Evaluation Of Cultivation Performance Of Five Pear Varieties In Bazhou

In order to find out the cultivation performance of five pear varieties in Bazhou area,the varieties with strong cold resistance,flowering,growth characteristics,and fruit quality similar to’Kuerlexiangli’were screened out.In the experiment,the main local cultivar’Kuerlexiangli’was used as the experimental control,and four pear varieties,’Xuexiang’,’Xinli No.7’,’Yuluxiang’,and’Hongxiangsu’were used as experimental materials.Characteristics,shoot growth characteristics,leaf photosynthetic fluorescence characteristics,fruit quality characteristics,and stress resistance（cold resistance and pear Erwinia amylovora）were studied and analyzed.In order to screen suitable local cultivated pear varieties,as the tree species planted with’Kuerlexiangli’,to provide reference for supplementing local cultivated varieties.The main findings are as follows:（1）In terms of flowering biological characteristics,the flowering phenology of the four tested pear cultivars differed within 3 days from the experimental control’Kuerlexiangli’,and the stigma was receptive in the first 3 days after flowering.The characteristics of the flowering period of’Xuexiang’are similar to’Kuerlexiangli’,the amount of pollen in a single anther is about 5000,the germination rate of pollen is about 50%,the amount of pollen is high and the vigor is high;’Xinli No.7’has male sterility characteristic.The seed setting rate of five pear cultivars was below 5%by self-pollination,and the natural pollination result rate of’Xuexiang’was the highest at 54.40%.（2）In terms of shoot growth characteristics and photosynthetic fluorescence characteristics,the growth cycles of the four tested pear varieties were similar to’Kuerlexiangli’.,Internode length,thickness,leaf area,and chlorophyll SPAD value increased rapidly.The diurnal variation of P_nof the five pear cultivars showed a"double peak"curve,and there was a phenomenon of"photosynthetic lunch break".Although there were differences in the monthly changes of photosynthetic fluorescence parameters,the overall change trend was consistent.The P_n,G_s,and Tr of’Xuexiang’were higher than those of other cultivars at each stage,indicating that the photosynthetic capacity of’Xuexiang’leaves was better than other cultivars.After the phenomenon of photoinhibition,the F_v/F_m,F_v/F₀,and RET of’Xinli No.7’were higher than those of other varieties,indicating that the photoinhibition phenomenon was relatively mild,that is,the tolerance to high temperature and strong light was relatively strong.（4）In terms of fruit quality characteristics,’Xuexiang’is a middle-late-maturing variety,with a vitamin C content of 24.56 mg/kg and a fruit firmness of 5.38 kg/cm²,which is relatively low among the five pear varieties,and the fruit surface and fruit point are relatively low.dense.The sugar-acid ratio and Vit.C content of’Xinli No.7’were significantly lower than those of the experimental control,but it belonged to an early-maturing variety.The fruit size of’Yuluxiang’is about twice that of’Kuerlexiangli’,the single fruit weight is 258.03 g,and the sugar-acid ratio is higher than’Kuerlexiangli.The fruit ripening period of‘Hongxiangsu’was about 1 week later than that of‘Kuerlexiangli’,and the sugar-acid ratio was the lowest at 5.77,but the Vit.C content was the highest at 47.72 mg/kg among the five pear varieties.（5）In terms of stress resistance,five pear varieties were subjected to gradient low temperature stress,and the cold resistance was comprehensively evaluated from physiological indicators,membership functions and recovery tests.The results showed that the cold resistance of’Xinli 7’and’Xuexiang’was better than that of’Kuerlexiangli’,and the other two varieties was weaker.Through the research on the resistance of five pear varieties to Erwinia amylovora,it was found that the five varieties were all highly susceptible varieties,of which the disease index of leaves of’Kuerlexiangli’reached 88.89,and the disease index of branches reached 55.56.The disease index of leaves of’Xinli No.7’was 82.22,and the disease index of branches was 40.74,which were both lower than those of’Kuerlexiangli’,indicating that its resistance to Erwinia amylovora was better than that of’Kuerlexiangli’.To sum up,the five pear varieties were compared and analyzed in terms of flowering,growth,fruit quality,and resistance.The results showed that’Xinli No.7’and’Xuexiang’could be used as tree species for’Kuerlexiangli’to complement the local Cultivated varieties provide reference.