Tomato Fruits Show Wide Phenomic Diversity but Fruit Developmental Genes Show Low Genomic Diversity

PLoS One. 2016 Apr 14;11(4):e0152907. doi: 10.1371/journal.pone.0152907. eCollection 2016.

Abstract

Domestication of tomato has resulted in large diversity in fruit phenotypes. An intensive phenotyping of 127 tomato accessions from 20 countries revealed extensive morphological diversity in fruit traits. The diversity in fruit traits clustered the accessions into nine classes and identified certain promising lines having desirable traits pertaining to total soluble salts (TSS), carotenoids, ripening index, weight and shape. Factor analysis of the morphometric data from Tomato Analyzer showed that the fruit shape is a complex trait shared by several factors. The 100% variance between round and flat fruit shapes was explained by one discriminant function having a canonical correlation of 0.874 by stepwise discriminant analysis. A set of 10 genes (ACS2, COP1, CYC-B, RIN, MSH2, NAC-NOR, PHOT1, PHYA, PHYB and PSY1) involved in various plant developmental processes were screened for SNP polymorphism by EcoTILLING. The genetic diversity in these genes revealed a total of 36 non-synonymous and 18 synonymous changes leading to the identification of 28 haplotypes. The average frequency of polymorphism across the genes was 0.038/Kb. Significant negative Tajima'D statistic in two of the genes, ACS2 and PHOT1 indicated the presence of rare alleles in low frequency. Our study indicates that while there is low polymorphic diversity in the genes regulating plant development, the population shows wider phenotype diversity. Nonetheless, morphological and genetic diversity of the present collection can be further exploited as potential resources in future.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Fruit / genetics*
  • Fruit / growth & development*
  • Fruit / metabolism
  • Genes, Plant / genetics
  • Genomics*
  • Phenotype*
  • Polymorphism, Single Nucleotide*
  • Solanum lycopersicum / genetics*
  • Solanum lycopersicum / growth & development*
  • Solanum lycopersicum / metabolism

Grants and funding

This work was supported by the Department of Biotechnology, India (grant no. BT/PR/5275/AGR/16/465/2004; BT/PR/7002/PBD/16/1009/2012) to RS and YS; University Grants Commission, India to YS and RS; Department of Science and Technology, India (Young Scientist grants to SG and VSC); Council of Scientific and Industrial Research, India (research fellowship to VM, HM, CC, RK, SKG, KT, SN, PG); University Grants Commission, India (research fellowship to ST, KS, SS, HVK) and Indian Council of Medical Research, India (research fellowship to AK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.