The tomato, botanically known as Solanum lycopersicum, is one of the world’s most widely grown and economically valuable crops. Its popularity stems from its adaptability and the sheer diversity of its fruit, which ranges in color from deep purple and black to bright yellow and classic red. Whether encountered as a tiny, sweet orb or a massive slicer, the tomato’s presence in global cuisine is undeniable. Centuries of widespread cultivation have resulted in a staggering array of options, leading many to wonder exactly how many distinct types exist.
The Scale of Tomato Diversity
Determining a single, definitive number for the world’s tomato varieties is nearly impossible due to the continuous nature of breeding and the complexity of classification. Estimates of named varieties available to gardeners and commercial growers typically range upwards of 10,000 worldwide, reflecting types actively cataloged by seed companies and gardening resources. The true scale of genetic material is larger, as global seed banks and genetic resource centers maintain extensive collections.
For instance, genebanks worldwide conserve more than 75,000 “accessions” of tomato and its wild relatives. An accession represents a distinct sample of seed or plant material, which may include unique cultivars, breeding lines, or wild species. Understanding this inventory requires distinguishing between three terms: variety, cultivar, and landrace.
A “variety” is a botanical term for a group of plants within a species that have specific, consistent characteristics. A “cultivar” (cultivated variety) is a plant selected and maintained by humans for specific traits, such as color or disease resistance. A “landrace” represents an older, locally adapted population of plants that developed genetic diversity through traditional agricultural practices. Landraces often hold the genetic material breeders use to create new cultivars.
Primary Classification Systems
Tomatoes are fundamentally categorized by two practical characteristics important for farming: their growth habit and their physical form. The growth habit determines the plant’s final size and its fruiting pattern throughout the season, divided into determinate and indeterminate types.
Determinate varieties, often called “bush” tomatoes, grow to a fixed, compact height, usually between three and five feet. These plants set most of their fruit at the same time, producing a large, concentrated harvest over a short period. This synchronized ripening makes determinate types ideal for commercial processing or for home gardeners who wish to can or make large batches of sauce.
Conversely, indeterminate varieties are “vining” plants that continue to grow, flower, and set fruit continuously until frost. They can reach heights of ten feet or more and require significant staking or caging for support. Indeterminate types offer a steady supply of fresh tomatoes throughout the entire growing season, preferred for daily consumption and fresh market sales.
The second major classification is based on the fruit’s size and shape. Categories like Globe, Plum, Cherry, and Currant provide a straightforward way to group varieties for culinary use. Globe tomatoes are the standard, medium-to-large slicing tomatoes found in most markets. Plum or paste tomatoes, such as Roma, are elongated and prized for their dense flesh and low water content, making them superior for cooking and sauces.
The Role of Breeding: Heirloom Versus Hybrid
The sheer number of tomato varieties results from two distinct breeding approaches that determine genetic stability and desired traits: heirloom and hybrid.
Heirloom varieties are defined by their open-pollinated nature, meaning they are pollinated naturally by insects, wind, or self-pollination. When seeds from an heirloom plant are saved and replanted, they consistently produce plants and fruit that are “true-to-type,” identical to the parent. This genetic stability is a hallmark of heirlooms, which have often been passed down through generations of gardeners for their unique flavors and historical significance.
Hybrid varieties, designated as F1 (Filial 1), are the result of a deliberate cross between two distinct, genetically stable parent lines. This controlled cross combines specific desirable traits from both parents into the first-generation offspring, such as enhanced disease resistance, increased yield, or improved shelf life. While F1 hybrids often exhibit greater vigor (known as hybrid vigor), saving their seeds is generally unproductive. If hybrid seeds are planted, the resulting second generation (F2) reverts unpredictably to the genetic characteristics of the original parent lines, breaking the uniformity. Therefore, new hybrid seeds must be purchased each season to maintain the specific characteristics.
Common Types and Culinary Applications
The vast diversity of tomatoes translates directly into a wide range of culinary uses, with the practical application often dictating the variety chosen. The large, meaty Beefsteak types, such as ‘Brandywine’ or ‘Cherokee Purple,’ are characterized by their multiple seed chambers and high juice content. These are primarily used for slicing in sandwiches and on burgers, where their size and full flavor profile are appreciated.
The smaller, oblong Roma or Paste tomatoes are dense and contain fewer seeds and less water than slicing types. This makes them ideal for cooking down into thick sauces, pastes, and canned products, as the finished sauce achieves the desired consistency quickly. Their low moisture content also makes them suitable for sun-drying.
Conversely, the small, round Cherry and slightly oval Grape tomatoes are cultivated for their intense sweetness and thin skin, making them perfect for fresh consumption. These types have a high sugar concentration, which contributes to their desirable flavor profile, often measured by a high sugar-to-acid ratio. They excel in salads and as fresh snacks. The preservation of this broad genetic spectrum safeguards traits like disease resistance and adaptability to different climates, ensuring the tomato remains a sustainable global crop.