[Objective] This study was to reveal the genetic diversity and genetic relationship of the kenaf(Hibiscus cannabinus L.) resources from different origins, thus providing basis for genetic improvement and molecular marker-assisted breeding of kenaf. [Method] Ninety one ISSR molecular markers were used for amplification on 44 shares of kenaf germplasm resources, of which 21 showing good diversity and clear bands were chosen for PCR amplification. Based on amplification results, the genetic similarity coefficients among kenaf germplasm resources were calculated by using analytic software NTSYSpc-2.10e, and phylogenetic tree was then established via UPGMA. [Result] Totally 169 bands were amplified using the 21 screened primers, averagely 8.05 bands were amplified from each primer. Of them, 141 bands were polymorphic, accounting for 83.4%. When genetic similarity coefficient 0.887 was used as criterion L1, these 44 shares of kenaf germplasm could be classified to be 32 shares of cultivars and 12 shares of wild type or half-wild type varieties. When genetic similarity coefficient 0.897 was used as criterion L2, these 32 shares of cultivars could be further grouped into four sub-clusters. The genetic diversities between cultivars and wild type or half-wild type varieties were between 0.46-0.91, showing huge hereditary difference; while that among 32 cultivars were between 0.85-0.97, suggesting that genetic relationships among cultivars are relatively close and their genetic similarities are rather narrow. [Conclusion] ISSR could well determine the genetic similarities among kenaf germplasm resources and provide valuable molecular information for selecting parents of hybrid cross, which can lay a good foundation for DNA mapping of kenaf germplasm resources.
To isolate the cDNA partial sequence of key enzyme gene GalAT for pectin biosynthesis in ramie [Boehmeria nivea （L.） Gaud], and thus to understand the expression of GalAT gene in different tissues of ramie, degenerate primer was designed according to GalAT conserved sequence in other species reported, and the cDNA sequence of GalAT gene from ramie variety Zhongzhu 1 was cloned by RT-PCR method based on the degenerate primer. The cDNA revealed a 986-bp in length which encoded 328 amino acids. The cDNA sequence and putative amino acid sequence of GalAT shared high identity with previously reported Arabidopsis thaliana GA UT4 （GalAT） as 77 and 83%, respectively. Molecular evolution analysis showed that the putative amino acid sequence and Arabidopsis thaliana GAUT4 gathered to a same group. Real-time quantitative PCR analysis showed that GalAT mRNA accumulated most abundantly in root, and GalAT transcripts in all kinds of ramie tissues in turn revealed as follows： root 〉 leaf〉 bast 〉 or ≈ xylem.
LIU Jian-xinYU Chun-mingTANG Shou-weiZHU Ai-guoWANG Yan-zhouZHU Si-yuanMA Xiong-fengXIONG He-ping
