Combining Ability Analyses of Fruit Yield and Quality in Near-homozygous Lines Derived from Cucumber

Abstract

Abstract Combining ability estimates for characters relating to yield and fruit quality were undertaken to determine if lines derived from Cucumis sativus var. hardwickii (R.) Alef. (hardwickii) could be used in the development of higher-yielding commercial cucumbers. General and specific combining ability estimates were obtained in a North Carolina Design II experiment for nine near-homozygous processing cucumber (Cucumis sativus L.) lines, five of which were derived from hardwickii germplasm. Lines were evaluated under two planting densities (29,000 and 58,000 plants/ha) for three harvests, and environments sampled were two planting times (2 weeks apart within the same year). Traits evaluated included fruit number per plant, primary lateral branch number, percentage of pistillate flowers, days to anthesis, fruit length, and fruit length : diameter (L:D) ratio. General combining ability (GCA) mean squares were significant at both planting densities for all traits when combined over planting times, except for fruit L:D ratio at the higher density. Specific combining ability mean squares were significant for days to anthesis. Of the lines evaluated, WI 2963 and 4H261 produced the greatest GCA female and male effects, respectively, for three harvest yield and primary lateral branch number, but the lowest effects for fruit size. Our results suggest that further selection within these high-performance hardwickii derivatives for fruit shape will produce lines that perform well at a high planting density when crossed with sativus lines having good general combining ability.