Showing 3 results for Nekoei
Bahram Sharifnabi, Asghar Nekoei,
Volume 1, Issue 2 (fall 1997)
Abstract
In order to study fungi associated with seeds of sainfoin, several seed samples of sainfoin were collected from Isfahan, Ardabil, Zanjan and eastern Azerbaijan provinces, Iran. Seed lots, only half of which were surface sterilized, were allowed to grow on PDA, SMA, MA, sterilized wet paper and drenched sands. The dishes containing seeds were incubated at 25°C with alternate cycles of 12-hour fluorescent light. After seven days, fungi growing from the seeds were transferred to the selective media and subjected to morphological studies. Single spore or hyphal tips from these transfers were the basis for all identification procedures. The most prevalent fungi associated with sainfoin seed were Alternaria, Aspergillus, Penicillium and Rhizopus, although Ulocladium, Cladosporium, Fusarium, Mucor, Nigrospora, Stemphylium, Trichothecium and Botrytis were also isolated in low incidence from these seed lots. The isolates of Uromyces and Oidiopsis were also obtained when the seed samples were examined by washing method.
Sayed Farhad Mousavi, Mohammad Nekoei-Meher, Mohammad Mahdavi,
Volume 2, Issue 2 (summer 1998)
Abstract
As unit hydrograph is an important item in flood estimation of the rivers and since flood hydrograph and simultaneous rainfall hyetograph is needed to derive a unit hydrograph, hydrologists recommend synthetic unit hydrographs for areas lacking these hydrometeorological data. A research was conducted in the Zayandehrud-dam watershed (Pelasjan sub-basin) to test the efficiency of synthetic unit hydrographs (Snyder, SCS, and Triangular methods) in hydrological evaluations. For the purposes of this study, natural and synthetic unit hydrographs were determined and compared, using all morphologic, hydrometric and rainfall data. The results showed that Triangular and SCS methods fit natural unit hydrographs better than Snyder method does, but peak instantaneous flow is estimated to be higher than the observed flow. So, the constant 2.083 in peak flow equation is recommended to be changed to 1.74 in this watershed. The Snyder method predicts good peak flows, compared with the other two methods. Generally, it is concluded that Triangular, SCS, and Snyder methods are ranked 1 to 3 for determination of synthetic unit hydrographs in this watershed.
M Ebrahimi, S.m Khayam Nekoei, S Kadkhodaei,
Volume 12, Issue 46 (fall 2009)
Abstract
Somatic embryogenesis is affected by several factors. In this research project, we studied the effect of explant size, wounding and desiccation treatments on somatic embryogenesis and their conversion into plantlet among three genotypes of soybean. The explants were sampled from immature embryos of soybean in three different sizes (3, 5 & 7 mm) with wounding treatment on half of each, and then were cultured on the somatic embryogenesis medium. In order to determine desiccation effect on conversion amount of embryos into plantlets, the produced embryos were affected by three levels of desiccation treatments (2, 4 & 6 days). The increase ratio of callus mean weight, percentage of embryogenic calli, embryo number per explant and percentage of embryo conversion to plantlet were used for treatment evaluation. Variance analysis of the data showed significant differences (P<0.01) between treatments regarding the variables. The results indicated that BP was a superior genotype with embryogenic capability (24.19 %) and the best explant size for somatic embryogenesis was immature embryo with 3 mm length. The six day desiccation treatment caused highest percentage of embryo conversion into plantlet (74.7 %). Wounding increased callus production on explants and number of embryos per explant (20.28), but it did not show any significant effect on percentage of embryogenic calli. Germinated somatic embryos were transferred to pots containing peat-moss. Somatic embryogenesis is an efficient method for the plant regeneration and genetic transformation. However, this method still offers low percentages of plant regeneration, and is perhaps related to the maturation process and high morphological abnormalities of the matured embryos. This study aimed to find some solutions for soybean somatic embryogenesis problems.
