Skip to main content
ARS Home » Midwest Area » Columbia, Missouri » Plant Genetics Research » Research » Publications at this Location » Publication #68524
Title: HETEROCHRONY ASSOCIATED WITH NINE CYCLES OF DIVERGENT SELECTION FOR RIND PENETROMETER RESISTANCE IN MISSOURI STIFF STALK SYNTHETIC.

Author
item ABEDON, B - UNIV OF WISCONSIN
item DARRAH, LARRY
item TRACY, W - UNIV OF WISCONSIN

Submitted to: Maize Genetics Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Variation in the timing of development, called heterochrony, has adaptive value and evolutionary importance in a number of plant species. Stalk strength, an important component of resistance to stalk lodging, may be affected by the timing of vegetative phase change since juvenile and adult-vegetative tissues have differing cell wall composition. Efforts to understand the mechanism of stalk lodging resistance and develop stalk lodging resistant germplasm at the University of Missouri have focused on recurrent selection for rind penetrometer resistance (RPR) in Missouri Second Cycle Stiff Stalk Synthetic (MoSCSSS). Our objective was to determine if heterochrony was associated with nine cycles of divergent selection for RPR in MoSCSSS. Data were collected on 20 plants per cycle in replicated plots in 1995. Duration of the juvenile-vegetative phase (based on last leaf with juvenile wax and tiller number) decreased significantly between C9-low and C9-high. Initiation of the adult-vegetative phase (based on first leaf with adult wax and first leaf with pubescence) tended to occur more quickly between C9-low and C9-high. First leaf with adult wax decreased from 7.1 to 6.4 in C0 and C9-high, respectively, but did not change significantly between C0 and C9-low. Reproductive initiation (based on total leaf number) was not affected by selection. These results indicate that selection for high and low RPR resulted in faster and slower vegetative phase change, respectively, without altering the developmental timing of the reproductive phase, indicating that heterochrony is associated with RPR and stalk lodging in maize.