Rice is one of the most important staple crops in the world and its production is crucial for food security. However, the response of different rice genotypes to various cultivation practices has not been extensively studied. In this article, we explore the impact of transplanting and aerobic cultivation on the cell membrane stability, defense system, physio-morphological traits, and yield of varied rice genotypes. We present the findings from our study, which was conducted to identify the most suitable rice genotypes for different cultivation practices, which can support sustainable rice production. Our research offers valuable insights into the adaptation of rice genotypes to different environments and cultivation practices, which can aid in the development of new rice varieties with enhanced tolerance and yield potential.
Antioxidant enzymes activity is a crucial indicator of drought or low water supply for rice crops. This issue can be treated by antioxidants formation, which includes the activity of catalase, peroxidase, superoxide dismutase, and proline. The methods used for planting crops significantly influenced these antioxidants, as evidenced by a study conducted on several rice genotypes. Aerobic cultivation conditions resulted in the highest values of these antioxidants and proline when compared with transplanting methods in both seasons.
Remarkable variations were observed in the antioxidant defense systems of tested rice varieties. EHR1 and GZ9399 rice genotypes recorded the highest values of catalase and peroxides, followed by Giza179 and Giza178 in both seasons. As for SOD and proline accumulation, EHR1 values were the highest, followed by GZ9399, Giza179, and Giza178. The interaction between planting methods and varieties significantly affected catalase, peroxidase, proline, and superoxide dismutase. EHR1 surpassed in production of the antioxidant system under aerobic cultivation method followed by GZ9399 and Giza179.
The study also evaluated physio-morphological traits of rice crops, including leaf area index, flag leaf area, and leaf rolling. These traits were significantly influenced by the cultivation methods used in both seasons. Transplanting methods with well-watering treatment resulted in the highest values of leaf area index and flag leaf area and the lowest values of leaf rolling. Aerobic cultivation methods showed a slight reduction in vegetative and physiological growth traits.
The tested genotypes also exhibited marked differences in their leaf area index, flag leaf area, and leaf rolling in both seasons. EHR1 had the largest leaf area index and flag leaf area, followed by GZ9399 in leaf area and Giza179 in flag leaf area. The known sensitive rice varieties to drought, such as Giza177, Sakha102, and Sakha106, showed the narrowest leaf area index and flag leaf area in both seasons.
The interaction effects between planting methods and rice genotypes on membrane stability index, leaf relative water content, and chlorophyll content were significant in both seasons of the study. Aerobic cultivation with less irrigation water resulted in increased water loss through stomata and high transpiration rates, leading to low leaf water content, low chlorophyll content, and the highest electrolyte leakage (EL%) in terms of the cell membrane stability index values. The transplanting method with well-watering treatment had the highest mean of RWC and chlorophyll content and the lowest values of the membrane stability index in both seasons.
The study also evaluated the influence of planting methods on stomata conductance, root length, and root volume. The transplanting method with well-watering treatment resulted in the highest stomata conductance, root length, and root volume values. EHR1 had much more profound and extensive root distributions than Giza177 in both seasons. The maximum values of stomata conductance were shown by EHR1 and Giza179 rice varieties without any significant differences among them.
In conclusion, the study demonstrated that planting methods significantly affect the physio-morphological and antioxidant traits of rice crops. Transplanting methods with well-watering treatment resulted in higher values of most traits, while aerobic cultivation methods resulted in a slight reduction of vegetative and physiological growth traits. The study also highlighted the significant variation in the antioxidant defense systems of tested rice varieties, indicating a need for the selection of appropriate varieties for different planting methods. These findings can help farmers optimize crop management and improve crop yield under varying cultivation conditions.
