空心莲子草性可塑性影响下的克隆整合

Clonal integration of Alternanthera philoxeroides underlying effects of gender plasticity

关键词:  克隆整合, 性别特征, 可塑性, 异质环境

Key words:  clonal integration, gender characteristic, plasticity, heterogeneous environment

摘要:

植物的生活史由其有性生殖构件和营养体构件相互作用共同完成,克隆整合作为克隆植物的重要特征,其与有性生殖特征的相互作用关系却所知很少。该研究通过同质园种植实验,分析了空心莲子草的分株表型、生理、性别等与克隆整合的关系。结果表明:(1)克隆整合以及分株间是否连接对空心莲子草的表型特征、气体交换等生理性状和性别特征均有显著影响。(2)克隆整合显著缩小了雌雄同花和雄蕊心皮化两种性别植株间表型特征的差距,后代的性别特征与营养体表型特征显著相关。(3)在贫瘠的沙土基质中克隆整合明显增加了空心莲子草的营养体生长特征和气体交换等光合生理指标,但这种增加在富含有机质的塘泥基质中不明显。(4)居于不同土壤基质分株间的联系会减少分株表型特征和气体交换对生长环境的响应,并保持母体性别特征不受环境的影响,但单独居于沙土或塘泥单一土壤基质的分株性别特征却因受到环境影响而改变。因此,克隆整合有利于空心莲子草性别特征的稳定。

Abstract:

Life history of plant is accomplished by sexual reproductive components and vegetative growth components together. Clonal integration is an important characteristic of clonal plant, while the interactive relationship between clonal integration and sexual reproductive characteristic is known very little. In this paper, the interactive relationship between clonal integration and phenotypes, physiological traits and gender of Alternanthera philoxeroides were studied by homogeneous garden cultivation experiment. The results were as follows:(1)Both clonal integration and connection or disconnection had significant effects on the phenotypic characteristics, gender phenotypic traits, gas exchange properties and other physiological characteristics of A. philoxeroides.(2)Clonal integration significantly reduced the phenotypic characteristics of hermaphroditic plant and carpelloid plant of two sexes, and the gender characteristics of offsprings were apparently correlated with vegetative phenotype.(3)Clonal integration signicantly increased growth and gas exchange in barren sandy substrates, but did not show significant effect on both of these characteristics in abundant organic bog substrates.(4)Connection between ramets reduced both gas exchange and phenotypic responses to local conditions. Connection between ramets reduced both gas exchange and phenotypic responses to local conditions in different soil matrixes. At the same time, ramet gender was consistent with mother plant regardless of environmental conditions during clonal integration, while ramet gender was affected by environment in unconnected condition that cultivated in sand or bog alone. Therefore, clonal integration facilitates the stability of gender trait of A. philoxeroides.