01509naa a2200217 a 450000100080000000500110000800800410001910000140006024500670007426000060014130000180014749000080016552009530017365000200112665000160114665300130116265300220117570000160119770000150121377300630122816439951993-05-14               bl uuuu     u00u1 u    #d1 aHOMMA, Y.  aDefense mechanisms of citrus against melanose and stem-end rot  c0  ap.370-374 v.1  vv.1  aCitrus melanose and citrus stem-end rot are both caused by the same disease pathogen, Diaporthe citri (Faw.) Wolf. There are three very interesting facts associated with development of citrus melanose and citrus stem-end rot. First, citrus melanose occurs on fruit while they are on the tree. Second, the pathogens which invade the fruit from pedicels and twigs are transmitted to the stem-end where they incubate for a long time, up ot 9 months. Third, the fruits are damaged during the terminal period of storage. Even though the causal pathogen is present, the fruit does not decay. Two inhibitory factors were studied. One was ligth yellowish needle crystals which inhibit the growth of D. citri and obtained from the tissue under the disk. Another inhibitory factor, a phytoalexin-like material was obtainde from melanose. Therefore, the nature of the resistance of fruit peel to rot may be due to these inhibitory materials in citrus tissues.  aDiaporthe Citri  aFlavonóide  aCitrinol  aInhibitory factor1 aARIMOTO, Y.1 aMISATO, T.  tTokyo, Japan: International Society of citricultural, l981