Isolation and characterisation of ethylene insensitive mutants from a collection of Cucurbita pepo L.
Ethylene is a gaseous hormone that controls many physiological and developmental processes in plants. In zucchini squash (Cucurbita pepo L.), it regulates important aspects such as sexual expression, monoecy stability, senescence and flower abscission, parthenocarpy, and postharvest fruit quality, including chilling injury. The identification and characterization of ethylene-insensitive mutants will be a great advance not only for C. pepo functional genomics, but also to generate agronomically interesting traits for breeding programs in Cucurbita species. We have developed a mutant collection of 3,800 M2 families in the MUC-16 zucchini genetic background. In this text we are reporting the phenotyping of seedlings in the complete collection, including the response of etiolated seedlings to ethylene. The proportion of families with mutant phenotypes at the seedling stage, including albinos, was similar or higher than in other EMS collections of cucumber and melon. This along with alterations in the morphology and number of cotyledons, leaf colour and shape indicate that the quality of the Cucurbita collection is excellent. By using the triple response assay in etiolated seedlings, we have detected four partially ethylene insensitive M2 families. The phenotyping of ethylene-sensitive and insensitive adult plants of these four families indicates that the mutants are not only affected by seedling ethylene sensitivity, but are also altered in sex determination, sex expression, fruit set and parthenocarpy.
García, A., Manzano, S., Martínez, C., Megías, Z., Gázquez, J.C. and Jamilena, M. (2017). Isolation and characterisation of ethylene insensitive mutants from a collection of Cucurbita pepo L.. Acta Hortic. 1151, 151-156
zucchini squash, EMS, ethylene, triple response