مجله دانش گیاه پزشکی ایران
سال پنجاه و یکم شماره 1 (بهار و تابستان 1399)

The carob moth Ectomyelois ceratoniae (Zeller) is a serious pest on carob, pomegranate, dates, citrus and almond worldwide, and causes considerable losses in pomegranate orchards in Iran. Venturia canescens is one of larval parasitoids of this pest that is known as parasitoid of some stored products too. The present study assessed demographic parameters in two populations of the V. canescens (Hym.: Ichneumonidae) that were collected from pomegranate orchards, and stored products in storages. The each of two populations collected were developed on fifth instar larvae of Ephestia kuehniella as host under laboratory conditions at 25 ± 1°C, 65 ± 5% RH and a photoperiod of 16: 8 h (L: D). Life table data were analyzed using age-stage, two- sex life table procedure. The developmental time of parasitoid wasps of orchards, and stored products populations were 22.37 and 24.73 days and the values of oviposition period were 9.33 and 8.66 days, respectively. The life expectancy values were recorded 15.07 and 18.85 days, respectively. The intrinsic rate of increase (rm) were 0.168 and 0.153( females/female/days), the finite rates of increase (λ) were 1.183 and 1.185 (females/female/days), the net reproductive rates (R0) were 78.67 and 75.93 (females/female) and the mean generation time (T) were 25.97 and 28.23 days, respectively in above mentioned populations. This study suggests that orchard population may had highest performance than stored products population regarding the life table parameters. Complementary research to study biology and behavior of two populations needed.

Date cicala pest with, feeding of leaf or fruit juice, reduces the fruit's quality and marketability. The conventional method of spraying dates palm trees to control this pest is using of tractor lance sprayers. In this method, high pressure is increased drift, solution consumption and environment contaminates. Utilizing the new drone technology in spraying against date palm cicala can be a way to reduce the disadvantages mentioned. In this research, three different treatments were used to control the date cicala during a block completely randomized design with four replications in Farashband area (Fars province).Results showed the tractor lance sprayer and sprayer drone, the highest and lowest consumption of poisonous solution was 437.7 and 14.46 liter/ha respectively, the drift was 42.6 and 11.02%, the field capacity was 5.55 and 0.8 ha per hour respectively. There wasn't any significant difference between sprayer drone and tractor lance sprayer treatment in 3 days after spraying in terms of effectiveness, but this difference was significant in 7 days after spraying and the sprayer drone method was preferable. The spray quality coefficient in the drone sprayer was 1.35. The energy consumption of the tractor lance sprayer was 44.4 times higher than that of the sprayer drone. In terms of economically, the cost benefit ratio was 2.96 and 4.2 in sprayer drone and tractor lance sprayer respectively, that the tractor lance sprayer was superior than the drone sprayer, however, these methods were able to return capital over a period of one month.

This research was conducted to identify endophytic bacteria over five-year old citrus trees in the east of Guilan province. A total of 63 endophytic bacteria were isolated from symptomless leaves of Citrus aurantium, Citrus sinensis, Citrus sinensis var. thomson, Citrus unshiu, Citrus limon, Fortunella margarita and Citrus medica. The isolates were grouped based on colony type and color. Then the morphological and biochemical characteristics of the six isolates were assessed as candidate of different groups. According to the molecular studies and phylogenetic analyses of 16srRNA region these isolates were identified as Bacillus megaterium, Bacillus cereus, Arthrobacter agilis, Acinetobacter junii and Pseudomonas azotoformans species. . Among them, three species including A. agilis, A. junii and P. azotoformans are reported as citrus endophytic bacteria from Iran and the world for the first time. The morphological, biochemical, molecular and phylogenetical analyses are able to differentiate genus and species of the endophyte isolates.

Fruits dropping, the lesser moth (Batrachedra amydraula Meyrick), spider mite (Oligonychus afrasiaticus McGregor), Date bunch fading and Date palm inflorescence rot diseases (Mauginiella scaettae Cavara) are important injurious factors of date palm. This research was carried out in Abadan region from 2005 to 2014 to study the effects of temperature and humidity stresses on injury severity and simulation of date palm damages prediction model. Four different date palm orchards from four villages were selected and they were sampled monthly for the percentage of date fruit damage until harvest. Climatic data were obtained from Abadan meteorology station. Multivariate regression, thermal and humidity models were used to design the system. Results showed that fruits dropping, the lesser moth, spider mite, date bunch fading and Khamedje diseases damages reached to the maximum at thhe months of April, June, July, September and April coincide with the phenological stage of the Hababok, Kimri, Khark, turning Khark into Rotab and Hababok respectively. The damage of these factors started at temperature 21.4, 21, 26.7, 30.2, 21.4oc and relative humidity 14.7, 20, 14.7, 21.3 and 27.9 gradually increases to 40.9, 36, 50, 50 and 37.6°C respectively. Forecasting model of damage factors have been significant at level 1, 5, 5, 5 and 5 percent respectively. All of the forecasting models had coefficient higher than 0.7 and the detection error less than 25 percent. Among the meteorological indices, relative humidity and rainfall had the most influence on the variations in the severitis of damages.

Faba Bean (Vicia faba) is an important legume among cultivated plants and Alternaria leaf spot is a serious disease that causes broad damages and yield loss in Golestan and Mazandaran provinces. In current research, sampling was carried out from Mazandaran and Golestan provinces. Morphological and molecular surveys of the obtained isolates showed that they belong to A. alternata species. In order to evaluate resistance of nine Faba Bean cultivars against Alternaria leaf spot, area under disease progress curve (AUDPC) were calculated in greenhouse condition. In addition, variation of some resistance related enzymes between resistant and susceptible lines were tested at different time intervals after inoculation. Statistical analysis showed significant difference between cultivars (P≤ 0.05). The Otono cultivar with the highest AUDPC and Zereshki cultivar with the least AUDPC were suggested as susceptible and resistance cultivars, respectively. The ANOVA of antioxidant enzymes showed positive effects on CAT, APX and GPX levels after inoculation (P≤ 0.01). Increasing in the amount of enzymes in incompatible interaction (Zereshki resistant cultivar) was greater than that of compatible interaction (Otono susceptible cultivar), indicates the role of these enzymes in activating plant defense responses in Faba Bean to interact with the pathogen and induce resistance. In general, the results showed that Zereshki cultivar with low level of AUDPC and high expression of antioxidant enzymes has high potential to be used in breeding programs for resistance to Alternaria leaf spot.

Utilizing the essential oils (EOs) as natural antifungal agents and alternatives for chemical fungicides has increased the attentions. In this study, chemical components and antifungal activity of Cinnamomum zeylanicum (CEO), Zataria multiflora (ZEO), and Satureja khuzestanica (SEO) plants essential oil (EO) were identified to assess their effect in term of concentration and exposure time on control of Penicillium expansum and also, modeling and optimizing antifungal properties of these EOs via response surface methodology (RSM). The main components of three EOs detected by GC-MS analysis were as follows: Cinnamaldehyde (80.82%) for CEO, Thymol (32.68%), Carvacrol (30.57%), p-Cymene (8.94), and γ-Terpinene (5.96%) for ZEO and Carvacrol (38.43%), γ-Terpinene (21.89%), p-Cymene (16.55%), and α-Terpinene (5.76%) for SEO. Antifungal index (AI) in all EOs increased against the increment of concentration but the effect of time was vice versa; with passage of time, the AI decreased in all EOs. Moreover, based on the optimization results, it was determined that CEO and SEO at concentration of 288.633 and 590.841 μL.L-1 and time of 108.607 and 238.549 h had the highest and lowest inhibitory effect, respectively, on growth of Penicillium expansum. Furthermore, the results of this study showed that the response surface method can be applied to model and optimize the antifungal activity of these EOs as a suitable and accurate method.

Oak dieback is one of the most important diseases that presently affects the Zagros oak forests (Northwest to Southeast of Iran). The presence of Paecilomyces formosus, Biscogniauxia mediterranea and Neoscytalidium novaehollandiae associated with oak trees that show dieback and declining symptoms in the forests of Kermanshah province and the molecular and pathogenic characteristics of these pathogenic isolates were investigated. In molecular analysis using blast search tools, all three pathogens showed homology of 100% with the mentioned species in the GenBank. Pathogenicity test revealed that all isolates of these three pathogens were capable of producing cancers on detached branches and inoculated seedlings of oak trees. Our results showed that all three species obtained from oak trees could produce cankers on excised branches of other trees. In comparison with pathogenicity on two-years-old seedlings under drought stress, there was a significant difference between the three species in terms of the rate of disease progression, so that B. mediterranea caused symptoms on seedlings inoculated under drought stress in a shorter time. P. formosus caused symptoms in longer period on the inoculated seedlings than the other two species. After inoculation, all cankers that extended upward and downward from the point of inoculation were evident on stems of all inoculated seedlings. Re-isolation was performed, and isolates were compared to original cultures providing evidence for fulfilling Koch’s postulates. Investigation of the effect of temperature on radial growth of pathogenic species showed that all three species are thermophilic fungi, which may be related to warming and drought.

Grape powdery mildew (GPM) caused by plant pathogenic fungus Erysiphe necator, is the most widespread disease on grapevine in worldwide including Iran. Temporal analysis of disease epidemics was carried out by evaluating GPM in 30 vineyards in three cities of Sistan region, includeing Zabol, Zahak and Hamoon during 2017 and 2018. Field survey of vineyards to record disease incidence (I) and severity (S) was started from plant growth onset to harvest time, weekly program. Disease progress curves (DPCs) were evaluated by mathematical growth models including Linear, Monomolecular, Logistic, Log-logistic and Gompertz and their goodness of fit determined based on such statistics as coefficient of determination (R2), adjusted R2 (aR2)and standard error of estimates (SEE). Result showed that in total two years, for three variables of disease including: disease incidence, leaf disease severity and fruit disease severity, the Monomolecular model was fitted with 100, 100 and 98.33% of studied epidemics respectively. Means R2 of this model for three disease variables, calculated 91.64%, 89.60% and 90.27% respectively and this model was selected as the most appropriate model for describe GPM progress in Sistan region for two studied years.Also in total of two years rates of increase (rm) per unit of disease in the vineyards for three disease variables were 0.016, 0.004 and 0.005 respectively. This research is conducted for the first time in the region of Sistan and Iran.

Grapevine downy mildew caused by Plasmopara viticola is the most important factor in decreasing grape production in temperate and rainy regions. To investigate the disease progression curve in vineyards of North Khorasan province during two years of 2018 and 2019, Scoring of the target vineyards was carried out each week on a regular schedule from mid-April at the bud swelling time from the vineyard. The incidence rate and severity of the disease in 80 vineyards from four counties of Bojnourd, Maneh and Samolghan, Shirvan and Farouj were calculated. Linear regression was fitted to disease time progression curves with five population growth models as exponential, monomolecular, logistic, log-logistic and gompertz models. The model fitness was determined based on statistics as coefficient of determination (R2), standard error of estimates (SEE) and adjusted coefficient of determination (Ra2). The results showed that exponential, monomolecular, logistic, log-logistic and Gompertz models were fitted with 5, 27.5, 12.5, 17.5 and 37.5% of the disease in the studied gardens, respectively. Accordingly, Gompertz model with 96.76% coefficient of determination was selected as the most suitable model to describe disease progression in North Khorasan province. Rates of increase (rG) per unit of disease in each vineyard was 0.005 to 0.048 (with an average of 0.026). This is the first report of a study of the progression curve of grapevine downy mildew in Iran.

In this study, the fumigant toxicity of four essential oils, including eucalyptus leaf, eucalyptus flower, rosemary leaf, and mint leaf, was determined on the eggs (with less than 24 h) and the life span of the cowpea weevil (Callosobruchus maculatus). The results showed fumigant toxicity of these essential oils on the eggs in a dose-dependent manner showing the higher embryo mortality and the lesser hatching rate. Mint essential oil had the highest toxicity against the eggs with the 3.3% of eggs hatchability. Mint essential oil also increased the larval duration from 23.6 days in control to 27 days; however, the essential oils of eucalyptus leaf, eucalyptus flower, and rosemary showed no significant change in the larval duration as the survived embryos could complete larval stages in the equal time (statistically) with control. The use of herbal essential oils, especially mint essential oil, is very effective in controlling the cowpea weevil at the egg stage, and those may be a good substitute for common pesticides in warehouses.

In order to study the Bipolaris and Curvularia species associated with corn, sorghum and sugarcane, sampeling were performed from different regions of Iran (including Alborz, Ardabil, Fars, Gilan, Golestan, Khuzestan, Mazandaran and Zanjan provinces) during the summer of 2011 and 2012. Fungal species were identified based on morphological features and molecular data of ITS regions of ribosomal DNA. Eleven species including Viz. Bipolaris cynodontis (48 isolates), B. sorghicola (16 isolates), B. maydis (17 isolates), B. sorokiniana (seven isolates), B. bicolor (four isolates) and B. oryzae (two isolates), Curvularia spicifera (19 isolates), C. papendorfii (ten isolates), C. ellisii (two isolates), and C. hawaiiensis (one isolate) were identified. Pathogenicity test of the species were performed on four to six leaf stage of corn, sorghum and sugarcane seedlings. Finally, pathogenicity of B. maydis, B. sorokiniana and B. oryzae on corn and B. sorghicola on sorghum seedlings were confirmed. This is the first report of occurrence and pathogenicity of B. sorokiniana and B. oryzae on corn leaves in Iran.

Bean yellow mosaic virus, a species of the genus Potivirus, has a wide host range and a broad geographical distribution. BYMV causes high annual economic damage in various legumes such as faba beans in Iran. In this study, 13 BYMV isolates were collected from faba bean fields of different provinces of Iran (Sistan and Baluchestan, Hormozgan, Kerman, Khuzestan, Fars, Lorestan, Ilam, Hamadan, Ghazvin, Zanjan, Ardabil, East Azerbaijan). The coat protein (CP) region of the collected isolates was sequenced and then compared with the CP sequence of 178 isolates available in GenBank. The selected Iranian sequences showed 86-99% nucleotide sequence identities with other BYMV isolates. Phylogenetic relationships based on CP nucleotide sequences were estimated using the Maximum Likelihood method, after removing all recombinant sequences. Accordingly, all isolates excluding three isolates, AI38, PAC-1, BYMV-W were placed in eight monophyletic groups. Iranian isolates were located in two distinct groups, along with broadbean, lentil, bean, gladiolus and sunflower isolates from Japan, Australia, Iraq and Spain. According to the results there is no significant relation among clustering of BYMV isolates based on phylogenetic analysis of CP sequences and original host and country. The CP structure analysis of Iranian isolates and other selected isolates from GenBank revealed conservation of the C-terminus and the central region of the coat protein and the variation of the N-terminus.