为了探明罗甸小米核桃幼苗与光生境的关系,为罗甸小米核桃栽培管理提供科学依据,以罗甸小米核桃(Juglans regia L.f.ludianense Liu et Xu)一年生幼苗为试验材料,研究了不同光照强度对盆栽罗甸小米核桃生理生态的影响.结果表明:①随着光照强度的减少,地径增粗减少,全光照下的地径净增量最大,而中度遮阴环境下,罗甸小米核桃幼苗苗高净增量高于其他处理,且幼苗获得最大的苗高生长能力；②随着光照强度的减小,逐渐加大对复叶的资源投入,降低茎干方面的投入,根冠比增大,中度遮阴可使幼苗获得最大产量；③随着光照强度的减小,气孔导度和净光合速率呈现先升后降的趋势,并在轻度和中度遮阴环境下达到较高水平；④遮光条件下,罗甸小米核桃一年生幼苗的chla、chlb和chl(a+b)相对于全光照(CK)的差异显著,chl a/b在重度遮阴下显著降低.说明,适度的遮阴可能有利于罗甸小米核桃幼苗的生长.%To reveal the relationship between light environments and 1-year J. regia seedling, the investigation on eco-physiological responses of 1 -year J. regia seedling to different light intensity was done. The result showed that: (i) The stem diameter decreased, and the net increment of stem diameter reached the maximum under full sunlight. Moreover, J. regia got maximum height growth ability under moderate shading ; (ii) In biomasa, with the degree of shading reduction the plant gradually increased investment of resources on fronds and decreased investment of resources on stems, the root biomass/shoot biomass ratio increased at the same time. The biomass per plant reached the maximum under moderate shading; (iii) With the degree of shading reduction, the net photosynthetic rate( Pn) and stomatal conductance (cond) first increased and then decreased, besides, the net photosynthetic rate(Pn) and stomatal conductance (cond) leaves increased to maximal levels under moderate shading and light shading; (iv) Under shading, the leaf chlorophyll a, chlorophyll b and total chlorophyll contents of J. regia had significant differences to those in full sunlight, and the chlorophyll a/b ratio under severe shading decreased significantly. In general, moderate shading might be beneficial in 1 -year J. regia seedling growth.
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