Eficiência de acessos de Cucurbita maxima como polinizadores de abóbora híbrida do tipo "Tetsukabuto"

Abstract

'Tetsukabuto' pumpkins are interspecific hybrids between Cucurbita maxima x C. moschata accessions. Such hybrids, however, are often male-sterile due to the impaired ability of the staminate flowers to produce functional pollen. The use of intervening rows of staminate (pollen-donor) plants is one strategy employed in order to have commercial fruit production. In the present work, two C. maxima accessions ['Exposição' (E) and 'Nirvana' (N)] were employed as pollen-donors (staminate parents) and their efficiency was compared considering fruit and seed yield parameters. Two pistillate Tetsukabuto hybrids ['Jabras' (J) and 'Kyoto Tetsukabuto' (KT)] were employed in four possible unidirectional crosses (J x E, J x N, KT x E and KT x N). Fruits were produced using standard manual pollination techniques done on a daily basis (during the morning). After harvesting, the following traits were evaluated: fruit weight, fruit diameter, fruit flesh depth, number of seeds per fruit and total seed weight. The results indicated that both staminate parents are equivalent for all traits. The accession 'Nirvana' (a cultivar in a pre-release stage) could be considered a commercial alternative to 'Exposição' (the traditional staminate parent under Brazilian conditions) due to its improved fruit quality attributes, which could provide an additional source of revenues for the 'Tetsukabuto' growers.