Assessment of genetic diversity among some Iranian hazelnut genotypes using SSR markers

Abstract Studying genetic diversity is a preliminary step for conservation and utilization of germplasm. Talesh hills, located in Guilan province in northern part of Iran, are one of the main areas for natural distribution of hazelnut (Corylus avellana L.). Hazelnut trees in Talesh Mountains are a wild population (land race) and obtained from open-pollinated seedling. In this research, a population including 90 hazelnut samples was studied using 15 microsatellite markers. Totally, 98 polymorphic alleles were detected with an average of 6.53 alleles per locus. The lowest numbers of 3 alleles were observed in CaC-B005 and CaC-C114 and the highest number of 12 alleles in CaC-C101 locus. The average effective number of alleles (3.75), mean expected heterozygosity of (He=0.70) and average observed heterozygosity of (Ho=0.62) were estimated for studied loci. All loci showed high PIC with an average of 0.72 that the highest amount detected in CaC-B011 and CaC-B101 loci with values of 0.85 and 0.84, respectively. A dendrogram was generated by UPGMA clustering method that placed the 90 accessions into 7 main loose groups. According to the results a high genetic diversity was found in the studied population that mainly related to the hazelnut pollination nature that shows sporophytic incompatibility system enhancing out-crossing in natural populations

Improving the Vase life of Cut Carnation ‘Tempo’ (Dianthus carryophyllusL.) Flower by Silver Thiosulphate and Silver Nano-Particles

Nanometer-sized silver particle can be act as an anti-microbial compound. Thus, in this research, the efficacy of silver thiosulphate and silver nano-particles as antimicrobial agents in extending the vase-life of cut carnation flowers was evaluated. A factorial experiment carried out based on randomized completely blocks design with two factors: silver thiosulphate (0, 0.1, 0.2 and 0.3 mM) and silver nano-particles (0, 5, 10 and 15 mg/L). Mean comparison of the data showed that the combined treatments of 0.3 mM silver thiosulphate + 15 mg/L silver nano-particles had the highest vase life, water uptake and super oxide dismutase enzyme. Thus, the mentioned above treatment was proposed to increase prolong vase life and improvement of water relations and control of stem end blockage. Based to results of this study, silver thiosulphate and silver nano-particles can be used for increasing postharvest longevity of cut carnation "Tempo"

Rapid micro-propagation of Aloe vera L. via shoot multiplication

Aloe vera L. is a medicinal plant. Regeneration of A. vera in nature (in vivo) is too slow and insufficient to meet the industry demand. Therefore, it is necessary to use in vitro propagation for rapid plant production. Explant used for the in vitro culture was shoot tip. The shoot tip explants was disinfected with 2% NaOCl and washed thoroughly with sterile water. Then, explants were placed on solid MS medium with the addition of various concentrations of benzyladenine and ∝-naphthaleneacetic acid. After 8 weeks, the best proliferation of shoot per explant (9.67) and the best rooting was shown on the medium supplemented with 0.5 mg/l benzyladenine + 0.5 mg/l ∝ naphthaleneacetic acid. The rooted plantlets were gradually acclimatized in plastic pots containing a mixture of cocopeat and perlite (1:1) covered with transparent plastic. About 95% of the transplanted plantlets survived

Improvement of Micropropagation and Proliferation of Robinia pseudoacasia L. Using Plant Growth Regulators and Extracts of Brown Seaweed Ascophyllum nodosum

The present study was conducted to test the effect of Ascophyllum nodosum extract on the growth of Robinia pseudoacasia L., ornamental tree. In vitro and ex vitro clonal multiplication of Robinia pseudoacasia L. was achieved using embryonic axes and seeds as explants, respectively. Factors affecting shoot and root production of R. pseudoacasia L. were investigated by comparing various growth regulators [α-naphthalene acetic acid (NAA) and 6-benzylaminopurine (BA)] and culture media [Murashige and Skoog (MS) and WPM (woody plant medium)] on in vitro conditions, also culture beds (sand, perlite, compost and cocopeat) with different ratios and extracts of brown seaweed Ascophyllum nodosum on ex vitro conditions. Both of BA and NAA were used at concentrations of 0, 0.5, 1 and 1.5 mg l-1. Concentrations used from extracts of A. nodosum were 0, 1000, 2000 and 3000 mg l-1. The optimum plant growth regulator (PGR) combination for maximal plant height, shoot number, node number, root number, root length, leaf number, fresh and dry weight on in vitro condition was 1 mg l-1 NAA and 1 mg l-1 BA in MS medium. The 1000 mg l-1 of extracts of A. nodosum led to optimum plant height, node number, longest root, leaf number, dry weight, fresh weight.  The most appropriate plantlets survival on ex vitro condition was observed when the culture medium was a bed containing sand + perlite + compost with proportion of 1:1:1. About 75% of the propagated plantlets and 90% of the micropropagated plantlets were established successfully in acclimatization medium. Regenerated plantlets were morphologically identical with mother plants. Present study showed positive modifications in shoot proliferation, rate of rooting of stem and some morphological and physiological characters due to subjection of R. pseudoacasia L. to optimum treatments

The role of Pseudomonas strains and arbuscular mycorrhiza fungi as organic phosphate-solubilizing in the yield and quality improvement of strawberry (Fragaria × ananassa Duch., cv. Selva) fruit

This study evaluated the effect of Pseudomonas strains and arbuscular mycorrhiza fungi (AMF) in enhancing strawberry yield and phenolic and antioxidant capacity on a phosphorus (P) deficient calcareous soil. The experiments were conducted in three replicates with six treatments (four Pseudomonas strains, AMF and control) and three rates of P-fertilizer (0, 75, 150 kg P ha–1). Application of higher phosphate rates decreased total antioxidant capacity, total phenolic and flavonols content, whereas AMF and Pseudomonas strains increased quality and P concentration of fruit. The use of AMF and Pseudomonas strains resulted in better quality when used along with 75 kg P ha–1. These results demonstrated that the rhizospheric microorganisms improved the quality of fruit, especially when they applied in combination with lower rates of chemical fertilizers. Therefore, application of these microorganisms in sustainable agriculture is recommended

Effect of Silver Nanoparticles and Sodium Silicate on Vase Life and Quality of Cut Chrysanthemum )Dendranthema grandiflorum L. (Flower

Dendranthema grandiflorum L. is one of the widely cultivated flowers around the world for producing of cut flowers. Nanometer-sized silver particles are used in various applications as an anti-microbial compound. This experiment was carried out to study the effects of silver nanoparticles (0, 5, 10 and 20 mg/L) and sodium silicate (0, 50, 100 and 150 mg/L) on longevity and quality of cut chrysanthemum (Dendranthema grandiflorum L.) flowers. A factorial experiment was conducted based on randomized complete block design with 16 treatments, 3 replications, 48 plots and 192 cut flowers. The cut flowers were pulsed for 24 h with pulse solutions and then transported to 300 mg L-1 8-hidroxy quinoline sulfate and 3% sucrose. The characteristics such as vase life, loss of fresh weight, number of bacterial colonies in stem, lipid peroxidation, and activity of superoxide dismutase (SOD) were measured. Results showed that all treatments had positive effects on the vase life of flowers. Pulse solution with 10 mg/L silver nanoparticles and 100 mg/L sodium silicate and interaction between them, increased vase life compared to the control (3.21, 4.46 and 8.50 days, respectively). In addition, the flowers pulsed with silver nanoparticles and sodium silicate exhibited higher activity of SOD, compared to control. The present study showed that using proper concentrations of silver nanoparticles and sodium silicate can enhance the vase life of cut chrysanthemum flowers

Physiological Response to Salinity Stress by Primed Seedsof Three Species of Lawn

Salinity is one of the most important ecological stresses which have undesirable effects on seed germination. This study was carried out to evaluate the germination of three species of lawn (Poa pratensis, Lolium perenne, Cynodon dactylon) seeds under salinity stress. The effect of different treatments (Gibberellins 50 mgl-1, 2% CaCl2 and hydroprimig in 24 hours) was evaluated on total germination, mean daily germination, maximum and mean germination percent in three species of lawn, under four levels of salinity (0, 3, 6, 9 dS/m). Priming factor (Gibberellins and water) was more effective than salinity on the seed germination. Among lawn types, Lolium perenne and Cynodon dactylon indicated greater seed germination percentage and germination rate. The least rate and percentage of germination belonged to Poa pratensis. Among priming treatments, gibberellins had the greatest effect on germination, followed by hydropriming. However, interaction effects of "Lolium × CaCl2" were greater than other treatments on the mean daily germination and germination value. Based on the results, seed priming specially Gibberellins could be an appropriate substrate to improve seed germination in lawns, when grown under salinity