Karyomorphology and genome size of 15 St John’s wort (Hypericum perforatum L.) populations are reported for the first time. Root tips and fresh young leaves were used for karyological studies and flow cytometric (FCM) measurements, respectively. The chromosome types were determined as “m” and the basic chromosome number was x = 8 in all examined populations. Eight different somatic chromosome numbers were found (2n = 16, 22, 24, 26, 28, 30, 32, 38). Based on the observed basic (x) chromosome numbers of x = 8, 11, 13, 14, 15, 19, this may correspond to diploid (2x), triploid (3x), tetraploid (4x), respectively. Interestingly, we found mixoploidy (3x − 4x) in the root tips of one of the populations. Hybridization, polyploidy and dysploid variation may be the main factors associated with the chromosome number evolution of this species. FCM showed that 2C DNA contents vary from 0.87 to 2.02 pg, showing more than a 2-fold variation. The mean amount of 2C DNA/chromosome and the mean of monoploid genome size were not proportional to ploidy.

<p>This study aimed to characterize if dust sprayed on soybean foliage impacts its yield and yield component characteristics. In 2017 and 2018, soybean [<em>Glycine max</em> (L.) Merr.] was planted using a factorial randomized complete block design with three replicates. Plants were sprayed with a 20 g m^-2 of dust at four stages of the growth cycle, including third-node, the beginning of flowering, the beginning of podding, and the beginning of seed formation. Dust spraying was then continued twice weekly until the late full seed stage. Plant measurements included yield, yield components, stomatal conductance, peroxidase, and superoxide dismutase antioxidant enzymes activities. Results showed that depending on the time of application, the dust coverage created a range of yield loss in soybeans, most likely due to a reduction in stomatal conductance, grains plant^-1 and 100-seed mass. Therefore, soybean fields that are regularly exposed to dust might be subjected to reduced yield.</p>

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Sugar beet is one of the most important industrial crops in Iran. For the last two decades it has been mainly affected by a destructive virus, beet necrotic yellow vein virus (BNYVV). The Polymyxa betae is the only natural transmitting agent of the disease among the plants. Developing accurate diagnostic methods may have a major impact on the rising of resistant germplasms. In the present study, specific monoclonal recombinant antibodies in the form of single chain variable fragments (scFv) were obtained from naïve phage display libraries. The fungus specific glutathione-S-transferase (GST) protein was chosen as an antigen for developing antibodies and diagnostic purposes. To generate specific scFv, screening of Tomlinson phage display libraries was performed by applying both recombinant and native fungal GST. Using the recombinant GST in the panning process resulted in the isolation of an antibody only bound to recombinant GST but it failed to detect native GST in the infected plants. Alternatively, the process of panning was carried out by applying native fungal GST trapped to immunotubes through specific polyclonal antibody intermediate. The recent approach resulted in the selection of a specific scFv binding to native GST which was able to detect the presence of the fungi within infected plants. To the best of our knowledge, this is the first report on the generation of recombinant antibodies against Polymyxa betae, fungal vector of sugar beet rhizomania disease.

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