英文摘要 |
The exine of Artemisia vulgaris L. is made up of substructures 10-15 nm in diameter. These are parts of units, referred to as tufts, about 100 nm in diameter which extend from the spinules down through the tectum, columellae, foot layer and endexine. They also protrude from the tectum between the spinules. These tufts have coiled binder subunits around them which in normal (axial) surface views usually appear as ''C''-shaped gyres. Our results show that the resistant exine remaining after degradative treatment consists entirely of tufts. We suggest that the portion of the exine removed by oxidation, plasma ashing, and fast atom erosion is extra tuft sporopollenin. |