| To explore the correlation of among leaf morphological characteristics,photosynthetic characteristics,leaf endophyte community and leaf essential oil accumulation characteristics of camphor tree(Cinnamomum camphora [Linn.] Presl.),the leaf morphology and photosynthetic characteristics of C.camphora CT.citral and C.camphora CT.linalool were determined respectively,and the leaf essential oil was extracted by steam distillation,and the chemical composition of essential oil was analyzed by GC-MS method.The community composition of leaf endophytic fungi and leaf endophytic bacteria was analyzed by high throughput sequencing technique.The specific results are as follows:(1)The yield of essential oil from C.camphora CT.citral leaves was the highest in August,which was 1.05 ±0.35%,and the relative content of principal components reached the highest in August,which was 53.16%.The yield of essential oil from leaves of C.camphora CT.linalool was the highest in September,2.47 ±0.24%,while the relative content of principal components was 97.47% in November,and reached more than 90% in June-December.(2)There was no significant difference in leaf area,perimeter,leaf length and leaf width between the two chemotypes of C.camphora.With the change of seasons,the leaf area showed an increasing trend.The growth was vigorous in spring and summer,but slow in winter.The growth rate of leaf length was higher than that of leaf width.(3)The annual variation of photosynthesis of the two chemotypes of C.camphora increased gradually from May to July,reached the peak from August to September,and then decreased rapidly,but the peak appeared in different months,and the highest value of C.camphora CT.citral appeared in August.The highest value of C.camphora CT.linalool appeared in September.(4)1468 endophytic fungi OTU,of C.camphora leaves were found to belong to 470 genera and 7 phyla.2265 OTU,of bacteria in C.camphora leaves were obtained,belonging to 886 genera and 36 phyla.The endophytic fungal community of C.camphora leaves is mainly composed of unclassified＿p＿Ascomycota,Dothideomycetes,Eurotiomycetes and Cystobasidiomycetes.The endophytic bacterial community of C.camphora leaves is mainly composed of Proteobacteria,Actinobacteria,Firmicutes and Bacteroidota.It was determined that the core OTU,of 21 leaf fungi belonged to 18 genera,among which Dothideomycetes was the dominant endophytic fungus,and 29 leaf endophytic bacteria core OTU,belonged to 22 genera,among which Proteobacteria was the dominant endophytic bacteria in C.camphora leaves.(5)The essential oil yield of the two chemotypes of C.camphora leaves was significantly correlated with the distribution of intra-leaf fungi and bacterial communities,and the leaf essential oil yield was significantly positively correlated with Epicoleosporium in intra-leaf fungi and Massilia in leaf bacteria.However,the correlation between the yield of essential oil and leaf morphology and photosynthetic physiology of the two chemotypes of C.camphora was different.The leaf morphology and chlorophyll an of C.camphora CT.citral were significantly positively correlated with the yield of essential oil.The content of chlorophyll an in the leaves of C.camphora CT.linalool was positively correlated with the yield of essential oil.There was a significant positive correlation between the relative content of essential oil and transpiration rate of C.camphora CT.linalool leaves.The results showed that there were significant differences in essential oil yield,relative content of essential oil principal components and photosynthesis between C.camphora CT.citral and C.camphora CT.linalool leaves.Correlation analysis showed that the yield of essential oil from C.camphora leaves was significantly correlated with intra-leaf fungi and bacterial community structure,which proved that there was an interaction between microbial community and essential oil in camphor leaves,while different chemotypes of C.camphora leaves had different correlations with leaf morphology and photosynthetic physiology. |
