Citrus breeding: Frequency and vigor of hybrids

The Brazilian Citrus Industry is leading the world production, with about 270 million plants, in an area superior to 900 thousand ha. Provide that it is very vulnerable, due to the excessive use of 'Rangpur' time (Citrus limonia) as rootstock; it demands urgency in a diversification program of rootstock varieties. Therefore, Embrapa Cassava& Fruits is accomplishing a breeding program at Bahia State, Reconcavo Baiano, seeking the development of new varieties, mainly rootstocks, adapted to different geographic regions, with emphasis in the Northeast of Brazil. Considering the characters tree height and stem diameter, 554 seedlings hybrids from 38 progenies between Citrus and relatives, mainly Poncirus, were analyzed. The hybrids were planted between August 1995 and July 2000, according to their obtainable time. The 'Argentina' citrange (C. sinensis x P trifoliata) stood out as important male parent for producing hybrids. The mandarins 'Common Sunki'(C. sunki),'Florida Sunki', 'King' (C. nobilis),'de Nules Clementine' (C. clementina) and 'Palazelli Clementine' can generate vigorous progenies. 'Sunki' and 'King' seedlings hybrids can be so or more vigorous than seedlings of nucellar origin of these mandarins.