Structural differences in stigma Arachis species (Leguminosae) and their probable significance in pollination

English

The stigmas of the cultivated peanut ("rachis hypogaea L.) and some of its wild relatives in section Arachis, and one accession from section Rhizomatosae of the genus Arachl,sp were studied with scanning electron microscopy. Three morphological types were observed and two of them correlated well with the two main growth cycle types observed in section Arachis. The annuals possessed large. globular stigmas with many. papillae and with no guard hairs; the perennials had small, stigmatic surfaces with prominent guard hairs that over-arched the surfaces. The third stigma type can be described as intermediate in size and extent of hair growth on the surfaces. The implieations of the different stigma structures in pollination in Arachis are discussed.

Akromah, R.