Salinity is one of the greatest environmental challenges facing plant growth and development in the 21st century. Salicylic acid (SA) is a phenolic compound and signal molecule involved in the regulation of plants responses to biotic and abiotic stresses. This greenhouse experiment was conducted to determine effects of SA application on Kentucky bluegrass (Poa pratensis L.) responses to salinity stress. The three salinity levels (0, 40 and 80 mM NaCl) were applied in nutrient solutions, and foliar SA treatments (0, 1 and 2 mM) were applied at 2-weeks intervals. The study was carried out as a factorial experiment based on completely randomized experimental design with four replications. Salinity reduced root and shoot dry weight, visual turf quality, leaf chlorophyll and potassium content, whereas electrolyte leakage, proline and sodium content were increased with salt concentration in nutrient solution. Salicylic acid application ameliorates adverse effects of salinity in all factors and this effect was more pronounced in 80 mM NaCl. In terms of root dry weight, leaf sodium and proline content as well as electrolyte leakage, SA application at 2 mM had better results than 1 mM. These results suggest that further studies are required to find proper SA application rate in different salinity levels. پرونده مقاله

Phalaenopsis is an important genus of orchids that is grown for economical production of cut flower and potted plants. The objective of this study is the evaluation of correlation between morphological and physiological traits of self and cross-pollination of 5 varieties of Phalaenopsis orchid. Some morphological traits were measured: Capsule length (CL), capsule volume (CV), weight of seeds in capsule (WSC), full weight of capsule (FWC) and empty weight of capsule (EWC) and physiological traits: Time to first pollination symptom (TPS), time to capsule swelling (TCS) and capsule ripening (CR). The results showed that correlation (canonical r) was 0.91 in first pair canonical variables; second and third pair canonical variables had correlation 0.68 and 0.30, respectively. The first canonical variable in physiological traits revealed 66.1% variation of physiological variables. Special values were 0.820, 1.388 and 4.850 for Wilks' Lambda, Pillai's Trace and Roy's Greatest Root, respectively. Canonical correlation was significant for physiological and morphological characteristics in all statistical tests. The first canonical variables in physiological characteristics had positive correlation with TCS and TPS, so it was resulted that if TCS was fewer, TPS and CR characteristics were fewer. In pollinated varieties, the lowest TCS belonged to Nottingham× Nottingham and Bucharest × Nottingham; and the most CR belonged to Dubrovnik× Dubrovnik and Memphis× Dubrovnik of pollination states; Therefore, it can be concluded that white and yellow female parent require fewer and more days for capsule swelling respectively. پرونده مقاله

The quality and quantity of lily cut flowers depend mostly on the composition of growing media. To evaluate the effect of two sources of the palm peat substrate (the palm trunk: Prepared from the trunk of the date palm; the palm tree: Prepared from all parts of the date palm) on plant growth traits related to cut lily flower, a factorial experiment arranged in a completely randomized design with three replications. The impact of eleven root growing media consisted of mixtures of palm peat, cocopeat, and perlite on two cultivars (‘Tiber’ and ‘Candy Club’) were evaluated under hydroponic conditions. The results showed that the stem diameter, the time of flower emergence, buds length, leaves relative water content (LRWC), leaves and petal's electrolyte leakage (LEL and PEL), bud visual quality, and quality index criteria were as more in the ‘Candy Club’, but SPAD1 and bud diameter characters were higher in the ‘Tiber’. The highest amount of chlorophyll a, b, and total, SPAD1, SPAD3, stem diameter, bud diameter, and quality index were observed in control (80% cocopeat + 20% perlite), which was not significantly different from some palm trunk, and reused cocopeat substrates. The higher value of LRWC, bud length, and carotenoid was observed in 20% palm trunk treatment, while the higher flower longevity occurred in 60% palm tree treatment. 80% reused cocopeat treatment was showed the highest number of bulblets, SPAD2, and time to harvest. The lowest amount of LEL, harvest time, and time of flower emergence was observed in the control. Various cultivars differently respond to growing media, and palm trunk and reused cocopeat could replace a part and, or whole of expensive imported cocopeat. The palm trunk substrates were superior to the palm tree substrates, but there was a low advantage of control than the palm trunk substrate. پرونده مقاله