Lycopene Content Profiling In Tomato Lines Derived From Diverse Genetic Background by Colorimetry and Infra-Red Absorbance Methods

Lycopene is an important anti-oxidant available in tomato with anti-cancer properties. Because of the potential medicinal use, there is an increased interest in this compound. Improvement of tomatoes for lycopene is in the research priority in a number of breeding programs. As the first step of the improvement effort, we were interested to screen the tomato lines derived from a diverse genetic background for lycopene content with the objectives of identifying the superior lines that could be used as parents to develop high lycopene tomato varieties. We screened 139 lines derived from Solanum lycopersicum, Solanum pimpinellifolium,  Solanum pennellii, and Solanum habbrachaetes with two replications at Mountain Horticultural Crops Research and Extension Center (MHCREC), Mills River, NC. The lines consisted of grape, plum, large fruited round and cherry tomatoes. The lines were characterized for morphological traits such as growth habit, external fruit color, fruit shape, fruit size, foliage color and fruit pedicel jointness. Fruits were sampled at full ripe stage and sliced into two half before capturing the images with DigiEye instrument. The same fruits were used for lycopene analysis by colorimetric method,  Data generated from DigiEye and colorimetric method were analyzed separately as well as correlations were determined to see if DigiEye can be used for lycopene prediction in tomato breeding program. Statistical analysis revealed that lycopene content ranged from 32 to 132 mg/kg of tomato sample indicating that there is a possibility of using some of the lines as parents for improving lycopene content in tomato varieties. Most of the high lycopene containing lines were grape tomatoes. No single equation could be developed on the basis of data generated from DigiEye to predict the lycopene content but individual equation for different color group can be used to predict the lycopene content with reasonably high correlation coefficient (r=0.77). Information reported here is expected to be useful in tomato breeding program aiming to improve lycopene content.