【摘要】 为了解栓皮栎幼苗各器官在不同季节的生长动态,以便进一步研究和探讨幼苗生长受阻和死亡的原因,本研究详细跟踪0～3年生栓皮栎幼苗的生命进程,测定幼苗各器官生长量、干物质量以及糖分浓度。结果表明:1) 1年生幼苗夏季茎和叶片有明显的生长受阻现象; 2) 1～2年生幼苗根生长除12月至翌年3月的冬季停止伸长外,一直伸长生长,3年生幼苗根则伸长生长缓慢; 3)由种仁干物质消耗和糖分浓度分析可知,1年生幼苗夏季(6月上旬开始)的生长受阻,与种仁剩余量和糖分浓度最低相匹配; 4) 6月上旬种仁总糖浓度开始低于叶片总糖浓度,此时起种仁不再是植株主要的营养供体; 5) 2、3年生幼苗从3月中旬开始生长,至7月份生长变缓,没有生长停滞现象;因此,0～3年生栓皮栎幼苗生态策略为保证主根生长,1年生幼苗存在夏季生长受阻现象,这与幼苗抗性最弱(异养自养转换)的时期密切相关,2、3年生幼苗无生长停滞现象。更多还原

【Abstract】 [Background] Plant growth dynamics reveals the impacts of the environment on plants.Quercus variabilis is one of the afforestation species widely used in rocky mountainous areas. It is prone to growth retardation or death under environmental stress. In order to further reveal the reasons for the stunted seedling growth and death,this paper traced the life course of each organ. [Methods] In this study,the seedlings of Quercus variabilis were sampled by hand-excavation in the nursery field. The sampling interval was 10 d in the first year,one month in the second year,and one season in the third year,and the growth,dry biomass and sugar concentration of every organ in the seedlings were measured by drying and Anthrone colorimetry. [Results]1) During the first growing season,there was obvious growth-stasis-regrowth of stem and leaf,showing the phenomenon of blocked growth in summer. 2)Except for the winter season( December-March of the next year),the roots of 1/2-year-old seedlings grew continuously. At the age of 3,the rate of root elongation was slower than at 1/2 years,with root thickening and lateral root growth being the main growth. 3) Analysis of seed kernel dry matter consumption and total sugar concentration showed that the growth of seedlings in their first summer( from early June) was blocked,which was in line with the lowest seed kernel residue and total sugar. 4) In early June,the total sugar concentration of the seed kernel began to fall beneath the total sugar concentration of the leaf,indicating that the seed kernel was no longer the main nutrient donor of the plant. 5) Seedlings aged 2 to 3 years began to grow from the middle of March,and growth slowed down in July,and they did not show the phenomenon of blocked growth. [Conclusions] The ecological strategy of 0-3 years old seedlings of Q. variabilis was to ensure the growth of the main roots,the 1-year-old seedlings have stunted growth in summer,which is closely related to the period of weakest seedling resistance transform( heterotrophic autotrophic transformation),and there was no stagnation in the growth of 2 or 3 year old seedlings.更多还原