An Absolute Review on Oxalis corniculata Linn. - International ...

International Journal of Research in Pharmaceutical and Biomedical Sciences ISSN: 2229-3701
manual hoeing), two types of weeding on inter-row
(with or without manual hoeing), and four nitrogen
levels applied after planting (00, 60, 90, and 120 kg
yield at harvesting. Plants and first ear insertion
height were affected when nitrogen fertilizer was not
applied. Treatments without weed control showed
that weed interfered negatively with plants height.
There were no correlation between weeds and
nitrogen fertilizer for all parameters evaluated.
Parcels without weed howed the highest ear weights
and final grain production. Treatments that received
nitrogen fertilizer, independently of studied
arrangement, provided higher yields 47 .
Oca (Oxalis tuberosa Mol.) is an under-utilized tuber
crop from the <strong>An</strong>dean region. A protocol for the
cryopreservation of in vitro grown shoots has been
developed using the vitrification solution PVS2. Two
genotypes were studied (G1 and G27). Nodal
segments were cultured on MS medium and
incubated at 10 degree C with 16 h photoperiod and
10 mol per square meter per second irradiance, for
two weeks. Apices were then excised and cultured on
MS+0.15 M sucrose for 3 days at 5 degree C in
darkness. Subsequently, apices were immersed in a
loading solution (liquid MS medium+2 M
glycerol+0.4 M sucrose), and then treated with the
vitrification solution PVS2 for 0 to 40 minutes.
Cryovials were then immersed in liquid nitrogen.
Four weeks after rewarming and culture on recovery
medium, genotype G1 showed approximately 60
percent recoveries (normal growth) with 20 min
PVS2 treatment. Genotype G27 showed lower
recovery (30 percent). Differential scanning
calorimetry yielded a TG midpoint for PSV2 solution
of ca. -120 degree C. Calorimetric studies on apices
at different stages of the cryopreservation protocol
showed a change in calorimetric parameters
consistent with a decrease in the amount of frozen
water as the protocol advanced 48 .
ECOLOGY
Changes in plant affinity to communities of different
types are viewed by the example of the North-
European forest studied in 1993-2001. Species
occurring near their range limits prefer habitats with
smoothed amplitudes of minimum factors ("the law
of preference for non-varying environments"). That's
why Oxalis acetosella and other boreal-nemoral
species demonstrate affinity to riparian forests of the
middle-boreal. Plant dispersal could be rather fast in
the course of the corresponding primary succession
following the glacier retreat or the marine
retrogression (the "impulse" hypothesis). Since the
climax pattern is established running waters and
disturbed lands serve as "migration channels" for
plant 49 .
The reproductive components of plant invaders have
mostly been studied in species reproducing sexually
but little is known about invaders that depend
exclusively on vegetative reproduction. In this paper,
the importance of the different recruitment stages on
population growth is quantified and, thus, the
invasion potential of the South African annual
geophytes Oxalis pes-caprae invading Mediterranean
ecosystems is assessed .Oxalis pes-caprae has a
transient bulb bank that remains dormant in the soil
during summer. High levels of bulb predation after
dispersal, followed by bulb mortality during summer
or a failure to germinate in autumn were the most
critical factors limiting plant establishment. Bulb
germination was high. However, plant establishment
and bulb production is constrained by intraspecific
competition, but is not affected by soil disturbance.
No symptoms of spatial discordance could be found
between recruitment stages because the spatial
variability of the life cycle was extremely low at all
the scales examined (i.e. among populations, habitats
and microsites). It was estimated that, on average, 4
% of bulbs can become plants the following year and
the field rate of population increase (lambda) to be
0.08. The results suggest that invasion is constrained
by post-dispersal bulb predation, loss of viability of
the propagule bank due to summer drought and high
intraspecific competition. However, a high spatial
concordance between recruitment stages and
probably a high propagule pressure due to human and
livestock bulb dispersal determine the success of this
invader across Menorca Island 50 .
There are two large oil shale fueled power plants,
Baltic PP and Estonian PP. On burning oil shale the
main atmospheric pollutants are fly ash, sulphur
oxides and nitrogen oxides. The radial increment was
measured and concentrations of Ca and Cu were
estimated in the stemwood of Scots pine (Pinus
sylvestris L.) from four sites in the influence area of
the Narva power plants. Increment cores were taken
also from two sites in an unpolluted area located 112
and 120 km northwest from the Estonian PP. The
stands selected for investigation were similar as to
their edaphic conditions and forest survey indicators
(75- to 80-year-old (Oxalis-) Myrtillus-type pine
stands of 0.7-0.8 density and of quality class II). The
strongest effect of air pollution on radial increment
was observed on the sampling site in the direction of
dominating winds at a distance of 22 km to northeast
from the Estonian PP. Using the annual rings, the
core samples were divided into five-year sections
(1945-1949; 1950-1954 etc.). The concentration of
Ca increased and that of Cu decreased from the
youngest, outermost annual rings towards the centre
of the stem 51 . The cavermiculatus andinus n.sp.is
described and illustrated from Oxalis tuberose
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