Effects Of Disturbance Degree And Genetic Bottleneck On Genetic Diversity And Genetic Structure Of Natural Population Of Acer Mono

Acer mono is one of the associated tree species with symbolic significance in Korean pine broad-leaved forest in Northeast China.It is also the tree species with the greatest application value and the most development and utilization prospect among the Acer species distributed in Northeast China.At present,due to unreasonable cutting and utilization,large-scale cutting in the process of thinning and tending,and a large number of removal for landscaping purposes,the natural population of Acer Acer has been greatly damaged.With the increasing intensity of development and utilization of Acer mono,this interference will continue to increase,but there is no relevant report on the impact of human activities(including tending measures)on the genetic diversity and genetic structure of Acer Acer population.In this paper,six pairs of nSSR primers were used to study the populations of Acer mono with different degrees of interference(undisturbed original population,secondary forest species formed after destruction,population after artificial tending,population in areas with intensive human activities)and populations with different degrees of genetic bottle neck(mild genetic bottleneck,moderate genetic bottleneck,serious genetic bottleneck and obvious inbreeding effect)detected in previous studies,The genetic diversity and small-scale spatial transmission structure of the population and individuals in different regeneration periods(plant height>0.5m)were studied by measuring the age class by diameter class.The results showed that:(1)After understory tending and human disturbance,the population size is small(121individuals in the undisturbed population L1 and 50 individuals in the serious human disturbance population W1),but the expected heterozygosity is high(H_E>0.5).Although appropriate understory tending and human disturbance will affect the total number of individuals in the population,as long as a certain number of population individuals(or appropriate diameter class ratio)is maintained,It will not have a significant impact on the genetic diversity of the population.(2)Although young individuals make a great contribution to the current high genetic diversity of the population,it is also one of the reasons for the small-scale spatial genetic structure of the population.With the decrease of the population(young individuals compete and eventually die),the population genetic diversity still needs to be maintained by adult individuals.Therefore,proper understory tending and clearing activities will not affect the long-term genetic diversity of the population,but also be more conducive to regulating the spatial genetic structure of the population.(3)Moderate genetic bottleneck and inbreeding effect have no significant impact on the current overall genetic diversity of the population,but when the population number decreases,the genetic bottleneck has a greater impact on the long-term genetic diversity of the population than inbreeding effect.On the contrary,for the spatial genetic structure of the population,the influence of inbreeding effect is significantly greater than the genetic bottleneck below moderate.This study not only provides effective basic data for maintaining the genetic diversity level of Acer mono,but also provides a scientific basis for resource cultivation and management measures such as artificial tending and transformation of natural forests of Acer mono and other tree species.