The objective of this study was to elucidate the genetic control of the semideterminate growth habit in tomato (Lycopersicon esculentum Mill.). A semideterminate tomato line was crossed with determinate and indeterminate lines; their F1, F2, and backcrosses were grown; and the growth habit recorded and analyzed. Plants with six or more inflorescences on the main stem were defined as semideterminate, while those with fewer were defined as determinate. The F2 and backcross to determinate were bimodal, indicating a single recessive gene for semideterminate, which was denoted as sdt. The goodness-of-fit chi square for a single recessive gene model was 88% and 69% for F2 and backcross generations, respectively. In the cross between semideterminate and indeterminate types, the results indicated control by two genes, sp and sdt, with the sp+ indeterminate type epistatic over semideterminate. The goodness-of-fit to this model was 70% and 82% for F2 and backcross generations, respectively.
Fruit of pepper (Capsicum annuum L.) is hollow by nature, which limits its water reservoir capacity, and as such, small amounts of water loss result in loss of freshness and firmness, which reduce fruit quality, shelf life, and market value. In order to understand the basis for water loss from fruit, 10 pepper accessions with wide variation in water loss rate were used to study physiological and biochemical factors associated with postharvest water loss in ripe pepper fruit during storage. Postharvest water loss rate in ripe pepper fruit stored at 20 °C, and 85% relative humidity, was found to be associated with cell membrane ion leakage, lipoxygenase activity, and total cuticular wax amount. Total cuticular wax amounts were highest in the high-water-loss pepper fruit, and lowest in the low-water-loss fruit. However, total cuticle amount (isolated enzymatically and quantified gravimetrically), total cutin monomer amount, and the amount of individual cutin monomer and wax constituents (determined using gas chromatography mass spectrometry) indicated no direct association with postharvest water loss rates. Fruit fresh weight, pericarp weight, pericarp surface area, pericarp thickness, initial water content, and dry matter were highly associated with each other, but less so with water loss rate. Fruit of accessions displaying high fruit water loss rate matured and ripened earlier than fruit of accessions displaying low-water-loss rate. Cell membrane ion leakage and lipoxygenase activity were higher after storage than immediately after harvest. Pepper fruit total cuticle wax amount, lipoxygenase activity, and cell membrane ion leakage were directly related to postharvest water loss rate in pepper fruit during storage.