Changes of Main Nutritional Components in Inbred and Hybrid Fruits of Pyrus calleryana Decne
Morphological indexes such as transverse diameter,longitudinal diameter,single fruit weight,and physiological and biochemical indexes such as nutrients,antioxidant protective enzyme activities and mineral elements were measured in the development process of the two combined fruits with inbred and hybrid fruits of Pyrus calleryana Decne as the test materials to reveal the physiological mechanism of hybrid embryo abortion of the Pyrus calleryana Decne,and to investigate the morphological differences and changing rules of physiological indexes in the development process of inbred and hybrid fruits of Pyrus calleryana Decne.The results showed that:(1)the transverse diameter,longitudinal diameter and single fruit weight of the two fruit combinations increased during the development process,and that of the inbred fruits were always greater than that of the hybrid fruits.The fruit shape index of the two fruit combinations showed a downward trend,and the fruit shape was nearly round.(2)The mass fraction of soluble sugar and soluble protein in the two fruit combinations showed an increasing trend.(3)SOD activity showed a downward trend,POD activity increased first and then decreased,CAT activity increased,and MDA mass molar concentration decreased first and then increased in the two fruit combinations.POD and CAT activities of hybrid fruits were always lower than those of the inbred fruits.(4)The mass fraction of N,P,K and Zn in the two combined fruits showed a decreasing trend,while the mass fraction of Mn showed an increasing trend.The development process of hybrid fruits was slower than that of inbred fruits.The decrease of nutrient mass fraction,antioxidant enzyme activity,N,P,K,Zn mass fraction and the accumulation of MDA mass molar concentration and Mn mass fraction in hybrid fruits were the internal causes of hybrid fruit abortion.