Selection Methods Biology
The speed of spread of lettuce in European countries and on the American continent in the late XIX – XX centuries. was ensured by the success of selection. The variety of varieties adapted to different growing conditions, as well as high taste and commercial qualities, made this culture the most popular among vegetable plants.
The assortment of lettuce cultivated in the USSR is very limited and cannot satisfy the requirements for this crop in all ecological and geographical areas of the country, especially in protected ground, where it is grown all year round. In the near future, due to an increase in demand for lettuce and an expansion of the assortment of vegetables cultivated in the country, including lettuce, there has been an increase in selection work. The main tasks of breeding this crop are to breed varieties suitable for cultivation in all areas of the country, both in open and in protected ground.
Despite the variety of requirements for varieties for various purposes, it is impossible to focus on highly specialized varieties with a limited genetic basis. This would lead to the creation of many varieties and would cause difficulties in the development of cultivation technology and seed production. The main task of breeding is to develop varieties of high ecological plasticity, a wide range, i.e. universal, suitable for cultivation in conditions with a wide range of variability.
In salad selection, hybridization is used mainly with subsequent individual, group and mass selection. When creating most modern varieties, hybrid material was used. The technique of salad hybridization is complex, it is due to the structure and size of the flower, adapted for self-pollination, as well as the flowering biology.