University of Isfahan Journal of Plant Biological Sciences 3041-9603 7 25 2015 09 23 Flora, life form and chorological study of soil seed bankin Sisangan box tree (Buxus hyrcanus Pojark) Forest Reserve Flora, life form and chorological study of soil seed bankin Sisangan box tree (Buxus hyrcanus Pojark) Forest Reserve 17 28 18975 FA Ghader Habibi Department of Biology, Payame Noor University, PO BOX 19395-3697 Tehran, Iran Zienab Sadeghipour Department of Plant Sciences, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran Roghieh Hajiboland Department of Plant Sciences, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran Journal Article 2016 06 14 Drought stress impact photosynthesis and stomatal conductance, and may reduce the overall production capacity of plants. Since exogenous application of salicylic acid (SA) can partially alleviatebe increased the negative effects tolerance of drought The present study involves the soil seed bank flora of the Sisangan Box tree (Buxus hyrcanus Pojark) reserve by using seedling emergence method. 150 soil samples were collected during late June and early November by hammering a hollow metal frame 400 cm2 to a depth of 5 cm. Results showed 67 species, representing 63 genera and 38 families germinated from soil seed bank. 45 species belonging to 28 families and 59 species belonging to 32 families were recorded in June and November soil seed bank respectively. The largest families were Asteraceae (7 species, 10.5%), Lamiaceae (6 species, 9%), Poaceae (5 species, 7.5%) and Rosaceae (4 species, 6%) which compromised 32.8% percent of the total species in the soil seed bank. Results also showed that Hemicrptophytes (28.4%) and Euro-Sibria elements (23/9%) were the most important biological spectrum and phytochorion respectivly in the soil seed bank of Sisangan forest. From the total number of species recorded in seed bank, 30 species (44.6 %) were found only in the seed bank and never observed in above-ground vegetation. In this regard, seeds of 10 woody species including Albizia julibrissin, Ficus carica, Morus alba, Diospyrus lotus, Celtis australis, Gleditsia caspica, Buxus hyrcana, Ulmus minor, Zelkova carpinifolia and Carpinus betulus were found in the soil seed bank, from which only 6 species were able to produce persistent soil seed bank. This condition confirmed low similarity between above-ground vegetation and persistent soil seed bank and it also reiterated the importance of soil seed bank study for introducing more accurate capacity of plant biodiversity. stress by improve the metabolism pathways and increase the net photosynthesison plant photosynthesis and metabolism, the main objective of this study was to clarify the roles of SA in enhancing 28 days tobacco (Nicotiana rustica Basmas) tolerance to drought stress (50% FC). The results indicated that foliar application of SA (0.5 mM) influenced negatively net CO2 assimilation rate and stomatal conductance and led to reduction of shoot and root dry masses. In contrast, the stress did not reduce significantly the maximal quantum yield of photosystem II (PSII). This that can be explained by enhancement of efficiency for dissipation of excess photon energy in the PSII antenna, determined as non-photochemical quenching, and consequently further protection of PSII from photodamage. Thus, under more drought stress, the reduction of photosynthesis of tobacco plants was due mainly to reduction of stomatal conductance. Under water-deficient conditions, plants showed an increase in chlorophyll a and amino acids concentrations in the leaves when treated with SA while this change for net photosynthesis was negligible. Our results indicated showed that the foliar application of SA had no ameliorative effect on tobacco growth under drought stress, because its effect on elevation of transpiration rate did not increase net photosynthesis under drought condition. Drought stress impact photosynthesis and stomatal conductance, and may reduce the overall production capacity of plants. Since exogenous application of salicylic acid (SA) can partially alleviatebe increased the negative effects tolerance of drought The present study involves the soil seed bank flora of the Sisangan Box tree (Buxus hyrcanus Pojark) reserve by using seedling emergence method. 150 soil samples were collected during late June and early November by hammering a hollow metal frame 400 cm2 to a depth of 5 cm. Results showed 67 species, representing 63 genera and 38 families germinated from soil seed bank. 45 species belonging to 28 families and 59 species belonging to 32 families were recorded in June and November soil seed bank respectively. The largest families were Asteraceae (7 species, 10.5%), Lamiaceae (6 species, 9%), Poaceae (5 species, 7.5%) and Rosaceae (4 species, 6%) which compromised 32.8% percent of the total species in the soil seed bank. Results also showed that Hemicrptophytes (28.4%) and Euro-Sibria elements (23/9%) were the most important biological spectrum and phytochorion respectivly in the soil seed bank of Sisangan forest. From the total number of species recorded in seed bank, 30 species (44.6 %) were found only in the seed bank and never observed in above-ground vegetation. In this regard, seeds of 10 woody species including Albizia julibrissin, Ficus carica, Morus alba, Diospyrus lotus, Celtis australis, Gleditsia caspica, Buxus hyrcana, Ulmus minor, Zelkova carpinifolia and Carpinus betulus were found in the soil seed bank, from which only 6 species were able to produce persistent soil seed bank. This condition confirmed low similarity between above-ground vegetation and persistent soil seed bank and it also reiterated the importance of soil seed bank study for introducing more accurate capacity of plant biodiversity. stress by improve the metabolism pathways and increase the net photosynthesison plant photosynthesis and metabolism, the main objective of this study was to clarify the roles of SA in enhancing 28 days tobacco (Nicotiana rustica Basmas) tolerance to drought stress (50% FC). The results indicated that foliar application of SA (0.5 mM) influenced negatively net CO2 assimilation rate and stomatal conductance and led to reduction of shoot and root dry masses. In contrast, the stress did not reduce significantly the maximal quantum yield of photosystem II (PSII). This that can be explained by enhancement of efficiency for dissipation of excess photon energy in the PSII antenna, determined as non-photochemical quenching, and consequently further protection of PSII from photodamage. Thus, under more drought stress, the reduction of photosynthesis of tobacco plants was due mainly to reduction of stomatal conductance. Under water-deficient conditions, plants showed an increase in chlorophyll a and amino acids concentrations in the leaves when treated with SA while this change for net photosynthesis was negligible. Our results indicated showed that the foliar application of SA had no ameliorative effect on tobacco growth under drought stress, because its effect on elevation of transpiration rate did not increase net photosynthesis under drought condition.

https://ijpb.ui.ac.ir/article_18975_bb1086c16a3c62c9bbda0f022ab064e6.pdf