Tm. Gradziel et Dc. Wang, EVALUATION OF BROWN-ROT RESISTANCE AND ITS RELATION TO ENZYMATIC BROWNING IN CLINGSTONE PEACH GERMPLASM, Journal of the American Society for Horticultural Science, 118(5), 1993, pp. 675-679
Rate of brown rot lesion development following inoculation with Monili
nia fructicola (Wint.) honey varied within clingstone peach (Prunus pe
rsica (L.) Batsch) germplasm evaluated in 1990 and 1991. High levels o
f resistance were identified in selections derived from the Brazilian
clingstone peach cultivar Bolinha. Resistance appeared to be limited t
o the epidermal tissue. No relation was detected between brown rot res
istance and concentration of phenolic compounds or polyphenol oxidase
activity in the susceptible California germplasm. An inverse relation
was observed between disease severity and rating for phenolic-related
discoloration when 'Bolinha' derived selections were analyzed. A moder
ate positive correlation was observed for all germplasm tested between
genotype means for phenolic content and enzymatic browning. Any causa
l relationship, if it exists, between phenolic content and brown rot r
esistance is obscured by an array of physical and chemical changes in
the maturing fruit.