Saikat Gantait

Induction and identification of tetraploids using in vitro colchicine treatment of Gerbera jamesonii Bolus cv. Sciella

To induce variation through chromosome doubling in Gerbera jamesonii Bolus cv. Sciella, two-week-old in vitro grown shoots were treated with various concentrations of colchicine (0.01, 0.05, 0.10, 0.50 or 1%xa0w/v) for 2, 4 or 8xa0h. Treated shoots were then cultured on Murashige and Skoog (MS) medium supplemented with 8.8xa0μM 6-benzyladenine (BA) and 155xa0μM adenine sulphate (ADS), and subsequently transferred to fresh MS medium containing 2.85xa0μM indole-3 acetic acid (IAA) for rooting. When shoots were treated with 0.1% colchicine for 8xa0h, 64% of recovered plantlets were tetraploid. Ploidy of plantlets was confirmed by flow cytometry, stomatal analysis, and morphological characters. Tetraploid plantlets displayed slower proliferation along with higher vigor and thickened broad leaves. Moreover, tetraploid plants developed larger flowers, longer stalks, and have improved vase-life, all contributing to higher ornamental value of gerbera.

Synthetic seed production of medicinal plants: a review on influence of explants, encapsulation agent and matrix

The present review illustrates the implementation of synthetic seed technology for mass propagation and short-term storage of several medicinal plants, popularly grown throughout the world. Biotechnology-based research with special reference to in vitro plant cell and tissue culture intervention created a new outlook in terms of mass propagation, germplasm storage and cryoconservation, production of secondary metabolites as well as genetic transformation. Synthetic seed technology involving alginate encapsulation of in vitro or in vivo generated explants proved to be a competent system to deal with multiplication, storage and exchange of seedless medicinal plants having traits of choice that are intricate to propagate via conventional approach. Nevertheless, optimization of production, storage and exchange of synthetic seeds are influenced by several factors. Manipulation of those factors such as explant selection, encapsulating agent and matrix determined the success of synthetic seed technology in medicinal plants. The present review elucidates an outline of past progress, present status and future prospects of synthetic seed technology intervention in medicinal plants with special emphasis on the factors which determine the success of this technology.

Effect of loading and vitrification solutions on survival of cryopreserved oil palm polyembryoids.

The present study evaluates the effect of six loading solutions and five vitrification solutions (VS) and their time of exposure on the survival of oil palm (Elaeis guineensis) polyembryoids in liquid nitrogen (LN). In vitro grown polyembryoids of oil palm were successfully cryopreserved by vitrification with 45% survival. Individual polyembryoids, isolated from 2-month old culture, were precultured in liquid Murashige and Skoog medium supplemented with 0.5xa0M sucrose for 12xa0h and treated with a mixture of 10% (w/v) dimethyl sulphoxide (DMSO) plus 0.7xa0M sucrose for 30xa0min. Polyembryoids were then subjected to plant vitrification solution-2 (PVS2) (30% (w/v) glycerol plus 15% (w/v) EG plus 15% (w/v) DMSO plus 0.4xa0M sucrose) exposure for 5xa0min at 26xa0±xa02°C and subsequently plunged into LN. Thawed polyembryoids resumed growth within 8xa0days of culture and shoot development was recorded at 25xa0days of growth. Scanning electron micrograph revealed that successful regeneration of cryopreserved polyembryoids was due to stabilization of cellular integrity through optimum VS exposure.

Storability, post-storage conversion and genetic stability assessment of alginate-encapsulated shoot tips of monopodial orchid hybrid Aranda Wan Chark Kuan ‘Blue’ × Vanda coerulea Grifft. ex. Lindl.

An efficient short-term storage system of synthetic seeds, produced using in vitro shoot tips of the monopodial orchid hybrid Aranda Wan Chark Kuan ‘Blue’xa0×xa0Vanda coerulea Grifft. ex. Lindl. (AV), was developed. In vitro shoot tips (3–4xa0mm) were successfully encapsulated, resulting in uniform spherical beads (capsules), using 3xa0% sodium alginate with 75xa0mM CaCl2·2H2O. Maximum (~100xa0%) conversion (into plantlets with shoot and root) of capsules (or synthetic seeds) was achieved on quarter-strength Murashige and Skoog regrowth medium, while full-strength MS medium was required for effective conversion of non-encapsulated shoot tips. The capsules showed distinct difference in their response to temperature during storage. The conversion efficiency declined upon storage duration at both 4xa0and 25xa0°C, with those stored at 25xa0°C being more tolerant to storage. Capsules stored at 4xa0°C had rapid deterioration and faced complete death within 160xa0days while those stored for 200xa0days at 25xa0°C showed relatively high conversion (71.6xa0%). An inter-simple sequence repeats fingerprinting approach, employed on indiscriminately chosen plantlets from converted capsules (following 4 and 25xa0°C of storage), ensured the post-storage genetic stability.

Alginate-encapsulation, short-term storage and plant regeneration from protocorm-like bodies of Aranda Wan Chark Kuan ‘Blue’ × Vanda coerulea Grifft. ex. Lindl. (Orchidaceae)

This article demonstrates the single bead alginate-encapsulation and conversion (complete plantlet regeneration) from protocorm-like bodies (PLBs) of Aranda Wan Chark Kuan ‘Blue’xa0×xa0Vanda coerulea Grifft. ex. Lindl. (AV) (a monopodial orchid hybrid) for the first time. PLBs, induced from leaf segments of AV were isolated from in vitro proliferating PLB clusters. Individual PLBs (4xa0±xa01xa0mm diameter) were encapsulated in calcium alginate beads to manage mass propagation, short-term storage and germplasm sharing. The superior gel matrix for encapsulation was obtained using 3xa0% sodium alginate and 75xa0mM calcium chloride (CaCl2·2H2O). Highest percentage of germination (98.1xa0%) and conversion (96.2xa0%) of encapsulated PLBs (capsules) was obtained on plant growth regulator-free half-strength MS (Murashige and Skoog, Physiol Plant 15:473–497, 1962) medium. Successful storage of capsules, until 180xa0days, was achieved at 25xa0°C under zero-irradiance with germination and conversion frequency of 76.9 and 70.2xa0%, respectively. Plantlets regenerated from capsules were acclimatized successfully with 92xa0% survival rate.

In vitro accelerated mass propagation and ex vitro evaluation of Aloe vera L. with aloin content and superoxide dismutase activity

An innovative protocol on accelerated in vitro propagation and acclimatisation was developed in Aloe vera L. Culture was initiated with rhizomatous stem where Murashige and Skoog (MS) medium fortified with 0.5u2009mgu2009L−1 α-naphthalene acetic acid and 1.5u2009mgu2009L−1 N6-benzylaminopurine (BAP) promoted earliest shoot induction. Maximum shoot multiplication was achieved in MS medium supplemented with 2.5u2009mgu2009L−1BAP. The best in vitro rooting was observed in the MS medium with 0.5u2009mgu2009L−1 indole-3-acetic acid plus 2u2009gu2009L−1 activated charcoal. The simple acclimatisation process, primarily with a combination of sand and soil (1u2009:u20091 v/v) and finally with a blend of sand, soil and farm yard manure (2u2009:u20091u2009:u20091 v/v), ensured a 98% survival rate. Overall, 192 true-to-type plantlets were achieved from a single explant within 85 days. Morphologically, in vitro generated plants performed better than conventionally propagated plants; nevertheless the similarity in aloin content, gel content and superoxide dismutase activity was corroborated.

Screening of rice landraces for salinity tolerance at seedling stage through morphological and molecular markers

The present investigation was carried out to evaluate 33 rice landrace genotypes for assessment of their salt tolerance at seedling stage. Growth parameters like root length, shoot length and plant biomass were measured after 12xa0days of exposure to six different levels of saline solution (with electrical conductivity of 4, 6, 8, 10, 12 or 14 dS m −1). Genotypes showing significant interaction and differential response towards salinity were assessed at molecular level using 11 simple sequence repeats (SSR) markers, linked with salt tolerance quantitative trait loci. Shoot length, root length and plant biomass at seedling stage decreased with increasing salinity. However, relative salt tolerance in terms of these three parameters varied among genotypes. Out of the 11 SSR markers RM8094, RM336 and RM8046, the most competent descriptors to screen the salt tolerant genotypes with higher polymorphic information content coupled with higher marker index value, significantly distinguished the salt tolerant genotypes. Combining morphological and molecular assessment, four lanraces viz. Gheus, Ghunsi, Kuthiahara and Sholerpona were considered as true salt tolerant genotypes which may contribute in greater way in the development of salt tolerant genotypes in rice.

Direct induction of protocorm-like bodies from shoot tips, plantlet formation, and clonal fidelity analysis in Anthurium andreanum cv. CanCan

Protocorm-like bodies (PLBs) were induced directly at high frequency from wounded surface of Anthuriumandreanum cv. CanCan shoot tip-ends, used as explants. In order to obtain PLB directly, the influence of different types and concentrations of cytokinins were evaluated. Amid the cytokinins, N6-(∆2-isopentenyl)-adenine (2-iP) at a concentration of 15xa0μM was most effective in inducing PLB whereby ~98 (97.8)xa0% of explants induced PLB with an average of 120 PLBs per shoot tip within 50xa0days of culture. Stereomicroscopic observation meticulously revealed the sequential changes from initiation to maturation of PLB gradually forming shoot apical meristem, shoot primordia and leaf primordia. Mature PLBs showed significant shoot proliferation (98.4xa0%) in media containing 10xa0μM 6-furfurylaminopurine forming 17 shoots per PLB within 30xa0days. The inclusion of activated charcoal (AC) in media containing auxin had promotive effect on rooting whereby 5xa0μM indole-3-butyric acid plus 500xa0μM AC resulted in highest number and length of roots. Successfully acclimatized plants, subjected to random amplified polymorphic DNA assessment for genetic fidelity, did not show any variation. Thus, this complete study has successfully outlined a rapid, high frequency direct induction of PLB of Anthurium from shoot tips inclusive of shoot proliferation, rooting and acclimatization.

Stevia: A Comprehensive Review on Ethnopharmacological Properties and In Vitro Regeneration

The present review illustrates the pharmacological properties and production of planting materials through in vitro organogenesis of Steviarebaudiana (Bertoni). The plant is native to Paraguay; however, the main producers of stevia are Japan, China, Taiwan, Thailand, Korea, Brazil, Malaysia and India. This plant is recorded as having a non-caloric natural sugar, alternative to artificially produced sugar substitutes and hence traditionally has been used to sweeten beverages. This article enumerates an overview on pharmacological and micropropagation aspects which are of use to researchers for further exploration for the indispensable improvement of this potential herb with medicinal importance.

An elite protocol for accelerated quality-cloning in Gerbera jamesonii Bolus cv. Sciella

A novel, efficient, and simple protocol was developed on in vitro mass propagation and acclimatization of Gerbera jamesonii Bolus cv. Sciella, an ornamental plant with attractive flowers. Shoot tip was used as the primary explant for in vitro establishment in which Murashige and Skoog (MS) medium supplemented with a low level of NAA (0.5xa0mgu2009l−1) and BAP (1.5xa0mgu2009l−1) promoted earliest axillary bud initiation within 5xa0d in 91.6% of the inoculants. Five axillary buds were initiated from a single explant within 13xa0d after inoculation. A very high rate of shoot multiplication (14 shoots per inoculated axillary bud) and proliferation was achieved when MS medium was fortified with a relatively higher level of BAP (2xa0mgu2009l−1) and 60xa0mgu2009l−1 ADS within 27xa0d of multiple shoot culture. A maximum number of well-developed roots per plant was observed in MS medium with 0.5xa0mgu2009l−1 IAA in the next 26xa0d. In the easy low-cost acclimatization process of 20xa0d, a combination of sand, soil, cow urine, and tea leaves extract (1:1:1:1; v/v) ensured 95% survival rate. Sixty-one well-acclimatized plants were obtained from a single shoot tip within 86xa0d. The sustained multiple shoot culture for 15xa0mo paved the way toward the conservation of genetic resources as well as beneficial economics. The clonal fidelity study of micropropagated and sustained cultured clones using ISSR primers ensured the continuous supply of quality propagules retaining genetic uniformity. The in vitro-generated plants performed better over conventionally propagated plants in the field condition.