Abstract:
【Objective】 The study aimed to comparatively analyze the relationship between root morphology and physiological indicators and yield of different rice varieties(lines) in saline-alkali land of Ningxia, and to screen high-yielding rice varieties(lines) suitable for planting in saline-alkali land of Ningxia, providing references for the breeding and planting of high-yielding rice varieties in saline-alkali land of Ningxia. 【Method】 Four conventional Ningxia rice varieties(Ningjing 52, Ningjing 57, 96D10, HJW14) and one Haidao 86 derivative line(Chen 2) were used as test materials to conduct field planting experiments in saline-alkali land of Ningxia. During key growth stages(seedling, tillering, heading and filling stages), root morphological indicators(root diameter, root length, root surface area, root volume, root fresh weight and root dry weight), physiological indicators superoxide dismutase(SOD) activity, peroxidase(POD) activity, root activity, total root absorption area and active root absorption area and yield and component factor indicators(spike number, kernels per spike, thousand-seed weight, setting rate, yield) were detected. Correlation analysis, principal component analysis and membership function method were used to comprehensively evaluate different rice varieties(lines). 【Result】 The root diameter of different rice varieties(lines) showed a gradual increasing trend as the rice growth period progressed. The root length, root surface area and root volume showed a gradual increasing trend from the seedling stage to the heading stage, and showed a decreasing trend from the heading stage to the filling stage. The root morphology of Ningjing 52, Ningjing 57 and Chen 2 was better than that of 96D10 and HJW14. The root vitality of Chen 2 and Ningjing 57 was better than that of Ningjing 52, 96D10 and HJW14. The total root absorption area and root active absorption area of Ningjing 52, Ningjing 57 and Chen 2 were generally higher than those of 96D10 and HJW14. SOD activity and POD activity of Ningjing 52, Ningjing 57 and Chen 2 during different growth stages were higher than those of 96D10 and HJW14. In terms of yield performance, Ningjing 52 had the highest yield of 7420.97 kg/ha, while HJW14 had the lowest yield of 4970.94 kg/ha. Correlation analysis results indicated that yield was significantly positively correlated with the total root absorption area(
P<0.05), and extremely significantly positively correlated with SOD activity and POD activity(
P<0.01). The principal component analysis results determined that root length, root surface area, root fresh weight, root dry weight, root activity, root active absorption area, SOD activity and thousand-seed weight were key indicators of salt-alkali tolerance. Using the membership function method combined with the weight analysis method, the comprehensive evaluation values(
D) for the salt-alkali tolerance of different rice varieties(lines) were ranked as follows: Ningjing 57>Ningjing 52>Chen 2>96D10>HJW14. 【Conclusion】 Considering the comprehensive
D value and the actual yield, Ningjing 52 exhibits relatively good performance in saline-alkali land, making it a suitable high-yield rice variety for planting and demonstration in saline-alkali land of Ningxia.