Flowering Biological Characteristics Of Some XinjiangPear Varieties And Its Effect On Pollination Of ’Korla Fragrant Pear’

The economic value of pear is very high.’Korla fragrant pear’ is widely popular and widely planted in Xinjiang local pear varieties.However,due to the phenomenon of pollen intuition,the yield and quality of pear are reduced.Therefore,exploring the suitable pollination tree of ’Korla fragrant pear’ is one of the tasks to be solved in the production process of ’Korla fragrant pear’.In this paper,ten local varieties of Xinjiang(brown Juju pear-HS,Luntai Juju pear-LT,Huocheng Donghuang pear-HD,Juju pear-JJJ,Bayue pear-BY,Qipan pear-QP,Yelike Amut-YL,Korla yellow acid pear-KH,Kuike Amut No.1-KK1,black acid pear-H)were used as experimental materials.Through pollination with ’Korla fragrant pear’,the fruit of each pollination combination and the fruit of male pear varieties were determined,cluster analysis and comprehensive evaluation,which provided the corresponding theoretical basis for ’Korla fragrant pear’ to explore suitable pollination trees.The results were as follows :(1)According to the investigation and analysis of flowering biological characteristics and pollination affinity of male pear cultivars,the cultivars with large differences in flowering phenology between male pear cultivars and ’Korla fragrant pear’ were ’KH’.In terms of floral organ characteristics,’H’ had the largest petal longitudinal diameter,petal transverse diameter and corolla diameter.Among the10 male parent varieties,’KK1’ had the largest pollen amount,the strongest pollen viability,and the highest fruit setting rate after pollination.’KH’ had the least pollen amount,the weaker pollen viability,and the lower fruit setting rate after pollination.In summary,’KH’ is not suitable as an alternative pollination tree for ’Korla fragrant pear’.(2)Analyze the fruit quality.The results showed that the quality indexes of each male parent fruit and each pollination combination fruit were different.The highest comprehensive evaluation score of male pear cultivars was ’KK1’.The correlation analysis of each measurement index between male parent fruit and pollination combination fruit showed that the single fruit weight,tissue water content and Vc content were positively correlated.The traits showed no significant negative correlation.(3)This study was conducted to investigate the effects of pollination on stone cells and lignin content in fruits of different Xinjiang local pear varieties and ’Korla fragrant pear’.In this study,stone cells,lignin and related enzymes(PPO,POD,PAL)activities were measured and analyzed in different pollination combinations at different growth stages.The results showed that the density of stone cell mass decreased rapidly from 60 d to 90 d and from 90 d to 120 d after flowering.The contents of stone cell and lignin,and the activities of PPO,POD and PAL decreased rapidly after 60 d after flowering.Moreover,the stone cell density,content,lignin content and enzyme activity of fruit in different growth stages and pollination combinations were different.And showed varying degrees of positive correlation.(4)The pericarp structures of seven pollination combinations were observed and analyzed by using paraffin section technique.The results showed that the longitudinal and transverse diameter of pericarp epidermal cells showed an upward trend with the growth and development of fruit,and the thickness of cuticle and wax layer decreased gradually.The thickness of epidermis also showed an upward trend with the growth and development of fruit.The longitudinal and transverse diameters of pericarp cells,the thickness of wax layer,cuticle and epidermic layer of each pollination combination at different growth stages were different.(5)Through systematic clustering and comprehensive evaluation of fruit quality and peel structure data of seven pollination combinations,the results showed that the seven pollination combinations could be divided into four categories.The fruit comprehensive score of pollination combination ’Korla fragrant pear×QP’ was the highest.Therefore,’YL’,’BY’ and ’KK1’ are suitable for ’Korla fragrant pear’ pollination tree by analyzing and summarizing the comprehensive score of pollination combination,pollen amount,pollen viability and pollination fruit rate of male varieties.