| This study was mainly to investigate the characteristics of postharvest diseases ofpeach and plum fruits, as well as the control methods. The results were shown as following.（1）Nine fungal strains were isolated from postharvest peaches and plums with rotincidence. Four of them were identified as Monilinia fructicola, and two strains wereAspergillus tubingensis by the use of morphology and ITS rDNA sequence analysis.Besides, Botryosphaeria dothidea, Penicillium oxalicum and Botrytis elliptica were alsoobtained from peaches or plums during storage. Carbon metabolic fingerprinting with FFMicroPlate showed that numbers of optimal substances among95different carbon sourceswere54,83,79for B. elliptica, P. oxalicum and A. tubingensis, respectively.（2）Food fungicides treatments including FP-1, FP-2, FP-5and FP-6alleviatedbrown rot of peaches caused by M. fructicola, and5%FP-5was superior to othertreatments for it could suppresse M. fructicola completely. Inreasing of POD activity, aswell as scavenging abilities of DPPH radical and hydroxyl radical was observed in the fruittreated by5%FP-5. Whether C.laurentii (5×107CFU/mL) was added or not,0.25%FP-2,0.25%FP-5and0.25%FP-6reduced the infection rate of M. fructicola. However, only themixture of C.laurentii and FP-6was more effective than C.laurentii or FP-6alone, andimproved antioxidant capacities in fruits simultaneously. In despite of innocuity topathogens in vitro test,0.25%ascorbic acid was effective in control of B. dothidea and M.fructicola, when evaluated in ‘15#’ peaches and ‘Okubao’ peaches of high maturityrespectively. Furthermore, C.laurentii+0.25%ASA delayed the rot symptom of ‘15#’peaches caused by B. dothidea and ‘Okubao’ peaches infected by M. fructicola. It wasindicated that the influnces of ascorbic acid or C.laurentii on postharvest diseasesdepended on fruit maturity as well as fungal strains. Plant extracts of70%C2,100%C2,70%D1and100%D1could inhibite the infection of M. fructicola on peach fruits, and70%C2was superior to other three extracts comparatively. Besides, the mixture plantextracts including F3, F7, F8, F10and F12were also effective against M. fructicola,among which F3extraciton was the best. However, the aboves extracts showed significantdifferent influences on fruit qualities and metabolism of reactive oxygen species (ROS)which indicating that each treatments possessed special patton on resistant reaction againstpathogen of fruits. （3）The storage period of ‘Black amber’ plums was prolonged at2℃, which allayedthe decline trend of superoxide, hydroxyl radical, as well as DPPH radical scavengingcapacities, and antioxidant capacities of plum fruits also depended on parts of fruits.Besides, ripening stage could affect fruit qualities as well as ROS metabolism, and lowermature plum was relatively suitable for commercial storage. Both of calcium chloride andcalcium propionate were effective in control of ‘Angeleno’ plum decay after12daysstorage at20℃while calcium lactate reduced a*value of plum skin as well as L*valueand b*value of pulp, but improved a*value of fresh. Superoxide scavenging activity andhydroxyl radical scavenging ability in ‘Angeleno’ plums were significantly differentbetween calcium trements. Calcium chloride also reduced the incidence rate of ‘Blackamber’ plums after3days storage while calcium propionate showed inhibition effect after6days, and the dereasing of hydroxyl radical scavenging capacity and MDA content wereobserved in calcium chloride and calcium propionate applications, respectively. It wasconcluded that1-MCP alone or combined with salicicy acid delayed the softness of‘Angeleno’ plum during storage at20℃or0℃, as well as shelf life, but the correlationbetween firmess and LOX activity was not significant. However,‘Bayuecui’ peachestreated by1-MCP or salicicy acid showed lower extract rate and fewer hydrogen peroxidecontent after35days storage at0℃comparing to conrol fruits. Chlorine dioxide waseffective in control of ‘Angeleno’plum decay and delayed the decline trend of SSC in‘Bayuecui’ peaches during storage at20℃, while1-MCP inhibited the changes of SSC, aswell as b*value of skin and pulp in ‘Bayuecui’ peaches. Generally, four volatilecompounds had different influences on production and scavenging system of ROS in peachor plum fruits. |
PDF Full Text Request