Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 7/23/2004
Publication Date: 6/7/2004
Citation: Sams, C.E., Zivanovic, S., Charron, C.S., Wu, T., Blodgett, A.B., Conway, W.S. 2004. Fungal chitosan extracts are as effective in reducing decay caused by botrytis cinerea, penicillium expansum, and penicillium solitum as commercial seashell chitosan extracts. Phytopathology. 95 (Suppl.):Abstract. P. S91.
Technical Abstract: 'Golden Delicious' apples were surface disinfested or disinfected insects with 70% ethanol and wounded once towards the top of each apple. Two % chitosan solutions in sterile deionized water were adjusted to pH 6 with sodium hydroxide or acetic acid. Five chitosan extract solutions were utilized as the following treatments: 1) a commercial chitosan extract, 2) a crude extract from P. expansum, 3) a purified extract from P. expansum, 4) a crude extract from P. solitum, and 5) a purified extract from P. solitum. These were compared to a water control. Each chitosan solution was pipetted into 3 mm x 3 mm wounds on 30 apples (25 uL per wound) and allowed to air dry. Apples were placed in boxes at 25C for 3 days. After the 3 days, an identical wound was made one inch below the original wound on each fruit and all wounds were inoculated with 25 uL of a 1 x 104 spore suspension of either Botrytis cinerea, P. expansum or P. solitum. Apples were placed in boxes at 25C and lesions were measured at 2-3 day intervals over 17 days. The area of decay caused by the three pathogens was reduced by all of the chitosan treatments. The rate of growth of P. solitum was significantly slower than the other pathogens. Chitosan from all three pathogens was effective at eliciting resistance to decay as was chitosan from commercial sources. Implications of this to host pathogen interactions and pathogen growth rate will be discussed.