| To separat and determine the contents of puerarin, daidzin and daidzein in the stems and the leaves of Puerariae lobata (Willd.)Ohwi and Pueraria thomsonii Behth., and to provide scientific basis for developing and using of the stems and the leaves. A RP- HPLC method was applied with a Diamonsil?C18 column (150 mm×4.6 mm, 5μm) by gradient elution using methanol-1% glacial acetic acid solution as the mobil phase. The flow rate was 1 mL·min-1 and the detective wavelength was 250 nm, the column temperature was 25℃. All of the three compounds showed good linearities(r>0.999 5) and the recoveries were in the range of 99.0%~101.6%. The contents of puerarin , daidzin and daidzein in the stems are higher than those in the leaves . The method was accurate and could be used to contral the quality of the stems and leaves of P. thomsonii.The physicochemical characteristics including chemical composition, morphological, crystal, pasting, thermal, and retrogradation properties of Radix Puerariae lobata (RPl) starche and Radix Puerariae thomsoniiare (RPt) starche were investigated. The starch content in the whole powder of RPt was 62.9%, much higher than that of the whole powder of RPl (51.3%). The surface of the two starch granules appeared to be smooth without evidence of cracks. Most of the RPt starch had irregularly polygonal shapes, with a diameter of 2–18μm, whereas the RPl starch had oval- and polygonal-shaped granules, with a granule size ranging from 2-10μm. Total protein, lipid, crude fiber and ash contents in RPt starch were lower than those of RPl starch. RPt starch presented an apparent amylose content of 34.7%, higher than that of RPl starch (33.2%). X-ray diffraction patterns of RPt and RPl starch were CA-type and CB-type, respectively. Both RPl and RPt starch pastes behaved as high shear-thinning liquids. RPt starch pastes had higher apparent viscosity than RPl starch pastes at the same shear rate. The RVA pasting properties of RPt starch were different from those of RPl starch, with pasting temperature of 74.3℃, higher than that of RPl starch (62.9℃). The gelatinization parameters of RPt starch were found to be 64.9℃(To), 74.7℃(Tp), 85.2℃(Tc) and 10.3 J/g (ΔH), while those of RPl starch were 60.3℃, 63.8℃, 69.6℃and 11.2 J/g. RPt starch displayed a higher retrogradation rate (20.3%) than that of RPl starch (13.3%) after storage at 4℃for seven days.Relationship between photosynthetic characteristics and environmental factors in leaves of P. Lobata were studied. The result provided scientific basis for high yield in planting. Photosynthetic characteristics and environmental factors in leaves of P. Lobata were measured using CIRAS-2 portable photosynthesis systerm. The relationship between photosynthetic characteristics and environmental factors were analyzed by correlation analysis. The net photosynthetic rate was in the range of 7.5-10.8μmol·m-2·s-1 in un-folding leaves of P. Lobata. The results also demonstrated that the net photosynthetic rate was largely affected by the concentration of the CO2 while the CO2 concentration was below 1600μmol·m-2·s-1. The photosynthetic capacity the apparent quantum yield in leaves of P. Lobata was 0.0173μmol CO2·μmol-1photon . The dark respiration rate was 2.9333μmol·m-2·s-1. Light compensation point of photosynthesis of P. Lobata in un-folding leaves was 180μmol·m-2·s-1. Light saturation point was 1600μmol·m-2·s-1. The carboxylation efficiency in leaves of P. Lobata was 0.0338μmol·m-2·s-1. The light respiration rate was 2.5μmol·m-2·s-1. The CO2 compensation point of photosynthesis of P. Lobata in un-folding leaves was 100μmol·mol-1. The CO2 saturation point was 1600μmol·mol-1. Photo flux density and air temperature are major environmental factors influencing diumal changes of net photosynthetic rate, Light compensation point of photosynthesis of P. Lobata is lower, but Light saturation point is higher. P. Lobata is adaptable widely to photo flux density and is a typical heliophyte. |
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