Search

Key message Geography and tree diameter were the major factors in determining oleoresin yield in Sindora glabra. The tangential diameter and area of secretory canals are reliable indicators of the oleoresin amount. Abstract Sindora glabra is a native tropical plant of China that exudes copious amounts of oleoresin from wounds on the stem. Elucidation of the mechanism affecting the oleoresin yield is of particular importance for development and selection of superior germplasm. In this study, the variation in oleoresin yield and anatomical traits of the stem of S. glabra were investigated in four main natural populations in Hainan. The results showed that annual oleoresin yield varied considerably among populations. The oleoresin yield exhibited an increasing trend with the increment of tree stem diameter until the diameter was over 80 cm. Moreover, oleoresin production in the wet season was higher than in dry season. The analysis of oleoresin chemical composition indicated that the four populations belong to the same chemotype despite the amount of four types of sesquiterpenes varying greatly among areas. Anatomical analysis revealed that quantitative traits of secretory canals including tangential diameter, area, density and frequency were significantly different among populations and tree diameters. Furthermore, the tangential diameter and area of secretory canals were positively correlated with oleoresin yield. These results suggested that the tangential diameter and area of secretory canals are reliable indicators of the oleoresin amount and can be used for selection purposes in S. glabra.

Sindora glabra, one of the second-class national protective plants in China, has important ecological and commercial values. To understand the genetic diversity and structure of S. glabra, eleven natural populations from four areas of Hainan Island in China were analyzed by inter-simple sequence repeat (ISSR) markers. Thirteen primers were screened out and used to amplify 157 DNA samples. A total of 122 bands were obtained, among which 114 (93.4%) bands were polymorphic. Genetic parameters including average number of effective alleles (1.547), Nei's gene diversity (0.321), Shannon's information index (0.482), and gene differentiation coefficient (0.1944) revealed a high level of genetic diversity maintained in S. glabra populations. The variation within populations accounted for 85.6% of total variation based on analysis of molecular variance. Genetic distance analysis showed that 11 populations could be divided into three groups and populations from the same areas were classified as one group, suggesting that high genetic diversity of S. glabra was attributable to geographic isolation. Together, introduction of germplasm from distant natural distribution areas would be a sound strategy for germplasm resource conservation of S. glabra and selection of elite individuals from populations of far relationship for hybridization is of great importance for breeding improvement programs in future.

Aluminous rocks from Xiuwen County, Guizhou are the main raw materials, mixed some kaolin mineral. Water glass and alkaline activators are used to product polymer materials, the main experimental indicators are the compressive strength. Here, the studies on amount of water glass and alkaline activator, solid-liquid ratio, amount of kaolin and effects on compressive strength of Geopolymer have been proceeded respectively. The result shows that: the highest compressive strength of geopolymers is17.94 Mpa, with aluminous rock 40g, solid-liquid ratio 2.2, water glass12g and alkali activator 2.01g, as well as kaolin 18.02g.