杉木种子与幼苗不同发育期的耐旱性研究

Drought Tolerance of Chinese Fir Seeds and Seedlings at Different Developmental Stages

以广东杉木(Cunninghamia lanceolata)第二代改良种子园种子为试材,利用不同浓度聚乙二醇(PEG-6000)溶液(5%、10%、20%和40%)模拟不同程度(轻度、中度、较强、重度)干旱胁迫,并对不同干旱条件下的种子萌发、幼苗子叶期和真叶期不同发育阶段的形态变化进行测定分析。结果发现,杉木种子萌发初期对水分尤为敏感,耐旱性不强,尤其是随干旱程度的加剧,种子起始萌发时间不断后延且发芽率显著降低。子叶后期的杉木幼苗较子叶前期耐旱,真叶期的杉木幼苗对轻度和中度干旱胁迫具有较强的耐受性。

The present study aimed to investigate the effect of the polyethylene glycol(PEG-6000)simulated graduated drought stress(5%,10%,20%and 40%PEG-6000 equaled to mild,moderate,strong and heavy levels,respectively)on the germination of seeds from Chinese fir second improved seed orchard and its seedlings regarding to their dynamic change at different stages(cotyledon and true leaf stages).The results indicated that germination of the Chinese fir seeds required adequate water and were rather drought-sensitive.Worsening drought largely delayed the germination time,and significantly reduced the germination rate.The late cotyledon state seedlings were more drought tolerant than those at early stage,while true leaf state seedlings seemed to have strong tolerance to mild and moderate stress.