Anwar Shahzad

Synseed technology—A complete synthesis

Progress in biotechnological research over the last two decades has provided greater scope for the improvement of crops, forest trees and other important plant species. Plant propagation using synthetic seeds has opened new vistas in the field of agriculture. Synseed technology is a highly promising tool for the management of transgenic and seedless plant species, polyploid plants with elite traits and plant lines that are difficult to propagate through conventional propagation methods. Delivery of synseeds also alleviates issues like undertaking several passages for scaling up in vitro cultures as well as acclimatization to ex vitro conditions. Optimization of synchronized propagule development followed by automation of the whole process (sorting, harvesting, encapsulation and conversion) can enhance the pace of synseed production. Cryopreservation of encapsulated germplasm has now been increasingly used as an ex vitro conservation tool with the possible minimization of adverse effects of cryoprotectants and post-preservation damages. Through synseed technology, germplasm exchange between countries could be accelerated as a result of reduced plant quarantine requirements because of the aseptic condition of the plant material.

TDZ-induced high frequency shoot regeneration in Cassia sophera Linn. via cotyledonary node explants.

Cassia sophera Linn. is an important medicinal plant belonging to family Fabaceae. It is extensively used in Homeopathy and is well known for its medicinal properties. The present study describes a simple, efficient and reproducible regeneration system for in vitro propagation of C. sophera through cotyledonary node (CN) explant excised from 21 d old axenic seedlings. Explants were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of thidiazuron (TDZ). Multiple shoots were produced on all the concentrations of TDZ; however 2.5 μM concentration proved to be optimal for the production of maximum number of shoots. To avoid adverse effects of prolonged exposure to TDZ in long term establishment, the cultures were transferred to TDZ free MS medium fortified with various concentrations of 6- benzyl aminopurine (BA) for multiplication, proliferation and elongation of induced shoots. Emergence of new shoot buds and multiplication continued up to second subculture passage and maximum number (14.9 ± 1.4) of shoots obtained on MS + BA (1.0 μM). Best rooting response was observed on half strength MS containing Indole-3-butyric acid (IBA) (1.0 μM). Regenerated plantlets were successfully acclimatized and hardened off inside the culture room and then transferred to green house with 100 % survival rate.

Histology of organogenesis and somatic embryogenesis in excised root cultures of an endangered species Tylophora indica (Asclepiadaceae)

This paper reports an efficient regeneration protocol through parallel organogenic and embryogenic pathways from green root segments (GRSs) of Tylophora indica (Burm.f) Merrill. GRSs explants from one year old in vitro cultures were cultured on Murashige and Skoog (MS) medium containing various cytokinins. Five µmol/L of 6-benzyladenine (BA) was most responsive for organogenesis in 1.5 cm long GRSs. Repeated subculture on medium containing both BA (5 µmol/L) and 1-naphthleneacetic acid (NAA) (0.1 µmol/L) promoted multiplication and proliferation of direct shoot buds (46.80 ± 0.96) and callus mediated somatic embryogenesis (18.07 ± 0.33). Germinated embryos isolated from callus were transferred onto maturation medium consisting of half-strength MS medium either devoid of plant growth regulators (PGRs) or with various concentrations of gibberellic acid (GA). Microshoots were excised during subculture and transferred onto root induction medium, thus ensuring a continuous supply of germplasm. Morphogenic variations were noticed in types of roots induced on various auxins. Regenerated plantlets and emblings hardened best on vermiculite with a survival rate of 90% and 70% respectively. However, the emblings were healthier in comparison to the regenerated plants. Histological analysis showed the origin and development of organogenesis.

Development of a regeneration system via nodal segment culture in Veronica anagallis-aquatica L. – an amphibious medicinal plant

Abstract The present study describes an effective, reproducible and rapid regeneration protocol for in vitro shoot development of the medicinally important, semi-aquatic plant Veronica anagallis-aquatica L. through mature nodal segments on Murashige and Skoog (MS) medium. The most effective medium for shoot regeneration was MS medium fortified with 0.5 µM 6-benzyladenine (BA), on which the maximum number (43.7±1.85) of shoots per explant having a shoot length of 5.0±0.25 cm were produced. The addition of auxins along with optimal concentration (0.5 µM) of BA did not further improve the regeneration capacity of the explants; instead, it resulted in an adverse effect. Nodal segments cultured in MS liquid medium without agar provided a better and early response for efficient shoot regeneration, and simultaneous rooting as compared to solidified medium. The optimal liquid medium comprised of MS+BA (0.5 µM) on which a maximum 20.7±1.76 shoots per explant were produced and grew healthier. Both half strength MS and MS basal medium supplemented with α-naphthaleneacetic acid (NAA) responded equally for root induction. Rooted shoots were successfully transferred to field conditions with 80% survival. Histological studies revealed the de novo origin of shoots which would make this protocol suitable for transformation techniques.

Improved shoot regeneration system through leaf derived callus and nodule culture of Sansevieria cylindrica

Long-term culture establishment and efficient in vitro regeneration protocol for Sansevieria cylindrica Bojer ex Hook was developed using leaf derived callus and nodule culture. Profuse callus induction on leaf discs was achieved on Murashige and Skoog (MS) medium supplemented with 10 µM indole-3-butyric acid (IBA), while a high frequency of nodulation was induced on 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) containing media. Shoot regeneration ability from cultured tissues occurred at varying degrees on all media. Through callus culture a maximum of 17.6 ± 0.14 shoots per culture was formed on medium containing 5µM 6-benzyladenine (BA) and 2 µM α-naphthaleneacetic acid (NAA). Among nodule cultures, the 2,4-D generated nodules were more proliferative and regenerative as compared to 2,4,5-T induced nodules and a maximum of 25 ± 0.16 shoots per culture was produced on a medium containing 5 µM BA plus 1 µM NAA. The regenerated shoots were successfully rooted on a semi-solid half strength MS medium containing 5 µM IBA with an average root number 3.5 ± 0.18 and root length 6.5 ± 0.14 cm. The regenerative ability of callus tissues was steady upto one year, while the nodules retained the totipotency to regenerate on optimal medium even after 3 years of subculturing. The histological sections of nodules confirm the typical anatomy exhibiting the vascular elements in bundles with well demarcated cortex and epidermal covering.

Somatic embryogenesis and plantlet regeneration of Cassia angustifolia from immature cotyledon-derived callus

Plant regeneration through indirect somatic embryogenesis was attempted from the immature cotyledon-derived explant of Cassia angustifolia Vahl. — a valuable leguminous shrub. The highest frequency (90.5 %) of somatic embryos was obtained on a Murashige and Skoog (MS) medium augmented with 10.0 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.0 μM benzyladenine (BA) with the production of a maximum of 22.8 embryos per explant, of which 35.3 % germinated on the same medium after 6 weeks of culture. A half strength MS medium without plant growth regulators facilitated better conversion of embryos into complete plantlets compared to a full strength MS medium. Regenerated plantlets were successfully acclimatized in sterile Soilrite and transferred to field conditions with a 70 % survival rate. Histological studies performed at different stages of embryogenesis revealed the mode of differentiation of embryos from the callus. The content of chlorophylls (a + b) and carotenoids, and the net photosynthetic rate (PN) in the regenerated plantlets were tested during different periods of acclimatization.

Factors affecting in vitro plant regeneration from cotyledonary node explant of Senna sophera (L.) Roxb. - A highly medicinal legume

An efficient in vitro regeneration protocol has been developed for a medicinal legume Senna sophera (L.) Roxb. using Cotyledonary Node (CN) explants. The plant exhibits high medicinal potential and is being used in several traditional and homeopathy system of medicine. The present study described an in vitro regeneration protocol, where different factors were optimized for maximum multiplication and propagation. The age of the explant, plant growth regulators, basal medium, pH of the medium and sucrose concentrations markedly influenced in vitro propagation of S. sophera. Among 14, 21 and 28 day-old CN explants, 21 day-old explants were found to be the most responsive. A maximum of 19.50 ± 0.51 shoots/explant were produced from 21 day-old seedling explants, having an average shoot length of 5.23 ± 0.14 cm in 86.00 ± 2.08% cultures after 6 weeks of incubation on Murashige and Skoog (MS) medium supplemented with benzyl adenine (BA) (5.0 μM) + naphthalene acetic acid (NAA) (1.0 μM) and containing 3% sucrose with pH value adjusted at 5.8. The highest rooting frequency (96.00 ± 2.08%) with maximum of 7.63 ± 0.23 roots/shoot having an average root length of 4.86 ± 0.35 cm was obtained on half-strength MS medium with 1.0 μM indole-3-butyric acid (IBA) and solidified with 0.25% phytagel. The plantlets were acclimatized in sterile soilrite under controlled conditions, hardened and successfully transferred to soil in natural conditions with 90% survival rate. The regenerated plants showed no morphological variations in terms of leaf shape, flower shape, pod size, number of seeds etc., when compared with the naturally grown plants in the field. Keywords: Senna sophera , fabaceae, cotyledonary node, in vitro shoot regeneration, rooting, acclimatization African Journal of Biotechnology , Vol. 13(3), pp. 413-422, 15 January, 2014

Efficient Micropropagation of Spilanthes acmella (L.) Murr.: A Threatened Medicinal Herb

The present study describes an efficient and reproducible protocol for micropropagation of S. acmella . Shoot tips taken from 3 week-old aseptic seedlings were cultured on Murashige and Skoog (MS) semi-solid medium supplemented with different concentrations of TDZ. Among various concentrations, 0.25 µM TDZ was found to be optimum for shoot regeneration as it induced a maximum of 30.0 shoots per explant however with retarded growth (1.0 cm). Among different volumes of culture media, 15 ml liquid culture medium favored best response wherein a maximum of 80.2 shoots per explant with an average shoot length of 7.0 cm were induced after 6 week of subculturing. Successful in vitro rooting was induced on 2.5 µM NAA containing half-strength MS medium. Almost 96% rooted plants successfully transferred and acclimatized ex vitro under green house conditions. Morphological and physiological parameters compared with the in vivo -grown seedlings of the same age appeared to be ‘normal’ in respect to the fundamental characteristics examined.

Enhanced multiplication and improved ex vitro acclimatization of Decalepis arayalpathra

The proposed work describes a protocol for high-frequency in vitro regeneration through nodal segments and shoot tips in Decalepsis arayalpathra, a critically endangered medicinal liana of the Western Ghats. Nodal segments were more responsive than shoot tips in terms of shoot proliferation. Murashige and Skoog’s (MS) basal medium supplemented with 5.0 μM 6-benzyladenine (BA) was optimum for shoot initiation through both the explants. Among different combinations of plant growth regulators and growth additive screened, MS medium added with 5.0 μM BA + 0.5 μM indole-3-acetic acid + 20.0 μM adenine sulphate effectuated the highest response: 11.8 shoots per nodal segment and 5.5 shoots per shoot tip with mean shoot length of 9.2 and 4.8 cm, respectively. Half-strength MS medium with 2.5 μM α-naphthalene acetic acid was optimum for in vitro root induction. The plantlets with the well developed shoot and root were acclimatized in Soilrite™ with 92 % survival rate in the field conditions. During acclimatization, chlorophyll content, net photosynthetic rate, stomatal conductance, and transpiration rate were gradually changed in dependence of formation of new leaves. Further, the changes in activities of antioxidant enzymes, i.e., superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) as well as activity of carbonic anhydrase were also observed: a continuous rise in SOD activity, but a rise and fall in the activities of CAT, APX, and GR were also noticed. Maximum fresh mass (3.1 g plant-1), dry mass (0.35 g plant-1) of roots and 2-hydroxy-4-methoxybenzaldehyde content of 9.22 μg cm-3(root extract) were recorded after 8 weeks of acclimatization.

Biotechnological strategies for the conservation of medicinal and ornamental climbers

Since time immemorial human beings are utilizing plants, apart from food and shelter, as medicine to cure ailments and ornamentals as aesthetic value. The recognized plants for medicinal uses mostly belong to tree, shrub and herbs, but there is another group of plants categorized as CLIMBERS . The climbing habit is a key innovation in angiosperms evolution. Climbing plant taxa have greater species richness than their non-climbing sister groups. Although it is considered as highly diversified clades but a much neglected group of the plants. In contrast with either erect or prostrate species, which occupy a narrow range of the light, climbers may use a very broad range of light availability. With the occupation of such an expanded ecological niche-ranging from forest floor to understory to forest canopy- a greater exposure to different pollinator, fruit/seed dispersers and herbivores would be granted. Almost one-third of the plant families includes climbers and contributes significantly to the function of any forest system. Climbers are not well investigated by the researchers, however considerable information has been gathered in this book, which delineates for the researchers and readers to exploit medicinal and ornamental climbers for their benefit. As concerted efforts have not been made to popularize climbers for medicinal and aesthetic uses, the contributions made in this book will provide a platform to move ahead for better utilization of climbers in the service of human beings. This book offers an insightful look on different biotechnological interventions for the conservation of medicinal and ornamental climbers. The book starts with a discussion on the evolution and diversification of climbers among the angiosperms. Thereafter chapters describe various approaches of conservation, biotechnological strategies like micropropagation, synseed production, genetic transformation for the quality improvement, production of bioactive compounds under in vitro conditions. This book also provides a compilation of standardized in vitro micropropagtion protocols for some threatened climbers. It also includes chapters on various molecular markers and their application in medicinal and ornamental climbers for their desired improvement. The book provides an essential information for advanced students, teachers and research scientists it the field of plant biotechnology, pharmaceutical industries and medical sciences