Progress in Biological Sciences
Volume:7 Issue: 2, Summer-Autumn 2017

In the present study, JajroudRiverloach, Oxynoemacheilus bergianus (Derjavin, 1934), was examined monthly for a previous observation of oocyte presence within testes tissues. Accordingly, the gonad development in O. bergianus is examined histologically. Although our data show typical fish gonad development and differentiation in female and some male individuals, some males show intersexuality. Gonad histology and development of females’ ovaries were carried out to provide comparative data on oocyte staging in testes. Intersex males were observed throughout the year except in March and July, especially in individuals larger than 5.3 cm total length. Occurrence of intersex males seems to be associated with sex ratios and their deviation from 1:1 and fish age at different times of the year. As no real ovotestes were observed, histological changes were considered to be a transient stage in the testicular tissue with no evidence of sex change in fish. In the absence of testes fully transformed to ovaries, this type of change was considered as intersex.

Life history parameters of the ladybird populations, Propylea quatuordecimpunctata (L.) (Coleoptera: Coccinellidae), collected at two locations in Iran (Karaj and Sari) were recorded on two prey species, Aphis fabae Scopoli, 1763 and Aphis gossypii Glover, 1877 (Homoptera: Aphididae). The duration of most developmental stages (egg, first, second and third instar larvae) of two local populations of P. quatuordecimpunctata differed significantly, except for the fourth instar and pupal periods. A comparison of life table parameters between the two populations with different preys, showed that the net reproductive rate (R0) was not significantly different (P > 0.05). The intrinsic rate of increase (r), the mean generation time (T) and the finite rate of increase (λ) of the population from Sari on A. gossypii, differed significantly from the same population fed on A. fabae (P < 0.05). Our results demonstrated that reproductive traits of two populations of P. quatuordecimpunctata were affected by the geographic conditions and the prey species.

Effects of four tropical plant (Aframomum melegueta, Zanthoxylum zanthoxyloides, Piper guineense and Eugenia aromatica) were investigated under tropical laboratory storage conditions for the protection of cowpea seeds against insect infestation. The plant materials were pulverised into fine powder after air drying and admixed with 20 g of cowpea seeds at the rates of 0.2, 0.3, 0.4 and 0.5 g in 125 ml plastic containers for contact toxicity experiment and 0.5 g of each plant powder to 50 g cowpea seeds for the fumigant toxicity experiment. Ten unsexed Callosobruchus maculatus were used for contact toxicity experiment, while two copulating pairs of C. maculatus were used for fumigant toxicity experiment. Callosobruchus maculatus response to the plant powders was recorded at 24 and 48 hrs post treatment for contact toxicity bioassay, while observation for fumigant activity was recorded at 24, 48, 72 and 96 hrs after treatment. All plant powders significantly (P < 0.05) exerted adult mortality in relations to dosage and exposure time. Cowpea seeds treated with 0.5g of E. aromatica had highest mortality of 90% and 100% at 24 and 48 hrs after exposure respectively for contact toxicity, while A. melegueta recorded the highest adult mortality for all exposure periods for the fumigant toxicity. The insects’ reactions to the plant powders admixed with cowpea seeds were restlessness, loss of coordination, knock-down and eventual death. The study indicated that the plant powders could be used as suitable alternative to synthetic insecticides to suppress C. maculatus infestation in stored cowpea seeds among the resource-poor farmers.

In this study, the aim was to determine the effect of 12 hours delay and time advancement of Bombyx mori larvae transfer to spinning frames on the economic traits of harvested cocoons. Our experience focused on the transfer of three lots of silkworm mature larvae to cocoon frames with 12 hours delay or advancement from usual spinning time. Commercial silkworm eggs were obtained and three replications of 100 larvae per each treatment were used. The larvae and cocoon conditions of hatching and rearing, feeding conditions, silkworm egg production stages were performed based on standard protocols. Rice straws were used as cocoon position (framework) in the cocoon spinning stage separately for each replication. After completion of the pupa development, total cocoon production was collected and classified based on appearance, hardness, softness, and cleanliness levels of the cortex and outer cortex into four categories, viz. good, moderate, low and double cocoons. Economic characteristics were calculated and compared between treatments using the Duncan test at p < 0.05. The comparison of economic traits of cocoons produced in perfected treatments showed no significant difference between treatments and the control. This result suggests that the 12 hours’ time anticipation or delay of larva transfer to cocoons building frames has no effect on the quantity or the quality of produced cocoons. Therefore, it is possible to shorten the rearing duration of Bombyx mori larvae by 12 hours without affecting the cocoon economic traits, and this could improve cocoon production and generate an important economic advantage in commercial sericulture.

Ludab region, known for its unique landscape comprising a vast fertile plain surrounded by high mountains and covered by loose oak forests, is a part of Boyer-Ahmad County in southern Zagros mountain range (West Iran) with an area of 87,715 km2 located 110 km north-west of the capital city, Yasuj. The aim of this research is to assess floristic elements, life forms, chorology, and endemic, medicinal, pasture, and poisonous species in Ludab region. For this purpose, several field trips were done and specimens of three regions of Ludab including Dar-e Bid, Chin, and Gelal were collected during different seasons. A total of 235 species representing 184 genera and 52 families were recognized in the region among which 55 species were endemic to the country. Regarding the life form, the majority of species were hemicryptophytes (45%; 106 species), followed by therophytes (33%; 77 species), phanerophytes (9%; 22 species), geophytes (9%; 22 species), and chamaephytes (4%; 8 species). Most of the species showed the Irano-Turanian (61%) chorotype, while Irano-Turanian/Eurosiberian (16%) chorotype was the next frequent one. From an economical point of view, we recognized 157 medicinal, 67 pasture, and 73 poisonous plant species. A conservation status survey indicated most plant species to be at a low risk (74%), and only few species to be endangered (2%), and vulnerable (2%). Overall, north-west of Ludab region presents a valuable genetic resource due to high number of endemic, medicinal, pasture, and poisonous species.

Lippia citriodora H.B.K. is a valuable medicinal plant of Verbenaceae family. This study was calculated to evaluate potential role of salicylic acid (SA) in diminish the harmful effects of drought stress on L. citriodora plants. SA (0.5 and 1 mM) was used to L. citriodora plants grown under stressed (5, 10, 15 and 20% PEG) and unstressed conditions. Fresh weight (FW) and relative water content (RWC) significantly decreased under water deficit stress. Increase in hydrogen peroxide (H2O2) and malondialdehyde (MDA) content indicated drought-induced oxidative stress in L. citriodora. Water deficit stress significantly increased the protein content, proline content and antioxidative enzymes activities. The exogenous application of SA to drought-stressed plants reduced the content of MDA and H2O2 and increased superoxide dismutase (SOD), peroxidase (POX) and chlorophyll content. It is suggested that SA minimizes the negative effects of drought stress and could be used for amelioration of drought stress in L. citriodora.

The subtribe Eritrichiinae belongs to tribe Rochelieae (Borginaceae; Cynoglossoideae) which is composed of about 200 species in five genera including Eritrichium, Lappula, Hackelia, Lepechiniella, and Rochelia. The majority of the species are annual and grow in xeric habitats. The genus Lappula as an arid adapted and the second biggest genus of Eritrichiinae with over 50 species is distributed predominantly in Irano-Turanian region. Here, we employed BEAST Bayesian inference for divergence time estimation based on nrDNA ITS, plastid trnL-F and rpl32-trnL (UAG) sequence data of 46 species of Eritrichiinae extracted from GenBank. The results obtained from molecular dating analyses indicated that the date of Eritrichiinae crown group back to late Oligocene. Diversification events took place for Lappula in Asia from the late Miocene to the late Pleistocene. The North American species have been derived from the Asian relatives at the late Miocene.

Scutellaria with about 360 species is one of the largest genera of Lamiaceae. The Iranian highlands accommodate about 40 Scutellaria spp., and is considered as one of the main centers of diversity of the genus. Here, we present a phylogenetic study for 44 species of Scutellaria especially from Iranian highlands, representing major subgeneric taxa, based on nuclear ribosomal ITS and trnL intron and trnL-F intergenic spacer using Maximum Parsimony (MP) and Bayesian Inference (BI) analyses. The monophyly of Scutellaria is confirmed in our study, but Scutellaria subg. Scutellaria is shown to be paraphyletic with S. subg. Apeltanthus embedded within it. Moreover, our results reveal that S. subg. Apeltanthus is paraphyletic including one accession of S. repens of S. subg. Scutellaria nested within. In addition, the two sections of S. subg. Apeltanthus, i.e. sect. Apeltanthus and sect. Lupulinaria, are not supported as monophyletic by our plastid and nuclear topologies. Thus, the subgeneric classification of Scutellaria which is mainly based on morphological characters such as the type of inflorescence, shape of calyces, presence of a scutellum and a bladder-like appendage on the upper calyx lip is not supported by our molecular data. Additionally, our phylogenetic study corroborates Paton’s finding on primitive position of S. sect. Scutellaria, but disagrees with the intermediate position of S. sect. Salviifolia between S. subg. Scutellaria and S. subg. Apeltanthus.

Interspecies interaction of actinomycetes will express new gene clusters and may therefore affect the pigmentation, sporulation and production of secondary metabolites. Actinomycetes strains were isolated from Howze Soltan Salt Lake. Binary actinomycete interaction assay was conducted to evaluate its effect on colony morphology and antibiotic production. The molecular identification of the induced strains was performed. A total of 18% of isolates induced antibiotic production of 22% of the other strains against methicillin resistance Staphylococcus aureus (MRSA) and 44 % of them inhibited that of 31 % of antibiotic production in other actinomycete strains. The extract of the selected strains had an inhibitory effect on the pathogen growth. Based on molecular identification, the selected isolates, called act 32, shared 98% similarity with Streptomyces peucetius. It is expected that by screening of actinomycetes from untouched environments and co-culture method, new metabolites can be found to treat antibiotic-resistant infectious diseases.

Production of Extended spectrum β-lactamases (ESBLs) is a common mechanism of resistance in multidrug- Pseudomonas aeruginosa, but the frequency of different ESBLs may vary significantly in different parts of the world. The aim of this study was to investigate the prevalence of OXA-2/OXA-10 type ESBLs and class 1 integron among clinical isolates of P. aeruginosa in Tabriz, North West of Iran. A total of 110 P. aeruginosa isolates was entered in the study. Antibiotic susceptibility was determined by disk diffusion method. Production of ESBL was confirmed by combined disc method, and polymerase chain reaction was used for detection of OXA-2/OXA-10 beta-lactamases and class 1 integrons. Antibiotic susceptibility tests revealed that the highest resistance rate was against aztreonam (82%) and cefepime (77.3%), whereas the highest susceptibility was to imipenem (71%), meropenem (66.4%) and piperacillin/tazobactam (37.3%). In combined disc test, 68 isolates (61.8%) were ESBL producers. PCR analysis showed that 47 (42.7%) isolates carried class 1 integron, among them 22 (32.3%) contained blaOXA-10 and 7 (10.3%) contained blaOXA-2 genes. In conclusion, high prevalence of OXA-10 and OXA-2 type ESBLs were detected in the study region and that imipenem and meropenem were the most active agents against P. aeruginosa isolates.

A rapid DNA cloning system is a research interest of many scientists. TA cloning is one of the methods used for the cloning of PCR-amplified DNA molecules. The TA cloning method is a convenient and labor-saving replacement to traditional, restriction enzyme-mediated cloning strategies. A T-vector called pBlueskript ΙΙ SK-1 with the lethal gene ccdB was designed to construct a positive selection vector. This lethal gene was inserted in multiple cloning sites of pBlueskript ΙΙ SK. Then the vector digested with the endonuclease SmaΙ producing the blunt end. To directly clone the PCR product, a single 3'-A was added to a double-stranded DNA fragment by Taq polymerase and a T-vector with 3'-T overhang at each end using ddTTP and terminal transferase enzyme. The recombinant vector was transferred to the competent cells of host Escherichia coli. After DNA fragment entry, the activity of the ccdB gene eliminated, and the survival probability and host colony formation increased after transformation with the recombinant vector. The proliferation of the host of the T-vector was highly specific, and only hosts with the ccdA gene were able to receive this vector, to replicate the vector and survive. Therefore, after the insertion of the target gene, the lethal gene becomes inactivated, so there was no need to use a specific host and other selective markers, such as antibiotics. The TA cloning with a positive selection marker strategy is both simple and much more efficient than blunt-ended ligation and cohesive-end cloning.