ABSTRACT
OBJECTIVE@#The population density and diversity of Sinomenium acutum (Menispermaceae) have been greatly reduced recently by overharvesting for medicinal purposes in China. Therefore, it is urgent that the remaining populations are investigated, and that strategies for the utilization and conservation of this species are developed. This study aimed to find the possible glacial refugia and define the genetic diversity of S. acutum for its proper utilization and conservation.@*METHODS@#A total of 77 S. acutum samples were collected from four locations, Qinling Mountains, Daba Mountains, Dalou Mountains, and Xuefeng Mountains, in subtropical China. Genetic diversity among and between these populations were phylogenetically analyzed using four chloroplast DNA molecular markers (atpI-atpH, trnQ-5'rps16, trnH-psbA and trnL-trnF).@*RESULTS@#A total of 14 haplotypes (C1 to C14) were found in collected samples. Haplotypes C1 and C3 were shared among all populations, with C3 as the ancestral haplotype. Haplotypes C11 and C12 diverged the most from C3 and other haplotypes. No obvious phylogeographic structure was found in four locations using the GST/NST test. There is no evidence of rapid demographic expansion in S. acutum based on the mismatch distribution, and the results of Tajima's D test, and Fu's FS test. Our analyses of molecular variance revealed a high level of genetic variation within populations. In contrast, the genetic differentiation among S. acutum populations was low, indicating frequent gene flow.@*CONCLUSION@#Xuefeng, Dalou, and Daba Mountains were possible glacial refugia for the populations of S. acutum. C1, C3, C11 and C12 haplotypes of S. acutum should be carefully preserved and managed for their genetic value.
ABSTRACT
Wood elements and anatomical ratio of Dipterocarpus indicus were studied to evaluate variation among populations and to recommend for end selection. The variation of wood element [fibre length (FL), fibre diameter (FD), lumen diameter (LD), cell wall thickness (CWT), double wall thickness (DWT), and lumen volume (LV)] and anatomical ratio [fibre lumen area (FLA), slenderness ratio (SR) and runkel ratio (RR)] were investigated in a girth class of 100 - 120 cm among eight populations of Dipterocarpus indicus in Western Ghats, India. The study revealed a significant variations in FL (0.2426), FD (4.7019), LD (3.1689), CWT (2.7104), DWT and (5.4298) among populations. The variations in anatomical ratios were significant among populations except in case of LV. The causes of variations among populations in their wood traits were attributed to the site factors. The interaction between genetic makeup of wood traits combined with effects of edaphic, local and regional climatic conditions reflect the amount of variation among populations. The highest coefficient of variation (CV %) for FL, FD, CWT and DWT was recorded in population of Gundya whereas low coefficient of variation were recorded in the population of Makuta (FL), Devimane (FD, CWT and DWT), and Sampaje (LD). The wood of Dipterocarpus indicus was found undesirable for pulp wood but can be utilized for plywood timbers.