نشریه تحقیقات نوین در گیاه پزشکی
سال ششم شماره 2 (پیاپی 16، تابستان 1393)

Feeding potential and survival of predator, Chrysoperla carnea on nymphal population of greenhouse whitefly, Trialeurodes vaporarium were studied in lab conditions. Daily consumption rate of larval different stages of green lacewing on pest nymphs was 16.04±1.74, 21.5±2.56 & 22.3±1.92 for 1st instar, 2nd instar and 3rd instar respectively and predator consumpted 215 different stsge nymphs of greenhouse whitefly totally. Survival percent reduced from egg(85%) to 3rd instar(4%) so that not convert to pupariom stage anyone and died. So in spite of enough population of pest, the predator could not complete it, s development.

Cereal cyst nematodes are one of the most important damaging nematodes of wheat and barley in the world. Heterodera filipjevi is widely distributed on wheat in Iran. In this study, an experiment was conducted with four wheat cultivars (Cvs. Chamran,Virinak,Yavarus and Behrang), barley (Cv. Zehak) and triticale (Cv. Janilo) in a randomized complete block design with 6 treatments (1 plot not sprayed and 1 plot sprayed with a nematicide as control) and four replications in a nematode infested wheat field in Ramshir region of Khuzestan province during growing season 2008-2009. The results indicated that usage of nematicide reduced grain yield, shoot dry weight, shoot height and tillering by 31-73, 6-47, 1- 21 and 11-40 percent respectively as was compared to control. H. filipjevi was multiplied on the all plants in the test, but durum wheat cultivars were better than bread wheat cultivars to the nematode.

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.

Citrus bacterial canker, caused by Xanthomonas citri subsp. citri, is one of the most important diseases of citrus in tropical and subtropical regions. Accumulation of pathogenesis-related proteins such as β -1, 3 glucanase against plant pathogen attack, as plant defense mechanisms against plant pathogens is considered. To investigate the expression of PR-2 genes related β -1, 3 glucanase and the effective enzymes in induced resistance to citrus canker, an experiment was conducted in a completely randomized design. The amino acid methionine at a concentration of 25 mM and distilled water as control, were used for this study. After 48 hours post treatment, plants were inoculated with 5 ml of bacterial suspension (at a concentration of 108 colonies per ml) by syringe without needle and contained under greenhouse conditions. Based on phenotypic tests results, there were significant difference in the level of 0.05 between the amino acid methionine treated plants and control plants treated with sterile distilled water. The molecular test results indicated an increase in the expression of PR-2 at 24, 48 and 72 h after inoculation. Based on the results of antioxidant enzymes activity study in stressed plants, plants treated with the amino acid methionine significantly increased the enzyme activity of peroxidase and phenylalanine, however, did not affect on catalase activity.

Lesser grain boror Rhizoperta dominica in widly distributed in the world wide. Its caused damage to stored product pests, specially on wheat. Damage of this pests, terminating to decrease seed weight and Viability The averege of damage and feeding rate of above pest was studied with eight lines and cultivar such as: Kouhdasht, Zagros, Morvarid, Darya, Pastor, Line 17 and N-80-19. Experiment was down as randomly complete black design with explications in laboratory canditions. A hundred grams of wheat plased in a crystal container and with 10 adult ware put on each container and them, bottle door will cover with net. seed weight, Viability Pure varietis in two stage, before pests at end to meas used expsmate. Analysis of variances has been shown all characteristics of wheat varietis todamege and feeding of Lesser grain boror wese not signiticant differences. comparison average of varieties of wheat Viability and seed weight before experimant, has not shown signiticant differences, but effect to feeding and damege of Lesser grain boror to Viability and wheat varietis has been decrease of except Morvarid variety. Morvarid variety least decrease Viability (10.34). and decrease un purity of seed (12.84) and less percantage decrease seed weight (13.07). Morvarid variety with weight of hectoliters (66.50). Darya variety with more percentage decrease weight (21.97) and more percentage decrease un purity was (21.94),but with more weight Hectoliter (67.32) after experimant and more percantage of decrease of Viability (27.33) belong to pastoor variety. These bore, feeding and damage of Lesser grain boror, these was lesse effect on Viability and physical characteristics of Morvarid seed variety and resistance (possible used that in programm of IPM) Darya varietys and Pastor was more effect feeding of pests, and it was mor on resistance variety in between other varietys has been investigcated.

Wheat take-all, caused by Gaemannomyces graminis var. tritici, has been observed in recent years in different areas of Iran. In this study, in order to investigate the possibility of biological control of pathogen, seven isolates Trichoderma include T. harzianum S, T. harzianum A, T. harzianum M, T. koningi, T. longibrachiatum and T. virens and four isolates of Talaromyces include Talaromyces flavus 134, Talaromyces flavus 136, Talaromyces flavus 75 and Talaromyces flavus 60 used against the pathogen by extracellular fluid method in vitro condition. The experiment was arranged as randomized complete design with 3 replication. The effect of extracellular fluid of antagonistic isolates on mycelia growth of Ggt indicated that the extracellular fluid of Talaromyces flavus 136، T. harzianum and T. harzianum S isolates the rate of 5 ml after 72 hours of rate (41/51, 40/88 and 37/73 %) and T. longibrachiatum isolate at rate of 10 ml at two times of measurement (52/83 and 52/38%) had the most inhibition effect on the growth of pathogen. This study has been the first study related to biological control of wheat take-all by T. flavus.

The efficacy of locally available organic amendments such as neem cake, castor cake, pungam cake and vermicompost @ 400 and 500 kg/ha were evaluated against Meloidogyne incognita in medicinal Thymus vulgaris under glasshouse and field conditions. Results revealed that all the organic amendments were found to reduce M. incognita population and increase yield of test plant. Further, among all organic amendments, neem cake was found significantly superior in reducing the nematode population and increasing growth and yield of medicinal Thymus than pungam cake, vermicompost and caster cake. Neem cake application reduced M. incognita population 28.6 – 31.2 % in soil and neem cake amended Thymus plants recorded the gall index by 3.3 – 4.0. It increased the yield by 39.8 – 42.4 % under glasshouse condition and 9.0 % under field conditions.

A field trial was conducted to find out the efficacy of neem based [neem seed water extracts (NSWE) @ 40 ml/lit and Vanguard @ 5 ml/lit], comparison with bavistin @ 1.5 g/lit, against the Fusarium wilt of chickpea (Fusarium oxysporum f.sp. ciceri). Bavistin proved to be the most effective against the Fusarium wilt between these treatments. Maximum plant height was recorded in case of plot treated with Vanguard followed by seed water extract. Maximum number of pods was collected from plots sprayed with Vanguard. Highest grain yield was obtained due to bavistin, applied at 30, 50 and 70 days after sowing (DAS) but the benefit/cost ratio was highest (3.03:1) in one spray of NSWE, applied at 70 DAS which was more economical than other treatments.