OBJECTIVETo establish the seed quality grading standard of artificial tuber of Pinellia ternata.

METHODHundred-grain weight, moisture content, germination rate, viability, single-grain diameter, purity and visual form of mature artificial tuber seed from tissue culture of P. ternate were determined. The key indicator and reference indicators for artificial tubers quality grading were defined statistically by SPSS analysis.

RESULTGermination rate and viability were the primary indicators, hundred-grain weight, moisture content and purity were important reference indicators.

CONCLUSIONThe quality of each grade should reach the following requirements: for first grade, hundred-grain weight > 10 g, moisture content > 70%-80% , germination rate > 80%, viability > 85%, single-grain diameter > 0.7 cm, purity > 80%; for second grade, hundred-grain weight 8-10 g, moisture content > 70%-80%, germination rate 60%-80%, viability 70%-85%, single-grain diameter 0.3-0.7 cm, purity 75%-80%; moisture content > 70%-80%, and the others don't reach second grade was the third grade.

Germination ; Pinellia ; chemistry ; physiology ; Plant Tubers ; chemistry ; physiology ; Quality Control ; Seeds ; chemistry ; physiology

Objective::To explore the effect of strong light stress on the growth, physiological and biochemical and key enzyme gene expression of the Atractylodes lancea, in order to provide the scientific basis for the standardized cultivation of the A. lancea. Method::The two-year-old A. lancea seedlings were taken as experimental materials. Poplar forest (light transmittance between 18.26%-36.04%) was taken as control group(ck). Different density shading networks were used to simulate different degrees of high light stress (51.10%, 80.73%, 100%) in late July. The growth state of A. lancea was observed. On the 0^th, 5^th, 10^th, 15^th, 20^th days, the physiological and biochemical indexes of malondialdehyde (MDA) content, cell membrane permeability, proline (Pro) content, antioxidant enzyme activity and chlorophyll content in the leaves of A. lancea were measured. The relative expression levels of 3-hydroxy-3-methylglutarate monoacyl coenzyme A reductase (3-hydroxy-3-methylglutaryl coenzyme A, HMGR) and farnesyl pyrophosphate synthase gene (farnesyl pyrophosphate synthase, FPPS) in leaves of A. lancea under intense light stress were determined by real-time fluorescence quantitative PCR(Real-time PCR). Result::After strong light stress, the color of the leaves of A. lancea changed from dark green to light green and yellowish green, and the burn of leaves became more and more serious. The contents of MDA, conductivity and Pro showed an upward trend with the increase of transmittance. Peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) tended to increase first and then decrease. The chlorophyll content decreased with the increase of light transmittance. The relative expression of HMGR in leaves of A. lancea decreased with the increase of light transmittance, while FPPS increased first and then decreased. Conclusion::The results showed that A. lanceaa could alleviate the inhibition of strong light stress by increasing the activity of antioxidant enzymes and regulating the content of osmotic pressure under certain strong light stress. Excessively strong intensity light stress leads to disequilibrium of metabolic mechanism of A. lancea, and seriously inhibits the plant growth.