Identification of Pollenkitt Variation among Alfalfa Germplasm Sources
- John A. Henning and
- Larry R. Teuber
Pollenkitt is the outermost lipid and fatty acid layer of the pollen grain and is thought to contain aroma-producing volatile compounds that are attractive to pollinators. Honey bee (Apis mellifera L.) nonpreference for alfalfa (Medicago sativa L.) pollen may result from a deficient pollenkitt. This study was conducted to determine if: (i) a pollenkitt is present on alfalfa pollen, (ii) pollenkitt quantity differs among germplasm sources and among plants within germplasm sources, and (iii) pollenkitt measurements (scores) are reproducible over time. Pollen from ≥24 individuals in each of eight germplasm sources were stained for lipids with Sudan IV, observed by light microscopy, and then scored using a five-point rating system for the presence and amount of pollenkitt. Pollenkitt was present in all eight germplasm sources. Arabian germplasm had greater (P ≤ 0.05) amounts of pollenkitt (mean score 3.77) than all other sources. All sources exhibited within-population variation. If attractive volatiles are associated with alfalfa's pollenkitt, then breeding for increased pollenkitt may increase honey bee preference for alfalfa pollen.
Copyright © 1992.