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In vitro propagation of Dendrobium aphyllum (Orchidaceae)—seed germination to flowering
No full textThis communication describes asymbiotic seed
germination, protocorm development, micropropagation
and flowering in in vitro and hardened seedlings of Dendrobium
aphyllum (Roxb.) C.E.C. Fischer. Effects of four
culture media viz., Murashige and Skoog (MS); Phytamax
(Sigma Chemical Co. USA; PM); Mitra et al. (M) and
Knudson ‘C’ (KC), 6-benzylaminopurine (BAP) and 2,4-
dichlorophenoxyacetic acid (2,4-D), peptone and activated
charcoal were studied on seed germination and protocorm
development. Maximum germination (97 %) was recorded
in PM basal medium. Peptone (2.0 gl−1) remarkably enhanced
germination percentage (100 %), vigorous growth,
high survival and subsequent development of protocorms,
while in activated charcoal the response was not encouraging.
BAP improved germination percentage, however, 2,4-D
showed noticeably low seed germination. The morphogenetic
response of protocorms and nodal segments of in vitro
raised seedlings varied depending on type of explants and
concentrations and combinations of plant growth regulators
used. Stout root system was induced in 1/2PM + 0.5 mgl−1
IAA. Approximately 10 % of the in vitro raised plants (4–
5 cm) with 3–4 leaves flowered in vitro irrespective of
flowering season. The well-rooted plants showed 80 % survival
under green house conditions and flowering was noticed
after 5–6 months in 10 % of hardened plants
Spatial and Temporal Variation of Secondary Metabolite Profiles in Ginkgo biloba Leaves1)
No full textTerpene trilactones (TTLs) are the main bioactive constituents of Ginkgo biloba used for the
preparation of drugs for several ailments. Flavonoid glycosides (FGs) are the significant group of
compounds found in Ginkgo leaves used in food and healthcare products. The variation in the content of
bioactive constituents, as well as antioxidant activity, with respect to change in altitude and the time of
sample collection was investigated. The amount of TTLs varied from 0.218–0.709% w/w, whereas FGs
were observed in the range of 0.130–0.209% w/w. Ginkgolides J and A showed significant variation (p� 0.05) with the change in altitude, while other components remained more or less unaffected. The amount
of TTLs and FGs were not affected significantly by the time of sample collection. The antioxidant
capacity (by using DPPH, ABTS, and FRAP assays) of ginkgo extracts was highly dependent on the
altitude, and was at maximum in the samples collected from 1000–2000 m, followed by the samples
collected from altitudes lower than 1000 m and higher than 2000 m. Thus, Ginkgo harvested from 1000–
2000 m of altitudinal range irrespective of the season could provide better nutraceutical formulations,
whereas that from below 1000 m may yield a terpene trilactone-enriched fractio
Determination of Major Viral and Sub Viral Pathogens Incidence in Apple Orchards in Himachal Pradesh
No full textApple is the major commercial horticulture
crop in Himachal Pradesh and other hill states of Jammu &
Kashmir, Uttarakhand and some parts of Northeastern
states of India. In order to gather data on health status and
incidence of virus and virus-like pathogens in apple orchards,
survey was conducted in the month of June and
September, 2010 in Hatkoti, Rohru, Kuthara, Jubbal and
Khadapathar areas of major apple producing Shimla district
of Himachal Pradesh. A total of 250 samples were
collected and analyzed by DAS-ELISA, NASH and RTPCR.
NASH results indicated that a total of 117 samples
were infected with Apple chlorotic leaf spot virus (ACLSV),
Apple mosaic virus (ApMV), Apple stem grooving
virus (ASGV), Apple stem pitting virus (ASPV) and Apple
scar skin viroid (ASSVd). Results showed that ASSVd is
predominant in these areas with highest infection rate of
27.6% followed by ASPV (17.2%), ACLSV (16.8%),
ApMV (15.2%) and ASGV (12%). Mixed infection of
these viruses and viroid was frequently detected in apple
trees in Himachal Pradesh. The trees, which were positive
for viruses and viroids, showed a variety of fruit deformation
and rusting symptoms besides leaf deformation,
mosaic and chlorosis
Long-term ecological and biodiversity monitoring in the western Himalaya using satellite remote sensing
No full textThe IPCC in its Fourth Assessment Report (AR4)
described the Himalayan Region as data-deficient in
terms of climate monitoring. This is a serious impediment
to global research initiatives and thus necessitates
long-term ecological monitoring (LTEM) across
the Himalaya. Being governed by low temperature
conditions, the high-altitude regions in Himalaya are
more responsive to changing environmental conditions
and hence serve as better indicators. We identified few
Protected Areas (PAs) and selected forest core area
and ecotones along the temperate, sub-alpine, alpine
and cold desert ecosystems in Himachal Pradesh to
establish a network of permanent monitoring plots
(PMPs). Land and vegetation cover map of three
selected PAs has been prepared using Landsat TM
satellite data. Among the 10 PMPs, the temperate and
tree line forests in the GHNP were found to have the
highest tree diversity with Taxus wallichiana showing
good stand density and regeneration. The soil pH was
found to be higher for cold desert and lower for tree
line forests and alpine meadows. Soil total carbon and
nitrogen contents ranged from 1.08% to 13.37% and
0.094% to 1.14% respectively. It was observed that
the herbs diversity showed a positive trend with
increasing soil carbon and nitrogen concentrations.
Satellite remote sensing proves to be a useful tool in
an LTEM study, including biodiversity assessment
and climate change research in complex terrains such
as the Himalaya
Nickel Phthalocyanine Assisted Highly Efficient and Selective Carbonyl Reduction in Polyethylene Glycol-400
No full textNickel phthalocyanine with polyethylene glycol-
400 is described as a reusable green catalytic system
for highly chemo- and regioselective reduction of carbonyl
compounds to corresponding alcohols at room temperature.
The catalytic system showed wide substrate scope covering
aromatic, hetero aromatic and aliphatic carbonyl compounds
with high turnover number and frequency. In the
present study, 1,3- and 1,4-benzenedicarbaldehydes have
been regioselectively reduced to corresponding alcohols
for the first time. The catalyst was reused up to seven times
without any significance loss in activity
Selection of a compatible biocontrol strain mixture based on co-cultivation to control rhizome rot of ginger
No full textRhizobacteria and Trichoderma spp. that were antagonistic against Fusarium oxysporum f.sp. zingiberi and
Pythium splendens inciting rhizome rot disease of ginger were identified. In vitro assays identified positive
interactions for growth, antifungal and chitinase gene expression between antagonistic TEPF-Sungal
(Burkholderia cepacia) and S2BC-1 (Bacillus subtilis) with S17TH (Trichoderma harzianum), and vice
versa. In comparison with the other strains and strain mixtures, one strain mixture, TEPFSungal
þ S17TH, recorded a maximum rhizome production of 84% efficiency with less incidences of
yellows and rhizome rot at an 84.2 and 79.7% reduction over the pathogen control, respectively, in
a polyhouse with a challenge inoculation with the pathogens. Inoculation of the mixture of biocontrol
agents was associated with an increase in known defence gene products such as chitinase etc., so we
speculate that these are involved in the mechanism of disease suppression. In field experiments, the
strain mixture reduced yellows and rhizome rot to 45.9 and 49.3% over the untreated control, respectively,
which is comparatively better than that produced with fungicide (44.3 and 45.3%, respectively).
The treatment also produced an increased rhizome yield with an average increase of 60.0% relative to the
contro
Synthesis of substituted amines and isoindolinones: catalytic reductive amination using abundantly available AlCl3/PMHS
No full textAlCl3 has been employed for highly chemoselective reductive amination of carbonyl compounds in
ethanol using polymethylhydrosiloxane as an inexpensive, stable and safe reducing agent without an inert
atmosphere. A large range of functional groups such as nitro, carboxylic acid, acetyl, nitrile, halogen,
methoxy, alkene and heterocycles were well tolerated. AlCl3 also catalyzed tandem amination–amidation
of 2-carboxybenzaldehyde with different amines to afford N-substituted isoindolinones. The catalyst can
be recycled at least three times without any significant effect on activity and selectivity
Diversity and regeneration status of tree species in Khokhan Wildlife Sanctuary, north-western Himalaya
No full textThe Khokhan Wildlife Sanctuary (KhWLS) located in the Kullu district of
northwestern Himalaya and covering an area of 14 km2 has not been explored for documenting
the structure and composition of vegetation. In this study we examine the site/habitat
characteristics, assess the diversity of tree species, delineate forest tree communities, assess the
regeneration pattern of tree species, and suggest conservation measures. Sixty-five sites were
sampled between 1640 - 2400 m asl and for each site, habitat characteristics, altitude and
dominant species were noted. Seventeen forest tree communities were recorded. Cedrus deodara
community was the most widely distributed followed by Quercus leucotrichophora, Abies
pindrow and Quercus semecarpifolia communities. Cedrus deodara community had maximum
density of trees (1468 Ind ha-1), seedlings (1290 Ind ha-1) and saplings (1172 Ind ha-1), while
Picea smithiana community recorded the maximum total basal area (186.2 m2 ha-1). Of the 17
forest tree communities identified, eight showed maximum regeneration of the dominant
species, six showed maximum regeneration of the co-dominant species indicating the possibility
of at least partial replacement of the dominant species by the co-dominant species in the future;
and three communities showed poor or no regeneration of the dominant species indicating a
total replacement of the dominants in the coming years. Long term monitoring of these tree
communities for their conservation management is suggested
Steviol Glycosides from Stevia: Biosynthesis Pathway Review and their Application in Foods and Medicine
No full textStevia rebaudiana, a perennial herb from the Asteraceae family, is known to the scientific world for its sweetness and steviol
glycosides (SGs). SGs are the secondary metabolites responsible for the sweetness of Stevia. They are synthesized by SG
biosynthesis pathway operating in the leaves. Most of the genes encoding the enzymes of this pathway have been cloned
and characterized from Stevia. Out of various SGs, stevioside and rebaudioside A are the major metabolites. SGs including
stevioside have also been synthesized by enzymes and microbial agents. These are non-mutagenic, non-toxic, antimicrobial,
and do not show any remarkable side-effects upon consumption. Stevioside has many medical applications and its role
against diabetes is most important. SGs have made Stevia an important part of the medicinal world as well as the food and
beverage industry. This article presents an overview on Stevia and the importance of SGs
Understanding crop-ecology and agronomy of Rosa damascena Mill. for higher productivity
No full textCrop-ecology and agronomic factors are the major determinants of crop growth and development. Medicinal and aromatic plants synthesize and store a variety of biochemical compounds. The secondary metabolites of Rosa damascena are used in the pharmaceutical, flavours, and fragrance industries. The rising demand of essential oil is causing an accelerated replacement of natural fragrance by synthetic fragrance. Out of 200 species of the genus Rosa, the R. damascena is the important essential oil bearing plant. The content and relative composition of major components of rose oil predominantly depend on temperature, light, soil, pruning, nutrient supply, harvesting time and other management factors. Natural rose oil is most expensive in the world market as compared to its synthetic substitute, and the global demand of high grade rose oil is likely to increase in near future. In order to meet the rising demand, reconciliation of crop-ecological and agronomical approaches is required. Thus, there is pressing need to understand how these two factors and their interaction would provide noble strategies to stabilize yield of R. damascena in fluctuating environment. We do not attempt comprehensive review on R. damascena, rather we focus on crop ecology and agronomy, which determine the yield of flower and secondary metabolites