摘要
【目的】探究遮荫对降香黄檀容器育苗生长发育和形态生理的影响,为林木育苗的光环境控制条件提供一定的理论依据。【方法】以当年生降香黄檀幼苗为试验材料,设遮荫程度0(T_0)、40%(T_1)、60%(T_2)、80%(T_3)、95%(T_4)5个处理,用不同遮荫程度处理4个月后,每隔15天监测降香黄檀幼苗的地径、苗高、叶片数等生长指标,观察其生长进程;并于试验处理结束后测量降香黄檀幼苗的生物量、比叶质量、叶绿素含量(Chl)、净光合速率(Pn)、胞间二氧化碳浓度(Ci)、气孔导度(Gs)、蒸腾系数(Tr)等。【结果】随着遮荫程度的增加,处理时间的延长,降香黄檀幼苗的苗高、地径逐渐降低,生长越来越弱,且表现越来越明显,其中T_4的苗高和地径增量分别为7.7和1.0 mm,是T_0的39.2%和35.6%。随着遮荫程度的加强,降香黄檀幼苗的干物质积累、比叶质量以及质量指数(QI)、根冠比、存苗率显著降低,表明遮荫程度的增加使降香黄檀幼苗的生长发育受到抑制;随着遮荫程度加强,幼苗叶片的叶绿素b(Chlb)、叶绿素a(Chla)和植株各部分含水量显著增加,而叶绿素a与叶绿素b比值(Chla/Chlb)、Pn降低,表明遮荫程度的增加引起降香黄檀容器苗的光合利用效率下降,进而导致幼苗生长发育缓慢,存苗率下降。【结论】综合分析生长进程和生理形态指标,降香黄檀容器育苗幼苗期宜在全光照环境下进行,遮荫不利于其生长发育。
【Objective】Dalbergia odorifera is one of the rare tree species for timber forest in our country,and there is an increasing demand for its seedlings. Aiming to explore the influence of shade on growth,development,morphology and physiological characteristics of D. odorifera seedlings,this paper could provide a sound theoretical foundation for the control of light environment on forestry seedling cultivation. 【Method】Five shade treatments including 0%（ T_0）,40%（ T_1）,60%（ T_2）,80%（ T_3） and 95%（ T_4） were set to annual D. odorifera seedlings for four months. Growth index（ i. e. ground diameter,seedling height,and leaf number） of D. odorifera seedlings were measured every 15 days during the experiment. The plant biomass,specific leaf weight,chlorophyll content（ Chl）,net photosynthesis rate（ Pn）,intercellular CO_2concentration（ Ci）,stomatal conductance（ Gs）,and transpiration coefficient（ Tr） were measured at the end of the treatment.【Result】The results showed that the ground diameter,seedling height and biomass of D. odorifera seedlings descend gradually with the increase of shade degree and the extension of treatment time,indicating the weakened growth of D. odorifera seedlings. The increment of seedling height and ground diameter in T_4 treatment was 7. 7 cm and1. 0 mm and which was 39. 2% and 35. 6% of T_0 treatment respectively during the test process. The dry matter accumulation,specific leaf weight,quality index and root / shoot ratio were significantly decreased with the increase of shade degree,indicating that shade inhibited the growth and development of D. odorifera seedlings. On the contrary,the shade markedly increased the Chl b and Chl a content of leaf and water content for all plant organs,while the Chl a / Chl b and Pnwere decreased. These results demonstrated that the increase of shade level could cause a decline of photosynthetic use efficiency,and then leading to a slower growth and development rate and a descend in the deposit rate of D. odori
出处
《林业科学》
EI
CAS
CSCD
北大核心
2016年第12期50-57,共8页
Scientia Silvae Sinicae
基金
中央林木良种培育计划
温州市森林生态重点科技创新团队(C20150002)
关键词
降香黄檀
遮荫
容器幼苗
生长
形态生理
Dalbergia odorifera
shade
container seedlings
growth
morphology physiology
