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Genetic diversity of maize inbred lines in relation to downy mildew

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Relation http://oar.icrisat.org/5723/
http://dx.doi.org/10.1023/B:EUPH.0000014904.80451.7f
 
Title Genetic diversity of maize inbred lines in relation to downy mildew
 
Creator George, M L
et al, .
 
Subject Genetics and Genomics
Maize
 
Description A major emphasis in maize breeding in Asian countries has been the improvement for resistance to downy mildew,
a serious disease that causes significant yield losses. A total of 102 inbred lines, including lines from Asian breeding
programs, Mexico, USA and Germany, were analyzed with 76 SSR markers to measure diversity and investigate
the effect of selection for downy mildew resistance. A mean polymorphism information content of 0.59, with a
range of 0.14 to 0.83, was observed. Diversity at the gene level showed an average of 5.4 alleles per locus and a
range of two to 16 alleles per locus, with a total of 409 alleles. About half of the alleles in the Asian lines had
frequencies of 0.10 or less, and only 2% had frequencies > 0.80, indicating the presence of many alleles, and
thus a high level of diversity. Some of the high-frequency alleles were in chromosomal regions associated with
disease resistance. However, the frequencies of alleles in three SSR loci that are linked to a QTL for resistance to
downy mildews in Asia were not significantly different in the subtropical/tropical Asian lines as compared to all
the lines in the study. Lines from the US, Germany, and China, comprised three clusters of temperate maize (GS =
0.31), while those from India, Indonesia, Philippines, Thailand, Vietnam and CIMMYT comprised seven indistinct
clusters of subtropical and subtropical maize (GS = 0.29). We conclu
 
Publisher Springer
 
Date 2004
 
Type Article
PeerReviewed
 
Format application/pdf
 
Language en
 
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Identifier http://oar.icrisat.org/5723/1/Euphytica135_145%E2%80%93155_2004.pdf
George, M L and et al, . (2004) Genetic diversity of maize inbred lines in relation to downy mildew. Euphytica, 135 (2). pp. 145-155. ISSN 1573-5060