8种湿地植物不同苗龄植株的表型特征及相关性分析

对水葱(Scirpus validus Vahl)、香蒲(Typha orientalis Presl)、小香蒲(T.minima Funk.)、再力花(Thalia dealbata Fraser ex Roscoe)、黄菖蒲(Iris pseudacorus Linn.)、灯芯草(Juncus effusus Linn.)、梭鱼草(Pontederia cordata Linn.)和菖蒲(Acorus calamus Linn.)8种多年生湿地植物1年生和3年生植株的地上和地下部分干质量、株高(包括花序高和叶层高)、根长、根数和根粗进行了测定,并对各表型特征指标间以及苗龄与各表型特征指标间的相关性进行了分析。结果显示:8种湿地植物3年生植株的地上和地下部分干质量普遍高于1年生植株;从生长量分配情况看,除小香蒲外,其余种类3年生植株地下部分干质量所占比例均高于1年生植株。多数种类1年生和3年生植株的株高差异较小。从根系特征看,根数小于100、根粗1.0~2.0 cm的植株以1年生为主,而根数大于100、根粗1.0 cm以下和2.0~3.5 cm的植株以3年生为主;根长15~25 cm的植株以1年生所占比例较高(62.5%),而根长25~35 cm的植株1年生和3年生所占比例相等。相关性分析结果表明:1年生植株的地上部分干质量与株高、根长与根粗呈显著正相关(P<0.05),3年生植株的地下部分干质量与根粗也呈显著正相关;但不同苗龄植株的其他表型特征指标间的相关性均不显著。苗龄与植株地下部分干质量呈极显著正相关(P<0.01),但与地上部分干质量、株高、根长、根数和根粗的相关性不显著。总体而言,8种湿地植物3年生植株的表型特征优于1年生植株,更适用于污染水体及退化湿地生态系统的修复。

Analyses on phenotypic characteristics of eight wetland species with different plant ages and their correlation

Dry weights of above- and under-ground parts, plant height （ including heights of inflorescence and leaf layer）, root length, root number and root diameter of eight perennial wetland species including Scirpus validus Vahl, Typha orientalis Presl, T. minima Funk., Thalia dealbata Fraser ex Roscoe, Iris pseudacorus Linn., Juncus effusus Linn., Pontederia cordata Linn. and Acorus calamus Linn. with one- and three-year-old were determined, and correlation among phenotypic characteristics and correlation between plant age and phenotypic characteristics were analyzed. The results show that dry weights of above- and under-ground parts of three-year-old plant of eight species are generally higher than those of one-year-old plant. From status of growth amount allocation, except T. minima, ratio of dry weight of under-ground part of three-year-old plant of other species is higher than that of one-year-old plant. Difference in plant height between one- and three-year-old plants of most species is small. From root characteristics, the majority of plants with root number lower than 100 and root diameter from 1.0 to 2.0 cm is one-year-old plant, while that of plants with root number higher than 100, root diameter lower than 1.0 cm and from 2.0 to 3.5 cm is three-year-old plant. Ratio of one-year-old plant with root length from 15 to 25 cm is higher with a value of 62.5%, while that of one- and three-year old plants with root length from 25 to 35 cm is equal. The correlation analysis result shows that there are significantly （P〈 0. 05 ） positive correlations between dry weight of above-ground part and plant height, between root length and root diameter of one-year-old plant, and there is also significantly positive correlation between dry weight of under-ground part and root diameter of three-year-old plant, but correlations between other phenotypic characteristics indexes of plants with different ages all are not significant. There is an extremely significant positive correlation between plant age and dry weight of under-ground part （P〈 0. 01 ）, but not significant correlation between plant age with dry weight of above-ground part, plant height, root length, root number and root diameter. Overall, phenotypic characteristics of three-year-old plant of eight species are better than those of one-year-old plant, and the former is more suitable for repairing polluted water and degenerated wetland ecological system.