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IntroductionPhysalis peruviana L. is a species from the family Solanaceae and genus Physalis, commonly known as Cape gooseberry (also known as physalis, golden berry, etc.). It is an herbaceous, semishrub, perennial plant, native to tropical Peru and other warm temperate and subtropical regions throughout the world (Ramirez et al., 2013). Cape gooseberry resembles tomato in flavor and appearance, though the sour and sweet taste is richer in this tropical fruit. This plant has increasing popularity due to its nutritional and medicinal values. Cape gooseberry is a source of health-related compounds found in the fruits and other parts of the plant, including leaves and stems. It has been widely used for treating diabetes, hepatitis, ulcers, and several other diseases (Mayorga et al., 2002;Arun and Asha, 2007). It also contains high levels of vitamins A, C, and B-complex, as well as compounds with antiinflammatory and antioxidant properties (Strik, 2007). Wu et al. (2009) reported that supercritical carbon dioxide extracts of P. peruviana leaves induced cell cycle arrest and apoptosis in human lung cancer cells. Similarly, Çakir et al. (2014) reported that phenolic content of ethanolic leaf extracts (100 µg mL -1 ) possessed high cytotoxic effects on HeLa cells (an immortal cell line).The use of tissue culture methods for the selection of the best cultivars for agricultural practices and clonal propagation might be conducive for micropropagation, especially when taking into account high consumption due to value-added natural compounds, limited plant production, and requirements of manpower, transport, and storage (Rodrigues et al., 2013a). Though P. peruviana was reported as recalcitrant for shoot organogenesis through adventitious regeneration from leaf explants (Torres, 1991), there are a limited number of in vitro regeneration studies concerning the micropropagation of P. peruviana (Rodrigues et al., 2013b), not containing information about the synergistic effects of plant growth regulator (PGR) combinations on growth parameters. Several studies on in vitro propagation of other Physalis species, including P. minima, P. ixocarpa, and P. pruinosa,

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Stevia is a natural, zero-calorie, intensively sweet extracted from the leaves of Stevia rebaudiana. Its sweet taste derives from a group of compounds known as steviol glycosides. In this study, an efficient micropropagation protocol for S. rebaudiana was developed for possible commercial implementation using Murashige and Skoog (MS) basal medium without plant growth regulators for most of the process. Direct shoot formation was achieved after cultivation of nodal segments on MS medium with or without plant growth regulators (benzyl amino purine [BAP], kinetin [KIN]) at various concentrations (0.1, 0.5, 1.0, or 2.0 mg L −1 ). Although all treatments produced two shoots per explants after 3 wk of culture, high concentrations of KIN and BAP (1.0 or 2.0 mg L −1 ) induced more callus formation. Rooting was achieved on MS medium containing 0.25 mg L −1 indole-3-acetic acid (IAA), which produced 8.1 roots per shoot after 3 wk of cultivation. After acclimatization of the regenerants in a portable greenhouse for 3 wk, all regenerants and seedderived seedlings were transferred to field conditions for 16 wk. Steviol glycoside contents (% leaf dry weight) did not differ between leaves collected from regenerants and seed-derived plants. Rebaudioside A content ranged from 4.7 to 5.0% (w/w), while stevioside ranged from 6.4 to 6.9% (w/w). There was no significant difference between the two sampling periods (late vegetative and flowering stages) for the plants grown in the field. In this study, a cost-effective in vitro regeneration protocol was established that enables efficient, large-scale in vitro production of S. rebaudiana for field cultivation.

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The present study reports the first efficient in vitro regeneration of Ananas erectifolius via indirect organogenesis. Leaf segments (leaf base, middle, and apex) excised from 3-or 5-week-old in vitro plantlets were cultured on 1/4 strength MS medium supplemented with different concentrations and combinations of plant growth regulators. The explants were also exposed to pulse treatment with thidiazuron (TDZ) and 2,4-dichlorophenoxyacetic acid (2,4-D) for different periods of time. The results showed that using juvenile rather than old explants enhanced the frequency of callus induction (35.0% and 16.0%, respectively). Among the explant types tested, only leaf base segments induced calli; the highest frequency occurred via culture treatment containing 4-amino-3,5,6trichloropicolinic acid (picloram; 48.57%), 2,4-D (40%), or TDZ (35.71%). However, only calli generated in treatments containing TDZ or N 6-isopentenyladenine (2ip) were able to develop shoots (maximum 35.71% and 14.28%, respectively). A combination of TDZ and 2,4-D improved callus induction (60.0%) but did not increase shooting response. However, both callusing and shooting response increased when 10 days of pulse treatment with TDZ and 2,4-D was applied (66.83% and 48.7%, respectively). Rooted plantlets that exhibited normal growth and development were acclimatized in a greenhouse and had a survival rate of 95%.