The genetic relation of four ethnic populations in China's Guizhou is revealed by sequence variations of mtDNA D-loop / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>Through maternal inheritance, to explore the genetic structures and relationships of Dong, Gelao, Tujia and Yi ethnic population in Guizhou of China.</p><p><b>METHODS</b>The mtDNA D-loop hypervariable segment I (HVS I ) in 108 samples of four ethnic populations were sequenced. Then, the nucleotide diversity was estimated and a phylogenetic tree was constructed by Neighbor-Joining method.</p><p><b>RESULTS</b>In the detected 497 bp fragments, 86 polymorphic sites were found, and 82 different haplotypes were identified. The phylogenetic tree of four ethnic populations showed: Yi, Tujia and Gelao clustered more closely than Dong did.</p><p><b>CONCLUSION</b>Yi and Tujia population are very closely related, the reason may be that they either originate from a common ancestry or frequently undergo the gene exchanges and admixtures. The genetic relationship between Tujia and Gelao population is nearer, perhaps because they have settled in the adjacent regions. Dong and Yi population show the farthest genetic relationship, this is probably due to their different historical origins and geographic segregation.</p>

Callus formation and its isoflavonoid accumulation in Maackia amurensis / 中国中药杂志

<p><b>OBJECTIVE</b>To obtain Maackia amurensis callus and investigate some factors influencing total isoflavonoid production in callus.</p><p><b>METHOD</b>Different media were used for callus induction from cotyledonary and hypocotyl explants. Total isoflavonoid content was determined by UV spectrophotometer.</p><p><b>RESULT</b>Medium types and hormone combinations influenced both callus formation and their developmental states. MS medium supplemented with NAA/BA or containing 2,4-D was suitable for callus induction from cotyledonary explants. Among the basal media tested, MS, N6 and B5 were suitable for cotyledonary callus formation and SH for hypocotyl callus formation. The formed callus could synthesize isoflavones. Media containing NAA were suitable for isoflavonoid production in cotyledonary callus and media containing 2,4-D/BA were suitable for hypocotyl callus, but 2,4-D/KT at high concentration inhibited the isoflavonoid accumulation in hypocotyl and coytledonary calli. According to the developmentally morphological characters, the formed callus could be classified into four types. II-type callus with yellow in color and friability in texture showed the highest accumulation of isoflavones.</p><p><b>CONCLUSION</b>The influences of medium type and hormone combinations on Maackia amurensis callus formation are reflected in both developmentally morphological characters and isoflavonoid accumulation of calli. Yellow, friable callus induced from cotyledonary and hypocotyl explants in MS or N6 medium supplemented with 2,4-D and BA exhibit the optimum growth and isoflavonoid production.</p>