Kanan Nanda

Development of shoots and roots in anther-derived callus of Azadirachta indica A. Juss. - a medicinal tree

Callus originated in microsporangial wall layers and connective tissues of anthers containing uninucleate microspores on Nitschs or Murashige and Skoogs medium supplemented with growth regulators. A higher percentage of cultures (43) produced callus on Nitschs medium containing 10 μM indole-3-acetic acid + 1 μM 6-benzyladenine. After 13–15 weeks, green nodular structures and prominent roots developed in 25% of the cultures on Murashige and Skoogs medium + 10 μM α-naphthaleneacetic acid + 1 μM kinetin. Multiple shoots were induced in this anther-derived callus when subcultured on Murashige and Skoogs medium augmented with 4.44 μM 6-benzyladenine + 0.53 μM α-naphthaleneacetic acid along with 18.75 μM polyvinylpyrrolidone. The excised shoots formed roots after subculturing on Murashige and Skoogs medium + 4.90 μM indole-3-butyric acid + 18.75 μM polyvinylpyrrolidone, thus developing complete plantlets. Examination of callusing anthers also revealed two- to multi-celled pollen masses with intact exine.

Micropropagation of Sesbania rostrata from the Cotyledonary Node

Multiple shoots were induced from the cotyledonary nodes derived from seedling of Sesbania rostrata on Nitsch (1969; N) medium supplemented with various concentrations of benzyladenine (BA). 1 mg dm−3 BA proved to be the best, eliciting 5.8 ± 1.0 shoots per explant in 100 % cultures. The elongation of shoots was best at 2.0 mg dm−3 BA. The shoot proliferation capacity increased to 7.5 shoots per explant following transfer of explants to the fresh shoot multiplication medium (MS + 1.0 mg dm−3 BA), after an initial incubation of 30 d. To further enhance number of shoots per explant an alternative strategy of cultivation of mother explant on fresh shoot multiplication medium after excision of shoots was adopted. Following the repeated harvesting of shoots an average of 33 shoots per explant could be obtained. The in vitro regenerated shoots produced roots when transferred to half-strength MS medium supplemented with 3 % sucrose and 1 mg dm−3 IBA. The developed plantlets were planted in the soil and transferred to the field after an acclimatization period of 3 – 4 months. These plants produced flowers and fruits in the field and exhibited the development of prominent and more organized stem nodules as compared to the in vivo raised plants of the same age.

Occurrence and Histochemistry of the Anther Tapetal Membrane

Abstract Several angiosperm and one gymnosperm taxa were investigated. The development and localization of the membrane was studied and differences were found between genera with an amoeboid or with a secretory tapetum. Several histochemical tests and fluorescence microscopy were used to investigate the chemical composition of the membrane. These studies indicate that the membrane consists of (a) insoluble polysaccharides, mainly callose, pectin and a cellulose-like substance, in addition to (b) an acetolysis-resistant cemponent (probably sporopollenin).

In vitro regeneration of plantlets from somatic explants of Matthiola incana

Abstract Multiple shoot buds have differentiated from cotyledonary explants of Matthiola incana (Brassicaceae), cultured on Murashige and Skoogs (MS) basal medium supplemented with benzylaminopurine (BAP) (0.1–0.8 ppm). After subculturing on MS + naphthaleneacetic acid (NAA) (1 ppm), they produced roots. However, only a few shoots developed on hypocotyl explants reared on MS + kinetin (Kn) (0.1 ppm) or MS + adenine (Ad) (1 ppm). NAA (1 and 4 ppm) induced profuse rooting in both cotyledonary and hypocotyl explants, whereas 2,4-dichlorophenoxyacetic acid (2,4-D) (2 ppm) could mainly induce callusing with sporadic rooting only in cotyledonary explants.

Production of adventitious shoots and plantlets from the hypocotyl explants of Sesbania rostrata (Bremek & obrem)

SummaryAdventitious shoots were induced from the hypocotyl explants derived from 12–15-d-old seedlings of Sesbania rostrata on Nitschs medium (Nitsch, 1969) supplemented with 1 mgl−1 (4.4 μM), of N6-benzylademine (BA). A maximum of 5.9±3.4 shoots per explant in 100% of cultures were obtained. The BA treatment for different time durations (1, 3, 5, 7, 10, 17, 21, or 30 d) exhibited significant variation in the caulogenic potential of the explants. BA treatment for 10–17 d proved optimum for the response. Although at all concentrations of kinetin the explants developed multiple shoots, they were malformed. Sucrose at 3% exhibited the development of the maximum of 3.5±0.9 shoots per explant with an average shoot length of 4.7±3.9 cm. Among the different carbon sources, i.e., fructose, galactose, maltose, mannose, and sucrose at 3% (w/v), sucrose supported the best caulogenic response. The role of various other factors (viz. size, orientation of explant, and seedling age) on the caulogenic response of the hypocotyl explants of S. rostrata were also studied. The shoot development in all cases was accompanied by the development of moderate to profuse callus at the basal cut end of the explant. The in vitro-regenerated shoots produced roots when transferred to half-strength MS medium (Murashige and Skoog, 1962) supplemented with 3% sucrose and 1 mgl−1 (4.9 μM) indole-3-butyric acid (IBA). The developed plantlets were transferred to the field after an initial acclimatization period of 3–4 mo. Such transferred plants produced flowers and fruits in the field and exhibited the development of prominent and organized stem nodules.

Fibrous Endothecium, Tapetum, and Pollen Development in Belamcanda chinensis DC.

The ontogeny of the anthers of Belamcanda chinensis has been studied with special reference to the behavior of the tapetum and its influence on the development of the endothecium and fertile pollen. When the tapetum malfunctions (either hypertrophies or forms a persistent band), besides the development of sterile pollen, the endothecium neither attains normal size nor develops fibrous thickenings. It seems that a factor (or factors) controlled by the malfunctioning tapetum inhibits the development not only of the fertile pollen but also of the fibrous endothecium.

Micropropagation of Sesbania sesban from the Mature Tree-Derived Explants

The nodal and internodal explants excised from the orthotropic shoots of Sesbania sesban var. bicolor elicited the development of shoots directly from the explants as well as via an intervening callus phase on Nitsch (N) medium. On benzyladenine (BA) supplemented media, the adventitious shoot buds developed involving a callus phase. An average of 8.9 ± 4.1 shoots developed per nodal explant on N medium containing 0.5 mg dm−3 BA in 95 % cultures, whereas 65 % cultures of internodal explants developed shoots with an average of 5.9 ± 3.6 shoots per explant on N medium supplemented with 1.0 mg dm−3 BA. On kinetin (Kn) supplemented medium shoots developed directly from the surface of both the explants at all the concentrations tried. Nodal explants on N medium supplemented with 1.5 mg dm−3 Kn developed an average of 12.5 ± 7.9 shoots per explant in 100 % cultures, while internodal explants induced an average of 11.6 ± 7.4 shoots per explant in 75 % explants at 0.5 mg dm−3 Kn. The in vitro regenerated shoots developed roots when implanted on N medium supplemented with 2 mg dm−3 indole-3-butyric acid (IBA), after 30 d of inoculation. The in vitro developed plantlets were initially acclimatized under controlled conditions for four months, prior to their transfer to the field.

Development of tapes in the pollen exine of ipomoea (convolvulaceae)

Abstract The origin and organization of ‘lamellae’ or ‘tapes’ has been investigated in pollen exine of Ipomoea purpurea (L.) Roth. At tetrad stage, microspores develop highly vesicular cytoplasm. The vesicles probably originate from golgi bodies. Gradually they move to the plasmalemma and then some of them, through exocytosis, empty out their contents exterior to the plasmalemma of microspore while others are extruded out as such. Subsequently, it seems that they are compressed forming characteristic ‘tapes’ with a central electron rare area bound by electron dense streaks on either side. Around these tapes the carotenoids and their esters are believed to polymerize,organizing the lamellar nexine.