|Mcgrath, J Mitchell - Mitch|
Submitted to: Annual Beet Sugar Development Foundation Research Report
Publication Type: Research Notes
Publication Acceptance Date: 5/6/2005
Publication Date: 6/1/2005
Citation: Trebbi, D., McGrath, J.M. 2005. Self-fertility in beets: obligate or facultative? 2004 Annual Beet Sugar Development Foundation Research Report. p. D5-D6.
Technical Abstract: Beets are normally out-crossing, enforced by a complex system of self-incompatibility, asynchronous flowering, and different times of maturation of pollen and stigma in the same flower. The Self-fertile trait (Sf), a monogenic dominant character, can overcome self-sterility. This character is very useful in developing defined segregating populations for genetic analyses. Single seed decent on a population derived from a cross between self-fertile sugar and red table beets presented an opportunity to test for the strength of the Sf trait by examining seed harvested from green male-sterile (nuclear) and male-fertile plants when provided with a red beet pollinator. The monogenic Red trait (R) is dominant to green (rr), thus any seed with intensely red hypocotyls harvested from a green plant were due to out-crossing, and thus the rate of cross pollination could be estimated. Results indicated that self-fertility is not obligate. As expected, seed harvested from bagged red beets paired with green beets showed all red hypocotyl. Out-crossing as determined from the proportion of red hypocotyl seedlings from seed harvested from the green plant of the pair-cross averaged 8.8%. This represents the level of contamination that could be expected due to proximity and contact of flowers of different self-fertile plants (inbreds), and likely was a consequence of normal plant care activities such as watering, fertilizing, and pest control.