干旱胁迫对白枪杆幼苗生长生物量及C、N、P化学计量特征的影响  

Effects of Drought Stress on the Growth Biomass and C,N,and P Stoichiometric Characteristics of Fraxinus malacophylla Seedlings

作　　者：张梅 叶澜 李树萍 茶晓飞 董琼[1] ZHANG Mei;YE Lan;LI Shuping;CHA Xiaofei;DONG Qiong(Key Laboratory of National Forestry and Grassland Administration on Biodiversity Conservation in Southwest China/Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountainous China,Ministry of Education,Southwest Forestry University,Kunming 650224,China)

机构地区：[1]西南林业大学西南地区生物多样性保育国家林业和草原局重点实验室/西南山地森林资源保育与利用教育部重点实验室,昆明650224

出　　处：《四川农业大学学报》2024年第2期397-404,共8页Journal of Sichuan Agricultural University

基　　金：国家自然科学基金(31260191);云南省教育厅科学研究(2021J0166、2022Y581)。

摘　　要：【目的】研究不同干旱胁迫程度对白枪杆幼苗生长、生物量积累与分配,以及不同器官C、N、P积累与分配,探究白枪杆对不同干旱环境的适应性。【方法】以1 a生白枪杆幼苗实生苗为试验材料,研究干旱胁迫处理分别是对照(CK)、轻度干旱胁迫(LS)、中度干旱胁迫(MS)和重度干旱胁迫(SS)对白枪杆幼苗生长、生物量的积累量与分配、根冠比、各器官C、N、P含量及化学计量特征的分析和各器官C、N、P的积累和分配规律等指标测定。【结果】随干旱胁迫程度的上升,白枪杆幼苗的苗高和地径的增长量显著降低(P<0.05)。叶片、茎和根的生物量及总生物量、叶片生物量占比降低,茎和根生物量占比和根冠比降低。白枪杆幼苗C、N和P的积累量随干旱胁迫程度的上升呈下降趋势;与适宜的水分处理相比,白枪杆幼苗各器官的C∶N均呈先下降后上升的趋势,叶片和根的C∶P呈先下降后上升的趋势;白枪杆幼苗各器官N∶P低于14,表明生长主要受N限制。【结论】白枪杆幼苗生长及生物量和C、N、P含量及化学计量特征对不同干旱胁迫程度的响应有差异,主要表现在随干旱胁迫程度的上升,白枪杆幼苗的苗高、地径增长量呈下降趋势,生物量的分配也倾向于地下部分,干旱胁迫处理下不利于白枪杆幼苗的生长,生物量的积累减少,C、N和P的积累量降低。【Objective】Our aim is to investigate the adaptability of F.malacophylla seedling to various drought environments by examining the impacts of different degrees of drought stress on the growth,biomass distribution patterns,as well as the accumulation and distribution of carbon(C),nitrogen(N)and phosphorus(P)in different organs of F.malacophylla seedlings.【Method】We used 1-year-old of F.malacophylla seedlings as experimental materials and established four drought treatments,including control(CK),mild drought stress(LS),moderate drought stress(MS),and severe drought stress(SS).The growth,biomass,and C,N and P contents in various organs of the F.malacophylla seedlings were measured to investigate the effects of drought stress on their biomass allocation patterns and the stoichiometric characteristics of C,N and P.【Result】The growth in height and ground diameter of F.mala⁃cophylla seedlings significantly decreased(P<0.05)with increasing drought stress.Additionally,the biodoimass of leaves,stems,and roots,along with the total biomass,and the proportion of biomass of leaves,stems,and roots,as well as the root-to-crown ratio,decreased with increasing drought stress.Similarly,the contents of C,N and P of F.malacophylla seedlings exhibited a decreasing trend with with drought stress.However,the C to N ratio of various organs and the C to P ratio of leaves and roots in the F.mala⁃cophylla seedlings exhibit a trend of initially decreasing,followed by increasing with the increase of drought stress.The N to P ratio of each organ in the F.malacophylla seedlings was lower than 14,suggesting that growth was primarily limited by N.【Conclusion】These findings indicate that the biomass and C,N and P stoichiometric characteristics of F.malacophylla seedlings respond differently to drought stress.Drought stress negatively impacts the growth and the accumulation of C,N and P in F.mala⁃cophylla seedlings,leading to a greater allocation of biomass underground.

关 键 词：白枪杆 干旱 生长 C∶N∶P 适应策略 

分 类 号：S718.43[农业科学—林学]