|Flint-Garcia, S - UNIV OF MISSOURI-COLUMBIA|
|Jampatong, C - NATL CORN & SORGHUM RES.|
Submitted to: NCR-167 Corn Breeding Committee Meeting
Publication Type: Abstract Only
Publication Acceptance Date: February 6, 2001
Publication Date: N/A
Technical Abstract: Stalk lodging in maize (Zea mays L.) causes losses estimated to range from 5 to 20% annually in the United States. Selection for rind penetrometer resistance has proven useful in enhancing germplasm for stalk strength, and therefore improving stalk lodging resistance. We conducted quantitative trait locus (QTL) analyses for rind penetrometer resistance in four F2:3 populations. The populations were constructed using MoSCSSS-High (selection for high rind penetrometer resistance), MoSCSSS-Low (selection for low rind penetrometer resistance), MoSQB-Low (selection for low stalk crushing strength), Mo47, and B73. Simple sequence repeat and restriction fragment length polymorphism markers were used to genotype individuals in each population and data was collected for rind penetrometer resistance, plant height, and ear height. Means combined over locations were used to conduct composite interval mapping using QTL Cartographer. Ten, thirteen, eight, and nine QTL were detected for rind penetrometer resistance in the four populations and accounted for 60.3, 70.3, 41.9, and 76.8% of the phenotypic variation, respectively. Only one QTL was in common among all four populations, while eight QTL were in common between two of the four populations. Differences in the QTL detected among the populations may be explained by lack of variation at a QTL between parents of a population, epistasis, or a combination the two. Possible candidate genes include bm1 and bm3 involved in lignin content, and gl15 which has been implicated in timing of vegetative phase change.