Aliyeh Shafiei; Mehdi Hadadinejad; Saeed eshghi; kamran ghasemi
Abstract
The present research tries to investigate the effect of potassium silicate and mycorrhizal fungus on heat stress tolerance of strawberries and evaluate the possibility of increasing plant tolerance to heat at research greenhouse in Sari Agriculture and Natural Resources University at 2019. It is in a ...
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The present research tries to investigate the effect of potassium silicate and mycorrhizal fungus on heat stress tolerance of strawberries and evaluate the possibility of increasing plant tolerance to heat at research greenhouse in Sari Agriculture and Natural Resources University at 2019. It is in a completely randomized factorial design with three factors including two levels of mycorrhizal fungi (presence and absence of mycorrhizal fungi), three levels of potassium silicate (0, 50 and 100 mg.l-1) spray in heat stress (25 and 41 °C) with three replications. The results show that application of potassium silicate reduces the Photosynthtic active radiation (PAR) damage in strawberry leaves, which PAR of leaves bottom reduce three folds in comparison to the control, when the PARtop is 1133 umol.m2.s-1. In contrast, treatment of the plant with potassium silicate in the presence of mycorrhiza prevented increases transpiration and stomatal conductivity for water cooling the leaves during heat stress. Inoculation of the roots with mycorrhiza fungi leads to a wide network of hyphae in root uptake, improving water use efficiency by up to 72%, which in turn results in increaseed net photosynthesis. However, heat stress increases minimum fluorescence and reduces maximal quantum efficiency of photosystem II. But the simultaneous application of mycorrhiza and potassium silicate is able to improve this index to a good level (0.76). Finally, it has been found that high temperature stress affects many photosynthetic factors of strawberry plant that the use of potassium silicate in combination with mycorrhizal fungus, despite their separate use, to a large extent prevents heat damage to different parts of the plant.
laleh Abaslu; SEYED ABDOLREZA KAZEMEINI; Mohsen Edalat; Ali Dadkhahi
Abstract
In order to evaluate the effects of drought stress and planting method on some physiological and biochemical characteristics of two chickpea cultivars (Cicer arietinum L.) an experiment was conducted at the research station of College of Agriculture, Shiraz University using a split factorial based on ...
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In order to evaluate the effects of drought stress and planting method on some physiological and biochemical characteristics of two chickpea cultivars (Cicer arietinum L.) an experiment was conducted at the research station of College of Agriculture, Shiraz University using a split factorial based on randomized complete block design in four replications. The main factor was stopping irrigation at different growth stages of chickpea (full irrigation=I1, flowering=I2 and two weeks after emergence =I3) and the sub-factor included a combination of pea varieties (Arman and Azad) and sowing methods (planting on ridges, furrow and basin), respectively. Results showed that under drought stress, leaf area index, stomatal conductance, photosynthetic rate, chlorophyll a and b and total chlorophyll content decreased while proline content increased. The cultivar Azad had higher than to Arman, leaf area index, stomatal conductance, photosynthesis rate and chlorophyll. The highest photosynthesis rate obtained under full irrigation treatment (16.09µmol m-2s-1) and it’s reduced to 25.79 and 14.23 percent under water stress in I3 and I2 treatments respectively. Based on these results, it can be concluded that the cultivar of Azad is suitable for this region and it is suggested to be planted on the ridge as has higher photosynthesis rate and lower stomatal conductance reduction leading to a higher yield.