Showing 4 results for Survival
Dr. Jafar Nabati, Prof. Ahmad Nezami, Prof. Mohammad Kafi, Dr. Elaheh Boroumand Rezazadeh,
Volume 8, Issue 34 (2-2020)
Abstract
Lack of chickpea cultivars tolerant to extreme freezing is a limiting factor for autumn planting of this crop in cold areas. In this study, 58 Kabuli-type chickpea genotypes and a control (an international sensitive genotype) were planted in pots and first exposed to -10°C and then to -15°C after being acclimated in natural conditions. No destructive effect of -10°C was observed in plants. So, acclimation was repeated and plants were transferred to -15°C. Survival percentage was measured after three-weeks recovery period. In continue, 19 genotypes with higher survival percentage along with the control were exposed to temperatures of -16, -18 and -20°C after they were acclimated in controlled conditions. Experiments were arranged as Completely Randomized Design with three replications. Results indicated that seven genotypes had survival percentage more than 80%, 24 genotypes more than 25% and 25 genotypes could not survive in -15°C. MCC803 had the highest and MCC808 and MCC510 the lowest survival percentage. All the genotypes were killed in -18 and -20°C. Among 19 studied genotypes, eight were able to tolerate -16°C. Among factors affecting cold tolerance such as soluble carbohydrates, proline, total phenol, photosynthetic pigments, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and malondialdehyde, soluble carbohydrates showed significant positive correlation with chickpea survival percentage. Generally, among the studied genotypes four genotypes (MCC53, MCC770, MCC776, MCC809 and MCC815) are recommended as promising genotypes for freezing tolerance.
Arshad Joudmand, Roghieh Hajiboland, Nasser Aliasgharzad,
Volume 9, Issue 40 (3-2021)
Abstract
Cold stress is an important limiting factor for cereal production. Barley is a host species for arbuscular mycorrhizal fungi (AMF) with a high genetic diversity in response to cold stress. In order to explore the mechanisms for the ameliorative effect of AMF under cold stress, an experiment was undertaken using completely randomized block design with three factors including temperature treatment, AMF inoculation and plant cultivar. Two spring barley cultivars with different cold tolerance (‘Reyhan’ as tolerant and ‘Torkaman’ as susceptible) were inoculated with two AMF species (Diversispora versiformis and Rhizophagus irregularis) and grown under chilling (CH, 5 °C) and freezing (FR, ‒5 °C) temperatures for three weeks. Dry matter production, photosynthesis rate, and membrane integrity parameters decreased, while the antioxidant defense and the synthesis of phenolics were activated under CH stress. Inoculation of plants with AMF alleviated the adverse effects of CH stress on growth and membrane parameters, while exacerbated CH effect on the antioxidant system and phenolics accumulation. Plants could not survive FR stress when they were not cold acclimated through prior exposure to CH treatment, unless they were inoculated with AMF which results in survival rates almost similar to cold-acclimated plants. Our results suggested that AMF alleviated CH stress through reducing H2O2 and improving membrane integrity while the substituting effect of AMF for cold acclimation and increasing FR survival was mediated by the activation of antioxidant defense and phenolics synthesis and accumulation of proline.
Azadeh Sadat Jafarinasab, Shahab Maddah Hosseini, Arman Azari,
Volume 12, Issue 53 (5-2023)
Abstract
In order to study the effect of cold stress on some physiological characteristics of nine ecotypes of grass pea, a factorial split plot experiment based on completely randomized design with two factors and four replications was carried out in growth chamber. The first factor was cold treatment at two levels (25 and -3˚C) and the second factor was ecotype at nine levels collected from local areas named Bam, Sirjan, Torbat Heydariyeh, Baft 1 (Kiskan area), Baft 2 (Bidgerdoyeh area), Shiraz, Kuhbanan, Rabar and Bardsir. Traits measured in this experiment included content of soluble sugars, proline, starch, chlorophyll a, b and total chlorophyll, as well as the activity of antioxidant enzymes. The results showed that in all ecotypes with decreasing temperature from 25 to -3 degrees the content of soluble sugars, proline, ion leakage and the activity of catalase and peroxidase enzymes increased whereas the content of starch and chlorophyll a, b and total decreased. Significant variation was observed between ecotypes in terms of cold stress tolerance. In Baft 2 and Bardsir ecotypes, proline content was higher than other ecotypes. Also, the highest soluble sugar content was related to Baft 2 ecotype and the highest catalase activity was related to Bardsir ecotype. In addition, these ecotypes had higher survival score. Based on the results of survival score, Baft2 and Bardsir ecotypes showed the highest resistance to cold stress and Bam, Shiraz and Sirjan ecotypes showed the lowest resistance.
Jafar Nabati, Rezvan Ramezannejad, Ahmad Nezami,
Volume 12, Issue 54 (7-2023)
Abstract
Salinity is one of the most important non-biological stresses that has an adverse effect on the growth and production of crops. Chickpea (Cicer arietinum L.) is sensitive to salt stress. This study was performed to select the salt tolerance genotypes of chickpea. For this purpose, 72 genotypes were screened for dSm-112 salinity tolerance. This study was performed in a completely randomized design with three replications as hydroponic culture. Among the studied genotypes, 53 genotypes had a survival of more than 75%, and no genotype had a survival of less than 25%. The highest mean content of soluble carbohydrates, total phenol, proline, osmotic potential, inhibition of free radical activity of DPPH and relative water content were observed in genotypes with a survival range of 100-76%. The mean malondialdehyde content was highest in genotypes with a survival range of 50-26%. The results of cluster analysis showed the relative superiority of the second group genotypes including MCC1037, MCC1212, MCC1286, MCC1138, MCC1278, MCC1129, MCC1140, MCC1234, MCC1299, MCC1289, MCC1041, MCC1132, MCC1276, MCC1211, MCC1211 and MCC1010 in most of the studied traits. Chickpea genotypes appear to use a variety of mechanisms to tolerate salinity, which helps to replace more salinity-tolerant genotypes in tolerant chickpea.
