3种枫香的根系构型及功能特征对干旱的响应

以 3 种 2 年生枫香幼苗：中国枫香(Liquidambar formosana)、缺萼枫香(Liquidambar acalycina)、北美枫香(Liquidambar styraciflua)为供试材料，采用完全随机区组试验研究了自然干旱对枫香实生苗根系构型和功能特征的影响。结果表明，除根系碳含量以外，各处理根系特征之间(包括树种及干旱处理)差异极显著 (P<0.01)。干旱胁迫下，缺萼枫香比根长、比表面积、根系分叉相对增长率最高，分别为 56%、30%、-4%，北美枫香最低，分别为 9%、-3%、-19%；北美枫香根尖密度、根系平均直径相对增长率最高，分别为 40%、-10%，缺萼枫香最低，分别为?-27%、-16%；北美枫香根系氮含量相对增长率最高，为 127%，中国枫香最低为 41%；中国枫香根系 C/N 比相对增长率最高为 -26%，北美枫香最低，为 -56%；0北美枫香>缺萼枫香。

Response of Architecture and Functions of Roots in Three Kinds of Sweet Gums Under Drought Stress

With the three kind of two-year-old Liquidambar seedlings: Liquidambar formosana, Liquidambar acalycina and Liquidambar styraciflua as study object, studying the influence of natural drought on conformation and functional characteristics of Liquidambar seedling root system, by using a randomized complete block experiment. The results showed that except the carbon content, the difference of all indexes in all treatments (including seed and drought treatment) was significant (P < 0.01) under the drought stress, the relative growth rates of specific root length, specific surface area and root bifurcate of the Liquidambar acalycina were the highest, which reached to 56%, 30% and -4% respectively; which of Liquidambar styraciflua were the lowest, reached to 9%, -3% and -19% respectively. While the relative growth rates of Liquidambar styraciflua root density and roots average diameter were the highest, which reached to 40% and -10% respectively, which of Liquidambar acalycina were the lowest, reached to -27% and -16% respectively. The relative growth rate of the Liquidambar styraciflua root system nitrogen content was the highest, which reached to 127%, which of Liquidambar formosana was the lowest, reached to 41%. The relative growth rate of Liquidambar formosana C/N was the highest, which reached to -26%, which of Liquidambar styraciflua was the lowest, reached to -56%. The results also indicated that the rootlet at 0 Liquidambar styraciflua> Liquidambar acalycina.