Micropropagation, genetic fidelity assessment and phytochemical studies of Clerodendrum thomsoniae Balf. f. with special reference to its anti-stress properties

Clerodendrum thomsoniae commonly known as bleeding heart vine or bag flower which is a good candidate for a new crop for the floriculture industry. In this study, in-vitro callus regeneration of C. thomsoniae through nodal culture has been attempted. Murashige and Skoog’s medium supplemented with 2 mg/l BAP and 0.5 mg/l

Small Inflorescence Bulbils Are Best for Micropropagation and Virus Elimination in Garlic

Garlic (Allium sativum L.) plants were cultured from immature inflorescence bulbils. The primordia of bulbils appeared initially as protuberances on reproductive apices, swelled, and then formed bulbils with protective leaves. Excised bulbils sprouted on Murashige and Skoog's medium with 5.4 μm naphthaleneacetic acid (NAA) and grew into plantlets. The frequency of sprouting in culture increased with the development of bulbils before excision, and immature bulbils 0.4 to 2.4 mm in diameter sprouted at a frequency of >85%. A dot immunoblot assay revealed a remarkable reduction in levels of garlic mite-borne mosaic virus in plantlets grown from immature bulbils, suggesting that such bulbils might be suitable for the propagation of virus-free garlic plants.

Induction of somatic embryogenesis in carrot by heavy metal ions

A new method for the induction of somatic embryos has been demonstrated. Somatic embryos were formed without a visible interventing callus stage when apical tips from 1-week-old seedlings of carrot (Daucus carota cv. US-Harumakigosun) were cultured for 1–3 weeks on Murashige and Skoog's medium without growth regulators but containing heavy metal chlorides, such as CoCl2, NiCl2, ZnCl2, and CdCl2, and then transferred to Murashige and Skoog's medium. These results suggest that the stresses caused by these chemicals trigger the induction of somatic embryogenesis in carrot. Key words: Daucus carota, somatic embryo, stress, tissue culture.

Comportement in vitro de bourgeons axillaires de type indéterminé du palmier dattier (Phoenix dactylifera)

Indeterminate axillary buds excised from young offshoots of date palm (Phoenix dactylifera L.) developed into flowering or vegetative buds when cultured under different in vitro conditions. Floral induction was observed in explants cultured in the dark on Murashige and Skoog's medium supplemented with 50 g∙L−1 of sucrose and several auxins and cytokinins in a ratio favouring the auxins. In contrast, vegetative buds were obtained from explants cultured under a 16-h photoperiod on Murashige and Skoog's medium supplemented with 30 g∙L−1 of sucrose and 1 mg∙L−1 of indolebutyric acid. The results showed that numerous vegetative meristems can be produced from indeterminate buds cultured in vitro. The results also confirmed the observations made during an in vivo study of flowering and vegetative bud development. The importance of the nutritional contribution of the leaves surrounding the flowering buds was pointed out. Key words: Phoenix dactylifera, axillary buds, indeterminate buds, in vitro culture, floral state, vegetative state, morphogenesis.

Conditions d'apparition d'une embryogénèse somatique sur des cals issus de la culture de tissus foliaires du chêne vert (Quercus ilex)

The proliferation of parenchymatous foliar tissue of Quercus ilex was obtained from current year leaves taken from old trees and cultivated in vitro on modified Murashige and Skoog's medium supplemented with benzylaminopurine (4 mg ∙ L−1) and naphthyl acetic acid (0.5 mg ∙ L−1). Only the fragments cultured in October reacted. The neoformations only appeared on calluses that had not been subcultured for 7 months. Primary nodules arising on these calluses were removed and subcultured on the same medium either in the dark or in the light. In the dark only, they produced secondary nodules, which were the source of somatic embryos both in light and dark. Presently, they seem to regulate their structure in the dark but they do not develop in a way that leads to germination.

In vitro initiation of adventitious buds and its modification by high concentration of benzyladenine in leaf tissues of mulberry (Morus alba)

Leaf explants of mulberry (Mortis alba L.) derived from aseptically grown shoots and seedlings were cultured on Murashige and Skoog's medium. Normal and abnormal leaves were grown by varying the concentration of benzyladenine. They differed in the way of forming adventitious buds. In normal leaves bud initiation occurred exclusively at the cut ends of midribs after removing petioles, while in abnormal ones buds formed at any region on midribs and petioles. Histological observations were made to study different patterns of bud initiation.

Callus multiplication of Anthurium andraeanum Lind. in liquid media.

The growth of callus tissue from adult A. andraeanum plants was best in a modification of Murashige and Skoog's medium. On this medium genotype A 42-3 reached a fresh weight multiplication rate of 30.7 when grown for 5 weeks at a rotation speed of 120 rev/min, at 25 deg C and in continuous darkness. The fresh weight multiplication rate of 6 other genotypes of the same species varied considerably when grown on the best medium for A 42-3. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Freesia plantlets from flower-buds cultivated in vitro.

Flower-buds of 10 freesia cvs were grown in vitro and were induced to regenerate adventitious buds on a modified Murashige and Skoog's medium containing PBA and IAA. The formation of adventitious buds was strongly enhanced by growing the explants first in darkness and subsequently in light. Subcultured shoots, grown on a medium with IAA, could be rooted easily and viable plants were obtained. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Plantlet formation from Lycopersicon esculentum leaf callus

Explants were obtained from leaves of three strains of tomato and grown on a modified Murashige and Skoog's medium with various combinations of indole-3-acetic acid (IAA) and kinetin. Callus proliferation began by 8–10 days. Root initiation was very common, particularly at 2 mg/liter IAA and 2 mg/liter kinetin. Shoot formation occurred within 30 days but only at a specific combination of concentrations of the two growth hormones (4 mg/liter IAA + 4 mg/liter kinetin). Most shoots became plantlets by 10 days after transfer to basal Murashige and Skoog's medium. Shoot-forming potential was neither correlated with callus-forming potential nor with vigor of strain.