A utilização de germoplasma mexicano no melhoramento de trigo no Brasil

Wheat in Brazil is exposed to a number of adverse circumstances to crop development and there is a need for a broad genetic basis in order to promote the genetic breeding of the species. The International Maize and Wheat Improvement Center (CIMMYT), located in Mexico, is exchanging genetic material with Brazilian institutions. Relevant traits of cultivars developed in Mexico, which have interest to the wheat breeding program under way in Brazil, are: good agronomic type, low plant height, and, many times, good resistance to rusts, and/or good industrial quality. This work aims at showing the influence of Mexican germplasm of the wheat cultivars recommended in Brazil and also the many ways in which such germplasm is used. As a result of wheat crop expansion in the states of Parana, Mato Grosso do Sul, and Sao Paulo, initiated in the seventies in areas without aluminum toxicity problem in the soil, several cultivars introduced from Mexico were recommended. Thirteen Mexican cultivars, which have been cropped in Mexico, were also recommended in Brazil; among them were INIA 66, Cocoraque 75, and Anahuac 75, which were widely grown in Brazil. Twenty-six cultivars were recommended in Brazil from introduced Mexican lines. Over fifty Brazilian cultivars descending from crosses using Mexican germplasm were recommended. In 1990, out of 104 cultivars recommended in Brazil, 29 cultivars were Mexican or Mexican-derived, and 35 were Brazilian cultivars descending from crosses involving Mexican germplasm. Therefore, the contribution of Mexican germplasm towards wheat genetic breeding in Brazil was of utmost importance, both in direct use (introductions), in soils without toxic aluminum, and in crosses for all the conditions in which wheat is grown locally.