Comparison Of Fruiting And Kernel Traits Among Different Jujube Cultivars

To investigate the flowering and fruiting characteristics,kernel rate,seed kernel characteristics and seedling establishment characteristics of different jujube cultivars,it provides theoretical basis for jujube breeding,variety classification,production and cultivation.This study used 15 jujube cultivars as experimental materials to study the pollen quantity,pollen germination rate,seed setting characteristics,kernel characteristics and seedling characteristics of different jujube cultivars.Artificial controlled hybridization experiments were conducted to compare the seed setting rate and fertility rate of different hybrid combinations.The main research findings are as follows:（1）There are significant differences in pollen quantity and germination rate among different cultivars,pollen quantity was generally low.‘Dongzao’and‘Zaocuiwang’belong to male sterile cultivars.‘Dongzao’contains pollen but does not germinate,while‘Zaocuiwang’does not contain pollen.Through paraffin section observation,it was found that the anther chambers of the‘Zaocuiwang’were empty and shrunk during the bud yellow stage,and there were no pollen grains present.（2）Spraying 1500 mg/L KH₂PO₄ at full flowering stage can significantly improve the fruiting rate,and spraying 1500 mg/L H₃BO₃ can remarkably improve the fertile rate.The size of the same cultivar’s fruit affects the fertility rate,with large fruit having a higher fertility rate and small fruit having a lower fertility rate.According to the seed setting rate and fertility rate under self pollination and natural pollination conditions,jujube can be divided into 5 categories:self-fruitless and natural-sterility,self-fruitless and natural-fertility,self-sterility and natural-sterility,self flowering non fruiting sterile,self-sterility and natural-fertility,and self-fertility and natural-fertility,accounting for 13.33%,60%,6.67%,13.33%,and 6.67%of the tested cultivars,respectively.‘Dongzao’,‘Huizao’,‘Xiangzao’,‘Lengbaiyu’,‘Saimisu No.1’,‘Saimisu No.2’and‘Fucuimi’belong to self-fruitless and natural-fertility and have a high fertility rate.They are suitable as female parents in hybridization.（3）There are significant differences between different cultivars of fruit stones and kernels.Using the membership function to evaluate the germination potential,germination rate,and seedling emergence rate,the four cultivars‘Saimisu No.1’,‘Dongzao’,‘Saimisu No.2’and‘Zaocuiwang’performed better.