10,073 research outputs found
Effect of Growth Media on Seed Germination and Seedling Growth in Papaya (Carica papaya L.) Cv. Red Lady
The study was carried out to explore the effect of growth media on seed germination and seedling growth in papaya cv. Red Lady. Three types of media with three levels of cocopeat were studied. The experiment was laid out in Completely Randomized Design, with nine treatment combinations, and replicated thrice. Results showed that the medium Vermicompost + Sand + Pond soil (1:1:1) with 2cm cocopeat layer on top of the polybag (T9) gave highest germination rate (92.71%), maximum speed of emergence (493.34), highest seed vigour (89.33), maximum germination index (7.18), highest germination value (25.58), the least time required for imbibition (9.37 days) and minimum time taken to germination (3.22 days). Medium T9 was also found to be the best for growth of 'Red Lady' papaya seedlings as it gave the highest values for seedling growth parameters like seedling height (23.05cm), leaf area (339.26cm2), number of leaves (9.84), stem diameter (3.32mm), number of roots (16.68), root length (9.93cm), total biomass (4.89g plant-1) and lowest root/shoot ratio (0.21). This treatment significantly reduced seedling mortality and produced maximum number of healthy seedlings (92.69%) in minimum number of days (35.24), showing the highest net profit (Rs. 3470.65/1000 seedlings) and benefit:cost ratio (1.84) seedling production
Composition of Jupiter irregular satellites sheds light on their origin
Irregular satellites of Jupiter with their highly eccentric, inclined and
distant orbits suggest that their capture took place just before the giant
planet migration. We aim to improve our understanding of the surface
composition of irregular satellites of Jupiter to gain insight into a narrow
time window when our Solar System was forming. We observed three Jovian
irregular satellites, Himalia, Elara, and Carme, using a medium-resolution
0.8-5.5 micro m spectrograph on the National Aeronautics and Space
Administration (NASA) Infrared Telescope Facility (IRTF). Using a linear
spectral unmixing model we have constrained the major mineral phases on the
surface of these three bodies. Our results confirm that the surface of Himalia,
Elara, and Carme are dominated by opaque materials such as those seen in
carbonaceous chondrite meteorites. Our spectral modeling of NIR spectra of
Himalia and Elara confirm that their surface composition is the same and
magnetite is the dominant mineral. A comparison of the spectral shape of
Himalia with the two large main C-type asteroids, Themis (D 176 km) and Europa
(D 352 km), suggests surface composition similar to Europa. The NIR spectrum of
Carme exhibits blue slope up to 1.5 microm and is spectrally distinct from
those of Himalia and Elara. Our model suggests that it is compositionally
similar to amorphous carbon. Himalia and Elara are compositionally similar but
differ significantly from Carme. These results support the hypotheses that the
Jupiter irregular satellites are captured bodies that were subject to further
breakup events and clustered as families based on their similar physical and
surface compositions
Research Notes : United States : Measured and predicted yield response of soybeans to simulated acid rain
Modern soybean cultivars in the U.S. are highly related within the northern and within the southern maturity groups and they trace their genetic constitution to a small number of ancestral lines. On the other hand, there is much less genetic relationship between northern cultivars and southern cultivars. Examples of this can be seen in Figure 1, which shows the ancestral relationships among selected lines and cultivars developed from the northern and southern germplasm pools, respectively
Pollen Viability and Seed Setting in Egyptian Clover Under Open and Caged Conditions
Grown on an area of about 200Kha annually, Egyptian clover (berseem) is the most important winter forage crop of Punjab. Its seed production is erratic due to several factors, including high temperature during flowering, which may affect pollen viability and the role of insect pollinators. Hence, berseem seed production is an entomological problem as much as a botanical one. We studied pollen viability under open and caged conditions, and the role of honeybees in seed setting
Studies on Physico-Chemical, Sensory and Microbiological Quality of Kinnow Juice Blends under Refrigerated Storage
Various fruit juice blends were prepared as (i) Kinnow juice:Aonla juice:Ginger juice in 100:0:0; 95:5:0; 92:5:3 ratios and Kinnow juice:Pomegranate juice:Ginger juice in 90:10:0; 87:10:3 ratios for improving flavour, palatability, nutritive value and medicinal value. The juice blends were preserved by pasteurization at 75°C or 85°C for 15 minutes, and, by adding potassium meta-bisulphite (KMS) at 500 or 750 ppm. These blends were stored in 200ml colourless glass bottles under refrigerated conditions (4±1°C) for six months and tested at three month intervals for physicochemical sensory quality and microbial population. Individual effect of juice blending ratio, processing temperature and KMS treatment was found to be significant for prolonging storage life and for maintaining an acceptable quality of the juice blends. The blend of Kinnow:Pomegranate:Ginger juice at 87:10:3 ratio, followed by Kinnow:Aonla:Ginger juice @ 92:5:3, processed at 75°C for 15 min with 750 ppm KMS, was the most effective for obtaining superior physico-chemical and sensory quality of the blend. However, minimum microbial population was recorded in the juice processed at 85°C (and not 75°C) with the same treatment combination
Synthetic (p)ppGpp analogue is an inhibitor of stringent response in mycobacteria
Bacteria elicit an adaptive response against hostile conditions such as starvation and other kinds of stresses. Their ability to survive such conditions depends, in part, on stringent response pathways. (p)ppGpp, considered to be the master regulator of the stringent response, is a novel target for inhibiting the survival of bacteria. In mycobacteria, the (p)ppGpp synthetase activity of bifunctional Rel is critical for stress response and persistence inside a host. Our aim was to design an inhibitor of (p)ppGpp synthesis, monitor its efficiency using enzyme kinetics, and assess its phenotypic effects in mycobacteria. As such, new sets of inhibitors targeting (p)ppGpp synthesis were synthesized and characterized by mass spectrometry and nuclear magnetic resonance spectroscopy. We observed significant inhibition of (p)ppGpp synthesis by Rel(Msm) in the presence of designed inhibitors in a dose-dependent manner, which we further confirmed by monitoring the enzyme kinetics. The Rel enzyme inhibitor binding kinetics were investigated by isothermal titration calorimetry. Subsequently, the effects of the compounds on long-term persistence, biofilm formation, and biofilm disruption were assayed in Mycobacterium smegmatis, where inhibition in each case was observed. In vivo, (p)ppGpp levels were found to be downregulated in M. smegmatis treated with the synthetic inhibitors. The compounds reported here also inhibited biofilm formation by the pathogen Mycobacterium tuberculosis. The compounds were tested for toxicity by using an MTT assay with H460 cells and a hemolysis assay with human red blood cells, for which they were found to be nontoxic. The permeability of compounds across the cell membrane of human lung epithelial cells was also confirmed by mass spectrometry
Prospects of Kenaf as an Alternative Field Crop in Virginia
Kenaf (Hibiscus cannabinus L.), a warm-season annual plant, has shown potential as an alternate source of fiber in the United States. Although preliminary research has indicated feasibility of kenaf production in Virginia, production details are lacking. Field experiments were conducted during 1995 and 1996 to determine optimal row spacing and fertilizer needs, and to compare available kenaf cultivars. Although results indicated that differences in dry matter yields from four row spacings (30, 60, 90, and 120 cm) and four rates each of N, P, and K fertilizers (50, 100, 150, and 200 kg ha-1) were not statistically different, the yields were adequate ranging from 8.8 to 16.0 t ha-1 with an average yield of 12.5 t ha-1. Dry matter yields for narrow-leaf cultivars proved superior to broad-leaf, and the overall results demonstrate that kenaf can be easily produced in Virginia
The challenges and possibilities of earthquake predictions using non-seismic precursors
Open Access via the Springer Compact AgreementPeer reviewedPublisher PD
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