| Guizhou province is the genuine production area of Pinellia ternata, but the scarce wild resources & the degraded quality cultural resources can not meet the market demands. The past two years, it is becoming a hot spot that using AM fungi(Arbuscular mycorrhiza fungi) resources to improve the quality of Chinese medicines. Pinellia ternata can form AM, & AM fungi can obviously improve the growth of Pinellia ternata in a steriled conditions. Howerver, the studies were not reported which include dynamic formation of AM on tissue-cultured plantlets of Pinellia ternata, the symbiotic relationship between AM fungi & Pinellia ternata in the condition of three factors(phosphorus concentration in culture medium, other beneficial rhizosphere microorganisms & the water stress).Tissue-cultured plantlets & seedling by tuber propagation were used as host plant materials, Glomus mosseae was used as inoculating materilas in this experiment to study the infection progress of AM fungi. Efficiency of symbiosis between Pinellia ternata & AM fungi were operated under the condition of orthogonal test of three factors & levels. This study had some innovative & reality significance. The main results as following:1. MS medium supplemented with 6-BA 1.0 mg·L-1 & NAA 0.1 mg·L-1 was the best culture medium of one-step-seedling formation of Pinellia ternata. About 60 days culture, plants were regenerated directly from the young petiole explant, the plant regeneration rate was 62%.2. Formation progress of AM on tissue-cultured plantlets of Pinellia ternata was a dynamic progress, AM grows & developes of a dynamic "s" curve characteristic. The plantlet developed better under AM fungi inoculated than the non-colonised plantlet. It had more stomata, thick palisade tissue, thick sponge tissue, & the cells were tidy & tightly secondary tissue.3. The symbiont formation stage between AM fungi & Pinellia ternata reproduction by the tubers were:appressorium-like & entry point formed; both external & internal hyphae extended; AM developed; vesicles formed. Due to the reasons of temperature & material resilience, the infectional characteristic was that the appressorium-like were formed about one month after inoculated, compared to 10 days of tissue-cultured plantlets inoculated with AM fungi. With the P levels to 30 mg·kg-1 & 90 mg·kg-1, AM fungi infection was the best when double inoculated of EM. It illustrated that appropriate conditions of temperature & nutrients could promote AM fungal infection rate on Pinellia ternata.4. Microbial agent inoculated played a decisive role in Pinellia ternata growth & physiological activity, secondary inflenced factor was P treatment, & the water stress was the minimal impact. On the low P condition, at early stage of mature, single AM fungi inoculated could promote the growth & increase the contents of photosynthetic pigment & soluble sugar of Pinellia ternata leaf, enhance the activity of protective enzyme (SOD, POD) of Pinellia ternata leaf, while decreased the contents of soluble protein of leaf and contents of MDA. At stage of mature, double inoculation of AM fungi+EM enhance the activity of protective enzyme. With the low P levels, inoculated AM fungi could increase fresh weight & dry weight of Pinellia ternata tuber; double inoculation of AM fungi+EM treatment proved better effect on enhancing dry discount rate & propagation coefficient, increasing water extract contents, anedioic acid & alkaloid contents, while decreasing the water contents of Pinellia ternata tuber.With the low P levels (30mgP·kg-1,90mgP·kg-1), both inoculated single AM fungi & double inoculated AM fungi+EM could obviously enhanced N, P, K contents of Pinellia ternata tube, while obviously inhibited N, P, K uptake with the high P levels (270 mgP·kg-1). N, P, K contents had positive correlation with butanedioic acid contents, N, P contents had positive correlation with alkaloid contents while K contents had negative correlation with alkaloid contents of Pinellia ternata tuber.5. Cultivated Pinellia ternata had serious degradation problem, but AM fungi could improve Pinellia ternata growth & intrinsic quality obviously under the suitable P level, the suitable water level & other beneficial microbes interaction. At that levels, Pinellia ternata could formed the best symbiotic with AM fungi. When colonization enhanced, AM fungi can improve capability of absorbing water & nutrients such as N, P, K through taking part in many metabolism, then enhance stress resistence, improve Pinellia ternata growth, output & intrinsic quality. The study could be great value to Pinellia ternata when using of soil regime, fertilizer & microbial agents on the resolving degradation problem production. |
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