Study On The Ecology Of Endophytic Fungi In The Roots Of Lilium Davidii Var. Willmortiae

Arbuscular mycorrhizas (AM) are mutualistic associations that formed in about 80% of the terrestrial plants by the Glomeromycota which are obligately symbiotic fungi. Arbuscular mycorrhizas Fungi which have a wide distribution in a variety of terrestrial systems such as the farmland, forest, desert, barren soil and so on, play a very important role in promoting plant growth, nutrient uptake, ecosystem stability and vegetation restoration. Lanzhou lilies (Lilium davidii var. willmortiae) which is the best variety of the food lilies in our country have a number of problems in recent years, for instance mainly the weight of the lily decline, variety degradation, plant diseases and insect pests and so on. In this article, microscopic inspection of stained roots and PCR-DGGE technique were utilized to investigate the effects of organic and inorganic fertilizer and Benomyl on the biodiversity and community structure of arbuscular mycorrhizal fungi (AMF) in Lilium davidii var. willmortiae and then to explore the Symbiotic Relationship between arbuscular mycorrhizal fungi and Lilium davidii var. willmortiae. on the one hand there are provide theoretical foundation for biofertilizer that can enhanced growth of Lanzhou lily, on the other hand to investigate the effect of microbial factors of continuous cropping barrier of Lily from the symbiosis, expected to provide an effective way to solve the problem of continuous cropping barrier. The main results were abstracted as follows:1. The Lanzhou lilies (Lilium davidii var. willmortiae) have two major types of roots:Succulent root and Fiber root. They both form intimate symbiosis with arbuscular mycorrhizal fungi (AMF), dark septate endophyte (DSE) and the fine arbuscular mycorrhizal fungi (fine arbuscular fungal). Arbuscular mycorrhizal fungi (AMF) is mainly Paris-type, and also observed a small amount of Arum-type. The colonization rate of AMF in the frist year Lanzhou lilies was between 5-55%, and the AMF colonization rate in Succulent root was higher than Fiber root.2. The DSE colonization rate in Fiber root was higher than (that in) Succulent root, and the percent of DSE colonization is commonly under 15%, but the highest colonization rate is up to 45%, percent of DSE colonization were significantly correlated with the available P (AP) content of the soil but was positively negative correlated with soil pH.3. Soil spores of Lilium davidii var. willmortiae around the root was filtered by wet screening method and sucrose suspending method. Based on their exterior modality such as size, shape, color and whether had germination or not, the spores were differentiated into two genus and eight species were identified. these AMF species including:Gl. mosseae, Gl. geosporum, Gl.aggregatum, Gl. etunicatum, Gl. intraradices, Gl. sinuosum, Pa. franciscana, Gl.verruculosum and so on. There are still eight species need to be identified further.4. The AMF colonization rate of the first year lily shows different seasonal changes for different fertilizer treatments. For the plot without fertilizer treatment, the maximum colonization level of AMF hyphae, Vesicles and arbuscular are in August,and minimum level in May.5. We used PCR-DGGE method to estimate the molecular diversity of AMF in Lilium davidii var. willmortiae and found the AMF diversity was low in these experimental plots. Total of seven AMF species which belong to the genus of Glomus were detected in all samples. These AMF species including:Glo1,Glo2,Glo3,Glo4,Glo5, Gl. mosseae and Gl. intraradices. The dominant species of August is Glo2, and the dominant species of November is Gl. intraradices.6. Benomyl can significantly inhibited the growth and development of AMF but only reduced the colonization frequency of AMF, did not change the community structure of AMF. And benomyl did not significantly inhibit on DSE7. Through comparing to the physical and chemical indicators of high yielding and low-yielding fields,we can find out the content of organic matter, N and available K (AK)may be an important factor to the growth of Lily bulb.