Tobacco Tobacco Growing Areas Of Yunnan Dali Different Endogenous Flora And Its Dynamic Differences

Tobacco(Nicotiana tabacum) is a Solanaceae annual herb, about 60 species in total of Nicotiana have been reported in the world. As an economic crop tobacco plays an important role in Gross National Product, especially in Yunnan province. Facing the competitions and challenges from the domestic and international tobacco industry, how to improve the leaf quality of the tobacco has become a critical issue in Yunnan province. Previous studies of tobacco growth and leaf quality mainly focus on the outside ecological factors, while neglected the endophytic fungi in micro-ecological environment of tobacco tissue. During the past few years, the effect of tobacco endophytic fungi on leaf quality has got more and more attentions.In this paper endophytic fungi in tobacco leaves from Dali in Yunnan province was isolated and identified. The dynamic changes of tobacco leaf endophytic fungi along various growth stages and ecological environment were also studied and some conclusions were listed as below:1. In total 1586 endophytic fungi strains were isolated from five districts in Dali. Based on the method of Classical morphology and DNA sequences of ITS rDNA gene. All these strains were divided into 129 species and belonged to 31 genera,14 families. Dominant genus is Alternaria and Fusarium, along with 9 common abundant genus and 20 rare genus. The endophytic fungi exist through all the development stages of tobacco leaves were: Alternaria,Fusariumv,Xylaria,Chaetomium,Phoma and Nigrospora.2. Both the richness and diversity of endophytic fungi in tobacco leaves found increasing along with the develop stages.3. In Weishan county, the endophytic fungi population reached the most in mature stage but the least in rosette stage and squaring stage. While in Yunlong county, the endophytic population reached the most in squaring stage but the least in rosette stage.4. In Weishan county, endophytic fungi species in the upper leaves were the most in vigorous stage but the least in the squaring stage. While the lower leaves were the most in mature stage but the least in rosette stage. In Yunlong county, the endophytic fungi species in the upper leaves reach the most in mature stage but the least in the rosette stage, while the lower leaves were reaching the most in squaring stage and the least in the rosette stage. 5.In consideration of various altitudes, either number of species, richness and diversity index don't have any significant difference. Both the number of species and diversity of endophytic fungi are negative correlated with longitude,but positively correlated with latitude.