Evaluation of Cucurbita pepo germplasm for staminate flower production and adaptation to the frozen food industry

Cucurbita pepo is the most economically important species of the genus Cucurbita (Cucurbitaceae). Its edible-fruited cultivated germplasm has been grouped into eight morphotypes (cultivar-groups) divided between two subspecies: pepo and ovifera. In this work, 93 accessions representative of all morphotypes were grown to investigate their genetic variability and to evaluate their potential for production and suitability of male flowers to be used as an Italian frozen food specialty. Results provid the first indications of a plant ideotype for such use. Principal coordinates analysis (PCoA) with nine SSR markers clearly separated the two subspecies, and yielded information on genetically similar vs distant genotypes to be used for parent choice in breeding programs. Analysis of morphological data allowed identification of seven accessions that met all the criteria for the specialty use of male flowers for the frozen food industry: production of many flowers, corolla length of 6-8 cm; and reduced spininess of the foliage. When accessions representing different morphotypes were compared for average male corolla length and average number of male flowers per plant, some accessions of the Pumpkin cultivar-group were observed to be the most suitable for the purpose. Overall, the information collected in the present work is a starting point for exploitation of C. pepo biodiversity in future breeding programs aimed at the production of male flowers for use by the frozen-food industry.