Distribution and phylogenetic analysis of the 3′UTR and coat protein gene of Iranian Beet black scorch virus

Journal of Plant Diseases and Protection - Beet black scorch virus (BBSV) was surveyed in major sugar beet cultivation areas in Iran in 2008–2013 growing seasons. A total of 148 out of 308...     

The Effect of Melanocyte Stimulating Hormone and Hydroxyapatite on Osteogenesis in Pulp Stem Cells of Human Teeth Transferred into Polyester Scaffolds

Presently, tissue engineering is employed in the restoration and repair of tissue defects. Degradable scaffolds, stem cells and stimulating factors are employed in this method. In this study, the effect of melanocyte-stimulating hormone (MSH) and/or hydroxyapatite (HA) on proliferation, osteoblast differentiation, and mineralization of human dental pulp stem cells (hDPSCs) seeded on PLLA-PCL nanofibrous scaffolds was evaluated. For this aim, PLLA-PCL-HA nanofibrous scaffolds were fabricated using electrospinning method. FE-SEM images exhibited that all nanofibers had bead-free morphologies with average diameters ranging from 150–205 nm. Human DPSCs seeded into PLLA-PCL nanofibers were treated with MSH. Cell viability, proliferation, morphology, osteogenic potential, and the expression of tissue-specific genes were assessed by means of MTT assay, FE-SEM, alizarin red S staining, and RT-PCR analysis. hDPSCs exhibited improved adhesion and proliferation capacity on the PLLA-PCL-HA nanofibers treated with MSH compared to other groups (p<0.05). Additionally, PLLA-PCL-HA nanofibers treated with MSH exhibited significantly higher mineralization and alkaline phosphatase activity than other groups. RT-PCR results confirmed that PLLA-PCL-HA nanofibers enriched with MSH could significantly unregulated the gene expression of BMP2, osteocalcin, RUNX2 and DSPP that correlated to osteogenic differentiation (p<0.05). Based on results, incorporation of HA nanoparticles in PLLA-PCL nanofibers and addition of MSH in media exhibited synergistic effects on the adhesion, proliferation, and osteogenesis differentiation of hDPSCs, and therefore assumed to be a favorable scaffold for bone tissue engineering applications.     

Study of Genetic Diversity of Pear Genotypes and Cultivars (<Emphasis Type="Italic">Pyrus communis</Emphasis> L.) Using Inter<Emphasis Type="Italic">-</Emphasis>Simple Sequence Repeat Markers (ISSR)

ISSR molecular marker was used to investigate genetic diversity of ‘Dare Gazi’ genotypes of Mashhad Esteghlal orchard and its relationship with other commercial and native cultivars of pear. Among ‘Dare Gazi’ genotypes of Mashhad Esteghlal orchard 23 genotypes were selected base on difference in tree vigor, leaf color, shape and color of fruit and also 33 other commercial and native pear cultivars from Esteghlal orchard and other Mashhad commercial orchards were studied. A total number of 230 DNA fragments were obtained using 11 primers of which 225 were polymorphic. On average, each primer produced 20.9 bands. Dice similarity coefficient ranged from 0.27 (between ‘Dom Kaj’ and Asian pear) to 1 (between ‘Dare Gazi’ 1 and 2 genotypes). Sample cluster dendrogram indicated that 56 genotypes were divided into 12 distinct clusters. The dendogram generated on the principle of Unweight Pair Wise Method using Arithmetic Average (UPGMA) was constructed by Dice coefficient and the genotypes were grouped into 12 clusters. ‘Dare Gazi’ genotypes did not show 100% similarity due to seed propagation or mutation, as ‘Dare Gazi’ 3 and 18 genotypes had the lowest similarity coefficient (0.64). Asian pears were placed in a separate group from European pears. And ‘Dare Gazi’ genotypes from different orchards were grouped separately, but all of them are called as ‘Dare Gazi’ pear for convenience. ISSR molecular marker can well identify the genetic variability among genotypes and cultivars and found suitable for grouping them.     

Physiological and anatomical responses of calendula (Calendula officinalis L.) cultivars to heat-stress duration

It is necessary to identify the heat-tolerant cultivars of bedding plants in order to cope with the challenges of the global warming. The physiological and anatomical responses of four calendula cultivars (Candyman’, ‘Zen’, ‘Indian Prince’, and ‘Pacific Beauty’) to four duration levels (0, 7, 14 and 21 days) of heat stress (in a mean range of 35–42°C), were investigated after their establishment under greenhouse conditions. The results indicated that calendula cultivars displayed different responses to various heat duration levels in most parameters. Although the gas exchange of ‘Candyman’ was the highest in control treatment, it showed a considerable reduction in all levels of stress durations. In contrast, ‘Indian Prince’ maintained gas exchange and chlorophyll content and exhibited the most resistance to heat stress among others, especially for longer duration exposure, which might be resulted from the greater soluble sugar content, higher stomatal density, and thicker leaves. Experiment to assess cell membrane thermostability showed heat stress resulted in significant increase in electrolyte leakage percentage as the incubation temperature of all cultivars was increased. However, the least membrane stability was observed in ‘Zen’, indicating the higher sensitivity of this cultivar to heat-stress conditions in comparison to three other cultivars.