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ARS Home » Midwest Area » Columbia, Missouri » Plant Genetics Research » Research » Publications at this Location » Publication #62677
Title: DOSAGE EFFECTS ON MORPHOLOGICAL AND QUANTITATIVE TRAITS IN MAIZE.

Author
item LEE, E - UNIVERSITY OF VERMONT
item Darrah, Larry
item Coe Jr, Edward

Submitted to: Genome Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/31/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: Corn productivity is the result of particular genes that have been combined by breeding into hybrids selected for optimum outcomes. These genes, which determine quantitative traits, have been and continue to be a challenge to identify and manipulate, and efficient new technologies are sought by breeders and geneticists. This study contributes a Segment Dosage method, by which to determine prospective locations on the chromosomes and in the genome of corn for genes with these properties. Using modified chromosomes termed B-A translocations, designed changes were produced in a number of copies of specific chromosome segments, with 1, 2, or 3 copies. Plants with changed copy number were then subjected to measurement of an array of 12 traits important to productivity. Over 2/3 of the genome was examined by this procedure. The experiment demonstrated the method's effectiveness by revealing effects of dosage of certain chromosome segments son certain traits; all segments showed effects on one or more traits, and all traits were affected by dosage for one or more segments.

Technical Abstract: In this study, we propose that dosage effects generated by loss or gain of a chromosome segment can be used to identify chromosome regions associated with genes for morphological and quantitative characters in maize (Zea mays L.). Using B-A translocation stocks introgressed into a B73Ht background, a chromosome arm dosage series in a Mo17Ht x B73Ht F1 hybrid background was created for 18 of the 20 chromosome arms. The dosage series was then evaluated for 12 quantitatively inherited characters in order to associate specific phenotypic changes in a trait with a specific chromosome arm. Not only did our results show the familiar aneuploid syndrome phenomenon, but differential dosage effects among particular chromosome arms were demonstrated. All segments showed effects on one or more traits, and all traits were affected by dosage for one or more segments. The paper considers possible bases behind those differences and their utility in identifying quantitative trait loci, as well as the genetic relationships among the quantitatively inherited characters studied.