Research Article Diversity among Modern Tomato Genotypes at Different Levels in Fresh-Market Breeding Krishna Bhattarai, 1 Sadikshya Sharma, 2 and Dilip R. Panthee 1 1 Department of Horticultural Science, North Carolina State University, Mountain Horticultural Crops Research and Extension Center, Mills River, NC 28759, USA 2 Department of Environmental Horticulture, University of Florida, 2550 Hull Rd, Gainesville, FL 32611, USA Correspondence should be addressed to Dilip R. Panthee; dilip panthee@ncsu.edu Received 13 February 2018; Accepted 19 March 2018; Published 22 May 2018 Academic Editor: Allen Barker Copyright © 2018 Krishna Bhattarai et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Cultivated tomato has been in existence for about 400 years and breeding activities have been conducted for only eight decades. However, more than 10,000 tomato cultivars have already been developed. Ninety-one tomato genotypes were characterized for twenty-one morphological traits using developmental, vegetative, and fruit traits. Correlation, principal component, and cluster analysis between the traits were carried out. Higher correlations between fruit traits including fruit shape, fruit size, and fruit types were observed. Tese correlations indicate that specifc fruit types require specifc traits like branched inforescence and a greater number of fruits per inforescence are benefcial only for smaller fruit sizes like cherry and grape tomatoes. Contrastingly, traits like determinate growth habit and fruit maturity are preferred in all fruit types of tomato for better cultivation practices and longer production duration and hence showed lower correlations. Principal component analysis clustered tomato genotypes into three main clusters with multiple subgroups. Similar tomato genotypes were placed into one or more clusters confrming the results from correlation analysis. Involvement of private breeding programs in cultivar development has increased the competition on introgression of novel and desired traits across new cultivars. Understanding the diversity present in modern cultivars and potential traits identifcation in related wild species can enhance tomato diversity and improve quality and production. 1. Introduction Tomato is one of the most important vegetables produced all over the world. It belongs to the diverse Solanaceae family along with potato, pepper from the South American origin, and eggplant from Asia. Tomato breeding in the modern era has focused on increased production and adaptation to diferent consumption need. With Latin American origin, the domesticated tomato was cultivated in South America with selection for edible fruits, attractive red color, and increased fruit size as compared to the wild tomato. Tere have been several bottlenecks over the ages leading to severe reduction in its genetic diversity during domestication, introduction to Europe, and introduction in the US [1]. Due to the broad adaptation of tomato from Alaska in summer to tropical conditions, there have been adaptive and morphological variations. However, introgression of highly desirable char- acteristics and higher selection pressure to select those traits in tomato population has decreased the genetic diversity [2]. Phenotypic characteristics have been used to study genetic diferences and for genetic diversity analysis and cultivar development [3–6]. Assessment of diversity in commercial cultivars provides the status of a crop in relation to its wild and domesticated relatives and assists in creating a breeding scheme to bring in the lost alleles due to extreme selection and bottlenecks during domestication or introduction [7]. In the absence of genetic variation, breeding eforts in crops remain without any gain [8]. Tis may lead to severe crop failure with the onset of new biotic or abiotic stress. Most of the disease resistant genes in modern varieties are not only the result of selection from these varieties but also originated from the wild species [9]. Hindawi International Journal of Agronomy Volume 2018, Article ID 4170432, 15 pages https://doi.org/10.1155/2018/4170432