Abstract:

【Objective】ISSR markers were used to study the genetic relationship and investigate the genetic diversity and genetic structure for providing a theoretical basis and technical support for appropriate conservation and application of existing genetic resources of ramie inbred line clones. 【Method】Genetic relationship of 40 inbred line clones (including 8 ramie inbred line clones from Brazil and 32 from 5 provinces of China)were analyzed using ISSR markers. 【Result】The genomic DNAs of 40 inbred line clones were amplified by PCR with 30 polymorphic ISSR primers, which produced 116 bands from 200 bp to 2 000 bp bands were polymorphism. While the polymorphism of ISSR was 78.45% (91 bands out of 116), ranging from 2 (ISSR6) and 10 (ISSR22), with an average of 3.87. Pairwise comparison was made among all the inbred line clones included in this study. The Nei's genetic distance was 0.2405, Shannon's Information index was 0.3679. Based on the appearance of the markers, the genetic relationships were analyzed using UPGMA and the genetic Dice coefficients were calculated. According to the regions of origin of 40 ramie inbred line clones, they were classified into 6 groups. The Nei's genetic distance was between 0.0964 and 0.2285, Shannon's Information index was from 0.1408 to 0.3310. The Mantel examination between cluster analysis and coefficients matrix showed good fitness. The results of principal components analysis showed that the accumulative variance contribution of the first three principal components was 80.15%, the variance contribution of the first principal component was 72.67%, and the second principal and third principal components were 5.63% and 2.11%, respecitively. 【Conclusion】The results of hierarchical cluster analysis were commendably in accordance with principal components analysis. The genetic relationship and genetic diversity of ramie inbred line clones could be assessed efficiently by ISSR markers.

Key words: ramie (Boehmeria nivea)')">ramie (Boehmeria nivea), inbred line clones, ISSR, genetic relationship