Assessment of the biological control capability of <Emphasis Type="Italic">Hippodamia variegata</Emphasis> (Col.: Coccinellidae) using functional response experiments

Lady beetles are among the most successful predators of aphids in different environments. The functional responses of different life stages of Hippodamia variegata (Goeze) towards cotton aphids were examined in two different set-ups, a two-dimensional Petri dish set-up with detached leaves and a three-dimensional set-up with whole plants. In addition, the functional responses in two-dimensional set-ups towards cotton aphids and the pea aphids were compared. H. variegata exhibited a functional type II response to both cotton aphids and pea aphids irrespective of life stage and spatial scale of the set-up. Females and fourth instars generally had higher search rates than third instars whereas handling times were consistently lower for the fourth instar stage compared with the preceding juvenile stage and with females. The spatial dimensions did not have any significant influence on the functional responses towards cotton aphids, except for third instars which in the three-dimensional set-up reduced their search rate and increased their handling time. Fourth instars reacted in the same way to both Aphis gossypii and Acyrthosiphon pisum whereas the functional response parameters for third instars and females were significantly different on the two prey species. Our study, a part of this first-step evaluation of H. variegata as a biocontrol agent against A. gossypii and A. pisum under field condition, suggest that the voracity of all tested stages of H. variegata towards both aphid species hold good promises for a use of especially fourth instars and females in inundative biocontrol.     

Effect of Fe,Zn and Cu on quantity and quality characteristics and nutrient accumulation in wheat

Journal of Crop Science and Biotechnology - Wheat is the most important food on earth. Therefore, to produce high-quality products with efficient utilization, the micronutrient groups are needed....     

Multilocus Sequence Typing for Molecular Epidemiology of Stenotrophomonas maltophilia Clinical and Environmental Isolates from a Tertiary Hospital in West of Iran

Background: Stenotrophomonas maltophilia is an opportunistic bacterium, contributing to different hospital-acquired infections and can be acquired from different hospital setting sources. Epidemiological study of S. maltophilia in the hospital also demonstrates the intrahospital distribution of certain strains of bacteria in healthcare facilities. The aim of the current study was to identify the molecular epidemiology of S. maltophilia isolates from clinical and environmental sources within a hospital. Methods:A total of 400 samples (clinical and environmental) were collected from the different settings of hospital. Following the standard biochemical testing and 23S rRNA genotyping, the molecular typing of S. maltophilia isolates was determined using the MLST technique. Also, the frequencies of zot and entF virulence genes among S. maltophilia isolates were examined by PCR technique. Results:Based on the biochemical testes and PCRs targeting 23S rRNA gene, 22 S. maltophilia isolates were identified. The MLST analysis demonstrated that these isolates were assigned to 14 ST, and 6 out of 14 STs were common among clinical and environmental samples. All 22 isolates were identified in the PubMLST database. The PCR screening demonstrated that none of 22 S. maltophilia isolates had zot virulence gene, while the entF gene with the 59% frequency was observed in 13 out of 22 isolates. Among these 13 isolates, 6 STs were common in clinical and environmental isolates. Conclusion:Our study showed the clonal relatedness between clinical and environmental sources of the S. maltophilia isolates in a hospital. Further studies are required to understand the epidemic situation of this pathogen in the clinic and the environment. Key Words: Environment, Multilocus sequence typing, Stenotrophomonas maltophilia     

An abattoir study on hepatic tumors of sheep

The aim of the present study was to assess the incidence and age distribution of hepatic tumors of sheep as well as study of their histopathologic characteristics. For this purpose, 3000 slaughtered sheep, consisting of 284 rams with approximate age of 7 to 20 months and 2716 ewes with approximate age of 3 to 7 years, were inspected during a routine postmortem examination. This study was conducted at Tabriz abattoir in the East Azerbaijan province of Iran, in a course of 8 months from March to November 2006. In this survey, two livers were encountered tumoral. Representative sections of the tumors were stained with hematoxylin and eosin. Gross and microscopic features of these tumors supported diagnosis of hepatocellular carcinoma and cholangiocellular carcinoma for a seven-years-old crossbreed ewe and a five-years-old native breed ewe respectively. In this survey, 0.074% of slaughtered ewes had hepatic neoplasia. That is, the prevalence of hepatocellular carcinoma and cholangiocellular carcinoma in aged ewes was equally 0.037% in this study.     

Extraction and purification of crocin from saffron stigmas employing a simple and efficient crystallization method

In this study, total crocin was extracted from saffron stigmas using crystallization method. Ethanol 80% was selected as the best extraction solvent. Crystallization process was carried out in one and two steps at different temperatures. Ethanol 80% was used as crystallization medium. Crocin crystals obtained from the first crystallization had low purity and thus were subjected to the second crystallization. The higher purity crystals were yielded in the second crystallization at -5 degrees C. The purity of crocin crystals was studied using UV-visible spectrophotometery and HPLC in comparison with Fluka product and methanolic extract of saffron stigmas. The results indicated that its purity was extremely higher, about 13 times, more than Fluka product. In spite of our expectation, the Fluka product was not a pure alpha-crocin sample; five other types of crocins in addition to an unknown impurity were seen in its chromatogram. The purity of crystallized total crocin in this work was more than 97%.     

Population genetic structure and ecological niche modelling of the leafhopper Hishimonus phycitis

Witches’ broom disease of lime, caused by ‘Candidatus Phytoplasma aurantifolia’, is responsible for major losses of Mexican lime trees in Southern Iran, Oman and the United Arab Emirates. The causative phytoplasma is transmitted by the leafhopper, Hishimonus phycitis. We combined ecological niche modelling with environmental and genetic data for six populations of H. phycitis from Iran and one from Oman. The mitochondrial cytochrome c oxidase I (COI) gene and nine microsatellite DNA markers were used for the genetic analyses. Although the Oman population had specific haplotypes, the COI sequences were highly conserved among all populations studied. In contrast, the microsatellite data divided the populations from Iran and Oman into two separate clades. An analysis of molecular variance indicated a high level of variation within populations. The Mantel test showed no correlation between genetic and geographical distances. Gene flow values were small between the populations from Iran and north of Oman but significantly higher among the Iranian populations supporting the differentiation between Iran and Oman. In addition, we found that patterns of genetic divergence within Iranian populations were associated strongly with divergence in terms of their ecological niches. Data on six climatic variables, including elevation, were used to create ecological niche models. Our results suggest that the genetic differentiation of H. phycitis may be attributable to climatic conditions and/or geographical barriers.