Genetic Diversity Analysis of Morinda officinalis Germplasm Resources in Fujian Based on Phenotype and ISSR Molecular Markers

ZHU Yan-ming; LIU Ling-ling; NIU Yu-qing; CHEN Hong; LI Luan-xiang; ZHENG Mei-xia; ZHU Yu-jing; SU Hai-lan; ZENG Ri-qiu

doi:10.13651/j.cnki.fjnykj.2025.11.001

Abstract：In order to evaluate the genetic diversity of Morinda officinalis germplasm resources in Fujian Province,a total of 27 germplasm resources collected from 10 sampling sites across 7 counties in Fujian Province were used as the research objects.Then,the phenotypic traits were systematically recorded and the pollen morphology was observed by using the electron microscopy.The genetic diversity was analyzed by ISSR molecular markers.The results showed that the pollen morphology of M.officinalis in Fujian Province was prolate(the P/E ratio of 1.66 to 1.99),with the polar axis length of 36.89 to 52.93 μm,and the equatorial axis length of 15.14 μm to 33.58 μm.The P/E ratio ranged from from 1.32 to 2.73,and exhibited the highest coefficient of variation(11.36％)among all the pollen traits.The leaf morphology(including elliptic,lanceolate,and ovate forms)and other phenotypic traits such as plant height,leaf number and branch number also displayed substantial variation,with the coefficients of variation ranging from 11.74％to 50.41％.The PCR amplification was performed by using ten ISSR polymorphic primers,generating 64 polymorphic bands with an average polymorphism percentage of 82.48％The results showed that 27 M.officinalis germplasms had high genetic diversity(Nei's gene diversity index H=0.305 2,Shannon's index I=0.457 8).The genetic distance analysis showed that the differentiation between populations was significant(Nei's genetic distance ranged from 0.080 0 to 0.693 1).The genetic relationship between M23 and M24 was the closest(similarity coefficient:0.923 1),and that between M26 and M2 was the farthest(similarity coefficient:0.500 0).The UPGMA clustering analysis divided the germplasm resources into three groups at the genetic distance of 0.654:Group Ⅰ(21 samples)representing the core genetic background,Group Ⅱ(5 samples)sharing common genetic characteristics,and Group Ⅲ(M8)as a unique ecotype.In summary,Morinda officinalis germplasm resources in Fujian exhibited rich genetic diversity,and clear geographical differentiation.It was recommended to give priority to the conservation of populations with high genetic diversity(such as M23/M24 population)and unique ecotypes(M8).The study could provide reference for the conservation,utilization and breeding of germplasm resources of M.officinalis in Fujian.