A genetic study of stomates in cucumber, Cucumis sativus L. and its relationship with fruit wilting and brining quality

Abstract

Individual fruit measurements of two inbred lines of cucumber (Cucumis sativus) SC-25 and TAMU 1055 and the F₁, F ₂, B₁CP₂ and B₁C P₂ populations were used to investigate the genetic control of stomatal size and frequency and epidermal cell number and the relationship of these traits to wilting and brining quality. There were significant differences from plants grown in the greenhouse and in the field in stomatal frequency and size and epidermal cell number, measured by latex impressions. There also were significant differences among the populations in stomatal frequency and size, and epidermal cell number. Stomatal size appeared to be quantitatively controlled and heritability estimates ranged from 18.5% in the greenhouse to 37.7% in the field. Stomatal frequency was a highly heritable trait (73% to 75%) and was quantitatively inherited. Epidermal cell frequency was a variable trait that was inherited in a partially dominant manner. There was no relationship between epidermal cell number and stomatal frequency but there was a small relationship between stomatal size and frequency. Wilting, measured as weight loss in harvested cucumber fruit, was determined to be influenced by stomatal number and the number of epidermal cells. Fruit with fewer stomates and greater number of epidermal cells consistantly wilted less than fruit with many stomates and fewer number of large epidermal cells. Brining quality was determined to be influenced by the number of epidermal cells and stomates. Fruit with many epidermal cells and few stomates were firmer than those having larger and fewer epidermal cells.