Evidence supporting the involvement of MHO in the formation of superficial scald in Dangshansuli' pears

摘要

The development of superficial scald in 'Dangshansuli' pears (Pyrus bretschneideri Rehd) was investigated in relation to 6-methyl-5-hepten-2-one (MHO). Over the course of a 180-day cold storage at 2 +/- 0.5 degrees C and a 9-day post storage at 20 degrees C, the effect of endogenous MHO was investigated in chemically untreated pears, and pears treated with diphenylamine (DPA) and 1-methylcyclopropene (1-MCP) after harvest. In the untreated pears, MHO began to accumulate in peel tissue after 60 d of cold storage and continued to do so until the end of cold storage, by which time superficial scald had developed. In DPA- and 1-MCP treated pears, on the other hand, there was very little MHO accumulation during cold storage and, at the end of this period, no scald had developed. Results from the cold storage period, therefore, indicate a positive relation between scald incidence and endogenous MHO concentration. Results from 9-day post storage reveal also a strong positive correlation between scald and endogenous MHO concentration, with a correlation coefficient of 0.97936 (P 0.05).