|Description of Trichomes:
Haired glandular secreting trichomes (GST); haired non-glandular trichomes.
Insect leafhopper resistant variety of alfalfa contains high densities of erect glandular trichomes containing multicellular stalks typically over 200 micrometer long toped by a glandular heads composed of a few cells with a diameter of approximately 15 micrometer. In potato, leafhopper resistance has been associated with certain varieties, such as G98A, that contain these trichomes. The fatty amide N-(3-methylbutyl)amide of linoleic acid has been associated with insect leafhopper resistance ( Ranger et al. Phytochem. 66:529-541).
Alfalfa also exhibits a second type of glandular trichome of unknown function similar to that shown for M. truncatula.
Alfalfa has non-glandular trichome as well, composed of a short base cell and a unicellular elongated shaft.
1) Christopher M. Ranger, Arthur A. Howerb. (2001) Glandular Morphology from a Perennial Alfalfa Clone Resistant to the Potato Leafhopper. Crop Science 41:1427-1434.
2) Ranger CM, Winter RE, Rottinghaus GE, Backus EA, Johnson DW. (2005) Mass spectral characterization of fatty acid amides from alfalfa trichomes and their deterrence against the potato leafhopper. Phytochemistry. Mar;66(5):529-41.