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Understanding the genetic and morphological basis of bushy root and bifuricate, two mutations affecting plant architecture in Solanum lycopersicum L

The classical ethyl methanesulfonate (EMS) tomato mutant bushy root (brt) was studied using a homozygous near isogenic line (brtNIL) in the Micro-Tom (MT) genetic background. The mutation has a pleiotropic phenotype comprising slow seedling development, which may be a consequence of a maternally-inherited small seed phenotype, and a more compact, smaller but not bushier, root phenotype. The number of lateral roots, total root length and taproot size are all smaller in brtNIL than the WT. The BRT locus was mapped to a 137 kbp region containing 9 candidate genes on chr 12; an InDel in the promoter region of Solyc12g014590 – containing two highly conserved pirin domains (Pirin_C and Pirin), was detected. Different expression patterns were confirmed by transcriptomic results, supporting Solyc12g014590 as the gene responsible for the brt phenotype. A naturally occurring recessive mutant named bifuricate (bif) shows an increase in inflorescence (truss) branching in comparison to the wild type (WT) control line, LAM183. In addition, the number of flowers per truss was 235% higher in bif plants than WT. Low temperature is known to increase truss branching, and so a four day low temperature treatment was applied and it was demonstrated that flowering increased significantly more in bif than in LAM183. The BIF locus was mapped to a 2.01 Mbp interval of chromosome 12 containing 53 genes. All coding region polymorphisms in the interval were surveyed, and two genes Solyc12g019420 (a BTB/TAZ transcription factor) and Solyc12g019460 (a MAP kinase) contained one stop codon predicted to disrupt gene function; both genes are excellent candidates for inflorescence branching control based on literature evidence. A newly developed introgression browser was used to demonstrate that the origin of the bif mutant haplotype is Solanum galapagense.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:720977
Date January 2017
CreatorsSilva Ferreira, Demetryus
ContributorsThompson, Andrew ; Mohareb, Fady
PublisherCranfield University
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttp://dspace.lib.cranfield.ac.uk/handle/1826/12322

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