e duas seleções ('KM-2' e 'KM-1') de castanheiro híbrido (Castanea crenata x Castanea sp.) foram analisadas em São Bento do Sapucaí-SP. Avaliaram-se o início e o término da colheita, a deiscência do fruto e a deiscência, as propriedades físicas, tais como dimensões e massas dos frutos e castanhas, além do formato das castanhas e a poliembrionia, e ainda as propriedades químicas e a composição mineral. Os dados apresentados indicam que as cultivares e seleções diferem quanto à deiscência dos frutos. A colheita das castanhas concentra-se entre a primeira quinzena de novembro e a segunda quinzena de abril. Algumas cultivares apresentaram reduzido número de castanhas dentro da cápsula, o que indica falta de sincronia no período de floração. Há diferença na constituição química das castanhas entre as cultivares e seleções. As castanhas analisadas possuem alta quantidade de proteínas e açúcares totais, baixa quantidade de sódio e extrato etérico, indicando que o amido é a principal substância de reservas das castanhas, das cultivares e seleções analisadas. Termos para Indexação: Castanea crenata x Castanea sp., florescimento, produção. MATURATION SEASON, PHYSICS AND CHEMICAL CHARACTERIZATION OF CHESTNUT CULTIVARS AND SELECTIONSABSTRACT -Nine cultivars ('Taishowase', 'Tiodowase', 'Tamatsukuri', 'Isumo', 'Okuni', 'Moriwase', 'Kinshu', 'Senri' and 'Ibuki') and two selections ('KM-2' and 'KM-1') of the hybrid chestnut (Castanea crenata x Castanea sp.) were analyzed in São Bento do Sapucai-SP. The beginning and the end of the harvest season, the fruit dehiscence and the dehiscence, the physical properties such as dimensions and masses of fruit and nuts, the format of the nuts and polyembryony, and even the chemical and mineral composition were evaluated. The data presented indicate that the cultivars and the selections differ in the dehiscence of the fruits. The harvest of the chestnuts concentrated between the first half of November and the second half of April. Some cultivars showed reduced number of nuts in the hedgehog, which indicates a lack of synchrony in the flowering period. There is difference in the chemical composition of nuts among cultivars and selections. The nuts analyzed have high amount of protein and sugars, low amount of sodium and ethereal extract, indicating that starch is the main substance of chestnuts reserves, in cultivars and selections analyzed.

Aiming the selection of rootstocks to produce seedlings, the objective of this study was to quantify the seminiferous propagation in chestnut seeds, with or without incisions. Nine cultivars were used (‘Ibuki’, ‘Isumo’, ‘Kinshu’, ‘Moriwase’, ‘Okuni’, ‘Senri’, ‘Taishowase’, ‘Tamatsukuri’ and ‘Tiodowase’) and two selections (‘KM-1’ and ‘KM-2’) of hybrid chestnut trees (Castanea crenata x Castanea sp.). An incision was held in half of chestnuts and the other half remained intact. Percentage of germination, emergence and root length were quantified. The germinated nuts were transplanted and were quantified the diameter and height of seedlings. Then, the chestnut selections ‘KM-2’ and ‘Jacutinga’ were grafted by the cleft grafting method, and were quantified the percentage of sprouting, besides the diameter and height of grafts. Incisions increase the germination and seedling emergence in most cultivars and selections. ‘Taishowase’ and ‘Tamatsukuri’ stood out over the others to germination, growth of the rootstocks.