Abstract

DENARDI, Frederico; BERTON, Onofre  and  SPENGLER, Márcia Mondardo. Genetic resistance to bitter rot on apples determined by the development rate of the disease on fruits with and without wounds. Rev. Bras. Frutic. [online]. 2003, vol.25, n.3, pp. 494-497. ISSN 0100-2945.  http://dx.doi.org/10.1590/S0100-29452003000300033.

Apple is one of the most important agricultural product of Santa Catarina State and represents the second most important temperate-zone fruit in Brazil. However the production is based on imported cultivars susceptible to many fungal diseases. Bitter rot caused by the fungus Glomerella cingulata (Stoneman) Spaulding & Schrenk, (amorphous = Colletotrichum gloeosporioides (Penz.) Sacc.), is one of the most important summer diseases of apple in southern Brazil. Severe damages may occur every year. In the present study, artificial inoculation of C. gloeosporioides on fruits with and without wounding was carried out to verify differences in the evolution of bitter rot and to identify sources of resistance to the disease among the new apple cultivars and selections of the Epagri breeding program. The establishment and the development of bitter rot on apple fruits were faster through wounds. The selections M-6/00 and M-13/00 showed higher level of resistance to bitter rot than the cultivars Gala, Fuji and Golden Delicious. These apple selections expressed an even higher level of resistance to this disease than cv. Melrose, indicated as resistant in previous studies.

Keywords : Apple; bitter rot; genetic resistance.