Showing 6 results for Rastegar
K. Noorollahi, M. Falahati Rastegar, B. Jafarpour,
Volume 4, Issue 1 (spring 2000)
Abstract
Four hundred isolates of Ascochyta rabiei (Pass.) Lab. collected from different parts of the country, such as Zarivar Marivan Lake in Kordestan Province Shabestar and Khosroshahr in Eastern Azarbaigan Province Serow, Bokan and Shahindeg in Western Azarbaigan Province Mashhad and Ilam were used in this experiment.
These isolates showed little differences in their cultural and morphological characters and pathogenic behaviors. They were categorized into 17 groups on the basis of collection regions and, based on cultural characteristics, were then reduced to 11 groups. Isolate number 16 from Mashhad showed the highest growth rate while isolate number 1 from Kordestan had the lowest growth rate.
One isolate was chosen as a representative for each group. Pathogenicity of representative isolates from each of the 11 groups were tested. Reaction type of all isolates was studied on differential hosts and one local chickpea line Jam was examined, using Reddy and Nene (1979) method. Races No. 4 and 6 were identified as the two physiologic races.
A. Dariaee, M. Falahati Rastegar, B. Jafarpour,
Volume 5, Issue 4 (winter 2002)
Abstract
This study was carried out on the biochemical aspects of chickpea cultivars and the genomic behavior of A. rabiei pathotypes 4 and 6 in four parts: 1) Determining the number of resistant genes in chickpea native cultivars, 2) Comparing the variation of sodium and potassium electrolytes concentrations in noninfected and infected seedling stems of resistant and susceptible cultivars, 3) Studying the effect of potassium deficiency on five differential cultivars by Hoagland nutrient culture, and 4) Using RAPD-PCR method to detect any genomic differences between the two pathotypes used in this study.
Eighteen native chickpea cultivars were chosen for this study. The result of the experiments showed that cultivar 1-60-144 possesses the highest number of resistant genes, while the others were either relatively tolerant or susceptible. The reduction of electrolytes concentration in infected cultivar ILC-1929 in comparison to resistant cultivar ILC-5928 is an indication of compatibility between the host plant and the pathogen. Increasing the level of resistance in differential cultivars and appearance of induced resistance as the result of potassium deficiency is due to the production of putrecine diamine. Eighty percent similarity of pathotypes genomic bands by using CG marker and primer 171 showed insufficient primer numbers and the necessity for using complementary methods.
F. Shokoohifar, A. Bagheri, M. Falahati Rastegar,
Volume 7, Issue 2 (summer 2003)
Abstract
The poor information available on variation of Ascochyta blight fungus is the most important factor limiting chickpea breeding programs for resistance to blight disease. In this study, efforts were made to detect genetic variation of the pathogen in Iran. The RAPD marker was employed to evaluate 26 isolates collected from 16 provinces. Twelve random primers were used to analyze genomic DNA of the isolates. Only ten primers showed polymorphism among isolates. Primer OPK-01 defined the highest number of polymorphism and primer OPK-09 confirmed relatively low degree of polymorphism. On the basis of this molecular marker, the estimated genetic diversity index was 98% and the pair-wise genetic distance of the isolates varied from 0.16 to 0.61. The least genetic distance belonged to isolates 20 and 22 from Qazvin and Golestan while the highest distance belonged to isolates 26 and 12 from Mazandaran and Markazi. The phylogenic tree was constructed by cluster analysis and all the isolates grouped to 22 genetic clusters at the 90% similarity level. The genetic groups were named from A to V and their distribution in Iran was determined. The results revealed that genetic variation among Iranian population of the pathogen is very high, and further that RAPD is a vigorous tool for genomic analysis of Ascochyta rabiei.
A. Zeynaddini, B. Jafarpour, M. Flahaty Rastegar,
Volume 9, Issue 2 (summer 2005)
Abstract
The study of dispersion of alfalfa mosaic virus (ALMV) infection based on DAS-ELISA indicated that the fields of Alfalfa, potatoes and tomatoes from Chenaran, Ghochan, Shirvan, Mashhad, Neishaboor and Torbat Heydarieh were infected with the virus. The Statistical analysis indicated that the amount of infection did not differ in the surveyed regions and total mean of infection was 53 percent. The samples collected from the Alfalfa field of Mashhad was propagated in the Nicotiana tabacum L.cv Samsun and then virus was purified. The Mechanical inoculation of this isolate of the alfalfa mosaic virus (ALMV) induced the local lesion in Chenopodium quinoa,C. amaranticolor,Vigna unguiculata, Phaseolus vulgaris cv Redkidney and the systemic vein clearing and mosaic in Nicotiana glutinosa, N. tabacum cv. Samsun, Ocimum basilicum, Cicer arietinum and Lycopersicon esculentum. In the case of the infected Cucumis sativus, no symptoms was observed. ALMV was purified by the method of the kaiser and Robertson(1976). The virus yield was 11/05 mg per 100g of infected tissue on the basis of serological properties. This isolate of ALMV is similar to the American isolation in SDS-PAGE and Western Blot analysis,the molecular weight of the virus coat proteins were estimated at about 24000 daltons.in this regard,this isolation of ALMV is similar to the other isolates of ALMV reported elswhere.
S. Rastegar , M. Rahemi,
Volume 11, Issue 42 (winter 2008)
Abstract
Navel oranges and Clementine mandarin are classified as early cultivars and when fruits are left on the trees, fruit firmness and juice content will decrease. Plant growth regulators have been used to improve fruit quality. Gibberellic acid (GA3) and 2,4-D isopropyl ester sprays were used to increase juice content ,peel firmness and delay senescence in Navel oranges and Clementine mandarin. Factorial experiments were arranged in a complete randomized block design with three replications and each block consisted of three trees. Chemicals were sprayed on the branches (north and south of each tree) with 10 liter sprayer to the point of run-off during fall of 2004 and 2005 ,in a commercial orchard in Jahrom in the south east of Fars province, Iran . In both years of study, GA3 at 100,150 and 200 mgl-l and isopropyl ester 2,4-D at 8,12 and 24 mgl-1 were sprayed on September 30 (diameter of Navel 64 mm and diameter of Clementine 46 mm), October 14 (diameter of Navel 69 mm and diameter of Clementine 48 mm ) and November 7 (diameter of Navel 70 mm and diameter of Clementine 50 mm) and fruits of Navel oranges and Clementine mandarin were harvested 45 and 35 days after last the spray treatment, respectively . The results of experiment revealed that Navel oranges responded better with second application (Oct.14, diameter 69 mm ) and Clementine mandarin with the first application (Sept.30, diameter 46 mm ). Juice content and fruit firmness at harvest increased. GA3 increased juice content even better than 2,4-D isopropyl ester but delayed senescence, 2,4-D was more effective in increasing fruit sizing in both cultivars. GA3 at 150 and 200 mgl-1 and 2,4-D at 24 mgl-1 when compared with the untreated resulted in highest juice content of fruits.
E Mahdikhani Moghadam, H Rouhani, M Flahi Rastegar,
Volume 13, Issue 48 (7-2009)
Abstract
Sugar beet cyst forming nematode (Heterodera schachtii) is one of the most important pathogens of the sugar beet in Iran. For biological control of Heterodera schachtii, 10 isolates of Trichoderma related to two species T. harzianum and T. virens were examined in laboratory and green house on eggs and cysts for two years. Results obtained from the laboratory assay showed that isolates of Trichoderma parasitized 60% eggs on average. Among them two isolates T. harzianum Bi and T. virens VM1with % 76.18 and %72.55 parasitism, respectively, showed more efficiency compared with the control. In green house, experiments were carried out in autoclaved and non autoclaved soils (field soils) separately with 12 treatments and 3 replications including non infested control (using Ragbi nematicide in field soils experiment), and infested control treated with isolates of Trichoderma using Randomized Complete Design. Then analysis of variance for the bio-control potential of isolates, final population of nematode, fresh and dry root weight, fresh and dry leaves weight inoculated with isolates of Trichoderma was carried out. The results revealed a significant difference (P<0.05) between treatments and control according to Duncan,s Multiple Range Test. T. harzianum Bi and T. virens VM1 decreased population of nematodes, and increased yield in autoclaved and field soils. In autoclaved soils, the two isolates (T. harzianum Bi and T. virens VM1) decreased population of nematodes by %76.68 and %72.65, respectively compared with the control. The Ragbi nematicide, T. harzianum Bi and T. virens VM1 decreased population of nematodes by %81.65, %75.15 and %72.85, respectively compared with the control in field soils experiments.
