关键词: 杜鹃花, 生长适应性, 重金属污染, 替代种植, 品种差异

Abstract: Soil heavy metal pollution is a serious problem in mining areas. A field experiment was conducted to select the Rhododendron varieties suitable for planting in a lead-zinc polluted mining area on the Yunnan Plateau. The traits screened among 13 varieties included seedling height, growth rate, chlorophyll content, nutrient content, and characteristics of heavy metal accumulation. The results showed that: (1) Compared with non-rhizosphere soil, rhizosphere soil of Rhododendron had significantly lower pH value, available potassium and alkali-hydrolyzable nitrogen concentrations, but higher available phosphorus concentration. (2) There were differences in growth factors and mineral nutrient concentrations among Rhododendron varieties. Varieties ‘Hongyang’ and ‘Hongyunlai’ had the greatest increase in plant height and biomass; Variety ‘Azalea’ had the highest chlorophyll content; Varieties ‘Huolieniao’, ‘Yangzhizhu’ and ‘Hongyang’ had the highest N, P, and K concentrations, while variety Duanyang’ had the lowest nutrient concentrations. (3) There were significant differences in the capacity to accumulate and transport heavy metals among different varieties. Variety ‘Hongyang’ had the greatest capacity to absorb heavy metals, whereas variety ‘Yangzhizhu’ had the lowest. In conclusion, all the 13 Rhododendron varieties screened could grow in lead-zinc polluted mining area. ‘Azalea’ had the highest score after an evaluation of growth adaptability factors, followed by ‘Huolieniao’. These two varieties should be considered as the primary varieties for alternative planting in lead-zinc polluted mining areas of the Yunnan Plateau.

Key words: Rhododendron, growth adaptability, heavy metal pollution, alternative planting, variety difference.