Tomato (Solanum lycopersicum L.) is an important and most widely grown vegetable crop of both tropics and sub tropics of the world. The high demand for tomato makes it a high value crop that can generate much income to farmers. Tomato fruits are an important source of fiber and nutrients in the human diet and a model for the studying fruit development. The combination of large germplasm collections, high-throughput genomic tools, and traits of economic interest provide a framework to apply genome wide association study (GWAS), which is promising genetic method for the dissection of complex traits in this species. The estimation of genetic relatedness among accessions and sub-populations is a prerequisite for the identification of true genome wide associations. The genotyping of accessions using wide genome simple sequence repeats could give correct estimates of genetic relatedness. The genotyping of enough markers also decides the outcome of true causal variants. Here we report the population structure of 264 tomato germplasm using the wide genome distributed simple sequence repeats (SSRs). The capital K value of population is estimated to K=4. The association mapping in structured population resulted in significant marker trait associations for fruit quality traits wise fruit firmness, shelf life, ascorbic acid, lycopene content, total soluble solids and locule number. Associations between SSR alleles and fruit quality traits were obtained using the generalized linear model (GLM) and the population structure matrix Q = 4. A total of 133 SSR alleles (P<0.05) were detected for six fruit quality traits.

Germplasm, Simple sequence repeats, Population structure, Genome wide association study, Alleles

A study on Genome Wide Association Study for fruit quality traits in Tomato (Solanum lycopersicum L.)” was undertaken to investigate variation in tomato association mapping panel. 264 genotypes were analyzed during kharif and rabi season for fruit quality traits viz; fruit firmness, shelf life, total soluble solids, lycopene content, ascorbic acid and locule numbers. The present findings established of superior structured population which was useful for identifying significant marker trait associations. The results explain the profound variability for fruit quality traits in germplasm. The significant associations will pave the path for hybrid breeding for fruit quality improvement using the marker assisted selection thereby accelerating the breeding program.

Sandeep R. Kadam, Satish D., B. Fakrudin, Mahantesha B.N. Naika, Jayashree Ugalat, Vasudeva K.R. and Basavraja N. (2022). Assessment of Population Structure and Association Mapping for Fruit quality Traits using Molecular Markers in Tomato. Biological Forum – An International Journal, 14(4a): 48-55.