Characterization of Onion Floral Nectaries
EMSL Project ID
1807
Abstract
Onion seed production has been an unpredictable venture over the last several decades due to precarious pollination of the crop by the honey bee. It has been noted since the advent of hybrid onion varieties that honey bees hold a particular dislike for the flowers of certain onion inbred lines. A thorough investigation of the properties of the onion flower nectar, the source of food for a honey bee foraging on a field of onion flowers, concluded the low volume of nectar produced by the undesirable lines leads to their unattractive nature. Nectar passes through the nectary in a variety of ways, one of which involves exudation through modified stomates found on the surface of the nectary. Several studies have been done involving the effect of stomates on the nectar production other species of plants and have concluded that the number of these stomates positively correlates with the nectar secretion capacity of the flower. The objective of this! study is to determine the reason for the differing capacities of onion flowers to produce nectar and ultimately to enhance floral attractiveness by further understanding the morphological and physiological factors which affect nectar production. This includes the characterization of nectary stomates of the onion flower. Flowers from nine different inbred lines of onions differing in their attractiveness to honey bees and their nectar production capabilities will be compared to determine if correlations exist between the number of nectary stomates present and the nectar production rate of the flowers. Nectary stomates will be viewed under the scanning electron microscope. The ESEM will be used to obtain real-time data on nectar exudation and to characterize the stomates from fresh tissue. The TEM will be used to view the vascular connections which supply the nectar sugar to the stomates. Previous work done at EMSL over the last several months has shown the instruments to be ideal to obtain the desired results.
Project Details
Project type
Exploratory Research
Start Date
2000-02-03
End Date
2000-12-31
Status
Closed
Released Data Link
Team
Principal Investigator