Journal Of Crop Protection
Volume:10 Issue: 1, Mar 2021

Environmental conditions can cause variation in morphology, behavior, and possibly epigenetic in the numerous species of the Gomphocerinae, especially in mountain habitats. Plasticity and changes in morphology in many of the species in this subfamily is caused by character segregation through the female choice of copulation that has produced various clines, sub-species or species groups. The variation and plasticity, as a result of environmental stress, besides morphology, affect physiology and epigenetics of many insect species. Environmental stress and female assortative mating might be accompanied by hybridization in populations, resulting in character divergence and speciation after a long period of time. Contemporary evolution and/or epigenetic inheritance may be a reason for their variation in acoustic and morphology of Gomphocerinae and the main factor in the present situation of difficulty in their classification. We review possible effects of environmental stress on plasticity, hybridization, and speciation by the appearance of endemic species. About half of the insect pest species have reduced their impacts as pests under global warming. The present insect pest situation in Iran is discussed.

Potato is one of the most important crops produced in Kurdistan province, western Iran. Although several species of plant-parasitic nematodes have been reported in association with these potato fields, no comprehensive nematode community structure has been investigated. The present study reports the frequency, abundance and prominence value of all nematode groups from 40 potato fields across Ghurveh and Dehgolan regions. Bacterivorous nematodes showed the highest frequency, abundance and predominance in the region, followed by herbivorous (plant-parasitic nematodes), fungivorous and omnivorous nematodes. Predatory nematodes (carnivores) were not recovered probably because field soils were highly disturbed. Root-lesion nematodes were the most predominant among the identified plant-parasitic nematodes. The calculation of the indices of ecosystem function, as well as the plotting colonizer-persister (c-p) triangle, food web faunal analysis and metabolic footprint of the potato fields revealed that most of the studied fields had high proportions of c-p1 and c-p2 nematodes, but nematode individuals of c-p3-5 counted fewer in the population. According to the present study, 50% of the sampled fields represent either stressed and enriched, 30% could be considered as stable and enriched, and 20% may be described as stressed and depleted in terms of their soil nematode food webs. The current study provides the first known study in Iran on nematode assemblages and their implication in soil health.

Three populations of criconematids belonging to the subfamily Macroposthoniinae, representing three species Mesocriconema kirjanovae, M. surinamense and Criconemoides amorphous were recovered from two different geographical localities in East Azarbaijan province, northwest Iran. The recovered populations were characterized morphologically. Iranian population of M. kirjanovae is characterized by 437-542 μm long females, having 86-97 retrorse body annuli with smooth to finely crenated margin, cephalic region with two, non-retrorse annuli, 56-62 μm long stylet, the anterior lip of the vulva with two projections and conical tail with acute tip. The recovered population of M. surinamense is characterized by 495-640 μm long females, having 87-94 retrorse body annuli with smooth margin, four very large and flattened submedian lobes, 74-82 μm long stylet, open vulva, its anterior lip with two small lobes, vagina straight and tail rounded with one or two terminal lobes. The Iranian population of C. amorphous is characterized by 502-697 μm long females, having 66-73 retrorse body annuli with smooth to rough margin, four pseudo-submedian lobs, labial disc elevated, 72-80 μm long stylet, vulva closed, tail bluntly conoid and its tip uni- to multi- lobed. The characteristics of the three studied species were in agreement with those of the original; and the data of other populations. The two species M. kirjanovae and M. surinamense are new to nematode fauna of Iran; and the morphological and morphometric data of the Iranian population of C. amorphous are presented for the first time.

Gut bacterial symbionts have an essential role in the nutrition and fitness of xylophagous insects. These bacteria produce several enzymes like cellulase and laccase which are important in industrial applications. In this study, laccase-producing bacteria were isolated and identified from the gut of the wood borer leopard moth. Four novel laccase positive strains were isolated using guaiacol-containing agar plates. Among the strains of dc4f, le2f, lc2, and lb8, the strain le2f displayed high laccase activity of 0.059 U ml-1 toward syringaldazine as a typical laccase substrate. The isolates were identified based on biochemical tests and 16S rRNA gene sequencing analyses. Nucleotide BLAST analyses of 16S rRNA gene sequence exhibited that the strains of dc4f, lb8, lc2, and le2f, had the most similarity (with more than 98% identity) with Enterobacter sp. strain W-6 16S (ACCN: MK505390), Serratia liquefaciens strain N112 (ACCN: MK629784), Brevibacterium sp. strain 773 (ACCN: MH777897) and Staphylococcus sciuri strain KSI 708 (ACCN: KC113150), respectively. Overall, the current study is the first research on alkaliphilic bacterial strains from the gut of leopard moth with laccase activity.

Sesamum indicum L. is an important oil seed in Iran which is cultivated as summer crop in alternation with cereals and cucurbits, playing an important role in sustainable agriculture. Sesame wilt disease caused by Fusarium oxysporum f. sp. sesami is one of the limiting factors in its cultivation. Application of genetic improvement of disease resistance is one of the effective strategies to solve the disease problems in sesame. In this project, the partial resistance of 24 genotypes including, some commercial cultivars and promising lines were tested against Fusarium wilt disease. The experiments were conducted in three different conditions (greenhouse, micro plot and field). In greenhouse and micro plot experiments, artificial inoculation was used while in field experiment, no artificial inoculum was used. For evaluating results, the infection percentage (wilted plants) was recorded on a scale of 1-6 scoring system. The results showed that in artificial inoculation conditions, none of sesame genotypes were immune. Infection mean percentages of sesame genotypes were calculated to be 58.34, 28.6 and 15.96, in greenhouse, micro-plot and field, respectively. Total results of the three experiments showed that 29.1% of the sesame genotypes (JL1, Jl14, JL10, JL11, JL13, Jl18 and Darab1) fell in resistant (R) category and 37.5% of the genotypes (JL2, Varamin37, Local, Yekta, JL29, JL16, JL6, JL14-1 and Darab2) fell in moderately resistant (MR) group. The resistant and moderately resistant genotypes can be used for breeding programs and development of resistant varieties, however further efforts are needed to identify highly resistant genotypes from among more native germplasms via screening program.

Genus Lentinula comprises some of the most important edible and medicinal fungal species of the world. To compare growth rate of the strains of this genus, samples were collected from different regions of the world including Iran during 2017-2018. Investigation of the growth of 40 strains on two substrates containing malt and wheat straw extracts showed their relatively excellent performance on both media. Based on preliminary growth characteristics of the strains, 20 strains were selected to study their growth rate on natural substrate containing defined proportion of straw (40%) + sawdust (40%) + wheat bran (20%). Three strains including VM230 (UK strain), VM267 (Belgium strain) and VM353 (Japanese strain) showed high growth rate (65.25, 63.75 and 64.50 mm d-1, respectively), and were identified as Lentinula edodes by ITS4 and ITS5 sequencing. Growth rate of the best strain (VM230) was evaluated on different substrates containing different proportions of straw, sawdust and wheat bran. The highest growth rate (58.75 mm d-1) for VM230 was recorded on wheat straw (80%) + wheat bran (20%). These three strains are promising for commercial production of Shiitake.

Rapid cold hardiness in response to sudden decline in air temperature plays an important role in the aphid survival. Rapid cold hardiness is a phenomenon that increases insect’s survival at sub-zero temperatures following a brief exposure to low temperatures above 0 °C. In this regard, the cabbage aphid Brevicoryne brassicae (L.) is able to increase its cold hardiness gradually during cold season and produce large population on host plants in Brassicaceae family. In this research, rapid cold hardiness of B. brassicae, and its effects on development time, longevity and fecundity were investigated. Direct transfer of aphids from 20 °C to a series of sub-zero temperatures for 2 h, resulted in a LT80 (estimated temperature required to kill 80% of tested population) of -7.3 °C. Preconditioning of first instar nymphs for 3 h and adults for 2 h at 0 °C resulted in the highest survival rates of 63% and 71%, respectively. Acclimation of aphids, by a cooling rate of 0.05 °C/min form 20 to 0 °C, prior the exposure to LT80 (-7.3 °C) resulted in the highest survival. No detrimental effects of rapid cold hardiness were observed on development time, longevity and fecundity. Results of the present study showed that rapid cold hardiness is induced in B. brassicae and increases the aphid survival in response to unexpected changes of temperature.

Efficiency of many herbicides can be increased by adding adjuvants to the spray solution. So, the addition of an appropriate adjuvant to foliar herbicides is important in weed control researches. To identify an appropriate adjuvant for sulfosulfuron and sulfosulfuron + metsulfuron-methyl herbicides against Japanese downy brome Bromus japonicus, two experiments were conducted in randomized complete block design with two factors under field condition separately in Zabol and Zahedan, Iran. Factor A was different doses of herbicide namely 0, 50, 75 and 100% of their recommended dose and factor B was adjuvants including: sweet almond oil, olive oil, sesame seed oil and D-Octil. Results showed that efficiency of sulfosulfuron and sulfosulfuron + metsulfuron-methyl herbicides increased by increasing their doses and adjuvant addition. The addition of sesame seed oil (followed by D-octil) had the highest effect on sulfosulfuron efficacy against Japanese downy brome control. In general, sulfosulfuron at 100% of its recommended dose (26.5 g ha-1) plus sesame seed oil was the best formulation to control of Japanese downy brome. In addition, this formulation significantly improved wheat grain and biological yield. Adding of D-Octil had the highest influence on sulfosulfuron plus metsulfuron-methyl performance in Japanese downy brome control. The highest wheat grain and biological yield were mainly obtained at 100% recommended dose (40 g ha-1) of sulfosulfuron + metsulfuron-methyl plus D-Octil followed by sesame oil.

The Greenbug Schizaphis graminum</em> (Rondani), one of the major pests of cereals, overwinter as adults and nymphs in temperate regions. The aphid population increases in early spring as the weather conditions become favorable, but it gradually decreases in mid-June as air temperature rises. Adult aphid colonies were acclimated to measure cold tolerance at 20, 15, 10, 5, and 0 °C for one week. In contrast, other colonies were acclimated to measure heat tolerance at 20, 25, and 30 °C for one week and 35 °C for two days. Then, the lowest temperature resulting in 50% mortality (LLT50</sub>) and the highest temperature resulting in 50% mortality (ULT50</sub>) of tested populations were defined. Moreover, changes of sugars and polyols were studied at the end of each thermal regime. The lowest LLT50</sub> was -13.2 °C at 0 °C and the highest ULT50</sub> was 40.1 °C at 35 °C. In the cold acclimation condition, glucose was the highest at 0 °C and reached to 80.9 µmol/g f.w. However, in the heat acclimation condition, the mannitol was the highest at 35 °C and reached to 43.7 µmol/g f.w. Findings indicate that high temperatures due to climate change could be a threat to aphid population size and distribution.

The present research was performed to evaluate the bioactivity of Citrullus colocynthis (L.) and Melia azedarach L. extracts against three major stored grain insect pests including Tribolium castaneum (Herbst), Trogoderma granarium Everts, and Sitophilus granaries (L.). Toxicity and enzyme inhibition activity of acetylcholinesterase (AChE), α-carboxylesterase (α-CE), β-carboxylesterase (β-CE), acid phosphatases (ACP) and alkaline phosphatases (ALP) in three insect species induced by both plant extracts were evaluated at four different dose rates viz., 5, 10, 15 and 20%. Results showed maximum mortality (34.29%) in S. granarius with M. azedarach at maximum interaction of time and dilution level. In T. castaneum and T. granarium maximum recorded values for mortality were 30.87% and 18.95%, respectively, with extract of M. azedarach. Plant extract of C. colocynthis reported a maximum mortality of 21.92%, 19.18% and 16.89% in T. castaneum, S. granarius and T. granarium, respectively. Findings proved that both plant extracts had decent lethal impacts on tested insect species. Exposure of studied insects to plants extracts also resulted in significant inhibition of AChE, α-CE, β-CE, ACP and ALP. All tested enzymes in three insects were maximally inhibited by plant extract of M. azedarach except α-CE which was slightly more inhibited in S. granarius and ACP which was highly inhibited in T. granarium and S. granarius, by plant extract of C. colocynthis. Outcomes exhibit that plant based extract of M. azedarach is more pronounced in stored grain insect pests and propose the capability of using these plant extracts for safety of stored commodities as a safe substitute for insecticides.

Cucumber root and stem rot disease caused by Fusarium oxysporum f. sp. radicis-cucumerinum (Forc) is one of the most important diseases of cucumber in Iran. In this regard, this study aimed to investigate the antifungal activity of some chemical salts against Forc in in vitro and greenhouse conditions. The experiment layout in the in vitro condition was based on a factorial experiment using a completely randomized design including three replications. Treatments included potassium sorbate (PS), mono-potassium phosphite, ammonium bicarbonate, salicylic acid (SA), di-potassium hydrogen phosphate (DPHP), and fungicide carbendazim (CAR) (Bavistin WP 60%) at 0, 0.5, 2, 4, and 5 g/l. In a greenhouse condition, the experiment was conducted using a randomized complete block design with three replications. The laboratory and greenhouse experiments showed that the treatments had a significant effect on fungal growth inhibition and disease severity. In in vitro condition, the highest control of the fungus was attributed to PS and fungicide CAR. Conversely, DPHP had the least control (8.74%) on the growth of Forc at 0.5 g/l. In a greenhouse condition, CAR prevented disease symptoms for one month. However, PS and SA controlled mycelial growth with an efficiency of 61.19 and 39.2%, respectively. Accordingly, it seems that PS and SA are fungitoxic against Forc and can control root and stem rot disease in the greenhouse by root and foliar application.

This study aimed to valorize Atractylis gummifera </em>rhizome (AGR) from a phytochemical study aspect of the aqueous and methanolic extract to determine the total phenolic, flavonoids, and tannins compounds and to evaluate the rat poison effect of the powder (AGRP), methanolic (MEAGR) and aqueous extracts against Wistar rats under laboratory and Rattus norvegicus</em> under field conditions in Tiaret, Algeria. The methanolic and aqueous extracts gave a yield of 9.4% and 20% respectively from AGR. The total polyphenols [mg gallic acid Eq/g dry matter (DM)], flavonoids (mg quercetin Eq /g DM), and tannins (mg catechin Eq/g DM) quantities were 27.14 ± 0.01, 17.73 ± 0.04, 9.71 ± 0.01, and 20.60 ± 0.01, 4.46 ± 0.46, 11.12 ± 0.02 in the methanolic and aqueous extract. The laboratory studies of toxicity showed that the three forms of plant rhizome have a poison effect against males and females of the Wistar rat with the highly toxic effect of AGRP. The results revealed a highly significant (< 0.01) increase in mortality with dose and time. Both LD50</sub> and LD90</sub> of the powder form were determined for males (471, 513 mg/kg/d) and females (471, 513 mg/kg/d) respectively. For the methanolic and aqueous extracts, the LD50</sub> values were 575 and 646 mg/kg/d for males and 676 and 708 mg/kg/d for females, respectively. While an LD90</sub> of 776 mg/kg/d was calculated for MEAGR in males, no LD90</sub> values were recorded for aqueous extract in either sex. Organs of dead rats were removed and examined for gross lesions. Histopathological examination confirmed the toxicity of the plant by pathological changes observed in the kidneys, liver, lungs, and small intestine, where hemorrhage and congestion were observed in the liver, kidneys, and lungs in all the subjects, also intestinal enteritis was present. In the light of the results obtained in the field test, the AGRP has proved its effectiveness in a significant reduction of rodent’s population in comparison with the chemical rodenticides. Powder of A. gummifera </em>rhizome may be a good alternative to chemical rodenticides.

The two-spotted spider mite, Tetranychus urticae</em>, is a major pest of crops and ornamental plants worldwide. It is a highly polyphagous pest that has a notorious reputation for its ability to rapidly develop resistance to commonly used pesticides. Thus, in the current study, the contact toxicity of propargite (EC 57%) and chlorpyrifos (EC 40.8%) was investigated against two populations of T. urticae</em> from Iran, Mahallat (MhR) and Karaj (KrS), using a leaf-dip bioassay. Findings showed that the LC50</sub> of propargite against MhR and KrS populations was 5337.90 and 116.81 mg a.i/l, respectively. While the LC50</sub> of the chlorpyrifos against MhR and KrS populations was 2760.83 and 479.25 mg a.i/l, respectively. Based on the median lethal concentrations (LC50</sub>), MhR and KrS populations were considered as resistant and susceptible populations to both pesticides, respectively. MhR population was 5.76-fold and 45.70-fold more resistant to chlorpyrifos and propargite than the KrS population, respectively. Insecticide synergists including triphenyl phosphate (TPP), piperonyl butoxide (PBO), and diethyl maleate (DEM)) revealed the contribution of esterases, glutathione S-transferases (GST), and cytochrome P450 </sub>monooxygenases (P450</sub>s) to resistance. Nonetheless, the involvement of esterases and P450</sub>s was more evident against chlorpyrifos and propargite, respectively. The activity of P450</sub>s, GSTs, esterases, and acetylcholinesterase (AChE) was measured in susceptible and resistant populations. All enzymes showed significantly higher activity in the resistant population than in the susceptible one. Additionally, zymogram analysis of esterase showed two distinct bands in the MhR population, whereas the stronger band was absent in KrS population. These results indicate that metabolic pathways are associated with chlorpyrifos and propargite resistance in the MhR population.

Septoria tritici blotch (STB) caused by Zymoseptoria tritici is one of the most important wheat diseases in the world and causes significant annual damage to wheat crops around the globe. The use of resistant cultivars is the most effective method for the management of this disease. Recently, the use of acquired systemic induced resistance has been proposed to manage wheat leaf blotch. In this study, the effect of salicylic acid (SA) on the relative changes of PAL and PR2 gene expression was investigated using qPCR technique. The expressions of catalase, peroxidase, and ascorbate peroxidase enzymes were also assessed in a sensitive wheat cultivar. Controlled and contaminated plants were sampled and compared at 0, 12, 24, 48, 96, and 240 hours after inoculation. The results showed that treatment with salicylic acid significantly reduced the level of disease compared to control plants. Comparison of gene expression patterns also showed that the expression of both PAL and PR2 genes in control and SA pre-treated plants increased after fungal inoculation; however, their expression was significantly higher (2.6 and 1.3 folds respectively for PAL and PR2) in plants treated with salicylic acid than the control. Moreover, treatment with salicylic acid significantly affected the activity of all three enzymes. It can be concluded that the high response of PAL and PR2 genes to salicylic acid pre-treatment, as well as increased activity of peroxidase along with the reduced activity of catalase and ascorbate peroxidase enzymes indicate the effective role of SA in inducing wheat resistance against STB.

Puccinia taeniatheri sp. nov., is newly described from Iran on Taeniatherum asperum (Poaceae) based on morphological study and rDNA ITS sequencing. An identification key for Puccinia species known on the genus Taeniatherum is provided. Re-examination of herbarium material of P. hordei on T. crinitum collected from Iraq revealed that specimen also belongs to P. taeniatheri sp. nov.