Our study was to develop a rapid and successful method for promoting asymbiotic seed germination and growth and development of protocorm like bodies (PLBs) and subsequent plantlets of Phalaenopsis orchid. Four basal media i.e. Murashige and Skoog (MS), half strength MS (½MS), Knudson C (KC) and, Vacin and Went (VW) supplemented with coconut water and peptone were examined for their effectiveness in large-scale multiplication by asymbiotic seed germination. Seed germination, leaf number, root number, root length, seedling length and fresh and dry weight were scored. Well-rooted plantlets 4-cm in height were transferred to a greenhouse in trays containing expanded clay, charcoal, cocopeat and perlite (4:2:1:1) or sphagnum moss. The seed germination frequency and seedling development was found significantly higher in organic growth supplement-enriched MS and ½MS media. The results indicated that the highest seed germination (94 %) was obtained in MS medium supplemented with 100 mg/L coconut water or 1 g/L peptone and ½MS containing 1 or 2 g/L peptone. However, the longest seedling was found in MS or ½MS media supplemented with 100 mg/L coconut water or MS containing 1 g/L peptone. Ninety-seven percent of plantlets survived after 1 month in mixture media expanded clay: charcoal: cocopeat: perlit. پرونده مقاله

Attractive and colorful cultivars of cactus have been developed that are mainly propagated by grafting. The aim of this study was to determine histological events during graft union formation in Gymnocalycium cactus influenced by BA (Benzyladenine) application, grafting method and rootstock. The basal end of the scions and the top end of the rootstocks were first dipped into BA solution at concentrations of 0, 100 and 500 mg L-1 for 10 s, before being grafted on Lemaireocereus marginatus and Myrtillocactus geometrizans rootstocks using horizontal or wedge techniques. Longitudinal sections of the graft union were taken weekly to observe the developmental process of graft formation. The rootstocks did not have a significant effect on grafting success and scion growth, while horizontally grafted Gymnocalycium showed better grafting success rate. The grafting rate and scion growth were enhanced by application of BA compared with the control. The best results were obtained from treating the graft cut-surfaces of both scions and rootstocks with 100 mg L-1 BA. Histological observations showed that the graft union process involved development of a thin necrotic layer, callus formation at the graft interface, cambium differentiation and initiation of new vascular elements, developing the new vascular tissue, and connection of scion and rootstock vascular bundles. BA stimulated rapid proliferation of callus between the scion and rootstock as well as differentiation of vascular elements. We suggest the horizontal graft and application of BA (100 mg L-1) on the cut surfaces of both scion and rootstock as an easy and reliable method for successful graft union in Gymnocalycium cactus, which may have potential use in the commercial production of other cactus species as well. پرونده مقاله