**Abstract**

Crop diversity of vegetable species is threatened by the current homogenization of agricultural production systems due to specialization of plant breeders and increasing globalization in the seed sector. With the onset of modern agriculture, most traditional vegetable cultivars were replaced by highly productive and often genetically uniform commercial breeds and hybrids. This led to the loss of landraces, especially in countries with a super-intensive agriculture. The agricultural biodiversity erosion represents a huge risk for food safety and security. Vegetable landraces are associated with the cultural heritage of their place of origin being adapted to local agro-ecological areas and are more resilient to environmental stress than commercial cultivars. The chapter aim to highlight the importance of keeping and using vegetable landraces as valuable sources of genes for traditional farmers, but also for future breeding processes. We analyze the historical role of landraces, genetic diversity, high physiological adaptability to specific local conditions in association with traditional farming systems, as well as the breeding perspectives and evaluation of genetic diversity based on molecular markers.

**Keywords:** old local populations, biodiversity, food security, stress tolerance, quality, tomatoes, onion, breeding, molecular markers

## **1. Introduction**

In 1996 World Food Summit stated that "food security is ensured when the entire population has at all times, physical and economic access to sufficient food resources, safe and of high nutritional value, to meet food needs and preferences providing an active and healthy life".

Food security has long been associated with the abundance of cereal products, roots and tubers, vegetables and fruits from the main agricultural crops, which could provide affordable sources of nutritional energy. But this image has changed as the concept of nutritional security has become the essential element of food safety, and nutritional diversity has become the basic component to ensuring the human population health. Healthy diets, qualitatively superior, determine the consumption of a variety of foods in optimal quantities [1].

The vegetables are an affordable and relatively inexpensive source of fiber, vitamins and minerals. In general, they have the highest nutritional value when are eaten fresh. Unfortunately, a large part of primary (unprocessed) horticultural products have a relatively short life before they begin to degrade. The extent to which the nutritional value of vegetables deteriorates during harvesting, processing and storage depends both on the type of product (species, organ, ripening level) and on the used technologies [2].

Also, the vegetables are recognized as essential for food and nutritional security of humanity. Producing them offers multiple economic opportunities, reducing poverty and unemployment in rural areas especially, and is also an essential component of plant biodiversity maintaining strategies. The systematic production of vegetables for local markets not only provides income for small farmers, but also contributes to strengthening their resilience to external risks. Diversification of vegetable crops, short cycles of growth and development, the use of local, environmentally friendly inputs and the efficient use of fertilizers, pesticides and irrigation can reduce farmers' vulnerability to climate changes. For economic resilience, farmers may choose either to integrate vegetables into existing large crop systems or to focus exclusively on specialized vegetable production.

Vegetable production has increased more than twice in the last 25 years and the economic value generated by their cultivation has exceeded the commercial value of cereals [3].
