Effects of leaf removal on growth and physiological characteristics of Rehmannia glutinosa / 中国中药杂志

Effects of the leaf-clipped treatment on growth and physiological properties of Rehmannia glutinosa were studied. Result showed that with the increase of the cutting leaves degree, growth rates of shoots and roots were decreased, sugar contents declined, chlorophyll contents decreased and root activities also inhibited. Compared with the normal plant (CK), the root inhibit rates in T1, T2, T3 were 17.53%, 33.41%, 59.47%, respectively. Physiological indexes including chlorophyll contents, root activities and sugar contents also were impacted by the leaf-clipped treatment. The results indicate that to balance source-sink relationship is a very essential method for improving production of R. glutinosa.

Construction and analysis of suppression subtractive cDNA libraries of continuous monoculture Rehmannia glutinosa / 中国中药杂志

<p><b>OBJECTIVE</b>To explore the molecular mechanism of continuous monoculture problem by constructing the cDNA libraries of continuous monoculture Rehmannia glutinosa.</p><p><b>METHOD</b>To use the suppression subtractive hybridization (SSH) technique to construct the forward and reverse subtractive cDNA libraries of continuous monoculture R. glutinosa to adopt blue-white colony screening and PCR to detect the positive clones which would be sequenced and analyzed by bioinformatics.</p><p><b>RESULT</b>The subtracted cDNA libraries of continuous monoculture R. glutinosa. were successfully constructed, and the result showed that the forward and reverse subtracted libraries obtained 300 positive clones, respectively. The forward and reverse libraries got different ESTs, and produced 232 (forward library) and 214 (reverse library) unique ESTs by sequencing. Based on homology search of BLASTX and BLASTN in NCBI, 200 and 195 of unique ESTs were homologous to known genes in the forward and reverse libraries, respectively. Categories of orthologous group (COG) showed that the forward and reverse libraries got 60 and 61 ESTs with the corresponding gene annotation, involving 21 metabolic pathways.</p><p><b>CONCLUSION</b>The information of differential expression genes in continuous monoculture R. glutinosa, and their functional annotation of differentially expressed genes indicate that continuous monoculture has a profound effect on expression of the genes in R. glutinosa. Furthermore, the research analyzed several key genes in response to replant problem, which provided a foundation for revealing the molecular mechanism of continuous monoculture R. glutinosa.</p>

Research on abatement measures of allelopathic autotoxicity of Rehmannia glutinosa / 中国中药杂志

<p><b>OBJECTIVE</b>To explore effects on allelopathic autotoxicity of Rehmannia glutinosa of different abatement measures.</p><p><b>METHOD</b>The experiments for abating allelopathic effects of R. glutinosa were designed with the reducing rate as a indication, three measures of the treating soil with lime nitrogen, and water washing were employed, R. glutinosa- Achyranthes bidentata rotation system and using Achyranthes bidentata as green manure, and seedling transplant were also studied for the abatement effect.</p><p><b>RESULT</b>Effect of seedling transplant was the best, reducing rate of transplant and bare root transplant on the 20th day after emergence was 76.80%, 71.70%, respectively. The reducing rate of the treating soil with microorganism reached 54.25%. The effects of water washing and R. glutinosa-A. bidentata rotation system and using A. bidentata as green manure were not satisfied. Especially only using A. bidentata as green manure without rotation system worsened the allelopathic effects of R. glutinosa.</p><p><b>CONCLUSION</b>All measures can abate allelopathic effects of R. glutinosa to some extent except only using A. bidentata as green manure.</p>

Responses of physiological ecology and quality evaluation of Rehmannia gltinosa in continuous cropping / 中国中药杂志

<p><b>OBJECTIVE</b>To study responses of physiological ecology and quality evaluation of Rehmannia glutinosa in continuous cropping.</p><p><b>METHOD</b>The potted plant R. glutinosa which consists of first cropping, 1 year continuous cropping and 2 year continuous cropping were used as experimental materials. The photosynthetic activity, descending axis vitality, the protective enzymes system and MDA content were measured, the quality was evaluated by FTIR and HPLC.</p><p><b>RESULT</b>Continuous cropping reduced the content of chlorophyll in the non-first cropping R. glutinos, the photosynthetic activity and descending axis vitality were weakened. Because of the increase of the free radical in the R. glutinos due to the continuous cropping, the activity of protective enzymes including POD, SOD and CAT were enhanced and MDA content were increased, more importantly the medical potency declined . And along with the increasing years of the continuous cropping, this effect becomes even stronger.</p><p><b>CONCLUSION</b>Continuous cropping affects the descending axis ability of absorbing water and nutrition and photosynthesis are inhibited R. glutinosa, at the same time, it also causes the disorders of antioxidation systems in R. glutinos, resulting in continuous cropping obstacle and decline of the medicinal materials quality.</p>