Located in Cruz das Almas, BA, Brazil, the Citrus Breeding Program of Embrapa Cassava and Fruits has activities regarding to the development of new rootstocks better adapted to tropical conditions, including controlled hybridizations aiming the use of the large genetic variability found in Citrus and related genera, introduction of new citrus varieties from several regions in the country and from abroad, as well as selection of nucellar clones related to traditional rootstocks that present desirable agronomic characteristics which are different from the variety pattern. The present work refers to studies on this last research line, concerning the evaluation of 20 selections of 'Sunki' mandarin, which the main objective was to identify individuals showing fruit production with seed number higher than the average seed number commonly found on that rootstock. Analyses were carried out on the following characters: average number of seeds per fruit and embryos per seed, variation in the range of embryo number per seed, percentage of polyembryony and embryo size. The results allow to recommend 'Tropical' selection of 'Sunki' mandarin, as alternative to use in rootstock diversification programs, under conditions in which that mandarin is well adapted, mainly due to its higher number of seeds per fruit (18.7) and predictable uniformity of seedlings as a result of its high percentage of polyembryony, almost 100%.
Citrus breeding; Citrus sunki; seeds per fruit; polyembryony; embryo size; rootstock diversification
