persistence that prevented their separation. It can be concluded that high concentrations of the two hormones inhibited the production of normal pollen grains and anther dehiscence, whereas intermediate concentrations of both hormones accelerated pollen development.
