A FRUITFULL-like gene is associated with genetic variation for fruit flesh firmness in apple (Malus domestica Borkh.)
- 505 Downloads
The FRUITFULL (FUL) and SHATTERPROOF (SHP) genes are involved in regulating fruit development and dehiscence in Arabidopsis. We tested the hypothesis that this class of genes are also involved in regulating the development of fleshy fruits, by exploring genetic and phenotypic variation within the apple (Malus domestica) gene pool. We isolated and characterised the genomic sequences of two candidate orthologous FUL-like genes, MdMADS2.1 and MdMADS2.2. These were mapped using the reference population ‘Prima x Fiesta’ to loci on Malus linkage groups LG14 and LG06, respectively. An additional MADS-box gene, MdMADS14, shares high amino acid identity with the Arabidopsis SHATTERPROOF1/2 genes and was mapped to Malus linkage group LG09. Association analysis between quantitative fruit flesh firmness estimates of ‘Prima x Fiesta’ progeny and the MdMADS2.1, MdMADS2.2 and MdMADS14 loci was carried out using a mixed model analysis of variance. This revealed a significant association (P < 0.01) between MdMADS2.1 and fruit flesh firmness. Further evidence for the association between MdMADS2.1 and fruit flesh firmness was obtained using a case–control population-based genetic association approach. For this, a polymorphic repeat, (AT)n, in the 3′ UTR of MdMADS2.1 was used as a locus-specific marker to screen 168 apple accessions for which historical assessments of fruit texture attributes were available. This analysis revealed a significant association between the MdMADS2.1 and fruit flesh firmness at both allelic (χ 2 = 34, df = 9, P < 0.001) and genotypic (χ 2 = 57, df = 32, P < 0.01) levels.
KeywordsMalus domestica Fruit flesh texture FRUITFUL Association mapping Tree improvement Genetic diversity
This project was carried out with the financial support from the UK Department for Environment, Food and Rural Affairs, and the Commission of the European Communities (contract N° QLK5-CT-2002-01492), Directorate-General Research-Quality of Life and Management of Living Resources Programme. We also would like to thank Plant Research International, Wageningen, The Netherlands, for making the reference population ‘Prima x Fiesta’ available to us.
- Costa F, Van de Weg WE, Stella S, Dondini L, Pratesi D, Musacchi S, Sansavini S (2008) Map position and functional allelic diversity of Md-Exp7, a new putative expansin gene associated with fruit softening in apple (Malus x domestica Borkh) and pear (Pyrus communis). Tree Genet Genomes 4(3):575–586CrossRefGoogle Scholar
- Doyle JJ, Doyle Jl (1990) Isolation of plant DNA from fresh tissue. Focus 12:13–15Google Scholar
- King GJ, Maliepaard C, Lynn JR, Alston FH, Durel CE, Evans KM, Griffon B, Laurens F, Manganaris AG, Schrevens E, Tartarini S, Verhaegh J (2000) Quantitative genetic analysis and comparison of physical and sensory descriptors relating to fruit flesh firmness in apple (Malus pumila Mill). Theor Appl Genet 100:1074–1084CrossRefGoogle Scholar
- Kosambi DD (1944) The estimation of map distances from recombination values. Ann Eugen 12:172–175Google Scholar
- Liu J (2002) Powermarker—a powerful software for marker data analysis. North Carolina State University Bioinformatics Research Center Raleigh North Carolina (www.powermarker.net)
- Smith MWG (1971) National Apple Register of the United Kingdom. Ministry of Agriculture Fisheries and Food, PinnerGoogle Scholar
- Van Ooijen JW, Voorrips RE (2001) JoinMap® 30 Software for the calculation of genetic linkage maps. Plant Research International, WageningenGoogle Scholar