European Journal of Academic Essays

1-5

Authors: Helal Ragab Moussa and Mohamed Abd El-Rahman EL-Galad

Abstract: Salinity stress is one of the most devastating stressful environments for plant growth and production. Two Zea mays cultivars, salt sensitive (Trihybrid 321) and salt tolerant (Giza 2), were grown in a complete nutrient solution in a growth room, to investigate the effect of silicon treatment, as Na2SiO3 (2.5 mM) on plants grown at two levels of salinity, 0.0 (Control), 150 mM of NaCl (S) which are equivalent to 15.5 dS m-1 , and supplied to the nutrient solution. Maize plants (Giza 2 and Trihybrid 321) grown at 15.5 dS m-1 show a decreased in the chlorophyll (a+b), carotenoids, total protein contents, transpiration rate, relative water content (RWC), enzyme activity of ribulose-1,5-bisphosphate-carboxylase/oxygenase (RuBPCase), photosynthetic activity ( 14CO2-assimilation) and macronutrient level (N, P, and K) as compared to the control plants. The results indicated that silicon (Si) treatment at 2.5 mM partially offset the negative impacts and increased tolerance of maize (Giza 2 and Trihybrid 321) to salinity stress by enhancing the above parameters. In contrast, salt stressed maize plants considerably increased proline content, Na+ and Clˉ levels, H2O2, malondialdehyde (MDA), and electrolyte leakage (EL). Application of silicon (2.5 mM) decreased significantly these parameters as compared to salt stressed maize plants. Salt tolerant (Giza 2), treated with silicon at 2.5 mM showed better performance than salt sensitive (Trihybrid 321). Salt tolerant (Giza 2), exhibited lower accumulation of Na+ and Clˉ levels, H2O2, MDA, and EL more than salt sensitive (Trihybrid 321). Overall, exogenously applied Si was found beneficial for improving salt tolerance of maize plants

10-14

Authors: A.S Ogungbe, C.O Ogabi A.A Alabi and O.O Ometan

Abstract: Heat retention in salt water and fresh water was compared with a view to identifying the one that is best at retaining heat. To achieve this, 150 ml and 100 ml of distilled water at room temperature (29oC) were heated separately to 100 oC (boiling point). Measured values (5g, 10g and 15g) of table salt were each added to 100 ml and 150 ml of distilled water to reach a level of salinity and the solution was heated to boiling point. A cooling system was set up to continuously mix the solution during cooling process to maintain uniform temperature and mercury-in-glass thermometer was used to record the temperature drop at every 10 minutes interval. The graphs of the temperature against time were plotted using Matlab to obtain the cooling rate. The results showed that the salt water has the capacity to retain more heat than the fresh water, and the concentration of salt in salt solution also determines the heat retention ability.

23-28

Authors: BhatTariq A, WaniAijaz A

Abstract: Cytological and genetical behaviors of two desynaptic plants induced in Viciafaba L. var. minor by Ethyl methane sulphonate treatment have been studied. Analysis of chromosomal behavior at different stages of meiosis has been thoroughly accomplished in the desynaptic plants. At diakinesis in one plant univalents and bivalents were present while in other multivalents along with univalents and bivalents were also noticed. Bivalents were randomly distributed in one plant while non-random in the other. Abnormalities like univalents, irregular distribution of chromosomes, laggards, stikiness, bridges and micronuclei were also observed at metaphase, anaphase and telophase respectively. Meiotic studies revealed that sterility was due to irregular chromosome pairing but the genetic data indicated that sterility was because of single recessive gene in homozygous condition. The desynapsis obtained during the present investigation fit into the medium strong type.