Showing 3 results for Zamanizadeh
Volume 9, Issue 2 (2-2020)
Abstract
In this study, 41 isolates of the genus Trichoderma including six species of Trichoderma arundinaceum, T. asperellum, T. atroviride, T. harzianum, T. longibrachiatum and T. virens were isolated from soils of cucumber fields in Kermanshah province, and their efficacy to control Phytophthora drechsleri, the causal agent of cucumber damping off, was investigated in laboratory and greenhouse conditions. In direct confrontation between Trichoderma isolates and the pathogen, all isolates were able to promote, establish, and sporulate on pathogen mycelia. Through dual culture test, the most inhibitory effect on pathogen growth (62.89%) was recorded for T. harzianum (isolate T1). Volatile compounds of T. harzianum (isolate T7) had the greatest mycelial growth inhibition (46.59%) compared with control. Complete growth inhibition of the pathogen was recorded when the growth medium was supplemented with culture filtrate of Trichoderma isolates at concentration of 15% and 30%. At the concentrations of 15% and 30%, 18 isolates and 22 isolates completely inhibited the pathogen expansion respectively. In the greenhouse, the results of data analysis on the survival percent of plants in various treatments showed significant differences between the isolates of Trichoderma in terms of preventing cucumber damping off. In conclusion, T. asperellum showed the highest ability to control Phytophthora damping off and promoting cucumber growth which is a new record for Iran. This species can be an appropriate choice for biological control of the disease caused by P. drechsleri in cucumber.
Volume 15, Issue 4 (7-2013)
Abstract
Leaf blotch disease of barley, caused by Rhynchosporium secalis is a major disease of barley in Iran. Its worldwide occurrence and economic importance in barley production has motivated studies on the population genetic structure of this pathogen. Random Amplified Polymorphic DNA (RAPD) method was utilized to investigate the genetic diversity of populations of R. secalis isolated from barley leaves. A total of 94 isolates, representing five geographically distinct populations, were collected from diverse climatic regions in Iran. Genetic diversity was studied using eleven RAPD primers. Out of a total of 119 fragments generated by random decamer primers, 89 (75.1%) were polymorphic with an average of 8.1 polymorphic fragments per primer. Cluster analysis of RAPD data using UPGMA and simple matching coefficient method distinguished 33 main groups at 75% similarity level. The similarity between isolates ranged from 0.62 to 0.89. In total, 42 molecular phenotypes (haplotype) were distinguished among the 94 isolates by 11 RAPD primers. Haplotype one was found in all the five regions of Iran surveyed. Some haplotypes were specific to a single region while others found in several regions. There was little correlation observed between genetic vs. geographical distance suggesting that they were independent of each other.
Volume 24, Issue 5 (9-2022)
Abstract
Chickpea wilt caused by Fusarium oxysporum f. sp. ciceris is one of the major yield-limiting factors in chickpea, particularly in west and northwest of Iran. Simple Sequence Repeats (SSR) were used to determine genetic structure of Fusarium oxysporum f. sp. ciceris populations from three infected areas located in west and northwest provinces of Iran during 2016-2017. A set of six microsatellite primer pairs revealed 35 alleles in each locus with an average of 5.83 per locus. The PIC value varied from 0.20 (FOAG11) to 0.39 (FODF7) with an average of 0.27 per locus. The average number of effective alleles (Ne), Number of private alleles (Na), allelic variability per locus (H), Shannon's Information Index (I) and percentage of Polymorphic Loci (%PL) in three populations were 1.33, 1.97, 0.2208, 0.357, and 74.29, respectively. The average genetic distance was calculated among the three populations. Nei’s pair-wise genetic distances between the populations varied from 0.0202 to 0.98. The total gene diversity (Ht) and gene diversities between subpopulations (Hs) were estimated to be 0.2208 and 0.2079, respectively. Gene diversity attributable to differentiation among populations (Gst) was 0.0585, while gene flow (Nm) was 8.0412. The AMOVA of genetic variation in Fusarium oxysporum f. sp. ciceris populations revealed that 5% of the variance occurred among populations and 95% within populations. PhiPT value was 0.054. The lowest genetic distance was found between Kurdistan and West Azerbaijan with Lorestan populations, while the highest genetic distance was observed between Lorestan and Kermanshah populations.
