Abstract:

Huanghua pear is highly susceptible to infection by infectious microorganisms during postharvest storage. Pear
ring rot, caused by Botryosphaeria berengeriana. f.sp. piricola, is one of the major postharvest diseases. The ability of the
yeast Kloeckera apiculata combined with CaCl2 to control ring rot of Huanghua pear fruit during storage and its possible
biocontrol mechanism were examined in this study. The results indicated that K. apiculata combined with CaCl2 inhibited
pear ring rot more effectively than Kloeckera apiculata or CaCl2 used alone at 20 ℃. K. apiculata around the wounds could
multiply quickly at the beginning of incubation and then remain at higher levels, while 2% CaCl2 had no negative impact on
its growth. Combined treatment with K. apiculata and 2% CaCl2 caused the accumulation of defense-related enzymes such
as polyphenol oxidase (PPO), peroxides (POD), phenylalanine ammonia-lyase (PAL), chitinase (CHI), and β-1, 3-glucanase
(GLU) in Huanghua pear fruit. These results indicated that K. apiculata combined with 2% CaCl2 could effectively reduce
the incidence of ring rot in Huanghua pear. The induction of resistance is one of the most important mechanisms by which
K. apiculata combined with CaCl2 controls pear ring rot.

Key words: Kloeckera apiculata, CaCl2, Huanghua pear, pear ring rot, biocontrol