Genetic diversity and population structure of a protected species: Polygala tenuifolia Willd.

Polygala tenuifolia Willd. is an important protected species used in traditional Chinese medicine. In the present study, amplified fragment length polymorphism (AFLP) markers were employed to characterize the genetic diversity in wild and cultivated P. tenuifolia populations. Twelve primer combinations of AFLP produced 310 unambiguous and repetitious bands. Among these bands, 261 (84.2%) were polymorphic. The genetic diversity was high at the species level: percentage of polymorphic loci (PPL)=84.2%, Nei's gene diversity (h)=0.3296 and Shannon's information index (I)=0.4822. Between the two populations, the genetic differentiation of 0.1250 was low and the gene flow was relatively high, at 3.4989. The wild population (PPL=81.9%, h=0.3154, I=0.4635) showed a higher genetic diversity level than the cultivated population (PPL=63.9%, h=0.2507, I=0.3688). The results suggest that the major factors threatening the persistence of P. tenuifolia resources are ecological and human factors rather than genetic. These results will assist with the design of conservation and management programs, such as in natural habitat conservation, setting the excavation time interval for resource regeneration and the substitution of cultivated for wild plants.

[Study on quality assessment of Polygalae Radix based on HPLC-DAD fingerprint].

OBJECTIVE: To establish an HPLC fingerprint to evaluate the quality of Polygalae Radix, root xylem, and those collected in different growth ages or harvest time. METHOD: Separation was performed at 30 °C on a Kromasil C18 column (4.6 mm x 250 mm, 5 µm); the mobile phases was acetonitrile and 0.05% H3PO4 water in the gradient elution; the flow rate was set at 1.0 mL · min(-1) and the detection wavelength at 314 nm; the quality discriminant analyses were accomplished by means of similarity analysis, cluster analysis, principal component analysis and neural network model. RESULT: In 26 batches of Polygalae Radix, 24 batches fingerprint similarities were above 0.8. In 5 different growth or harvest time batches, 4 batches were above 0.8; in 8 batches root xylem samples, the similarities were all above 0.875. The similarity analysis was in accord with the quality discriminant analysis of cluster analysis, principal component analysis and neural network model. CONCLUSION: Fingerprint combined with chemical pattern recognition technique can effectively evaluate the quality of Polygalae Radix. The active substance species are all similar in cultivated, wild, different growth or harvest time Polygalae Radix and polygala root xylem, but the chromatography peak areas are different. The effective material contents are similar between wild and cultivated Polygalae Radix, but each chromatographic peak area of the root xylem is much smaller than that of Polygalae Radix. The chemical substance accumulation mainly depends on harvest month, but little growth time in Polygalae Radix.

[Experimental report on cultivated density of Polygala tenuifolia].

OBJECTIVE: The proper cultivated density of P. tenuifolia was researched to improve cultural practices in producing region. METHOD: The experiment was determined by the randomized blocks design of three replications. RESULT: There is significance difference for the yield per mu in different cultivated density. CONCLUSION: The proper planted density is 20 cm x 3 cm, i. e. 111 thousand plants per mu.