Palynology of native Amaranthaceae and Araliaceae in forest fragments of the Northwest of São Paulo State

ABSTRACT We investigated the pollen morphology of two native species of Amaranthaceae and three of Araliaceae from forest fragments in order to contribute with the palynology, taxonomy, and conservation of degraded areas. The pollen grains were acetolyzed, measured, qualitatively described and photographed using light and scanning electron microscopy. Quantitative data were analyzed by descriptive statistics. The pollen grains of Amaranthaceae are monads, small, apolar, spherical, pantoporate, and with metareticulate exine. For Araliaceae, the pollen grains are monads, small to medium, isopolar, subcircular to subtriangular, oblato-spheroidal to subprolate, 3-colporate, sometimes with vestibulum, lalongate endoaperture and microreticulate exine. The pollen data confirmed Amaranthaceae as a stenopalynous family. On the other hand, the species of Araliaceae studied characteristically present pollen grains apertures that can be used to differentiate them.

摘要 本研究针对森林片段中的2种苋科（Amaranthaceae）本土物种与3种五加科（Araliaceae）本土物种的花粉形态展开调查，以期为退化区域的孢粉学、分类学研究及生态保护提供参考。本研究通过光学显微镜与扫描电子显微镜对花粉粒进行乙酰解处理、尺寸测量、形态定性描述与显微拍摄，定量数据采用描述性统计学方法进行分析。
苋科物种的花粉粒为单粒花粉，体积小型，无极性，呈球形，具散孔（pantoporate）萌发孔，外壁为复网状纹饰（metareticulate exine）。五加科物种的花粉粒则为单粒花粉，体积小型至中型，具等极性，轮廓呈近圆形至近三角形，形状为扁球形至近长球形，具三孔沟（3-colporate）萌发孔，部分个体具孔室（vestibulum），内萌发孔呈长圆形（lalongate endoaperture），外壁为细网状纹饰（microreticulate exine）。
本次花粉研究证实苋科为孢粉形态保守的科（stenopalynous family）。与之相对，本次研究的五加科物种的花粉萌发孔特征可用于区分不同物种。