Study On The Selection Of Superior Plants In The Hybrid Offspring Of Early-bearing Walnut ’Xilin 3’ And ’Chico’

Cross breeding is one of the important ways of breeding new varieties.In this study,the female parent walnut‘Chico’male parent walnut‘Xilin 3’and its 26 inter specific hybrid progeny and‘Xiangling’walnut were used as test materials.The differences,correlations and principal components of the hybrid progeny and their parents were analyzed from the aspects of phenology period,growth characteristics,photosynthetic characteristics,fruit quality characteristics,high yield and disease resistance.At the same time,the method of calculating membership function value and comprehensive evaluation value was used to select the excellent plants and sort them.The results not only provide theoretical basis for early selection and further utilization of heterosis,but also provide new excellent materials for walnut breeding.The main results are as follows:(1)F1-11 and F1-12 are male progeny,which are consistent with the male parent‘Xilin 3’,and the best pollination time between female and male is 1～4 days,indicating that the two individual plants have a certain self pollination ability;F1-05,F1-15 and F1-22 are late flowering than their parents,so they can be used as late frost avoidance varieties;The leaf length,leaf area,chlorophyll a and leaf water content of F1-08,F1-09,F1-20,F1-24 and F1-06 showed a certain super parent advantage.(2)The dry fruit weight per m~2crown projection area of F1-04,F1-06,F1-10,F1-16,F1-17,F1-20 and F1-23 was more than 60 g,which was significantly higher than that of other single plants.The crude fat content of F1-02 and F1-19 was more than 70%,which was significantly higher than that of male and female parents;The contents of total phenol and flavonoid in F1-06,F1-09,F1-16,F1-17,F1-20 and F1-26 were higher than those of their parents,indicating that the hybrid offspring had certain differences in young tree yield,nutritional quality and functional components.(3)Using k-means cluster analysis,F1-09,F1-12,F1-13,F1-25 and F1-26showed a certain high resistance to anthrax,and their resistance was significantly higher than their parents.The resistance of other hybrid offspring also showed a certain super parent advantage.It is concluded that F1-09,F1-20 and F1-26 have certain advantages in growth and bearing habits,fruit quality and resistance to anthrax,and are preliminary determined as excellent individual plants.The high yield and stress resistance should be further studied.