Romanian Journal of Biology - Plant Biology
Volume 57, No. 1, 2012
1. POTENTIALLY PHYTOTOXIC EFFECT OF AQUEOUS EXTRACT OF Achillea santolina INDUCED OXIDATIVE STRESS ON Vicia faba AND Hordeum vulgare
pp. 3 - 25
S.M. DARIER, A.A. TAMMAM
Determining the mode of action of allelochemicals is one of the challenging aspects in the allelopathic studies. Recently allelochemicals have been proposed to cause oxidative stress in target tissue and induced an antioxidant mechanism. Achillea santolina is widely distributed in northern western desert of Egypt, it grows well in crop fields under fig and olive trees. A field survey during spring 2008 indicated that the considered species exhibited a deleterious effect on the performance and yield of non tillage broad bean and barley field in the region. Aqueous shoot extracts of Achillea santolina decreased chlorophyll a and b levels, increased carotenoid content, increased levels of CAT, GPX, SOD and GR activity. (APX) increased up to 8% concentration of Achillea extract, a decrease at higher concentrations indicating the enhanced generation of reactive oxygen species (ROS) upon Achillea santolina exposure. Increased level of glutathione indicates their induction as secondary defence mechanism in response to Achillea santolina extract. Data revealed that broad bean was more sensitive to Achillea aqueous extract than barley. In conclusion, reactive oxygen species accumulation caused cellular damage despite the activation of the antioxidant system by Achillea santolina phytotoxins. There was an interspecies difference in the recognition of allelochemicals between Vicia faba and Hordeum vulgare. In order to determine the allelopathic potential against the two tested species, the experiment of decaying residues bioassay and test the soil under pure stand of Achillea santolina was conducted. Residues of Achillea santolina inhibited the growth of Vicia faba and Hordeum vulgare aqueous extract of residues of Achillea santolina soil inhibited seedling length of both plants. The phytotoxicity started after one week of decomposition and persisted for 6 weeks.
2. MERCURY INDUCED GENOMIC DISTURBANCE AND FLOWERING INHIBITION IN SESBANIA PEA (Sesbania cannabina POIR.)
pp. 27 - 35
G. KUMAR, N. SRIVASTAVA
Sesbania cannabina commonly known as Dhaincha or Sesbania pea is widely adaptable to different adverse climatic conditions. It has been found to be tolerant to heavy metal toxicity. The present investigation reports the result of the effect of mercury on seed germination, plant survival, pollen fertility and microsporogenesis of Sesbania cannabina. The effects of four serial doses of mercuric chloride viz. 25, 50, 100 and 200 ppm were studied. The different concentrations of mercury showed reduction in germination, survival and pollen fertility percentages along with the increase in concentrations. The microsporogenesis of plant also gets adversely affected by mercury treatment and various types of cytological aberrations were recorded and the frequency of different types of aberrations was calculated at each dose.
3. IN VITRO EVALUATION OF ANTIBACTERIAL AND ANTIFUNGAL ACTIVITY OF Jatropha curcas L.
pp. 37 - 42
J. SUNDARI, R. SELVARAJ
In the present study the effectiveness of Jatropha curcas extracts on inactivation of some microorganisms, i.e. gram positive bacteria Staphylococcus aureus and gram negative bacteria Escherichia coli, Klebsiella pneumoniae, Salmonella typhimurium, Pseudomonas aeruginosa and Vibrio cholerae and fungal pathogens, namely Candida albicans, Aspergillus niger, A. flavus, A. fumigatus and Rhizopus sp., were determined. The filter paper disc method was used for screening of crude extracts of leaves of J. curcas for antimicrobial activity. The paper discs saturated with extract were placed on the surface of the sterilized nutrient agar medium that had been inoculated with the test organisms by using a sterile swab. The diameters of inhibition zones were measured after 24 hours of incubation at 37 °C. The ethanol extract of J. curcas leaves was shown the largest inhibition zone (i.e. 18 mm) against S. typhimurium, when compared to other solvent extracts.
4. STUDY OF CITRUS DISEASE PREVALENCE ON FOUR CITRUS VARIETIES AT THE NATIONAL INSTITUTE OF HORTICULTURAL RESEARCH (NIHORT) MBATO, OKIGWE, IMO STATE, NIGERIA
pp. 43 - 49
Studies conducted to determine the prevalence of diseases on four varieties of Citrus, sweet orange (Citrus sinensis), Tangelo (Citrus paradise X Citrus reticulate), grape (Citrus paradise) and lemon (Citrus limon) showed that tangelo and sweet oranges were more susceptible to fungal attack than grape and lemon. Disease symptoms commonly observed included dieback on the four species of citrus as follows: tangelo (65%), sweet orange (60%), grape (55%) and lemon (40%). Effective integrated management practices including use of resistance varieties are recommended.
5. HERBICIDAL COMPARISON BETWEEN NATURALLY GROWING AND IN VITRO REGENERATED BISHOP’S
pp. 51 - 61
Ammi majus is a medicinal plant which has allelopathic and autotoxic effect. It can affect the germination of other species and its germination. To study its herbicidal effect, it was used calluses and somatic embryos were obtained through culturing of explants on modified Murashige and Skoog (MS) solid medium supplemented with different concentrations and various combinations of N6-Benzylaminopurine (RAP) and α-Naphthaleneacetic acid (NAA). The optimum culture conditions of primary callus induction were obtained in the case of culturing hypocotyl explants on MS medium supplemented with 5.37 μM NAA and 2.22 μM RAP. The optimum culture conditions of somatic embryos induction were obtained in the case of sub-culturing the primary calluses on MS medium supplemented with 2.68 μM NAA and 1.11 μM BAP. The aqueous extract treatments showed highly significant differences among the most target species in the sense of seed germination and dry matter inhibition. The aqueous extract of primary callus was the most effective one. The aqueous extract effect of the regenerant plant was superior to the naturally growing one. The sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) protein profile revealed a little difference between micro-propagated plants and naturally growing ones.
6. PHYTOCHEMICAL SCREENING OF Pleurotus tuberregium (Sing) GROWN ON DIFFERENT SUBSTRATES
pp. 63 - 70
C.I. ONUOHA,1 G.A. OBI-ADUMANYA, I.O. EZEIBEKWE1
The Sclerotia of Pleurotus tuberregium (Sing) were grown on four different substrates namely: humus soil, mixture of Sawdust and humus soil, sawdust and shreds of the wood of Treculia africana. The quantity and quality of the fruit bodies produced were measured using the following parameters: number of fruit bodies produced, height of fruit bodies, fresh weight, dry weight, diameter of pileus and length of the stipe. Sawdust which served as the control was better growth medium in terms of length of stipe, number of fruit bodies and height of mushroom. The fruit bodies from a mixture of sawdust and humus soil were better in terms of fresh and dry weight while humus soil alone produced fruit bodies with wider pileus diameter. The wood shreds of Treculia africana did not support the growth of the mushroom. The phytochemical composition of the sclerotium and fruit bodies from the different substrates showed that the sclerotium had more flavonoids, alkaloids, tannins, saponins and phenols than the fruit bodies from the different substrates. There was no significant difference between the alkaloid, tannin, saponin and phenolic composition of the fruit bodies from the different substrates. There was, however, a significant difference at P ≤ 0.05 between the flavonoid content of fruit bodies from humus soil, sawdust and those from a mixture of humus soil and sawdust.
7. ESTIMATION OF GENETIC VARIABILITY, HERITABILITY AND GENETIC ADVANCE IN AROMATIC FINE GRAIN RICE
pp. 71 - 76
A.K. CHAURASIA, PRASHANT KUMAR RAI,1ARVIND KUMAR
A study on genotypes was conducted in Randomized Block Design in three replications under rainy condition during 2010. The data were recorded for 15 qualitative characters viz., days to 50% flowering, number of tillers per hill, number of panicles per m2, number of spikelets per panicles, panicles length, flag leaf length, flag leaf width, plant height, days to maturity, grain yield per plant, grain yield per plot, biological yield, harvest index and test weight to study genetics variability, heritability and genetic advance. Analysis of variance among 41 genotypes showed highly significant differences for yield contributing traits viz., number of panicles per m2, plant height, days to 50% flowering, days to maturity, biological yield harvest index, number of spikelets per panicles. Grain yield per plant, panicles length, flag leaf length, number of panicles per hill, number of tillers per hill, test weight grain yield per plot and flag leaf width indicated the presence as substantial amount of genetic variability in study material and there is scope for selection. On the basis of mean performance yield traits it was conducted that “NDR-9542” was best performer for yield. The results showed higher GCV and PCV in parameters like grain yield per plot, flag leaf width, biological yield, days to 50% flowering and plant height. Maximum heritability was encountered for characters viz. plant height, days to 50% flowering, days to maturity, panicles length and number of panicles per hill. High genetic advance observed in number of panicles per m2, plant height and days to 50% flowering. Thus these characters could be improved by selection in breeding programme for crop improvement.
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