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Identification of genes affecting flowering time variation in Brassica species

Shavorskaya, Oksana (2004). Identification of genes affecting flowering time variation in Brassica species. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae. Agraria, 1401-6249 ; 453
ISBN 91-576-6467-6
[Doctoral thesis]

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One prerequisite for a deeper understanding of genetics of adaptive variation is the identification and analyses of genes affecting such variation. In this thesis, I have searched for genes affecting variation in the adaptive trait flowering time in diffe rent Brassica species. Comparative QTL mapping of flowering time indicated that duplicated copies of one ancestral gene, possibly CONSTANS (CO) might regulate flowering in several Brassica species. A region homologous to the CO region of Arabidopsis thal iana is present in three copies in diploid, and six copies in polyploid Brassica species, and QTL mapped to two out of three regions in the diploids, and three out of six in the polyploid. The two QTL identified in B. nigra were studied further. CO allele s from early and late flowering plants were isolated from both QTL regions (Bni COa and Bni COb). No effect of allelic variation at Bni COa on flowering time was detected when comparing A. thaliana co mutants transformed with the two B.nigra alleles. However, allelic variation at Bni CONSTANS LIKE1 (Bni COL1) located 3kb upstream of Bni COa showed association with flowering time in natural populations of B. nigra. Specifically, an 18 bp indel in Bni COL1 showed significant association with flowering time in several populations. These results and more thorough studies support a hypothesis where a naturally occurring quantitative trait nucleotide (QTN) for flowering time affects the function of Bni COL1 or the expression of Bni COa through variation in the intergenic region between COL1 and COa. Analysis of variation at Bni COb suggested that it has been turned into a pseudogene although some aspects of the data are difficult to reconcile with the loss of function.

Authors/Creators:Shavorskaya, Oksana
Title:Identification of genes affecting flowering time variation in Brassica species
Series Name/Journal:Acta Universitatis Agriculturae Sueciae. Agraria
Year of publishing :April 2004
Number of Pages:44
ALL1) Axelsson, T., Shavorskaya, O., Lagercrantz, U. (2001) Multiple flowering time QTLs within several Brassica species could be the result of duplicated copies of one ancestral gene. Genome Oct;44(5):856-64. 2) Osterberg, M.K., Shavorskaya, O., Lascoux, M., Lagercrantz, U. (2002). Naturally occurring indel variation in the Brassica nigra COL1 gene is associated with variation inflowering time. Genetics May;161(1):299-306. 3) Shavorskaya, O., Lagercrantz, U. (2004). Sequence divergence at the putative flowering time locus COL1 in Brassicaceae (manuscript). 4) Shavorskaya, O., Hedman, H., Lascoux, M., Lagercrantz, U. (2004). Molecular evolution of a recently duplicated flowering time gene in Brassica nigra (submitted).
Place of Publication:Uppsala
ISBN for printed version:91-576-6467-6
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:F Plant production > F30 Plant genetics and breeding
Subjects:Not in use, please see Agris categories
Agrovoc terms:brassica, flowering, genetic maps, replication, adaptation, genetic variation, genetic polymorphism
Keywords:Brassica, flowering time, comparative mapping, CONSTANS, duplication, adaptation, genetic variation, indel polymorphism, molecular evolution, silencing
Permanent URL:
ID Code:501
Department:(NL, NJ) > Dept. of Plant Biology and Forest Genetics (until 131231)
Deposited By: oksana shavorskaya
Deposited On:13 Apr 2004 00:00
Metadata Last Modified:02 Dec 2014 10:05

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