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面包树是墨西哥和中美洲潮湿热带森林的一个优势种,对其遗传生态学研究是在墨西哥韦拉克鲁斯的九个种源的自然分布区的一定区域内进行的。沿纬度梯度从每个种源中随机地选择5—11个单株进行采种。根据种子重、根系、茎、叶的干重分析种源间的变异。通过主分量和线性相关分析,结果表明:在种子大小(直径和重量)和能量分配到实生苗根系的差异方面存在着生态梯度变异。而这两种性状都与几个气候因子密切相关。同时也证实种子大小显著地影响着初期实生苗大小及其根系的相对大小,且种子大小随产地干燥度和经纬度而增加。研究结果表明,面包树实生苗在生长和定居初期,对旱季延长期发生的水分亏缺具有严格的生态适应性。
The bread tree is a dominant species of humid tropical forests in Mexico and Central America, and its genetic ecology is studied within a region of natural distribution of nine provenances in Veracruz, Mexico. Five to eleven individuals were randomly selected from each provenance along the latitude gradient for seed collection. According to the weight of seeds, root system, stem and leaf dry weight analysis of the variation between provenances. The principal components and linear correlation analysis show that there are ecological gradient variations in seed size (diameter and weight) and energy distribution to the root of seedlings. Both of these traits are closely related to several climatic factors. At the same time, it was also confirmed that the seed size significantly affected the initial seedling size and the relative size of its root system, and the seed size increased with the dryness of the place of origin and latitude and longitude. The results showed that the seedlings of sapwood had strict ecological adaptability to the water deficit that occurred during the extended dry season in the initial stage of growth and settlement.