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Moso bamboo (Phyllostachysheterocycla (Carr.) Mitford cv. Pubescens) is an economically valuable plant in bamboo production areas of southern China, for which the management mode is crucial for improving the comprehensive benefits of bamboo forest stands. In this respect, mixed forested areas of bamboo and broad-leaved tree species can provide sound ecological management of bamboo in forestry operations. To further this goal, an outstanding question is to better understand the spatial distribution of soil bacterial communities in relation to the proportion of mixed in bamboo and broad-leaved forest. We analyzed soil bacterial community diversity and composition along a proportional gradient of 0-40% mixed-ratio (as represented by the width and size of the broad-leaved tree crown over the plot area) of bamboo and broad-leaved forest in Tianbao Yan Nature Reserve using the highthroughputsequencing of the 16S rRNA gene.Specifically, the sampling plots for the mixed proportions were divided according to the percentage of summed projected area of live broadleaf tree crowns. The main broad-leaved species in the five mixed ratio plots are the same. Each plot was 20 m × 20 m in size, and a total of 15 plots were established, three per forest ratio class. From each plot, soil samples were taken at the surface (0-10 cm depth) in December 2017. Our analysis revealed that soil bacterial diversity community structure and dominant flora changed under different mixing ratios of bamboo and broad-leaved trees. In the stand with a mixed ratio of 10-20%, the bacterial diversity index is higher; however, the diversity was lowest in the 20-30% stands. Among the 20-30% forest soil, Acidobacteria (Solibacteria, Solibacteriales, Acidobacteriales) was more abundant than in soils from other mixed-ratio stands.Redundancy analysis showed that mixed forest stand structure, soil pH, organic carbon, total nitrogen, and soil moisture all contributed to shaping the bacterial community structure. Changes in microbial communities were associated with species diversity in tree layers, availability of soil nutrients (SOC and TN), and changes in soil physical properties (MS, pH). Together, these empirical results suggest that different mixing ratios in the bamboo-broad-leaved mixed forest could influence the soil bacterial community structure indirectly, specifically by affecting the soil physical and chemical properties of the forest.

Bambusapervariabilis × Dendrocalamopsisgrandis, a fast-growing and easily propagated bamboo species, has been extensively planted in the southern China, resulting in huge ecological benefits. In recent years, it was found that the pathogenic fungus Arthrinium phaeospermum caused the death of a large amount of bamboo. In this study, the transcriptome of B. pervariabilis × D. grandis, induced by inactivated protein AP-toxin from A. phaeospermum was sequenced and analyzed, to reveal the resistance mechanism induced by biotic agents of B. pervariabilis × D. grandis against A. phaeospermum at the gene level. Transcriptome sequencing was performed by Illumina HiSeq 2000 in order to analyze the differentially expressed genes (DEGs) of B. pervariabilis × D. grandis in response to different treatment conditions. In total, 201,875,606 clean reads were obtained, and the percentage of Q30 bases in each sample was more than 94.21%. There were 6398 DEGs in the D-J group (inoculation with a pathogenic spore suspension after three days of AP-toxin induction) compared to the S-J group (inoculation with a pathogenic spore suspension after inoculation of sterile water for three days) with 3297 up-regulated and 3101 down-regulated genes. For the D-S group (inoculation with sterile water after inoculation of AP-toxin for three days), there were 2032 DEGs in comparison to the S-S group (inoculation with sterile water only), with 1035 up-regulated genes and 997 down-regulated genes. These identified genes were mainly involved in lignin and phytoprotein synthesis, tetrapyrrole synthesis, redox reactions, photosynthesis, and other processes. The fluorescence quantitative results showed that 22 pairs of primer amplification products were up-regulated and 7 were down-regulated. The rate of similarity between these results and the sequencing results of the transcription group was 100%, which confirmed the authenticity of the transcriptome sequencing results. Redox proteins, phenylalanine ammonia lyase, and S-adenosine-L-methionine synthetase, among others, were highly expressed; these results may indicate the level of disease resistance of the bamboo. These results provide a foundation for the further exploration of resistance genes and their functions., (Copyright © 2019 Elsevier B.V. All rights reserved.)

A central aim of this microbial ecology research was to investigate the mechanisms shaping the assembly of soil microbial communities. Despite the importance of bacterial and fungal mediation of carbon cycling in forest ecosystems, knowledge concerning their distribution patterns and underlying mechanisms remains insufficient. Here, soils were sampled from six bamboo forests across the main planting area of Moso bamboo in southern China. The bacterial and fungal diversities were assessed by sequencing 16S rRNA and ITS gene amplicons, respectively, with an Illumina MiSeq. Based on structural equation modelling, dispersal limitation had strongest impact on bacterial beta diversity, while the mean annual precipitation had a smaller impact by directly or indirectly mediating the soil organic carbon density. However, only the mean annual temperature and precipitation played direct roles in fungal beta diversity. Moreover, the co-occurrence network analyses revealed a possibly much higher network connectivity in the fungal network than in the bacteria. With less dispersal limitation, stronger environmental selection and a potentially more connected network, the fungal community had more important roles in the soil carbon metabolisms in bamboo forests. Fungal beta diversity and the clustering coefficient explained approximately 14.4% and 6.1% of the variation in the carbon metabolic profiles among sites, respectively, but that of bacteria only explained approximately 1.7% and 1.8%, respectively. This study explored soil microbial spatial patterns along with the underlying mechanisms of dispersal limitation, selection and connectivity of ecological networks, thus providing novel insights into the study of the distinct functional traits of different microbial taxa., (© 2017 John Wiley & Sons Ltd.)

Dendrocalamus membranaceus Munro is a woody bamboo with a high economic and ecological value that often occurs as natural stands, such as in the large-scale forested areas of China's Yunnan Province. Due to its overexploitation, the habitat of D. membranaceus in Yunnan has been dramatically reduced, and the quality of the stands has declined. As a preliminary analysis in considering the effective protection for these germplasm resources, we assessed the genetic diversity of 12 natural populations in Yunnan, using inter-simple sequence repeat (ISSR) markers. From 10 ISSR primers, we generated 155 bands, of which 153 were polymorphic (98.71%). Compared with other species in the genus, this species demonstrated a greater genetic diversity (S = 0.349) and lower genetic differentiation (G(ST) = 0.252). Our analysis of molecular variance revealed that the genetic differentiation among the populations is significant. A large proportion of the genetic variation (78.95%) resides among the individuals within populations, whereas only 21.05% are found among populations. Mantel tests indicated no significant correlation between genetic and geographic distances among the populations. Given the low sexual reproducibility and characteristics of monocarpic plants, we recommend implementing in situ conservation measures for all of the D. membranaceus populations in Yunnan and collecting sufficient samples for ex situ conservation. Furthermore, the conservation area should be extended to its main natural habitats, the Lancang-Mekong River Valley.