Genetic Evaluation And Clone Allocation Of Breeding Resources In Pinus Sylvestris Var.mongolica From Different Improved Generations

Nowadays,the genetic improvement of Pinus sylvestris var.mongolica is in a critical period of upgrading and updating.But the frequent allocation and exchange of breeding resources in different areas without statistics lead to unclear information of breeding resources.The clones number are renamed in different regions,which leads to the identical clone has various clone number.On the other hand,breeding resources include the open pollination progeny groups without genealogical information and unknown relationships.All the disadvantage status above,whicih increased the difficulty of breeding resource management,increased the risk of inbreeding depression,and laid a great potential for the upgrading of Pinus sylvestris var.mongolica.In this paper,224 clones of Pinus sylvestris var.mongolica from the 1st,1.5th and 2nd seed orchards were studied.Genetic diversity,phylogenetic relationship and genetic diversity were analyzed based on SSR.Using Improved Adaptive Parallel Genetic Algorithm based on Python language,taking genetic distance as data,configurated and designed the clone seed orchard of Pinus sylvestris var.mongolica based on genetic relationship.Molecular Assisted Selection was carried out in this research for the first time taking Pinus sylvestris var.mongolica as material.The results of this research improved the breeding resources evaluation system of Pinus sylvestris var.mongolica,determined the genetic relationship of different generation breeding resources,and provided the material and information basis for the advanced genetic improvement work of Pinus sylvestris var.mongolica.The main research achievements are as follows:1.Screened out 11 pairs of SSR fluorescent primer of Pinus sylvestris,High Polymorphic primers with PIC>0.5 accounted for 54.55%of the totality;Moderate Polymorphic primers with 0.25<PIC<0.5 accounted for 27.27%of the totality:Low Polymorphic primers with PIC<0.25 accounted for 18.18%of the totality.2.Obtained the genetic diversity data of breeding resources.Categorized according to the information of collection locations,the TDQ,LZJD,TL2,YL1.5 groups have the highest genetic diversity level,the BGY and YL2 groups relatively fell behind,categorizing according to generation information,the genetic diversity level of breeding resources of different generations is higher than that of the other needle-leaved tree seed orchards;the expected heterozygosity(He)of the 1.5th generation and 2nd generation groups is 1.31%and 4.13%lower than that of the 1st generation;The genetic diversity of higher generation has decreased,the 2nd generation has the highest inbreeding coefficient(F=0.173),that is 1.9 times and 2.1 times of that of the 1 st generation and 1.5th generation groups respectively.3.Through genetic differentiation analysis,the difference situation between groups is confirmed.The average gene flow(Nm)between breeding resource groups was 6.436,illustrated that gene swapping phenomenon existed obviously between groups;the genetic differentiation coefficients(Fst)of the 1st and 2nd generation were 0.041 and 0.045 respectively,illustrated that the main genetic variation groups were existing between individuals(96%),no obvious variation took place between breeding resource groups with the same breeding resource location and different habitat.It could be seen from the result of genetic variation that,allocating and swapping breeding resources frequently within small range,could maintain higher similarity between groups.4.Calculating the genetic distance of Nei'1983 based on gene frequency,proceeding clustering analysis with UPGMA,obtained the genetic relationship between groups and individuals.Between the YL1.5 group and YL2 group,where parentage existed,the genetic relationship was closer,and separately gathered into one group;The CH2,TL2,LZJD groups,who had the closest genetic relationship,might have the same parents.The genetic relationships were very complicated between individuals,but as the breeding resource generations improved,the clustering phenomenon of genetic relationships between individuals gradually became obvious,the 2nd generation could be divided in 6 groups at the point of 0.8088 of the genetic distance.2 of the phenomenon were discovered in the research that the same clones possessed multiple clone number(CH3 and CH10 are the same.YL1417 and YL1411 are the same).5.Based on the genetic relationship between individual plants,using Improved Adaptive Parallel Genetic Algorithm(IAPGA)in configuration and design of clones could reduce inbreeding rate,and reduce inbreeding depression to the maximum extent.This research successively obtained the clone design scheme of the breeding resources of the 1st,2nd and hybrid generation,and provided practice guidance to Honghuaerji Forestry Bureau for carrying out Pinus sylvestris var.mongolica breeding improvement.