Genetic Diversity Analysis And Clonal Selection Of Catalpa Bungei

Catalpa bungei,belonging to catalpa genus of Lagerstroemia family,is a precious high-quality timber species and ornamental tree species,and is also an endemic tree species in China.It has a very high practical value,especially in the use of materials and landscape greening,it has an irreplaceable advantage.In recent years,through the selective utilization of wild resources,more catalpa germplasm resources have been produced.It has high practical significance to evaluate the existing germplasm and carry out the selection of excellent germplasm.In this study,44 Catalpa bungei germplasm resources were collected and preserved in the early stage,and the genetic diversity and genetic relationship of the resources were analyzed by AFLP molecular marker technology;The growth index and wind break resistance of Catalpa bungei were evaluated by building regional test forest of clones,in order to lay a foundation for the development and utilization of superior germplasm of Catalpa bungei in the future.The main results are as follows(1)Eight pairs of PstI / msei primer combinations were screened out,and 1087 clear bands were amplified from 44 Catalpa bungei germplasms,including 1043 polymorphic bands(NPB),and the polymorphism ratio(ppb)was 95.60%.The average number of effective alleles(NE),Nei’s average gene diversity(H)and Shannon’s average information index(I)of each locus were 1.3210,0.2003 and 0.3204,respectively.A total of 261 specific bands were produced by 8 primer combinations.(2)By calculating the genetic similarity coefficient and UPGMA cluster analysis,it was found that the genetic similarity coefficient of various materials ranged from 0.5022 to 0.7919,with an average of 0.6527.Based on the genetic similarity coefficient of 0.65,44 catalpa germplasm can be divided into 5 groups,the first group includes 15 Shandong germplasm and2 Henan germplasm;The second group included 18 Shandong germplasms and 3 Henan germplasms;The third group included 3 Henan germplasms;Group 4 included one Henan germplasm;Group 5 included 2 Henan germplasms.There was no significant correlation between genetic diversity and geographical distribution of Catalpa bungei in Luyu area.(3)Based on genetic distance and morphological characteristics,31 clones of Catalpa bungei were selected to set up regional experimental forest.The results showed that there were significant differences in growth indexes among clones.The differences of tree height,average crown width and individual volume among clones were extremely significant,but the effect of experimental sites on the growth of Catalpa bungei was not significant.Among them,7 clones(6 #,23 #,24 #)had strong wind resistance.(4)Through comprehensive evaluation of germplasm resources of Catalpa bungei,three clones with excellent comprehensive indexes were obtained: 5 #,6 #,and 16 #.Among them,5 were from Laiyang City,6 from Mengyin County,and 16 from Yanya Town,Shandong Province.