ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Infection of table grape bunches by Alternaria alternata.

Swart, A. E.; Lennox, C. L.; Holz, G.;

South African Journal for Enology and Viticulture Year: 1995 Vol: 16 Issue: 1 Pages: 3-6 Ref: 20 refs.

1995

บทคัดย่อ

Infection of table grape bunches by A. alternata was investigated by light, fluorescence and scanning electron microscopy. Conidia in 20- micro l drops of spore suspension germinated readily on the fruit surfaces. Within 16 h growth was extensive on berries, pedicels and rachises of immature and mature bunches. Appressoria were formed within 16 h at the tip of germ tubes and hyphae, and on short side branches on the different bunch parts. The pathogen penetrated the host tissue through stomata, lenticels and microcracks in the epidermis. Infection hyphae were localized in the substomatal cavities or surface cells of lenticels. Where penetration was via microcracks the hyphae were restricted to a few epidermal cells, but caused no cell necrosis. Under conditions of high humidity, the fungus grew out of the stomata, lenticels and microcracks and formed an extensive superficial growth within 168 h. The fungus was able to grow into epidermal cells adjacent to those surrounding wounds, though the pro

cess appeared to be slow.