Campus Units

Agronomy

Document Type

Article

Publication Version

Published Version

Publication Date

2002

Journal or Book Title

Crop Science

Volume

42

Issue

3

First Page

951

Last Page

957

DOI

10.2135/cropsci2002.9510

Abstract

Historically important public inbred lines continue to play an important role in maize (Zea maysL.) improvement in many different breeding programs. Their continued use means they have undergone numerous seed increases in diverse programs since their original release. Our objective was to estimate the level of genetic diversity among and within inbred lines from different sources using SSR markers. We sampled six inbred lines (B73, CM105, Mo17, Oh43, W153R, and Wf9) obtained from 14 sources (breeding programs). The data were analyzed by analysis of molecular variance (AMOVA), genetic diversity statistics, and genetic distance (Dice's coefficient). Of the total variation observed in gene frequency, 87.8% was found among inbred lines, 7.6% among sources within inbred lines, and 4.6% within sources. Genotypes of identically named inbred lines from eight different sources differed slightly on the basis of 44 SSR loci. The mean genetic similarity between sources of the same inbred was greater than 85%. It can be concluded that although more diversity exists among these six inbred lines than within them, a small but significant amount of variation exists among seed sources within inbreds. This variation may have arisen through differences in seed maintenance, since we found no evidence to suggest high mutation rates or extensive outcrossing. The small but statistically significant level of variation raises concerns in germplasm conservation, mapping studies, marker development, and long-term recombinant inbred line development, especially when high resolution is desired.

Comments

This article is published as Gethi, James G., Joanne A. Labate, Kendall R. Lamkey, Margaret E. Smith, and Stephen Kresovich. "SSR variation in important US maize inbred lines." Crop science 42, no. 3 (2002): 951-957. doi: 10.2135/cropsci2002.9510. Posted with permission.

Rights

Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.

Language

en

File Format

application/pdf

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