جستجوی مقالات مرتبط با کلیدواژه "تنش سرمای بهاره" در نشریات گروه "زراعت"

Plants are often exposed to a wide range of abiotic stresses, which have adverse effects on the survival, growth, quality, and quantity of crops. Coldness is one of these stresses that the late spring cold can cause great damages to the crop (cereal) planting during the reproductive period. The purpose of this research was to investigate the effect of spring cold on the physiological traits, associated with stress toleration including proline amino acid, and pigments (chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid) in the reproductive stage.To this end, an experiment was conducted in a controlled condition (greenhouse) with a combined analysis model based on a completely randomized design in four media (control temperature level of +8°C, +2°C, 0°C, and -2°C)for 20 cultivars of barley and three replicationin the Faculty of Agriculture of Tarbiat Modarres University, Iran, in 2016-17. The results of the analysis of variance showed that cold stress levels, cultivar, and interaction of cultivar on cold were significant for all the traits at 1% probability level.Cold-tolerant cultivars had higher levels of proline (Jolgeh cultivar) and plant pigments (Yousef and Nik) at different levels of cold stress. The cluster analysis was performed through the Ward method using the Euclidean distance coefficient to determine the genetic relationships between the studied cultivars, and the studied cultivars were divided into five groups at the control and severe stress (-2°C) levels and tolerated cultivars were grouped together. 12 pairs of microsatellite primers were used to study the genetic diversity in the molecular segment and the average polymorphism content information was estimated as much as 0.38. The cultivars were grouped through the Dice similarity coefficient as well as cluster analysis via the UPGMA model, and 20 cultivars of barley were divided into 4 groups. The results of correlation analysis through stepwise regression analysis showed a high correlation (highest coefficient of explanation) for Bmag0337 indicator with proline (R2=0.43), Bmac0518 indicator with chlorophyll a and total chlorophyll (R2=0.29), EBmac0602 indicator with chlorophyll b (R2=0.15), and Bmag0375 (R2=0.44) with carotenoid trait.

Plants are usually exposed to a range of environmental stresses. These stresses have undesirable effects on survival create growth, quantity and quality of agriculture products. Chilling stress is one of them that can damage cereals at the reproductive stage. The aim of present study was investigation of chilling effects on physiological traits, plant pigments (total, a and b chlorophyll and Carotenoid), proline content and ion leakage at reproductive stage under artificial conditions. To reach to this aim na experiment with 20 bread wheat cultivars with four levels of chilling stress ( (control), , 0, -2 Celsius) using factorial arrangement based on a completely randomized design was implemented. Results of variance analysis showed that cold levels, cultivars and effects of interaction signification at the 1% level. Comparison of means effects of interaction showed that the tolerant cultivars have little cell membrane leakage and more plant pigments and proline content at different levels of artificial chilling stress. Oroom and Aflak were known as the most tolerant cultivars and Line A and Mv17 as the most susceptible cultivars According to these criteria. Totally, this research showed that ion leakage, plant pigments and proline content can suitable traits for assessment of chilling stress.

Spring cold stress is a problem for wheat crops at heading and also may be damaged some other parts of this plant. The aim of this study was the investigation of spring cold stress on the physiological traits, plant pigments (total, a and b chlorophyll and Carotenoid) and cell membrane damage at the reproductive stage with the artificial conditions. For this purpose an experiment with 20 varieties of wheat with four treated cold level of stress (8 (control), +2, 0, 2 Celsius) in factorial arrangement in a randomized completely design implemented. Results of variance analysis showed the effects of interaction between cultivars spring cold levels is signification at the 5% level. Comparison between the interaction of all of traits showed the tolerant cultivars have more little cell membrane leakage and more plant pigments at the different levels of artificial Spring cold stress and PISHTAZ and AZAR 2, are the most tolerant cultivars andBECK CROSS.ROSHAN is the most susceptible cultivar. The results showed different reactions between cultivars and therefore these cultivars have considerably genetic diversity.

Genetic diversity is necessary for breeding program and increasing genetic gain of selection in crop plants. With the onset of spring growth, Spring cold stress is a problem for wheat crops at heading and also may be damaged some other parts of this plant. The aim of this study is the investigation of genetic diversity duo to artificial cold stress on the physiological traits, chlorophyll a, chlorophyll b, total chlorophyll, carotenoid and cytoplasmic membrane stability at the reproductive stage. For this purpose an experiment with 20 cultivars of bread wheat and four levels of cold stress, (8 (control), +2, 0 and -2 Celsius) was performed in factorial arrangement in a completely randomized design. Results of variance analysis showed the effects of interaction between cultivars and cold stress levels is significant at the 5% level which showed the existence of genetic diversity between studied cultivars.. There were significant correlations between chlorophyll a, b, total and carotenoid. In order to determination of genetic relation between cultivars, cluster analysis using was performed Ward method and cultivars were divided into 5 groups at -2 °C and 4 groups at +8 °C. Discriminate function and principal component analysis confirmed the results of cluster analysis. The third group of -2 °C including of GHODS, TAJAN and PISHTAZ had the lower level of ion leakage and higher level of plant pigments.