Journal of Applied Biology
Year:2000 | Volume:13 | Issue:2|Papers Count:7

Papilla diameter of glume and lemma and pit number at the base of papillae were studied for 12 species of Aegilops in Iran. In most species a positive relationship was seen between papillae diameter and their pit number. In some species pit number was equal to papillae diameter but sometimes as in Aegilops triuncialis it was less than papillae diameter.

Potato (Solanum tuberosum L.) is a valuable crop plant for agriculture, industry and medicinal products. Micropropagation of this plant via tissue culture technique results in pathogen free plants especially viruses. Accumulation of ethylene in closed culture vessels is a known problem for potato, in vitro culture. It has been reported that, ethylene decrease the leaf surface, dry weight or increase root initiation on stem. In this study, when 80 µM silver thiosulfate (STS) as ethylene action inhbitor was added to culture medium the leaf surface area, dry weight and total chlorophyll were increased. Root initation on stem with application of STS in the medium decreased. It also increased the number and weight of tubers. Inhibition of ethylene action by STS improved the growth and development of potato tissue culture via induction of cell division and interaction with GA3. Therefore STS can be recommended for normal potato multiplication.

Ethleneglycol (EG) and Di( ethyleneglycol) = (D.E.G) have the widespread use, EG is used in preparing synthetic fiber, anti-freeze, explosive materials, textile and paper industries, leather, etc. Therfore, identifying microorganisms consuming these products is very important and extermiation of the materials which are composed of EG. or D.EG, and left over after being used and may pollute the environment is necessary. In this research, The first step was the isolation and identification of P. aeruginosa using EG and D.E.G, and second step was the determination of quality of these materials being used by this microorganisme by microbiological methods as serial dilution tubes method, production of colony in the minimum agar + EG or D.EG as the sole carbon and energy source. The results showed that the strain of P. aeruginosa can survive and grows in a medium having concentration up to 30 mg/ml E.G and up to 5 mg/ml D.E.G. Determination of Quantity of these materials used by this microorganism in different intervals by gas chromatography method.

Inoculation experiments in pot culture were carried out to study the effects of vesicular-abuscular mycorrhizal fungi on the growth of Bromus. Four treatments were used to carry out this experiment; 1. strile soil plus inoculum, 2. strile soil without inoculum. 3. natural-non strile soil without inoculum and 4. naural-non strile soil plus inoculum. The source of inoculum was prepared from a suspension of mycorrhizal roots of Bromus (with root colonization at 45 percent level). Ptants were harvested after five month from the inoculation time. Some growth characteristics such as the hight of the plant, the number of the leaves, the surface of the leaf, the diameter of the stem, the dry weight of the whole plant, the shoot to root ratio, the amount of phosphoorus of the plant tissue, the percentage of the root colonizatin, the number of spores and available phosphorus level of the soil were measured. The results showed an increase in growth of inoculated plants as compared with non-inocuated plant. The available phosphorus level in inoculated soils were lower than the non-inoculated soils, which indicated increasing phosphorus uptake by inoculated plants. From inoculation experiments in pot culture two species of VA fungi were identified as being symbions of Bromus namely; Glomus fasciculatum and Glomus geosporum.

The electrical response of olfactory bulb to olfactory nerve or lateral olfactory tract stimulation is characterized by oscillating field potencials which reflect the activity of the various cellular components of this structure. In this study this oscilations were employed to determine the characteristics of development in normal bulbs of postnatal rats. The results revealed that although prior to day 10, some weak oscilations can be forced to appear specially by double stimulation, the onset of mature characteristic is oscilation occurs at this age and exhibits adult appearance by day 15. Based on the characteristics of the response, it was concluded that: The mitral to granular synapses mature before the granule to mitral synapses (about day 4)