蓝莓菌根真菌的多样性及菌根形成的调控机制

Blueberry as a result of health care is becoming a popular new generation of fruit, and China's blueberry industry is in rapid development. Blueberry was belongs to species which are shallow root system, no hair root, in the natural conditions, blueberry roots often form a reciprocal symbiotic relationship with mycorrhizal fungi, which can promote the absorption of nutrients on blueberries, enhance growth potential, improve the root environment and enhance resistance to pests and diseases and so on. And in the absence of mycorrhizal symbiosis, the growth and development of blueberries have been greatly affected and even death. Therefore, mycorrhizal fungi research has become a hot spot on blueberry in recent years..In China, our understanding is not enough on the blueberry mycorrhizal fungi, especially we have more unknown status of the diversity and the artificial control mechanism of mycorrhizal fungi. We mainly rely on the natural way of inoculation of mycorrhizal fungi, root infection rate is low and slow, which seriously affect the growth of blueberry plants and industrial development. In this project, we’ll collect the resources of mycorrhizal fungi in the wild and to separate, purify and identify those species of blueberry mycorrhizal fungi, are ion, ion and inoculation which from, the aim was to find out the species diversity of blueberry mycorrhizal fungi in the southern of China. We used the experiment method of combined by laboratory control and seedling pot to screen out species of mycorrhizal fungi which could effectively infect the blueberry cultivars, and master the environmental factors of mycorrhizal fungi infection and the control mechanism of mycorrhizal formation, by study on the basic bio-ecological characteristics of different mycorrhizal fungi and their ecological adaptability under different environments such as temperature, humidity, cultivation substrate, pH, soil nutrient and its morphology, Which proposed production control measures to promote the healthy growth of blueberry plants. The results of the study can be supplemented and perfected in the field of blueberry mycorrhizal fungi.

蓝莓属于浅根系、无根毛植物，自然条件下常与菌根真菌形成互惠共生关系，能有效促进蓝莓对营养元素的吸收，增强生长势，改良根系环境以及增强对病虫害的抵抗能力。而在没有菌根共生的情况下，蓝莓的生长发育受到极大影响甚至死亡。菌根真菌已成为近年来蓝莓研究的一个热点。.我国对蓝莓菌根真菌的认识还比较粗浅，尤其是南方蓝莓菌根真菌的多样性和菌根形成的人工调控机制还存在较多未知状态，生产上育苗主要依靠自然接种，根系侵染率低、速度慢。本项目通过广泛收集蓝莓菌根真菌资源，经分离、纯化、鉴定，初步摸清南方蓝莓菌根真菌种类。采取实验室控制和苗木盆栽试验相结合的方法，筛选出能人工侵染的菌根真菌，研究其基本生物生态学特性，及其对温度、湿度、栽培基质、pH、土壤养分及其形态等不同环境的生态适应能力，掌握菌根真菌侵染的环境要素和菌根形成的调控机制，提出生产调控措施。研究结果理论上可为蓝莓菌根真菌相关领域研究进行补充和完善。

蓝莓根系没有根毛，需要通过形成菌根以帮助其吸收水分和营养物质，对菌根的依赖性高。本研究对贵州省及四川省部分地区蓝莓根系内生真菌多样性、真菌生物生态学特性和对环境的适应能力开展了研究，并通过回接，研究接种后蓝莓的菌根侵染特性、根际土微生物多样性、土壤酶活性、养分利用、抗逆性、果实产量和品质特性。结果表明：1. 蓝莓根系中真菌资源丰富，共分离获得1766 株内生真菌，分类鉴定属于4 个门45 个属。其中子囊菌门（Ascomycota）为优势门，毛壳属（Chaetomium）为优势属，其次为镰刀菌属（Fusarium）。2. 筛选出的9株菌根菌，大部分菌株适宜的温度为25-30℃、pH4.0-7.0，不适应甘露醇和果糖为碳源，以及无机氮源。3. 菌根真菌能够显著促进蓝莓植株生长。与对照相比，苗高增长45.69%-85.93%，地径增长41.42%-78.57%；根长与表面积均超过对照200%，根系平均直径提高15.90%-25.40%，根尖数是对照1.53-2.39 倍。4. 菌根真菌能够增加根际土真菌种群的多样性和细菌的种群数量。其中子囊菌中青霉属（Penicllium）、接合菌中被孢霉属（Mortierella）、担子菌中隐球菌属（Saitozyma）和双担菌属（Geminibasidium）是蓝莓根际土中的主要真菌类群。接种菌根菌还有助于其它ERM和DSE真菌在土中定殖。变形菌门、放线菌、酸杆菌门、厚壁菌门、拟杆菌门、芽单胞菌门是根际土中的优势度较高的细菌种群。5. 部分菌株能够显著提高根际土壤酶活性。其中，蔗糖酶活性提高8.19%-18.01%，脲酶为45.87%-116.06%，酸性磷酸酶为10.15%-20.61%，过氧化氢酶为8.26%-16.52%。6. 人工接种显著提高了蓝莓根系菌根侵染率，侵染等级达到4级以上。7. 菌根真菌能够显著提高蓝莓植株对矿质元素的吸收能力。叶片氮元素含量提升了8.30%-19.89%、钾元素提升17.04%-35.43%；叶片中叶绿素含量和植株抗逆性显著提高。8. 接种真菌提高蓝莓的单株产量幅度达27.07%-29.25%。可有效改善果实可溶性固形物、糖酸比、花青素等主要品质指标。综上所述，蓝莓根系菌根菌资源丰富，多样性较高，能有效促进蓝莓生长、提升产量和改善果实品质。研究结果为进一步理论研究及菌根菌在生产上的应用奠定基础。