芒麻耐镐品种差异及其筛选指标分析

摘要

The rapid industrialization causes the large areas of heavy metal contaminated soils, which has become a threat to the local ecosystems.Cadmium (Cd) is a heavy metal which has aroused great concerns in the environmental science community, because of its toxicity to animals and humans.Screening and breeding high cadmium tolerant ramie genotype is one of the effective alternatives to utilize the cadmium contaminated soil, since ramie could minimize the potential hazard of bringing toxic metals into food chains.In this study, a hydroponic culture experiment and a field micro-plot trial were carried out to compare nine ramie genotypes and their respective screening indices for Cd tolerance.In the hydroponic culture experiment, substantial differences and significant genotypic variations in plant height, leaf number per plant, shoot dry weight and root dry weight were found in different Cd treatments.The shoot dry weight well correlated with plant height, SPAD of leaf and root dry weight.In the field trial, the shoot dry weight well correlated with plant weight, diameter of stem and thickness of bark.This suggests that these characteristics could be used as Cd tolerance indicators.Cluster analysis using comprehensive Cd tolerance characteristics as evaluation parameters indicated that nine genotypes were divided into three categories.These results suggested that it would probably be an effective method to use the plant height, SPAD of leaf, shoot dry weight and root dry weight in ramie hydroponic culture experiment with different Cd treatments as selection indicators.%以营养液盆栽试验结合田问微区试验调查9个苎麻品种耐镉差异并筛选耐镉指标.结果表明,营养液盆栽试验中,不同镉处理下苎麻株高、单株叶片数、地上部干重和地下部干重差异显著,各性状具有较大的品种问差异.地上部干重与株高、叶片SPAD值和地下部干重均呈显著或极显著正相关,相关系数分别为0.95,0.82和0.85.田间微区试验中,地上部干重与株高、茎粗、皮厚均呈显著或极显著正相关,相关系数分别为0.86,0.72和0.76.分别对营养液盆栽试验和微区试验各指标耐镉指数的隶属函数值进行聚类分析,9个品种均被分为3类,结果基本一致.说明以营养液盆栽苎麻的株高、叶片 SPAD 值、地下部干重和地上部干重作为指标筛选苎麻耐镉品种是一条有效途径.