Sadegh Azadbakht, Masoud Rafiee, Ali Khorgami,
Volume 13, Issue 60 (5-2024)
Abstract
Low irrigation is one of the ways to reduce water consumption in heat-loving and water-loving crops. On the other hand, the use of mycorrhiza as a biofertilizer is also one of the effective solutions in increasing the absorption of water and nutrients in the conditions of water shortage stress. In addition, the selection of varieties compatible with the region in order to achieve production potential is another way to deal with drought stress in each region. For this purpose, the effect of irrigation regime at three levels of 80 (control), 120 (mild stress) and 160 (severe stress) mm of evaporation from the evaporation pan of class A and biofertilizer including application and non-application of mycorrhiza on three grain sorghum cultivars Kimia, Payam and Sepideh It was investigated in the form of randomized complete block design in the form of a split plot in the summer cultivation of 2016 in Kohdasht city of Lorestan. The results showed that the amount of zinc, copper, manganese and iron in the seeds decreased with the increase in water shortage, but the crude protein content of the seeds increased. The application of mycorrhiza mainly increased the essential elements in shoots and seeds and helped to moderate water deficit stress. The presence of interaction between the factors indicated the different response of cultivars at the levels of mycorrhizal application to water deficit stress in terms of many traits; so, in the conditions of extreme stress of water shortage, the highest increase in catalase and peroxidase observed in Kimia cultivar without mycorrhiza application and Sepideh cultivar with mycorrhiza application, respectively. Also, Sepideh variety with mycorrhiza application showed the highest reduction in chlorophyll b and total chlorophyll. In total, Sepideh cultivar with the use of mycorrhiza under the conditions of mild stress of water shortage while producing the highest grain yield and crude grain protein, saved irrigation water consumption.
Masoomeh Bazgir, Masoud Rafiee, Ali Khorgami,
Volume 13, Issue 62 (10-2024)
Abstract
Selection of cultivars adapted to drought stress conditions in each region plays an important role in achieving production potential in that region. For this purpose, the effect of drought stress through the irrigation cycle after 80 (control), 110 (mild stress), 140 (relatively severe stress) and 170 (severe stress) mm of evaporation from the class A evaporation pan on four grain sorghum cultivars, Sepideh, Kimia, Payam and KGS32, was investigated in summer cultivation in Khorramabad, Lorestan. The results showed that the amount of photosynthetic pigments (chlorophyll a, chlorophyll b and total chlorophyll, ratio of chlorophyll a/b, carotene and xanthophyll) and the amount of starch, protein, sodium and the ratio of sodium to potassium decreased with the intensification of drought stress, but the amount of nitrate, proline and potassium increased in the sorghum shoot. Intensification of drought stress was accompanied by the suppression of catalase, which caused the antioxidant defense mechanism to work through increasing peroxidase production. The highest amounts of non-structural soluble sugars, peroxidase and proline in the aerial part were obtained from KGS23 and Payam cultivars under severe drought stress conditions, while the highest amount of starch under normal irrigation conditions was obtained from the Sepideh variety, as were the highest amounts of catalase and total protein in the aerial part under normal conditions. Watering was observed in Payam and KGS23 cultivars. The trend of grain yield changes of all grain sorghum cultivars under the influence of drought stress followed a significant and negative linear relationship, but the changes of peroxidase and proline with increasing drought stress had a significant and positive linear relationship. In general, grain sorghum cultivars KGS23 and Sepideh have different drought stress tolerance mechanisms and can be recommended for normal and stressful conditions in the temperate region of Khorramabad.
