h. rouhani

 Meloidogyne incognita is the most well-known root knot nematode, with more than 2000 host species. Integrated nematode management (INM) is recommended to manage the destructive plant parasitic nematode. Integrated management is generally performed by using the maximum available management methods (at least two methods) and the minimum use of chemical nematicides to bring the pathogen population below the economic threshold. The use of resistant cultivars is of particular importance in integrated management, due to environmental compatibility, economic efficiency, and sometimes the impossibility of implementing other methods, especially in developing countries. Therefore, it is necessary to evaluate the resistance of the important barley plant (Hordeum vulgare) to prevent damage and also to investigate nematode interactions with it.

 In the current study, the resistance of different barley cultivars (i.e., Nik, Nimrouz, and Zarjow) was evaluated based on plant growth factors (length, fresh, and dry weight of aerial part and roots) and nematode gall index at 60 days post inoculation. Then the activity of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) enzymes were measured on days 0, 1, 2, 3, and 4 days post inoculation.

 Regarding the mean number of galls, the Nik cultivar showed a significant difference compared to Nimroz and Zarjow cultivars (P ≤ 0.05). However, no significant difference was observed between Nimroz and Zarjow cultivars. Based on plant growth factors, M. incognita nematode was found to have a negative effect on the aerial part length and weight and a positive effect on root weight. Evaluation of the gall index showed Nik is moderately susceptible, and Nimrouz and Zarjow are moderately resistant cultivars. SOD enzyme in Nik, Nimrouz, and Zarjow showed maximum activity in 2.72, 1.91, and 2.15 U mg-1 protein on the 4, 4, and 3 days post inoculation, respectively. The enzyme in Nik was determined to be 1.42 and 1.25 times higher than Nimrouz and Zarjow. There was a significant difference between 0, 1, and 2 with the 3 and 4 days of the infected samples in Nik (P ≤ 0.05). In the other cultivars, enzyme activity increased with a slight slope. CAT enzyme peaked in Nik, Nimrouz, and Zarjow at 0.204, 0.09, and 0.11 μmol min-1 mg-1 protein on the fourth-day post inoculation. In the Nik cultivar, unlike the other two cultivars, the enzyme increased more and had a steep slope from the second to the fourth day. In infected plants of Nimrouz, despite the gradual increase of enzyme, no significant difference was found between any of the days. APX enzyme peaked at 0.26, 0.27, and 0.24 μmol min-1 mg-1 protein in Nik, Nimrouz, and Zarjow on the fourth day, respectively. The activity of the above enzyme had an increasing trend in three cultivars. The maximum activity of this enzyme was at Nimrouz, which was determined to be 1.03 and 1.1 times higher than Nik and Zarjow, respectively. In this cultivar, the upward trend was rapid, although there was a significant difference between all-time points at the level of 0.05. In the current research, it was found that the invasion of the root knot nematode M. incognita reduces the growth of length, fresh and dry weight in the aerial part, reduces the length of the root but increases the fresh weight of it.

The hallmark of inducing pathogenicity in the sedentary root knot nematodes is the formation of special feeding cells named giant cells, which require controlling the expression of host genes and manipulation of plant hormones like auxin and cytokinin hormones. It is obvious that during the invasion of root knot nematodes and the formation of giant cells in host roots, the plant is weakened due to impaired transport of water and nutrients, and the host growth factors, especially in the aerial part, are reduced. However, due to hormonal disorders and the formation of galls, the weight of the roots increases. The higher expression of antioxidant enzymes superoxide dismutase, catalase, and ascorbate peroxidase in Nik possibly has occurred due to the compatible interaction, as a result of lack of necrosis and programmed cell death and to tolerate stress (nematode invasion). Less expression of SOD, CAT, and APX enzymes in Nimrouz and Zarjow cultivars possibly have occurred due to their moderate resistance to M. incognita invasion.

One of the most important problems facing modern agriculture is soil born plant pathogens control, especially root-knot nematodes. Chemical control, crop rotation and using resistance cultivar are common methods in control of most plant pathogens; however, there are low efficacy in control of root-knot nematodes regarding host wide range, long-term survival ability in soil and plant residual even in absence of host. One of the new methods in the management of root-knot nematodes is resistance induction in host using chemical compounds and microorganisms.  In this method there are not any side effect. The aim of this study was to investigate the effectiveness and mechanisms involved in induced resistance by three chemical compounds (Hexanoic acid, Thiamin and Riboflavin) accompanied by Trichoderma harzianum BI in tomato plants against Meloidogyne javanica. The objectives of this study were addressed by monitoring the activity of peroxidase, polyphenol oxidase, catalase, phenylalanine ammonia lyase, accumulation of total phenolic compounds and nematode disease indexes.

This study was conducted in the Faculty of Agriculture, Ferdowsi University of Mashhad and was performed with susceptible cultivar to root knot nematode (Early Urbana). 2-4 leaf stage tomato seedlings were transferred to 3 Liter pots filled with 2 liter sterile soil and maintained under greenhouse condition to the end of experiment. 2000 Meloidogyne javanica J2 larvae (N) were added to each pot. Tomato plants were treated with Trichoderma harzianum BI (TH) with a population of 1×107 spores/mL, Hexanoic acid (HX), thiamine (TI) and riboflavin (RB) with a concentration of 20 mM. Distilled water was used as control treatment. Sampling was performed at specific time points from each pot and the samples were transferred to the laboratory. Enzyme extract was extracted from tomato roots to assay the Peroxidase (POD), Poly phenol oxidase (PPO), Catalase (PAL) and Phenylalanine ammonia lyase (PAL) enzyme activity. Also total phenol content and nematode pathogenicity indexes were measured at the end of the growing season.

 Based on the results, the highest POD and PPO enzyme activities were measured in TH + HX + N, TH + RB + N and TH + TI + N treatments, respectively, at a time point of 72 hours after treatment. The highest CAT enzyme activity was also recorded in the treatments TH + HX + N, TH + RB + N and TH + TI + N, respectively, at 96 hours after treatment application, the highest PAL enzyme activity was recorded in TH + HX + N, TH + RB + N and TH + TI + N treatments, respectively, at a time point of 120 hours after treatment. The highest total phenol content of roots  were measured, respectively,  in TH + RB + N, TH + HX + N and TH + TI + N treatments with values of 125.33, 114.67 and 109.33 mg gallic acid per gram roots. Also, nematode pathogenicity indexes including gall index, number of egg sacs and number of eggs in each egg sac were measured 45 days after the start of the experiment and a significant difference was observed in all treatments compared to the control treatment. The lowest values of pathogenicity indices were recorded in TH + HX + N, TH + RB + N and TH + TI + N treatments, respectively. Systemic resistance in plants can be induced with biotic and abiotic agents. The effects of chemical and microorganisms on plants resistance induction were investigated in many studies. However, effect of these agents on plant parasitic nematodes were considered less than other pathogens. Capability of different Trichoderma isolates on nematodes damage reduction are reported in many different studies. Several biocontrol mechanisms are reported for Trichoderma. As biocontrol ability of an isolate can be different mechanisms consequence. Effect of different chemical such as Hexanoic Acid, Thiamin and Riboflavin on plant disease have been investigated, however, there are little known about the effects of these chemicals on plant parasitic nematodes. The use of these chemicals as an enhancer of plant resistance to pathogens, due to their low risk to humans and the environment has been increasingly welcomed by researchers.

The results showed significant effect of used treatments on the reduction of root-knot nematode damage in tomato plants. These results justify further studies to investigate and identify the mechanisms of these compounds mode of action on increasing host resistance against this pathogen.

Over the last years, artificial intelligence models have been widely and successfully applied in many fields. In the present study, the efficiency of adaptive neuro-fuzzy inference system (ANFIS), SVM (Support Vector Machine) and Least Squares Support Vector Machines (LS-SVM) have been investigated to estimate the sediment concentration in four gauging stations, namely Jangaldeh, Nodeh, Arazkoosh, and Gazaghly along the Gorganrood River in Golestan province, Iran. The models were defined based on the five different combinations of the river flow and precipitation using time lags from 0 to 2 previous days. The results showed that the LS-SVM model with simplex search procedure had a better performance than the grid search method. Meanwhile, the results obtained from ANFIS model which estimated sediment concentration in Jangaldeh, Nodeh, Arazkoose and Ghazaghli stations with MEF Error of 5.3, 13.4, 4.8 and 2.8 percent, respectively, suggested a higher performance than other models. Overall, at all stations except Gazaghly, considering the antecedent flow with two-day time lag as the input data of the model increased the error magnitudes. Furthermore, the rainfall of the same day and one-day time lag could only enhance the efficiency of the model at Arazkooseh station.

Sugar beet is adaptable to be cultivated in different weather conditions and regions. In 2015, the overall area for sugar beet cultivation was estimated about 105,000 hectares which 19000 of this was in Khorasan Razavi province. Sugar beet is considered as a valuable agricultural crop both for economy and employment. Nevertheless, producing this crop faces many challenges including the high number of pests. One of these pathogenic factors is the nematodes. Among plant-parasitic nematodes cyst nematodes are a large group with economic importance in different countries. These nematodes cause much damage to agricultural crops. Among the different cyst nematode genera Globodera and Heterodera have species which are important due to economic damage.

During the year of 2016, 22 samples of soil and roots of sugar beet in cyst nematodes contaminated field in Khorasan Razavi were gathered. Cyst nematodes were extracted by the use of a small clip and a binocular and put in petri dish with some water. White materials were also taken from the root by a delicate needle and put in sterile distilled water after washing. Separating and purifying fungi were done in 3 parts: separating fungi from cysts and materials, separating fungi from eggs and larvae nematode, and making single spore fungi and pure culture. The cysts and separated materials were washed by distilled water for several times and antisepticised for 1, 2 or 3 minutes in 10% Sodium Hypochlorite, and 10% and 20% Ethyl alcohol. Cysts and materials were washed again with sterile distilled water and sterile sifter was used. The cysts and materials in petri dish containing PCA, PDA, CMA and MEA culture mediums were separately taken and cultured by a needle under laminar. Four cysts were placed at the 4 sides of each 8cm petri dish containing the above mentioned culture mediums. 16 brown cysts from each soil sample were cultured. Two petri dishes from each sample were kept and checked consistently in two hot and cold temperatures in incubator with 20-25 and incubator with 8-10. After 7-14 days the grown fungi were taken to a new culture medium of PDA for a better development and in later stages they were purified on WA culture medium by single spore or hyphal tip methods. Purified fungi were kept in test tubes containing PCA food environment and 4 temperature and also on sand for later studies. Cyst shells were destructed by cyst crusher (homogenizer) and their eggs and mash were released. Released eggs from cysts were formed into suspension in sterile water. 0.5-1 ml of suspension of eggs and larvae were taken by sterile micropipette and diffused on petri dish containing water agar culture medium. These culture mediums were kept and checked regularly in dark in the incubator with 20-25. Grown fungi from these eggs and larvae were taken to a new culture medium and purified by single spore and hyphal tip methods. WA culture medium was used for single spurring and purifying fungi. PCR based methods morphological and molecular identification, were used to identify the fungi isolates. Mycelium fungi growth phases, fungi DNA extraction, PCR reaction and electrophoresis were done to identify molecular fungi. Lipase and chitinase assays were performed on the isolates.

For Lipase test, each fungal isolate was cultured on peptone agar media and after 7 days isolates were examined. Around the colony of the isolates produced by the lipase enzyme formed a precipitate or a colorless aura, which is due to the formation of calcium salts from free lauric acid by the lipase enzyme, which indicates the positive activity of lipase. Among the isolates, Colletotrichum gloeosporioides had the highest sediment content, indicating the activity of lipase enzyme and the highest isolate in this test. After that, Neonectria macrodidyma and Penicillium chrysogenum showed the highest activity of lipase enzyme activity. Fusarium oxysporum showed no sediment and the lowest level of lipase enzyme activity was observed in this fungus. For chitinase test, isolates were cultured on colitic kitein medium. Around the colony and also the color of the culture medium, the chitinase-producing isolates changed the violet color, which indicates the positive activity of the chitinase enzyme in these isolates. Relative analysis of chitinase activity showed that the isolate of P. chrysogenum had the largest and fastest change in color to violet, indicating the highest production of chitinase enzyme by this fungus. The lowest chitinase production was by C. gloeosporioides, which showed the slightest and slowest changes in color compared with other isolates and the weakest isolate was introduced for the production of chitinase enzyme.

In this research, different fungi were isolated from sugar beet cystc. Most fungal isolates belonged to Torbat-e-Haidiriyah and Fariman, and the least isolates belonged to Khaf. The highest frequency of Fusarium isolates was found to be 37.35%. Isolation of Simplicillium lanosoniveum fungi, P. chrysogenum, C. gloeosporioides was the first reported cyst nematode in sugar beet. In the relative analysis of lipase activity, it was found that P. chrysogenum and C. gloeosporioides fungi exhibited the highest amount of lipase production, which was the highest marker in this test. Relative analysis of chitinase activity showed that P. chrysogenum had the largest and fastest color change to purple, indicating the highest production of chitinase enzyme by this fungus. The lowest chitinase production was obtained by isolate C. gloeosporioides, which showed the slightest and slowest changes in color compared with other isolates. The fungus P. chrysogenum showed the best results in both tests, this fungus is, therefore, recommended for further research with the observation of the necessary points.

In this study the HBV hydrological model and runoff indices have been applied to investigate the impacts of climate change on runoff in the ArazKoose watershed. Therefore, the projected future temperature and precipitation under the three representative concentration pathways (RCPs) 2.5, 4.5 and 8.5 scenarios for the first future epoch (2031-2051) and the second future epoch (2051-2071) were incorporated into the calibrated HBV model. The Dynamic Dimension Selection (DDS) optimization technique was used to calibrate the HBV model’s input data of precipitation, potential evapotranspiration and temperature in daily scale. Daily flow data from 1986 to 1999 and from 2006 to 2009 were used to calibrate and validate the model, respectively. The Support Vector Machine (SVM) model projected the evapotranspiration in two future epochs. Future runoff simulations compared to the base period with respect to hydrological indices of flow duration curves indicating a decreasing trend in monthly runoff of ArazKoose watershed. Furthermore, projected extreme events resulted in decreasing high flow and low flow by 60% and 25%, respectively, in the future when compared to the baseline period. While, the annual mean flow projected to increase by 25% than that of historical period in two scenarios except in RCP8.5.

In order to identify the plant parasitic nematodes of rapeseed fields in North Khorasan province، during 2007-2008، 40 soils and root samples were collected. Nematodes were extracted by centrifugal flotation technique and transferred to glycerine according to the modified De Grisse method (1969). The permanent slides were prepared from the extracted nematodes. The nematodes were identified by light microscopy based on morphological and morphometrical characters. In this study، from genus Geocenamus، three species G. quadrifer، G. tessellates، G. rugosus and genus Merlinius four species M. brevidens، M. microdorus، M. nanus، and M. nothus were identified. G. tessellates، is reported for the first time from Iran.

In order to identify the plant parasitic nematodes of rapeseed fields in North Khorasan Provice, during years 2007-2008, 50 soil and root samples were collected. Nematodes were extracted by centrifugal flotation technique and transferred to glycerin according to the modified De Grisse method (1969). The permanent slides were prepared from the extracted nematodes. The nematodes were identified by light microscopy based on morphological and morphmetrical characters. In this study, eight species of Helicotylenchus were identified as following: Helicotylenchus digonicus, H. vulgaris, H. exallus, H. pseudorobustus, H. californicus, H. canadensis, H. minzi and H. crassatus. Three species H. californicus, H. canadensis and H. crassatus were reported for the first time from Iran. H. californicus is recognizable from related species by the hemispherical lip region, functional spermatheca in female and shape terminus projection of tail,from H. canadensis by the truncate lip region with 4-5 annulations, long stylet and tail terminus hemispherical and from H. crassatus by the truncate lip region and tail shape.

Pythium aphanidermatum is one of the most important agent of root and foot rot of cucumber, particularly in the warm humid climate. Induction of host resistance by microorganisms or by the synthetic compounds is recently considered as one of the biological control method of disease. Trichoderma harzianum Bi is a good candidate for induction of resistance in plant against diseases. The maximum level of resistance of seedlings to P. aphanidermatum after inoculation with T. harzianum Bi was determined using completely randomized design in greenhouse condition. The results based on the fresh root weight and root rot index of seedlings showed that the maximum level of resistance against P. aphanidermatum is induced 7 days after treatment of cucumber seedlings by T. harzianum. The variation of peroxidase activity, its isozymes, and the total soluble proteins in root extract induced by T. harzianum Bi in cucumber seedlings was determined by colorimetric and native Electrophoresis methods before and after inoculation the seedlings by P.aphanidermatum. The results showed that the maximum level of resistance induction in seedlings treated by T. harzianum Bi coincide with maximum activity of peroxidase. The peroxidase activity was evaluated by Guaiacol oxidation rate in the presence of H2O2 and changing of solution color to orange reddish, measured by the variation of light absorption per min/ mg soluble protein of root extract. The same experiment realized on T. harzianum Bi, P. aphanidermatum and the combination of two fungi demonstrated that both fungi can influence individually the peroxidase activity, but it is more pronounced and more stable and persistent in the case of seedling inoculation by combination of two fungi in comparison to the control.

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.

In order to study the biological control of carnation vascular wilt disease caused by Fusarium oxysporum f.sp. dianthi, 141 bacterial strains were isolated from carnation rhizosphere, and their antagonistic activity was evaluated against fungal pathogen in dual culture method. Among the tested strains, 16 strains showed antagonistic activity seven of them with more activity were selected for further investigation. Based on phenotypic features, strains E31 and E57 were identified as Bacillus cereus E76, E93, E102 and E121 as Bacillus subtilis and E130 as Pseudomonas fluorescens bv. III. All bacterial strains inhibited mycelial growth of F. o. f. sp. dianthi by production of non-volatile and volatile metabolites under laboratory condition. Microscopical analysis showed that all strains caused deformation of pathogen mycelium, and metabolites of these strains reduced conidia production rate and as well as the ability of conidia germination. In the in vivo tests, in sterilized and nonsterilized soils, the effect of bacterial strains was studied on disease severity, percentage of healthy plants and the growth rate of plants using soil inoculating and root-dipping into bacteria-methyl cellulose mixture methods. The E57 and E121 strains, in both methods, and E130 in root-dipping method showed highest effect on decreasing of disease severity and increasing of healthy plants percentage. Strains E57, E121 and E130 significantly increased total dry weight of carnation. Maximum dry weight was obtained by E57 and E130 in soil inoculating and root –dipping methods respectively.