نشریه تحقیقات نوین در گیاه پزشکی
سال نهم شماره 3 (پیاپی 24، پاییز 1397)

Potato soft rot is a common and important disease on potatoes. Fifteen pectolytic bacteria with green metallic colonies on EMB medium were isolated from the tubers showing surface cracking and soft rot symptoms, simultaneously. All the isolates grew at 37 ˚C, no starch digestion, they were not sensitive to erythromycin and negative for phosphatase. They could not use sugars of Xylose, Trehalose, α-methyl D-glycoside and Malonate, while they were able to use Inositol, Rhamnose and Arabitol sugars. Based on These characteristics the isolates recognized as P. carotovorum subsp. carotovorum. The isolates were further identified by PCR amplification with primer G1/L1 which produces two bands similar to those produced in P. carotovorum subsp. carotovorum, but not from P. carotovorum subsp. atrosepticum and Dickeya chrysanthemi. Digestion of the amplified PCR product with restriction enzyme Rsa I resulted in identical 385 bp, 280bp and 180 bp bands formation as described for P. carotovorum subsp. carotovorum. The results of physiological, pathogenicity, biochemical and molecular tests, confirmed that all bacterial isolates induced soft rot symptoms in potato tubers are P. carotovorum subsp. carotovorum.

Essential oils and extracts are suitable compounds as alternative chemicals. Many plants have compounds with control properties that recently the use of herbal products as alternative to chemical pesticides for control of plant-damaging agents is more important and the essential oils and herbal extract are of particular interest. The present study was carried out to investigate the antibacterial effects of essential oil and ethanolic extract of Pimpinella anisum and Artemisia dracunculus leaves on Erwinia amylovora, Agrobacterium tumefaciens and Pseudomonas syringae pv. syringae. This study was done based on a completely randomized design with temperature conditions of 28 ± 1 °C and relative humidity of 65 ± 5%, in dark conditions with concentrations (10, 20, 30, 40 and 50 μl) plus 3 replicates for each concentration of essential oil and extract with control At one and two weekly visits. The results showed that antibacterial effect of essential oil and ethanol extract of Pimpinella anisum and Artemisia dracunculus on bacteria Erwinia amylovora, Agrobacterium tumefaciens and Pseudomonas syringae pv syringae were significant compared to the control. Also, whatever the concentrations of essential oils and extracts used in this study increased, so the rate of bacterial growth significantly decreased. Moreover, the results showed that the antibacterial effect of extracts on the growth of bacteria examined in this study is better than the essential oils studied and plant extracts in visit one or two weeks at the same time better than essential oils and show better appropriate action. According to the results of this study, essential oils and extracts of Pimpinella anisum and Artemisia dracunculus can be introduced as an appropriate alternative to commonly used Chemical bactericides against these bacteria.

This research investigated the time variation of aphid species diversity in wheat field of Saman, Chaharmahal and Bakhtiari province during 2017. Sampling was conducted from a 3 hectare wheat farm in Saman, twice a month, in each time 100 plants were randomly taken. Alpha species diversity indexes including Shannon-Wiener, Simpson, McIntosh and Pielou, Simpson, and Macintosh uniformity species indexes were calculated in each sampling period. The diversity of aphids was compared by Renyi's diversity ordering method. Estimation of maximum species richness was done using nonparametric indices. Analyzes and calculations were performed using SDR4 software. A total of 8258 individuals were collected from aphids during the whole sampling period, which is belonging to eight species as follows: Diuraphis noxia (Mordvilko, 1913), Ford hirsute (Mordvilko,1928), Rhopalosiphum padi (Linnaeus, 1758), Rhopalosiphum sp., Metopolophium dirhodum (Walker, 1849), Sipha elegans (Del Guercio, 1905), Sipha sp. and Sitobion avenae (Fabricius, 1775). The most abundant species were the Russian wheat aphid, D. noxia and the rose-grass aphid, M. dirhodum, with 53.05 and 43.47 percent of the total aphid individuals respectively. Non-parametric methods of estimating species richness showed that additional sampling would yield at most 12 wheat aphid species in Saman wheat fields. A discussion was provided on species richness and species composition of wheat aphids during time in Saman region and also compared to other studied regions in Iran.

The Sunn pest, E. integriceps, is the most important pest of wheat fields in Iran. In order to investigate the lines of Durum wheat in terms of resistance to E. integriceps, was conducted experimental in 2016, Neyshabour Research Center. The experimental design was a randomized complete block design with three replications. The treatments consisted of 20 genotype: 18 lines of durum wheat, two cultivars of Dena control and Parsi wheat cultivar. According to the results, the highest number of overwintered adults of E. integriceps was located in genotype 1 (Dena wheat) and the lowest in genotypes 12, 2 (Persian wheat) and 16. The highest number of damaged leaves was in genotype 11 and the lowest number was in genotypes 16, 10 and 6. Investigating the traits of number of sprouts showed that genotypes number 1 and 6 had the highest and lowest number of buds respectively. The days to spike emergence and number of days to physiological treatment were affected by the treatments. The highest number of days until the appearance of spike was genotype number 18 and the least of these traits were genotypes number 9, 1, 11 and 14. The maximum length of peduncle was recorded in genotypes Number 11, 9 and 15, and the lowest peduncle length was observed in genotypes1 (Dana), 16, 18 and 19. There was no significant difference between the 20 genotypes in terms of yield, biological yield and harvest index. Genotypes 1, 13 and 18, along with the important indices of Yp, Ys and GMP in the region with high production potential and low sensitivity to E. integriceps Genotypes adjacent to SSI and TOL sensitivity indexes (Genotyp 4) are also low 1000 seeds weight. Weight of 1000 grains in non-activity of E. integriceps condition (Yp) had a positive and significant correlation with geometric mean (GMP), stress tolerance index (STI) and yield index (YI). Weight of 1000 seeds in terms of activity of E. integriceps (YS), was a positive and significant correlation with all indices. Accordingly, the mean of productivity (MP), geometric mean (GMP), stress tolerance index (STI) and yeild index (YI) were the only indices that showed a positive and significant correlation with grain yield in terms of E. integriceps activity and E. integriceps inactivity. Finally, within the scope of the study, three genotypes 1, 13 and 18 were sunn pest tolerant genotypes in Neyshabur region and genotypes 4, 7 and 15 were susceptible to sunn pest with lowest 1000 seeds weight.

Ralstonia solanacearum is the cause of tomato bacterial wilt. Under favorable environmental conditions, it can cause rapid wilt and a lot of damage, and there is no practical remedy for it. The aim of this study was to separate endophytic bacteria B. cepacia from tomato stems of local cultivar and then to study the biocontrol effect of this bacteria against the bacterial wilt of tomatoes.
In this study four endophytic bacteria from tomato stem were isolated. Then after identification with bacteriology standard tests in order to investigation of their antagonistic effect and also effect on the growth rate of the plant in vitro with seed diffusion agar method were examined. Result of biochemical tests showed that all of endophytic bacteria which isolated from tomato stem were B. cepacia. In in vitro condition on the seed with B. cepacia bacteria in medium containing R. solanacearum bacteria showed the formation of 2- to-4.5 –mm haloes. In greenhouse conditions, these bacteria caused a suppression of the disease by about 60% and a significant increase in tomato plants, and a significant difference with the control was observed.

Codling moth, Cydia pomonella L. (Lepoptera: Tortricidae), is the key pest of apple orchards in Mahabad and West Azarbaijan province. To determine the best spraying time, male adults’ emergence was studied in Mahabad during 2016. Three types of delta, cylindrical and funnel-shaped traps were used in an apple orchard (5 hectare) in a randomized complete block design. The efficiency of three style pheromone traps was compared. According to the data obtained from regional weather station and larval activity, degree-day model was prepared. It was found that adults appeared in late spring and was showing four populations peaks during growth season. The results showed that there was a significant difference between the traps In terms of trapping male adults (P≤0.05). On the basis of the data available by funnel-shape traps, the results showed that 168.3, 722 and 1301.9 degree-days were required for egg eclosion at first (winter), second and third generation, respectively. Also, on the basis of the data available by delta and cylindrical-shape traps, the results showed that 154.2, 538.1 and 1198 degree-days were required for egg eclosion at first, second and third generation, respectively. On the basis of the data available by funnel traps the chemical control time was determined to be 10-14 May, 1-5 July and 9-14 August 2016 for three generation. Also, on the basis of the data available by delta and cylindrical traps, the chemical control time was determined to be 7-11 May, 17-21 June and 2-6 August for three generation. The comparison of means showed that the funnel traps had the most capture with means values of 41.00±8.64, 26.34±3.18, 85.67±19.37 and 73.67±3.89 number of male adults for wintering, first, second and third generation, respectively. Also, the cylindrical traps had the least capture with means values of 11.34±1.20, 5.67±1.76, 13.67±2.73 and 53.67±3.16 number of male adults for wintering, first, second and third generation, respectively.