Identification Of Pathogen Of Penicillium Rot And Different Control Measures During Yam Storage

Yam was rich in nutrition and had high nutritious and medicinal value.It was a kind of special vegetable with both medicine and food,which was deeply loved by people.As the harvest season of yam was relatively concentrated,it was necessary to store yam to ensure annual supply and improve economic benefits.The skin of yam was thin and brittle,which was easy to be damaged,the wound site was easy to be infected by rotting microorganisms during storage,caused a large number of losses,which seriously restricted the storage cycle of yam and the rapid development of the industry.Therefore,the microorganisms related to yam rot were identified,and different measures were researched through morphological and molecular biological identification,the aim was to provide technical basis for the prevention and control of rotten microorganisms.It was of great practical significance to guide the production to take targeted scientific control measures and minimize the rot loss during yam storage.1.The pathogens caused rot in Shui yam and Tiegun yam were isolated.According to the morphological characteristics of the strains,combined with ITS sequencing and phylogenetic tree construction,the fungi of the two yam varieties were identified as the same type,and the microorganisms caused yam rot were identified as Penicillium sclerotigenum.2.After inoculation of 10 yam varieties with p.sclerotigenum,the rot trend and length in different periods were observed.When stored for 30 days,the rot length of different varieties was significantly different,the results showed that xishi yam>Mi yam> Dahechangyu> Huai yam >Ma yam > Zi yam> Changshanximao yam>Xiaobaizui>Jipicao> Tiegun yam,and indicated that different varieties had different resistance to the rot disease caused by Penicillium sclerotigenum.200-400 times,propiconazole 100-400 times were the best,the control results of indoor inoculation test and cold storage test were 100%.Considering the food safety problems caused by pesticide residues,it was suggested to store yam seed stems.4.To reduce the environmental pollution caused by chemical agents and improve food safety,9 different proportions of lime and clay were used to screen and evaluate the inhibition activity of Penicillium and cold storage.The results showed that the best ratio of hydrated lime and deep clay was 2:5.5.The cold storage experiment was carried out on the selected optimal ratio of lime paste.The results showed that there was no mildew and rot in yam after 3 months storage,but when the thickness of 2-3cm was cut off,the white fresh cut would appear,which caused waste of yam to a certain extent.