Changes in the seed coat morphology of 12 annual legumes were studied using environmental scanning electron microscopy (ESEM). The seeds of Biserrula pelecinus L. cv. Casbah, Ornithopus sativus cv. Cadiz, Trifolium clypeatum L., T. spumosum L., T. subterraneum L. cv. Bacchus Marsh, Trigonella balansae Boiss. & Reuter., Trigonella monspeliaca L. and Vicia sativa subsp. amphicarpa Dorthes (morthes.) were examined by ESEM after exposure to field conditions for 6 months, while those of Medicago polymorpha L. cv. Circle Valley, Trifolium clypeatum L., T. glanduliferum Boiss., T. lappaceum L., T. spumosum L., and T. subterraneum L. cv. Dalkeith, were examined after 2 years' exposure. The entry of water into seeds was followed by covering various parts of the seed coat with petroleum jelly and soaking the treated seeds in dyes.As the seeds softened over time, more and larger fractures appeared on the seed coat. Water entered the seed either through fractures, over the seed coat as a whole or through the lens. It is hypothesized that the formation of fractures occurs after physicochemical changes in the seed coat, probably associated with changes in the amount and nature of seed coat lipids.The newly matured whole seeds of M. polymorpha cv. Circle Valley, T. clypeatum, T. glanduliferum, T. lappaceum, T. spumosum, and T. subterraneum cv. Dalkeith were analysed for lipid content in 1997. The seed coats of T. subterraneum cv. Dalkeith and T. spumosum were separated from the cotyledons and examined in detail for lipid content.The lipid content of whole seeds ranged from 48 (T. lappaceum) to 167 mg/g (T. subterraneum cv. Dalkeith). Total lipid of the whole seeds of T. subterraneum cv. Dalkeith and T. glanduliferum declined by about 9 mg/g over 2 years, while in T. spumosum it declined by about 17 mg/g.In contrast, the major fatty acids in the seed coat declined by 0·67 mg/g over the 2 years. Change in seed coat lipids showed a marked similarity to changes in hardseededness for both T. subterraneum cv. Dalkeith and T. spumosum. The results strongly suggest that seed softening is associated with loss of lipids in the seed coat, because lipids have physical characteristics that are altered at temperatures experienced in the field.

The antifungal activity of nonanal against Botrytis cinerea, one of the most important postharvest diseases of tomato gray mold, was tested by in vitro and in vivo experiments. Results of in vivo tests demonstrated that wax + nonanal treatment significantly decreased the incidence of gray mold during the entire storage period. After 8 d of storage, the disease incidences in Wax + nonanal (1×, 4× or 10× MFC)-treated fruits were 46.7%, 56.7%, 73.3%, respectively, in contrast to 100% of the control fruits. Loss of membrane integrity was examined and quantified under 10×MFC nonanal condition by the method of propidium iodide fluorescent staining. Wax + nonanal (10×MFC) treatment remarkably increased antioxidant enzyme activities, such as catalase (CAT), superoxidase dismutase (SOD), peroxidase (POD) and phenylalanine ammonia lyase (PAL). Meanwhile, this treatment (10×MFC) evidently exhibited a delayed decline in antioxidant enzyme activities. Furthermore, nonanal treatment retained the fruit quality of tomatoes because it reduced the coloration index and weight loss and retained fruit firmness. No significant differences were found between the pH, Firmness and total soluble solid (TSS) content for all treatment under the same storage time. Our results suggest that nonanal can be considered as a good alternative to conventional fungicides in controlling the decay of tomato fruits.