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The Sulpomag natural fertilizer, or potassium sulfate and magnesium, constituted by K2O 22%, MgO 22%, S 18% and Cl (chloride) 2.5% plus organic complexes of coconut water 10 to 20%, and casein hydrolyzate 250 and 500 mg.l-1, as partial substitutes for mineral salts of Murashige and Skoog (MS), were used in the in vitro propagation of banana, Musa sp., cv. Cavendish. The aim was that the in vitro plants grow and develop in minimum quantities of mineral salts, banned in the technical regulation for organic products. Shoot tips, established in vitro on MS medium, were transferred to 10 treatments for shoot multiplication supplemented with KH2PO4 (170 mg.l-1), CaCl2.2H2O (150 mg.l-1), NH4NO3 and KNO3, at 1/5 and 1/10 of the MS concentration, MS micronutrients and 0.1096 g.l-1 of Sulpomag, IAA (0.2 mg.l-1) and BAP (5 mg.l-1). The rooting medium was the same formulation of mineral salts, only varying on the growth regulators. Best results were obtained in culture media supplemented with NH4NO3 and KNO3 at 1/5 of MS concentration, 0.1096 g.l-1 Sulpomag and coconut water 10 y 20%. The results allow to consider the possibility of using Sulpomag and coconut water, as partial substitutes for MS mineral salts for in vitro propagation of Musa sp., cv. Cavendish for use in organic agriculture. [ABSTRACT FROM AUTHOR]

In order to protect the forest resources of Cedrela odorata L., currently threatened, it was considered necessary to establish a protocol for its cryopreservation. Research was conducted using shoots and seeds. Vitrification techniques were evaluated with shoots, using various solutions and rapid freezing in liquid nitrogen (LN). Initially the best results were obtained using incubation for 5 min in PVS3 solution before freezing, survival being 61% after 3 weeks of culture on Murashige and Skoog (MS) medium with 1.0 mg.l-1 BAP and 0.1 mg.l-1 GA3. Moreover, by incubating the apices in 0.3 M sucrose solution for 5 min prior to freezing, the survival rate reached 86% after 2 weeks of culture on MS medium with 1.0 mg.l-1 BAP, 0.1 mg.l-1 GA3 and 0.01 mg.l-1 IAA. When incubation in the solution of 0.3 M sucrose was used and recovery MS medium with 1 mg.l-1 KIN, 0.5 mg.l-1 GA3 and 100 mg.l-1 activated charcoal, the appearance of the surviving shoots improved significantly. For cryopreservation of cedar seeds, the methodology of dehydration and rapid freezing in liquid nitrogen (LN) was evaluated. Seeds with moisture content between 7.9% and 5.5% were placed in 5 ml polypropylene vials and these were directly immersed in NL. The effect of the storage period in NL (1 h, 24 h, 7 days, 1 month, 3 months and 6 months) on seed germination was evaluated. There were no statistical differences in ability of seeds to germinate after storage during different periods. [ABSTRACT FROM AUTHOR]

Pilon (Hieronyma alchorneoides) (Euphorbiaceae) is one of the native timber species of Costa Rica best adapted to conditions of open plantation. Due to its growth characteristics and variety of uses, the demand for planting material has increased. This species presents serious problems with seed reproduction; it is a dioecious, the fruit production varies over time and between trees, trees produce large quantities of fruit but are heavily predated by different birds. In recent years, the percentage of damaged fruit has increased due to wasps and the seeds lose their ability to germinate within days of harvest (recalcitrant). These factors make micropropagation an attractive option for mass propagation of the species. In the present study various stages of in vitro cultivation were evaluated. The aseptic establishment of the embryos was achieved by scarifying the seeds with concentrated sulfuric acid for 10 min, followed by incubation in 5.5% sodium hypochloride (NaClO) for 30 min, then embryos were inoculated on the culture medium described by Murashige and Skoog (MS) without growth regulators. When vegetative material was used as initial explant, the use of 0.095% mercuric chloride (HgCl2) during 5 min, allowed 50% of cuttings to develop shoots under aseptic conditions on a simple MS medium. It was observed that pilon does not require the addition of growth regulators during bud induction nor in the multiplication stages. During rooting, the addition of indole butyric acid (IBA) at concentrations of 0.1 mg.l-1 promoted the highest percentage of rooted shoots (80%), the largest number of roots per stem (5.0) and the best quality of the roots formed. Survival of in vitro plants after acclimation under greenhouse condition reached 70%. [ABSTRACT FROM AUTHOR]

Cultured cotyledon explants of OSO-1, OSO-2, OSO-3, PQRG-1, PQRG-2, PQRG- 3, and EM-1 "criollo" melon (Cucumis melo L) genotypes were evaluated with regard to their morphogenic response to combinations of N6-benzylaminopurine (BAP) (0.1, 0.5 and 1.0 mg.l-1) with indolacetic acid (IAA) (0, 0.05 and 0.5 mg.l-1). Regardless of BAP and IAA concentration in the shoot induction medium, the highest shoot formation percentages were obtained using EM-1>OSO-1>PQRG-3>OSO- 2>PQRG-2>PQRG-1>OSO-3. On the other hand, independently of the genotype, the shoot induction medium supplemented with 0.5 mg.l-1 BAP and 0.05 mg.l-1 IAA or 1 mg.l-1 BAP and 0 IAA mg.l-1 resulted in the highest average of shoots. Culture of cotyledons of the genotypes evaluated on induction medium supplemented with different BAP and IAA resulted in a different response. The in vitro culture protocol developed in this study will be useful in micropropagation of "criollo" melon genotypes. [ABSTRACT FROM AUTHOR]

The use of commercial foliar fertilizers was evaluated as a low-cost alternative to the Murashige and Skoog (MS) tissue culture-grade mineral salts, for in vitro culture of potato cv Atzimba microcuttings. Five foliar fertilizer formulations were evaluated, 2 of them equimolar to the MS mineral salts (AMSF, AMSF+Intra) and the other 3 (MF+Intra, MF+Micro+Intra, MF+Foli + Agro+Intra) adjusted to the N, P, K and Mg contents in the MS. The MS prepared with tissue culture-grade mineral salts was included as a control. Subcultures were carried out every month. Plant height, number of buds and roots, as well as chlorosis were evaluated monthly, while fresh weight was assessed at the end of the 5th subculture. Best results were obtained with MS, AMSF and AMSF+Intra culture media. In all other media plant growth decrease and chlorosis increased. The cost of 1 liter of AMSF medium was US$ 0.012, being the cheapest, followed by AMSF+Intra (US$ 0.025 l-1) and the MS with US$ 3.411 l-1. According to the results of this work, it is feasible to use commercial foliar fertilizers to replace the tissue culture-grade mineral salts normally used in the preparation of the MS medium for potato cv. Atzimba, at least for limited periods of time. [ABSTRACT FROM AUTHOR]

A method for plant regeneration via somatic embryogenesis was established in aloe (Aloe barbadensis Mill.). For explant disinfection, treatments involved 2, 3, 4, 5, 10 and 15 min sonication, in combination with 4% v/v NaOCl. Explant source and growth regulators were investigated. The highest survival rate (85%) and the lowest contamination (15%) were obtained with 5 min sonication. Friable embryogenic calluses were produced from apical meristems, leaf bases, and zygotic embryos of aloe. The best explants for callus induction (89%) were the leaf bases when cultured on callus induction medium with 2.5 mg.l-1 2,4-D, 2 mg.l-1 BAP, and 40 mg.l-1 adenine sulphate. The highest number of shoots was obtained from embryogenic calluses derived from zygotic embryos on a medium supplemented with 0.05 mg.l-1 2,4-D and 2 mg.l-1 BAP. High Performance Liquid Chromatography (HPLC) analysis revealed that acemanan concentration in embryogenic calluses (0.8-2.1 mg.ml-1) was much lower than fresh leaves (85 mg.ml-1). The protocol obtained in this investigation could be a useful tool not only for the propagation of this important medicinal plant but also for genetic transformation. [ABSTRACT FROM AUTHOR]

(STS) on somatic embryogenesis and artificial seeds of sugarcane (Saccharum spp.) var. CP-5243 was the aim of this work. Calli were obtained from 1 cm leaf segments from field plants. STS was applied at 7 μmol l-1. In all embryoid development stages, except in the case of germinated embryoids, treatments with STS showed better results than the control, whereas in artificial seeds the effect was adverse on embryoids' germination quality. Accumulation of Ag3+, promoted by STS, should not have surpassed the tolerance threshold for somatic embryogenesis from callus, but accumulated to toxic levels inside the alginate capsule. [ABSTRACT FROM AUTHOR]