为探讨 3 种木兰科植物灰木莲 Manglietia glauca、醉香含笑 Michelia macclurei 和乐昌含笑Michelia chapensis叶片 SPAD 值的分布特征及其与叶绿素含量之间的关系，采用SPAD 叶绿素计和分光光度法分别测定了三者叶片 SPAD 值和叶绿素含量。结果表明：3 种植物叶片 SPAD 值的差异主要源于树种和叶片成熟度，叶片成熟度间的差异性强于树种间的差异。成熟叶的 SPAD 值显著高于嫩叶（P<0.01），乐昌含笑叶片 SPAD 值显著高于灰木莲和醉香含笑（P<0.05）。叶片不同部位的 SPAD 值分布表现为叶基 > 叶中 > 叶尖，除醉香含笑嫩叶之外，其余 2 种植物叶基与叶尖均存在显著差异（P<0.05）。三者叶片 SPAD 值的最佳测定部位均为叶片中部。三者叶片 SPAD 值与叶绿素 a、叶绿素 b 以及总叶绿素含量均呈现极显著（P<0.01）相关，可以利用 SPAD 值和不同模型来快速无损预测其叶绿素含量。

In order to study the distribution characteristics of SPAD value and its relationship with chlorophyll content in leaves of three Magnoliaceae species, Manglietia glauca, Michelia macclurei and Michelia chapensis, SPAD value and chlorophyll content in leaves were measured by using chlorophyll meter SPAD and spectrophotometry. The results showed that the significant differences of leaf SPAD values of the three plants were derived from tree species and leaf maturity, and the difference in leaf maturity was higher than that of tree species. The SPAD value of mature leaf was significant higher (P<0.01) than that of young leaf in three Magnoliaceae species, and the leaf SPAD value of M. chapensis was significant higher (P<0.05) than M. glance and M. macclurei. The SPAD value of the same leaf at different leaf positions was in the order of apex < middle < base. Significant differences(P<0.05) were found between apex and base except the young leaf of M. macclurei. The middle of leaf of three Magnoliaceae species was considered to be the optimal position for determining the SPAD value. Leaf SPAD value of three Magnoliaceae species had a highly significant (P<0.01) positive correlation with chlorophyll a, chlorophyll b and total chlorophyll content, which showed that it was feasible to forecast chlorophyll content rapidly and non-invasively by SPAD value and different models.

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广州市科技计划项目（201803020010）；广州市地方标准制定（修订）计划项目（2019-21）；广州市部门预算科研项目（穗财编 [2017]50 号）； 广州市 2021 年部门预算科研项目（穗财环 [2021]15 号）