热带森林向农业系统的强烈转化导致栖息地的丧失和生态系统功能的下降。植物-传粉者相互作用缓冲了森林碎片化的过程,通过花粉转移确保基因在孤立的森林中流动。在这项研究中,我们确定了无刺蜜蜂的花粉中储存的花粉粒的成分,四角肌,通过双基因座DNA代谢编码(ITS2和RBCL)和光学显微镜,并比较了在四个管理强度级别(森林,灌木,橡胶,和油棕)进行景观表征。
在DNA元编码和光学显微镜之间,植物组成存在显着差异。通过光学显微镜和DNA元编码技术鉴定的植物家族的重叠度很低,范围为22.6%至27.8%。分类分配显示蜜蜂授粉植物的花粉占主导地位,包括含油作物,例如引入的物种Elaeisguineensis(槟榔科),是所有四种土地利用类型花粉样品中的主要分类群之一。本地植物科桑科,大鱼科,在分析的花粉材料中,大麻科以很高的比例出现。单因素方差分析(p>0.05),PERMANOVA(R²值范围从0.14003到0.17684,对于所有测试p值>0.5),和NMDS(胁迫值从0.1515到0.1859)表明在四种不同的土地利用类型中花粉类型的物种组成和多样性之间缺乏区别,支持来自邻近地区的花粉涌入。
无刺蜜蜂从各种农作物中采集花粉,杂草,和野生植物。从花粉样本中在家庭水平检测到的植物组成可能反映了景观水平而不是地块水平的植物组成。在我们的研究中,来自安装在具有不同森林转化水平的土地利用系统中的殖民地的花粉中的植物多样性是高度均匀的,反映了无刺蜜蜂通过不同的土地利用类型运输的大量花粉。双基因座方法应用于代谢编码研究和视觉花粉鉴定,在植物群落的检测中显示出巨大的差异,因此,建议将这两种方法结合使用,通过花粉鉴定进行生物多样性评估。
Intense conversion of tropical forests into agricultural systems contributes to habitat loss and the decline of ecosystem functions. Plant-pollinator interactions buffer the process of forest fragmentation, ensuring gene flow across isolated patches of forests by pollen transfer. In this study, we identified the composition of pollen grains stored in pot-pollen of stingless bees, Tetragonula laeviceps, via dual-locus DNA metabarcoding (ITS2 and rbcL) and light microscopy, and compared the taxonomic coverage of pollen sampled in distinct land-use systems categorized in four levels of management intensity (forest, shrub, rubber, and oil palm) for landscape characterization.
Plant composition differed significantly between DNA metabarcoding and light microscopy. The overlap in the plant families identified via light microscopy and DNA metabarcoding techniques was low and ranged from 22.6 to 27.8%. Taxonomic assignments showed a dominance of pollen from bee-pollinated plants, including oil-bearing crops such as the introduced species Elaeis guineensis (Arecaceae) as one of the predominant taxa in the pollen samples across all four land-use types. Native plant families Moraceae, Euphorbiaceae, and Cannabaceae appeared in high proportion in the analyzed pollen material. One-way ANOVA (p > 0.05), PERMANOVA (R² values range from 0.14003 to 0.17684, for all tests p-value > 0.5), and NMDS (stress values ranging from 0.1515 to 0.1859) indicated a lack of differentiation between the species composition and diversity of pollen type in the four distinct land-use types, supporting the influx of pollen from adjacent areas.
Stingless bees collected pollen from a variety of agricultural crops, weeds, and wild plants. Plant composition detected at the family level from the pollen samples likely reflects the plant composition at the landscape level rather than the plot level. In our study, the plant diversity in pollen from colonies installed in land-use systems with distinct levels of forest transformation was highly homogeneous, reflecting a large influx of pollen transported by stingless bees through distinct land-use types. Dual-locus approach applied in metabarcoding studies and visual pollen identification showed great differences in the detection of the plant community, therefore a combination of both methods is recommended for performing biodiversity assessments via pollen identification.