جستجوی مقالات مرتبط با کلیدواژه "لوبیا چشم بلبلی" در نشریات گروه "گیاهپزشکی"

The cowpea weevil, Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae), a destructive insect pest of cowpea, Vigna unguiculata (L.), in the field and storage, causes significant losses in seed weight, germination ability, and the market value. The effect of cowpea (Mashhad cultivar) fertilization with chemical fertilizers (triple superphosphate (TSP) and urea) and some biofertilizers (Bradyrhizobium japonicum, Pseudomonas putida, mycorrhizal fungi) was studied on biology and life table parameters of C. maculatus at 28 ± 1°C, relative humidity of 65 ± 5%, and complete darkness. The highest immature survival (%) was on the grains treated with P. putida and control (97.75 and 95.69%, respectively), and the lowest survival was on the grains fertilized with TSP and B. japonicum (65.06 and 75%, respectively). Although the developmental time of C. maculatus reared on TSP- and B. japonicum-treated grains was longer than the control, the intrinsic rate of increase (0.124 day-1) and net reproductive rate (34.34 offspring) on the grains treated with TSP were lower than the control (0.143 day-1 and 51.07 offspring, respectively). Results of this research showed that the nutritional value of the grains obtained from TSP and B. japonicum treatments were lower than those obtained from other fertilizer treatments.

Cowpea is widely cultivated worldwide and used as an important food source. Tartanychus urticae, Koch is one of the Cowpea is widely cultivated worldwide and used as an important food source. Tartanychus urticae is one of the most important pests of beans. This study was conducted to optimize the use of acaricides by Central Composite Design, CCD, and Response Surface Method, RSM, using Design Expert 7.00 software to reduce the use of chemical pesticides and to evaluate the optimal conditions for whole female mortality. Process input variables were in the temperature range of 25–30°C, 55–65% humidity and 200–1260, 900–2300, 69–2330  ml /1000 ml  H2O for Fenphyroximite, Propargitis and Fenazaquin, respectively. Eye– popping bean leaf discs were used for inoculation and bioassays. The results of analysis of variance confirm that the linear model and the dose and relative humidity factors are statistically significant with the best peak mortality of mite for Fenphyroximite, in H: 57.03% and D:1045.14 ml /1000 ml  H2O, M:22% and the significance of the 2FI quadratic model, temperature and relative humidity interactions for propargite mites with the lowest dosage,T:26.01 °C , H:62.97% about M:16% and linear model with humidity factor for use of Fenazaquin with best mortality rate of full female mites at H: 62.97%, D: 527.30 ml /1000 ml  H2O, about M: 9% which the most favorable conditions for use the three acaricides. s

Phytoplasmas were first discovered in 1967 and named mycoplasma-like organisms or MLOs. They are wall-less prokaryotes of the class Mollicutes causing diseases in many economically important plant species. Phytoplasmas are transmitted by phloem-feeding leafhoppers and planthoppers. Plants infected by phytoplasmas exhibit a variety of symptoms suggesting profound disturbances to the normal plant physiology. Restriction fragment length polymorphism (RFLP) and sequence analyses of rDNA have been used for the taxonomic characterization and phylogenetic analysis of phytoplasmas. Because of the high economic losses, in particular those of cultivated crops, annuals and high-value vegetables, detection of phytoplasmas is very important. Cowpea (Vigna unguiculata) is an important vegetable crop cultivated in Iran. Progressive growth abnormalities and phyllody symptoms with high economic loss have been observed in cowpea fields of East Azarbaijan province. Causal agent of the disease is, however, unclear. This study was, therefore, carried out to identify pathogen associated with cowpea phyllody in East Azarbaijan province of Iran.
Infected cowpea plants were collected from fields in East Azarbaijan province of Iran in summer of 2016. The disease agent was transmitted by dodder to periwinkle plants under controlled greenhouse conditions. Leaf midribs from healthy control and naturally-infected hosts were used for DNA extraction. Total DNA was extracted from midrib of six symptomatic cowpeas, inoculated periwinkle plants using CTAB buffer as previously described by Zhang et al., 1998. The universal primer pair P1/P7 was employed in first round PCR to amplify an 1830 bp fragment of 16S rDNA. A 30-fold dilution of the first round PCR product was then used as template for nested PCR using primer pair R16F2n/R16R2 which amplified an internal fragment of 1245 bp from the 16S rDNA. PCR products were ligated into pTZ57R/T using InsT/AcloneTM PCR Product Cloning Kit and transformed to Escherichia coli DH5a cells. The recombinant plasmids were sequenced. The sequences were assembled using DNA baser V. 3 program. About 100 ng of DNA from R16F2n/R16R2 primed PCR product from each province was separately digested with 2.5 μL of AluI, HaeIII, HpaII, HinfI, RsaI and TaqI restriction enzymes according to the manufacturer’s instructions. Restricted DNA fragments were analyzed by electrophoresis through a 2% agarose gel. Phylogenetic tree was generated using neighbour-joining method with MEGA7 software. Acholeplasma laidlawii, a culturable mollicute that is phylogenetically related to the phytoplasmas, was designated as the out-group to root the tree. The reliability of the tree was assessed by bootstrap analysis with 1000 times replication. Further, the sequences of the 16S rRNA gene were subjected to virtual restriction fragment length polymorphism (RFLP) using iPhyClassifier software (http:// plantpathology. ba. ars. usda. gov/ cgi- bin/ resource/ iphyclassifier. cgi) to determine ribosomal group affiliation.
Cowpea plants collected from East Azarbaijan province showed disease symptoms similar to those caused by phytoplasmas. In infected cowpea plants, symptoms of little and thickened leaves, phyllody, proliferation of shoot, wrinkled and malformed leaves, stem fasciation and stunting were observed. Inoculated periwinkles showed little leaf, internode shortening, yellowing, virescence, phyllody, stem and floral proliferation and witches’ broom. Amplification of 1830 and 1245 bp fragments in PCR and nested-PCR, respectively, and Blast analysis of the fragment sequences confirmed phytoplasma infection of cowpea plant associated with phyllody symptoms. No band was found at healthy control. Consensus sequences of 1,830 bp of three isolates (Tabriz, Nazarlou, Shabestar) were submitted in the NCBI GenBank under accession numbers KC633092 to KC633094. Phylogenetic analyses and restriction fragment length polymorphism (RFLP) of 1245 bp fragment with 17 restriction endonucleases using iPhyClassifier software indicated that phytoplasma associated with cowpea phyllody belong to Clover proliferation group or 16SrVI A subgroup (similarity coefficient 1.00).
Tomato (Solanum lycopersicum), potato (Solanum tuberosum), cucumber (Cucumis sativus), cabbage (Brassica oleracea) and periwinkle (Catharanthus roseous) were reported as hosts for 16SrVI phytoplasma group in Iran. Recently, maize (Zea mays) has also been reported as a natural host of the 16SrVI group. In addition, different phytoplasma groups and subgroups were reported infecting cowpea crops from different countries over the globe. A 16SrXII-B strain of 'Ca. Phytoplasma australiense' associated with witches’ broom and small leaves of V. unguiculata var. sesquipedalis in Australia. A Vigna little leaf phytoplasma belonging to group 16SrV has also been reported from Australia. In India, different phytoplasmas associated with cowpea from 16S rDNA groups 16SrI-B, 16SrXIV-A and 16SrII-D, have been characterized. Identification of the causal agent of phyllody of cowpea in Iran should facilitate studies concerned with epidemic aspects of the disease, and could contribute to knowledge of the genetic diversity of phytoplasmas in Iran. To the best of the present study authors’ knowledge, it is the first report of the Vigna unguiculata infection with phytoplasmas related to the “Clover Proliferation Group” from East Azarbaijan province of Iran.

Callosobruchus maculatus is an important cowpea pest in stored condition. The longer effects, safeness of gamma radiation doses are less hazardous for both human and environment. Effects of different gamma radiation (Co60) doses on amount of nitrogen, protein, pest damage, life cycle, fecundity were evaluated under laboratory conditions. Results of gamma radiation doses increased found ineffectual on cowpea nitrogen and protein contents. Insect larvae damage on cowpea in comparison to controlled treatment at different interval and during 21 days sampling period observed significant (f=17.89, df=5, 2) P=0.0001). Max. (29.8%) and Min. (2.46%) larvae damages recorded at 1st and 21st days after hatching. Effects of different gamma radiation doses (5to 50 Gy) on viability of 100 eggs in each treatment showed that significant (f=7.57, df=4, 8) P=0.0001). While least effects recorded for 5 and 10 Gy, hatchability reduced to 57% and 56% for influence of 20 and 25 Gy radiation, with increasing more gamma radiation complete eggs mortality recorded. Results of 20 to 80 Gy radiation on cohort population of adults found significant (f=5.27, df=6, 7) P=0.0001). Min. control recorded for 20 Gy in group a of Duncan method and with increasing gamma doses radiation, reduction on rate of insect fecundity observed and maximum 44.68% recorded for 70 and 80 Gy doses in comparison to control treatment. The positive controlof gamma radiations doses on cowpea seed beetle developmental stages seems to be a safe protective technique against this store insect pest.

The insecticidal efficacy of three Iranian diatomaceous earth (DE) deposits obtained from Maragheh, Mamaghan, Khorasan Jonoobi mines and a commercial formulation, Sayan®, was assessed against adults of Callosobruchus maculatus F. (Coleoptera: Bruchidae). Cowpea grains were treated with four concentrations including 200, 600, 1000 and 1500 mg/kg and each concentration replicated four times. Experiments were carried out at 28±1˚C and 55±5% R.H. in continuous darkness. The mortality was counted after 2, 5, and 10 days of exposure. After 10 days, all adults were removed from vials, and the vials were left at the same conditions for an additional 35 days, to evaluate the progeny production. The mortality percent increased with increasing concentration level and time exposed to each concentration. Mamaghan, Khorasan Jonoobi and Maragheh DE deposits have the most insecticidal toxicity against adults after 10 days of exposure, respectively. The concentration 1000 mg/kg of these DEs was sufficient enough to suppress C. maculatus progeny production. Therefore, Iranian DE deposits may be applied as a suitable tool in stored products pest management programs.

Population density, sampling program and spatial distribution pattern of the eggs and larvae of Callosobruchus maculatus on cowpea (var. Parastoo) were determined in Tehran region. Bean pod was selected as a sample unit and the reliable sample size with maximum relative variation of 20% was obtained 50. Taylor's power law and Iwao's patchiness regression, Index of dispersion and Lloyd's mean crowding methods were used for determining the spatial distribution pattern of eggs and larvae of the pest. The relationship between length and diameter of pods with number of laid eggs was determined using linear regression. There was significant positive relationship between number of eggs and the length of pods. The relationship between number of eggs and diameter of pods was also significantly positive. There was no significant relationship between number of larvae and length/diameter of bean pods. Moreover, the spatial distribution pattern of immature stages of pest using Taylor's method, index of dispersion and Lloyd's mean crowding was aggregated. Occurrence of the pest in field was observed early summer and irregular population fluctuation was recorded during growing season.

Bean common mosaic virus is widely spread in the world, and also causes functional impairment in the quality of the product. Using tolerant and resistant genotypes is one of the main approaches to the management of this disease. For this purpose, the present study was conducted in two separate sections. 20 cowpea genotypes were studied in two separate experiments, with and without infection in a randomized complete block design, with three replications in greenhouse. The infection was conducted in 2-leaf phase by mechanical inoculation and morphological evaluation was recorded 21 days after infection. ELISA test was used to determine the infection rate of genotypes. Infection of cowpea genotypes were also checked by RT-PCR test using specific BCMV primers. Results suggest amplified fragment with length of 373 bp in the infected plants. The infection rate of different genotypes was 66.6 to 80%. According to the symptoms caused by mechanical inoculation with BCMV to cowpea genotypes was scored between 0-4 which used to obtain disease severity. According the all results, the genotypes divided to hypersensitive, sensitive, semi-resistant and resistant group.

The effect of different artificial diets based on the seeds of one cowpea cultivar (Mashhad) and four chickpea cultivars (Arman, Azad, Binivich and Hashem) on biological and life table parameters of Helicoverpa armigera (Hübner) was studied at 25±1ºC, 65±5% RH and a photoperiod of 16:8 (L:D) hours. The larval period ranged from 13.26 to 21.54 days on Binivich and Mashhad, respectively. The longest and shortest development time of H. armigera was on Hashem (38.62±1.56 days) and Azad 33.81±0.09 days), respectively. The highest fecundity (total number of eggs laid per female) was obtained on Mashhad 1227.23±10.27 eggs) and lowest value of this parameter was on Arman (351.00±1.29 eggs). The highest net reproductive rate (R0) was on Mashhad 250.60 ±0.25 female offspring) and lowest value of this parameter was on Arman (59.49±0.49 female offspring). The intrinsic rate of increase (rm) was the highest on Azad (0.205±0.001 day-1) and lowest on Arman (0.140±0.006 day-1). In different host plants examined, the value of mean generation time (T) ranged from 24.11±0.25 to 30.41±1.30 days and doubling time (DT) ranged from 3.22±0.5 to 4.88±0.25 days. The results indicated that Azad and Arman were the most suitable and unsuitable cultivars incorporated into artificial diet for population growth of H. armigera, respectively.

In order to evaluate the competitive ability of legume cover crops on interference of weeds in corn، an experiment was carried out in Sari Agricultural Sciences and Natural Resources University during 2011 growing season. This research was carried out based on complete block design with three replications. Treatments consisted of three cover crops including: soybean (Glycine max L.)، fenugreek (Trigonella foenum gracu L.) and cowpea (Vigna unguiculata L.) planted at two different dates (simultaneous with corn and 21 days after planting of corn)، along with two controls (no weeding and weeding). In this study the competition index (CI)، ability of withstand competition (AWC)، grain yield and morphological characteristics of corn were evaluated. The results showed significant differences in the AWC and CI among the cover crops. 21 days after planting of corn for cowpea had the highest CI. At simultaneous with and 21 days after planting of fenugreek، the lowest CI (0. 64 and 0. 32 respectively) was observed. Planting cover crops such as soybean at the simultaneous with and 21 days after planting of corn and planting cowpea after 21 days was effective in weed control and also، AWC of corn was highest. Generally، the results of this research showed the highest ones of 11853/13 and 11447/4 Kg h-1 was achieved in control (with weeding) and the cowpea at the 21 days after planting of corn، respectively.

Proteases are considered as major digestive enzymes in alimentary canals of most insects، which are responsible for providing amino acids and energy from nutrients for insects’ growth. The substrate azocasein was used for measuring general proteolytic activity of midgut extracts from Helicoverpa armigera (Hübner) larvae reared on different chickpea cultivars (Arman، Azad، Binivich and Hashem) and a cowpea cultivar (Mashhad) when incorporated into artificial diets at different pH values (6 to 12). The experiments were preformed at 25 ± 1Cº، 65 ± 5% RH and a photoperiod of 16:8 (L: D) h. The results showed that the lowest general proteolytic activity of the third، fourth and fifth instar larvae was on Arman، Binivich and Arman (4. 31، 4. 26 and 4. 31 U/mg، respectively)، while the highest rate was in the larvae fed on Mashhad، Azad and Mashhad (6. 68، 6. 31 and 6. 67 U/mg، respectively)، respectively. The general proteolytic activity in H. armigera larvae on all examined cultivars had an increasing trend in pH from 6 to 12. The optimum pH value of proteolytic activity in the larvae fed on different cultivars was 12، suggesting the maximum proteolytic activity of H. armigera larvae at high alkaline pH. Mashhad and Arman cultivars were the most and the least suitable hosts for H. armigera، respectively.

The cowpea weevil, Callosobruchus maculatus is the one of the most destructive pests of the dried seeds including cowpea, chickpea, lentil, mung bean and broad bean. In the last few decades, the use of environmental friendly insecticides, particularly plant-based compounds, has attracted attention of many researchers. The objective of the present work was to evaluate the fumigant toxicity of the essential oils extracted from the aromatic species, Zataria multiflora and Lavandula angustifolia on the cowpea weevil, C. maculatus. The essential oils from Z. multiflora and L. angustifolia were extracted using a Clevenger apparatus. Bioassays were conducted on both sexes of one-2 day old C. maculatus adults within the enclosed 27 ml glass vials under 29±1ºC, 60±5% RH and dark condition. Differences in toxicities between essential oils were made by comparing the estimates of LC50s, LC90s and probit mortality-concentration regression lines provided by POLO-PC computer software. The toxicities of both materials were significantly and positively associated with concentration and exposure time. The males were more sensitive than females. The insects of both sexes were 9-10 times more tolerant to the extract from Z. multiflora comparing to that from L. angustifolia. The 24h LC50 values of Z. multiflora oil were 329 and 562 µlL-1 and the counterpart values of L. angustifolia oil were 34 and 54 µlL-1 for males and females, respectively. The results showed the essential oils from L. angustifolia can be a good candidate for more and practical assays.