Studies On Related Enzymes Of Lignin Synthesis And RAPD Analysis In Ramie (Boehmeria Nivea L)

In this research, six ramie varieties, varied in lignin content, were tested to determine the content of lignin in the fiber and PAL , CAD , POD activity in the leaves for studying lignin synthesis and dynamic change of relevant enzymes. Furthermore, genetic differences were revealed through random amplified polymorphic DNA(RAPD). The results are as follows:(1) Lignin content is different each other among the tested varieties. There are no differences in content of lignin between varied crops in the same variety. Lignin content is increasing with the development of ramie plant. And it was also affected by culture condition and harvest period.(2) PAL, CAD, POD aclivity peak appeared in fiber maturity period. Theirs activities rapidly increased at the fast growing stage of ramie, then decreased at the end of the fiber maturity period. The activities of PAL and CAD showed to be cynchronous. The changes of activities of PAL CAD and POD were consistent with lignin content. It indicated that CAD may be regarded as marker-enzyme of lignin synthesis.(3) An optional reaction system suitable for the assay and usage of RAPD in Ramie was established. It contained 40~50ng genomic DNA, Mg2+2.0mmol/l, dNTP 0.2mmol/l, decamer random primers 0.2umol/l, Taq DNA polymerase 1U in total volume of 25 ul. The reaction program was devised for 40 cycles ,each with 50s 94℃ denature,50s 37℃ annealing, 90s at 72℃ extension, and 3 min 94℃ perdenature in the former denature and 6min 72℃ postextension in the final extension. The program with fine reproductionable and high reliability was effectively used for RAPD analysis in the program of ramie genetics and breeding. Genomic DNA of 21 accessions of Ramie was amplified by RAPD from 150 arbitrary 10 decamer primers. The results showed that 15 primers producedreproducible amplified products and the band numbers of products varied 2-10 bands. All 85 bands were identified, of which, 17 bands were common in all varieties and 68 bands were polymorphic. The polymorphic bands accounts for 80% of the total amplified bands. Analysizing ploygenelic relationship through cluster of band of 85 amplified loci, the experimented accession could be divided among 3 types and 8 groups. 'Xiang Tan Da Ye Bai', 'Xiang Zhu Yi Hao' and 'Da Yong Qing Ke Ma' belonged to the same type, 'Yi Zhang Ya Ma' and 'Xiang Zhu San Hao' belonged to another type, while 'Wu Gang Hou Pi Zhong' belonged to a type alone. Genetic distance of 'Da Yong Qing Ke Ma' and 'Wu Gang Hou Pi Zhong' was 0.3956 as the longest, while genetic distance of 'Da Yong Qing Ke Ma' and 'Xiang Tan Da Ye Bai' was 0.1178 as the shortest in 6 varieties above-mentioned.