Impact of LC and FAS alleles on cross-section fruit morphology traits in tomato (Solanum lycopersicum L.) germplasm

VAZQUEZ, DANA V.; CAMBIASO, VLADIMIR; PEREIRA DA COSTA, JAVIER H; GODOY, FEDERICO N. I.; RODRÍGUEZ, GUSTAVO RUBÉN

Congreso; XLII Congreso de la Sociedad Española de Genética; 2021

The LOCULE NUMBER (LC) and FASCIATED (FAS) are major genes that influence shape, size, and locule numberin tomato fruits. Most fruit morphological studies focus on longitudinalsection traits. The objective of this study was to characterize the impact of LC and FAS alleles on cross-section fruit morphology traits in tomatogermplasm. A total of 183 cross-section fruit images from tomato accessions(n=1145) were download from https://solgenomics.net. The images were analyzedwith Tomato Analyzer 3.0 (1). The evaluated traits were: perimeter (P), area(A), maximum width (MW) and height (MH), thickness (PT) and area (PA) ofpericarp, and lobedness degree (LD). The locule number (LN) was visually counted.The LC and FAS data for the subset were available (2). Broad-sense heritabilityand phenotypic correlations were calculated. A principal component analysis(PCA) was performed. The relative frequency distribution for alleles at LC and FAS genes (LC/FAS when carrying mutated allele for bothgenes, lc/fas when carrying wild allele for both genes, and LC/fas,or lc/FAS respectively) for LN and LD ranges were evaluated.The broad-sense heritability was significant (p<0.05) for all normally distributedtraits, ranged from 0.72 for PA up to 0.94 for A. The phenotypic correlations weresignificant (p<0.05) and positive for most traits. The PCA showed that variationwas highly explained for the combination of LC and FAS alleles. Overall, the lc/fas combination had fewlocules and low LD, meanwhile LC/FASpresented high values for both traits. Also, we found that the accumulation ofmutated alleles directly increased the LN but this relation was not evident forLD. On the other hand, accessions with the same combination of alleles showedcontrasting LN and LD values. Our results, indicate that the thedistribution of LC and FAS alleles presented a stronger impact on the variation in LN than LD, and the effect of LC and FAS genes was not enough to explain the variability present in ourdata for cross-section fruit traits. As conclusion, these results suggest thepresence of unknown modifier genes for LC and/or FAS in tomato germplasm.