نشریه تحقیقات نوین در گیاه پزشکی
سال سوم شماره 2 (پیاپی 10، تابستان 1390)

Effect of color and design of the trap, dosage of pheromone component in rubber capsule and trap height on the efficiency of Grapholita (Aspila) funebrana Treitschke, 1835 (Lepidoptera: Tortricidae) pheromone traps were evaluated. The study was conducted in Bavanat of Fars province. A Randomized Complete Block Designused with four blocks and four replications in each block. To find the best trap color, yellow, green, brown, and white colors were tested. Using Duncan procedure, yellow and brown colors were significantly different from each other (P<0.01). Yellow and brown were ranked in a separate group, white and green were ranked in another group and were not significantly different (P<0.01). The majority of G. funebranamoths were caught in brown trap. To determine the best suitable trap design, three pheromone traps, Delta, Cylindrical and Wing shape, were tested. Delta with highest moth catches was superior in comparison with other trap designs. Three different heights, one meter from the ground, middle of the canopy of the tree and top of tree were tested on order to determine the role of the trap height on the efficiency of traps. The highest numbers of moths were caught in the traps which were positioned on the middle of the canopy of the trees. The doses of 0.5, 1, 1.5, and 2 mg doses of the pheromones formulated in Plant Protection Research Institute (PPRI) compared with a foreign rubber capsule (AgriSense, 1 mg). The results of the test revealed that the doses of 0.5 rubber capsule was superior and had more catch (P<0.01). The other doses were not significantly different (P<0.01).

Reaction of some almond cultivars including Sefid, Mamaei, Rabie, Non pariel, Shahrood 6, Shahrood 7, Shahrood 13, Shahrood 21 and Shahrood 12 to almond spider mite. Schizotetranychus smirnovi Wainst. Were evaluated in Saman region, during 2008-2009. In the first trial, after grafting of cultivars on GF677 root stock, they were transferred to an orchard and were kept under insect net to prevent natural infestation. Cultivars were infested artificially by introducing 5 adult female mites on each plant. Twenty one days after infestation, leaves were collected and mite population density (number of eggs, nymphs and adults) were counted. Results indicated that Sefid and Feraduel (Shahrood 12) cultivars supported the highest mite population; whereas, Shahrood21 and Shahrood 6 supported the lowest mite population. In the second trail, almond cultivars were evaluated under natural infestation during 2 sampling times (with 15 days interval). Mean comparison of the mite population density (eggs, larvae, nymphs and adults) showed that Mamaei cultivar (mean 63 and 206.2 mites in the first and second sampling times, respectively) supported the highest; whereas, Shahrood 21 (mean 6.2 and 22 mites) supported the lowest mite population density. Study density of leaf trichomes and concentration of leaf total phenolic compounds showed that there was not significant positive relation between them and resistance to the mite.

A research was conducted in Yasouj region to determine population dynamics of the gypsy moth in 2006 and 2007. Also it was aimed to calculate the correlation coefficient between the population densities of 2006 and 2007, in order to build a predictive model for the pest. The number of overwintering egg masses was counted during the winter months in ten different orchards. The number of egg masses of the pest was recorded at weekly intervals in ten orchards during the growth seasons in 2006 and 2007. Results indicated that the egg mass densities were 1.71 ± 0.2 and 2.88 ± 0.3 per fifty squares meter and 342 ± 22 and 576 ± 37 egg masses per hectare in winters 2006 and 2007, respectively. Regression analysis of the pest population density in 2006 and 2007 indicated that only 32.37% of the 2007 population variance could be accounted for the population density in 2006. It was obvious that more than 68% of the population changes are under the influence of unknown biotic and abiotic environmental factors.

Recently, there has been growing interest in research concerning the possible use of plant extracts as alternatives to synthetic insecticides. Essential oils are among the best-known substances tested against insects. These compounds may act as fumigants, contact insecticides, repllants, antifeedants and may affect growth and development of the insect. In an attempt to find a natural and inexpensive method for the control of stored-product pests, contact toxicity of essential oils of Mentha longifolia L., Tagetes minuta L. and Salvia macrosiphon Boiss. was investigated on adult insects of Sitophilus oryzae L. (Coleoptera, Curculionidae) on laboratory condition. The oils were extracted by using Clevenger apparatus. The experiment was conducted using a completely randomized design of factorial experiment with five concentrations and three replications at R.H in darkness. The results showed that the percentage of mortality was increased with increase in concentration and exposure of time. The highest contact toxicity was related to M. longifolia and the lowest toxicity was recorded for S. macrosiphon against insects. At the highest concentration of essential oils (35 µl/ml) by M. longifolia,T. minuta and S. macrosiphon the mortality were recorded as 93.3%,83.3% and 70% against S. oryzae after 48h, respectively. The LC50 values were evaluated by M. longifolia, T. minuta and S. macrosiphon 18.892, 21.003 and 24.482 for S. oryzae after 48h. According to the results, the essential oils of M. longifolia,T. minuta and S. macrosiphon are sources of biologically active vapor that can be used in protection of stored grains against rice weevil.

In this study, identification of fungal pathogens of banana trees (Musaacuminate L.) in Sistan & Bluchestan province during 2005-2007 was studied. After observed of disease symptoms, infected tissues were collected and cultured. For isolation of fungi from diseased samples, small pieces of leaf, corm, pseudostem and fruit were surface sterilized with 5% hypochlorite sodium and then were cultured on potato dextrose agar (PDA) medium contaning lactic acid. The growing colonies of fungi were purified by single spore and hyphal tip methods. Based on the morphological characters and pathogenicity test the fungi were identified as Colletotrichum musae,Aspergillus carnenus, Acremonium sp., Fuasarium verticillioides, F. semitectum, F. subglutinans, F. sambucinum and Musicillium theobromae causing fruit disease while F. oxysporum, Cylidrocarpon sp. and Rhisoctonia solani causing corm and root disease whereas, Alternaria alternate, Drechslera gigantean and Fusarium proliferatum causing leaf disease. This is the first report of occurrence of these fungi in banana trees in Sistan & Bluchestan province.

In 2010 and 2011 surveys of Fars provience were observed symptoms doubtful to phytoplasma diseases such as virescence and phyllody, floral proliferation, witches’-broom, yellowing and little leaf in eggplant fields. To determination of etiology this symptoms, seven infected eggplant plants from Fasa, Jahrom, Firouzabad, Darab and Sarvestan were planted in suitable pots, transferred to a greenhouse without any insects and used as sources of disease for further studies. The causal agents were transmitted from diseased to healthy eggplants by grafting and from eggplant to periwinkle by dodder. In inoculated eggplants, were appeared big bud, little leaf, yellowing and witches’-broom and in inoculated periwinkles, were appeared virescence, yellowing and witches’-broom. Total DNA were extracted from fresh midrib tissues of naturally infected eggplant, experimentally inoculated periwinkle plants and a healthy eggplant and periwinkle plant. In direct PCR using primer pairs P1/P7, DNA fragments of approximately 1800 bp were amplified from total nucleic acid samples extracted from symptomatic eggplant and periwinkle plants. Periwinkle reaction to inoculation with Eggplant Big Bud (EBB) different isolates was variable as based on difference in severity and type of symptoms in periwinkle, EBB different isolates, were placed in six groups. Direct PCR products of EBB different isolates were digested with AluI, HaeIII and RsaI enzymes. Comparison of RFLP patterns indicated that EBB different isolates place in two groups: Fasa 1, Fasa 2, Fasa 3, Firouzabad, Darab and Sarvestan isolates in one group and Jahrom isolate in other group. Based on disease symptoms, dodder and graft transmission and positive reaction in PCR, eggplant big bud in Fars province has phytoplasmal etiology. This is the first report of the presence of EBB in Fasa, Firouzabad, Darab and Sarvestan. With molecular testings in this study, were confirmed there are at least two phytoplasmas associated with EBB in Fars province. By using more restriction enzymes, it is likely to see more diversity in EBB agent in Fars province.

During 2009-2011, the faunistic studies were carried out on the edaphic mites of the suborder Prostigmata in the south of Kamfiruz and Estahban region,Fars province, Iran. In these researches a new cheyletid mite,Microcheyla parvula Volgin,1966 (Trombidiformes: Cheyletidae) is collected and identified. Record of this genus and species is new to the mites fauna of Iran.

In review conducted from fruit trees in Khorasan (Razavi, North and South) provinces, a bud gall mite species were collected on white mulberry trees, Morus alba L. (Moraceae) in 2005-2007. On the host trees, some branches were observed with swollen buds and without leaf. The mites were extracted by directly from buds for identification. Specimens were maintained in clearing media and after preparing slides, identified by scientific keys. The results showed that, this mite is Aceria mori (Keifer, 1939) belong to the family Eriophyidae. This is the first report of this mite from Iran. Necessary methods were presented to prevent the distribution on seedlings and older trees.