武夷科学

本研究旨在探究木荷幼苗在自然干燥条件下的生理响应，为其培育提供科学依据。采用自然干燥法研究不同水分梯度对木荷幼苗叶片生理指标的影响，通过预试验确定木荷幼苗在自然干燥条件下的生长情况，每隔3 d进行1次取样，测定不同干旱处理时间点(CK:第0天、P1:第3天、P2:第7天、P3:第11天、P4:第15天)叶绿素(Chl)、丙二醛(MDA)、可溶性蛋白(SP)含量以及过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)酶活性，并对测定的6个生理指标进行综合评价。结果显示，随着干旱程度的增加，Chl含量逐渐降低，MDA含量和CAT酶活性总体上呈上升趋势，POD和SOD酶活性先升高后降低，而SP含量呈先下降后上升的趋势；通过主成分分析和相关性分析，Chl、MDA、POD、SOD的得分较高，且存在显著的相关性；抗旱性综合响应函数Y值在干旱胁迫程度增加过程中呈先增后减趋势，在第3天达到最小值，第11天达到最大值。干旱初期，木荷幼苗适应能力较强，随胁迫持续，适应力渐弱。

The aim of this study was to investigate the physiological responses of Schima superba seedlings to natural drying conditions, to provide a scientific basis for their cultivation. We used a natural drying method to examine the effects of varying water gradi-ents on the physiological indices of S. superba seedling leaves. Preliminary experiments were conducted to assess the growth of S. superba seedlings under natural drying conditions. Samples were collected every three days to measure chlorophyll(Chl), malondialdehyde(MDA), soluble protein(SP), catalase(CAT), peroxidase(POD), and superoxide dis-mutase(SOD) activities at different drought treatment times(CK: 0th day, P1:3rd day, P2:7th day, P3:11th day, P4:15th day). A comprehensive evaluation of six physiological indices was conducted, and the results indicated that, as the severity of drought increased, the Chl content gradually decreased, whereas the MDA content and CAT enzyme activity generally showed an up-ward trend. POD and SOD enzyme activities initially increased and then decreased, and SP content exhibited an initial decreas-ing trend, followed by an increase. The principal component and correlation analyses revealed that Chl, MDA, POD, and SOD had higher scores and significant intercorrelations. The comprehensive drought resistance response function Y value showed an initial increase, followed by a decrease with increasing drought stress, reaching a minimum on the third day and a maximum on the eleventh day. Notably, S. superba seedlings exhibit a strong adaptive capacity in the early stages under drought condi-tions, but their adaptability diminishes as drought stress persists.