[Investigation of elemental concentration and extraction rate of polysaccharides from Liuwei Dihuang prescription" by ICP-MS].

A method was established for the simultaneous analysis of 25 trace elements and heavy metals in polysccharides from Liuwei Dihuang prescription, including Li, Be, B, Ti, Mg, Al, V, Cr, Mn, Co, Fe, Ni, Cu, Zn, Ga, As, Sr, Cd, Sn, Sb, Ba, Hg, Tl, Pb, Bi. The different rate of elemental extraction in Al, Fe, Mg, B, Ti, Mn, Zn, Sr, Ba was made in water and different concentration of alcohol. The samples, digested via microwave, calibrated by internal standard elements such as Ge and In, with bush branches and leaves as the controlled reference standard, were inlet into ICP-MS to analyze the contents of the 24 trace elements and heavy metals. The detection limits of the 24 elements were in the range of 0.007-2.225 µg · L(-1), while the RSD was below ≤ 4. 0%, with their recovery ranging from 84. 1% to 116%. Big different of the elemental extraction rates could be found by using different ethanol solutions. The method is simple, rapid and accurate, and can be used for the quality control of trace elements and heavy metals in Liuwei Dihuang polysccharides. With the aid of the obtained result, we may increase the extraction of necessary element while making an attempt at multi-element speciation in polysccharides from Liuwei Dihuang.

Insecticide-induced changes in protein, RNA, and DNA contents in ovary and fat body of female Nilaparvata lugens (Hemiptera: Delphacidae).

The widespread use of insecticides is known to cause resurgence in Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) populations, a serious insect pest of rice, Orzya sativa L., crops in Asia. The current study investigated insecticide-induced changes in protein, RNA, and DNA levels in the ovary and fat body of adult female N. lugens. Potted rice plants were sprayed with different concentrations of imidacloprid, triazophos, and detamethrin. The results showed that all three insecticides caused a significant increase in protein and RNA contents in the ovary and fat body of adult females developed from nymphs fed on treated plants compared with those from on untreated plants, although there was no significant effect on DNA content. In general, protein and RNA contents in both ovary and fat body increased linearly with insecticide concentrations or days after emergence (DAEs) when they were applied. There was a significant correlation between protein content and RNA content in both ovary and fat body. In addition, the relationship between ratios of RNA to protein in ovary and fat body of adult female N. lugens and insecticide concentrations showed a significant positive correlation for most DAEs of imidacloprid and several DAEs of triazophos and deltamethrin treatments. These findings suggest that RNA in both ovary and fat body was more sensitive to insecticides and that the insecticide-induced changes in RNA content in turn influence protein synthesis in ovary and fat body. Consistently, RNA-to-protein ratios in ovary and fat body were approximately 0.42 in all treatments and controls.

Cultivar and insecticide applications affect the physiological development of the brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae).

Nilaparvata lugens (Stål) (Hemiptera:Delphacidae) is a serious migratory pest of rice in Asia. Pest resurgence often occurs because of insecticide overuse. Using both susceptible (TN1) and moderately resistant (Xieyou 963) cultivars, we studied the effect of foliar insecticides on the percentage of brachypterous adults, female reproductive rate, and crude fat and soluble sugar contents in third- and fifth-instar nymphs and adults. The percentage of brachypterous adults and reproductive rate of adult females developed from nymphs that fed on insecticide-treated plants varied significantly with rice cultivar, type of insecticide, and its concentration. Feeding on susceptible plants increased the percentage of brachypterous adults and reproductive rate of adult females. Also, deltamethrin increased brachypterous production relative to imidacloprid and triazophos. The highest reproductive rate was on plants treated with triazophos. All insecticide treatments in both cultivars resulted in increase of soluble sugar contents in third- and fifth-instar nymphs and adults developed from nymphs feeding on insecticide-treated rice plants. This effect was stronger on the susceptible cultivar. Changes of crude fat content after N. lugens feeding on insecticide-treated plants were related to its feeding duration. Crude fat content in adult developed from nymphs feeding on treated plants was significantly higher that on control plants. These studies showed that plant and insecticide influences on physiological ecology of this planthopper will influence its population dynamics under commercial production of rice in Asia.