The multiple-flowering trait conferred by gene mf increases yield of field-grown Cocozelle and Zucchini squash

The plants of summer squash, Cucurbita pepo , are monoecious, bearing their flowers in leaf axils. Plants of C. pepo subsp. pepo , which includes Cocozelle and Zucchini squash, bear one flower per leaf axil whilst plants of C. pepo subsp. texana , which includes Crookneck squash, differentiate two or more flower buds at nearly all leaf axils. This multiple-flowering trait, conferred by the single recessive gene mf , was introgressed from a Crookneck squash (subsp. texana ) into several inbreds of Cocozelle and Zucchini squash (subsp. pepo ) through six backcross generations. The nearly isogenic hybrids derived from crossing these inbreds, single- and multiple-flowered, were compared with one another in replicated field trials with the purpose of determining whether or not the multiple-flowering trait can significantly increase yields of Cocozelle and Zucchini under field conditions. The results showed that the multiple-flowering trait can increase yield in Cocozelle squash by as much as 60% and in Zucchini squash by 24%. The differences in yield between the respective multiple- and single-flowered hybrids were based on number of fruits produced. The yield differences were most greatly expressed from the end of the first week through the third week of harvest in the Cocozelle and during the third week of harvest in the Zucchini.