Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/23/2007
Publication Date: 1/12/2008
Citation: Yue, B., Cai, X., Vick, B.A., Hu, J. 2008. The Identification and Molecular Mapping of a Major Gene Affecting Leaf Color in Sunflower (Helianthus annuus L.) [abstract]. Plant & Animal Genome XVI Conference, January 12-16, 2008, San Diego, CA. P651. Interpretive Summary:
Technical Abstract: A cross was made between two sunflower breeding lines, one with light green and the other with normal green leaf color, for genetic analysis. All 20 F1 plants from the cross had normal green leaf color and the 172 F2 plants segregated in a 3:1 ratio (130 green-leafed to 42 light-green leafed plants, Chi squared=0.03, p>0.9). The greenness degree of leaf color of individual F2 plants was measured with a hand-held chlorophyll content meter. The greenness degree varied from 15.3 to 27.1 and 30.2 to 41.6 within the light green- and normal green-leafed groups, respectively. These results suggested that leaf color trait is under the control of a major gene and the normal green is dominant over light green. Measurement of chlorophyll with a spectrophotometer revealed that the difference in leaf color resulted from chlorophyll content variation among the plants. The contents of chlorophyll a, chlorophyll b, and total chlorophyll in the green-leafed lines were 71.9%, 115.0%, and 79.4% higher than those in the light green-leafed lines, respectively. Genetic mapping with molecular markers positioned the lg gene to linkage group 10 of sunflower. A previously mapped SSR marker, ORS 595, cosegregated with the leaf color, and a TRAP marker, B26P17ga5-300, was linked to the lg locus with a genetic distance of 4.2 cM. Identification and characterization of this major gene controlling chlorophyll contents in sunflower offers the opportunity to achieve a higher photosynthesis level to increase biomass and seed yield through genetic manipulation in the future.