Climate Variations in the Low-Latitude Plateau Contribute to Different Sugarcane (Saccharum spp.) Yields and Sugar Contents in China.

In China, the main sugarcane (Saccharum spp.) planting areas can be found in the low-latitude plateau (21° N-25° N, 97° E-106° E), which has most of the natural ecological types. However, there is limited information on the climate conditions of this region and their influence on sugarcane yield and sucrose content. Monthly variations in the main climate factors, namely, average air temperature (AAT), average relative humidity (ARH), average rainfall amount (ARA), and average sunshine duration (ASD), from 2000 to 2019 and sugarcane yield and sucrose content of 26 major sugarcane-producing areas from 2001/2002 to 2018/2019 were collected from the low-latitude plateau in Yunnan for studying the impact of climate variations on sugarcane yield and sucrose content. The results showed that AAT in the mid-growth season had a significant positive correlation with sucrose content (p < 0.05), and AAT in the late-growth season had a very significant positive correlation with sucrose content (p < 0.01). ARH in the mid-growth season had a significant positive correlation with sugarcane yield (p < 0.05). ARA in the early-growth season showed a significant positive correlation with sugarcane yield (p < 0.05). ASD in the late-growth season had a significant positive correlation with sugarcane yield (p < 0.05) and sucrose content (p < 0.01). The rainy and humid sugarcane areas were characterized by high ARA and ARH during the entire growth period, low AAT and ASD in the mid-growth season, and low AAT in the late-growth season, contributing to a high sugarcane yield, but not a high sucrose content. The low temperature and sunshine semi-humid sugarcane areas were characterized by the lowest AAT in the early and middle stages of sugarcane growth, less ASD in the early and middle stages, and less ARA in the early and late stages, which are unfavorable for sugarcane yield and sucrose content. The high temperature and humidity sugarcane areas were characterized by higher AAT and ARA, and moderate ASD during the entire growth period, resulting in good sugarcane growth potential and contributing to the sugarcane yield and sucrose content. The semi-humid and multi-sunshine sugarcane areas were characterized by the lowest ARH in the entire growth period, the lowest ARA in the middle and late seasons, and the longest ASD, contributing to an increase in sucrose content. The humid and sunny areas were characterized by the longest ASD and high ARH in the early and late seasons of sugarcane growth and moderate AAT and ARA during the entire growth season, which are beneficial for high sugarcane yield and sucrose content. Overall, these findings suggest that the sugarcane variety layout should be based on the climate type (of which there are five in the plateau), and corresponding cultivation practices should be used to compensate for the climatic conditions in various growth stages.

[Effects of Different Planting Years of Dendrocalamus brandisii on Soil Fungal Community].

To explore the effect of soil fungal community under different planting years in Dendrocalamus brandisii, the soil samples from D. brandisii with different planting years (5, 10, 20, and 40 a) were taken as the research object. The soil fungal community structure, diversity, and its functional groups of different planting years were analyzed using high-throughput sequencing technology and the FUNGuild fungal function prediction tool, and the main soil environmental factors influencing the variations in soil fungal community were examined. The results showed that the dominant fungal communities at the phylum level were Ascomycota, Basidiomycota, Mortierellomycota, and Mucoromycota. The relative abundance of Mortierellomycota decreased and then increased with the increase in planting years, and there was a significant difference among different planting years (P<0.05). The dominant fungal communities at the class level were Sordariomycetes, Agaricomycetes, Eurotiomycetes, and Mortierellomycetes. The relative abundance of Sordariomycetes and Dothideomycetes decreased and then increased with the increase in planting years, and there were significant differences among different planting years (P<0.01). The Richness index and Shannon index of soil fungi increased and then decreased with the increase in planting years, and the Richness index and Shannon index in 10 a were significantly higher than those of other planting years. Non-metric multidimensional scaling (NMDS) and analysis of similarities (ANOSIM) showed that there were significant differences in soil fungal community structure with different planting years. The functional prediction with FUNGuild showed that the main functional trophic types of soil fungi in D. brandisii were pathotroph, symbiotroph, and saprotroph, and the most dominant functional group was endophyte-litter saprotroph-soil saprotroph-undefined saprotroph. The relative abundance of endophytes gradually increased with the increase in planting years. Correlation analysis showed that pH, total potassium (TK), and nitrate nitrogen (NO-3-N) were the main soil environmental factors affecting the change in fungal community. In summary, the planting year of D. brandisii has changed soil environmental factors and has thus changed the structure, diversity, and functional groups of soil fungal communities.

[Effects of plant community and soil properties on soil bacterial community in Bitahai Wetland, Southwest China]. / 植物群落和土壤理化性质对碧塔海湿地土壤细菌群落的影响.

Soil microorganism was the engine of the migration and transformation of biological elements in the soil-plant system of wetland ecosystems. Exploring the relationship between plant community, soil properties, and spatial structure with soil microorganisms is the key to maintain the health and stability of wetlands. In order to examine the effects of plant community, soil properties, and spatial structure on the bacterial community in wetlands, we used two-way indicator species analysis (TWINSPAN) to classify plant communities from 35 samples collected in Bitahai Wetland. We measured microbial community composition at the surface soil of the samples using high-throughput sequencing technology, and analyzed the relationship among plant community, soil pro-perties and spatial structure with bacterial community. The results showed that plant communities could classified into three different types by TWINSPAN. The physiognomy and structure of plant communities in same community type were relatively consistent. We found that quantitative classification had good applicability in vegetation classification of plateau wetland ecosystem. Acidobacteriota (21.0%), Chloroflexi (15.5%), Proteobacteria (15.3%) and Bacteroidetes (10.1%) had higher population densities (≥10%) in Bitahai Wetland. Analysis of similarities (ANOSIM) showed that different plant community types differed significantly in bacterial community composition, suggesting that plant communities could affect bacterial community. Cano-nical correspondence analysis (CCA) results showed that plant diversity, soil water content (SWC), pH, iron (Fe) and spatial structure were the dominated factors that significantly affecting bacterial community. The variance partitioning analysis (VPA) results showed that bacterial community was affected by single environment factors and their interactions. Our results highlighted that bacterial community is shaped by plant community, soil properties and spatial structure, with their effects being indivisible.

DNA barcoding and molecular phylogeny of Dumasia (Fabaceae: Phaseoleae) reveals a cryptic lineage.

Dumasia taxonomy and classification have long been problematic. Species within this genus have few morphological differences and plants without flowers or fruits are difficult to accurately identify. In this study, we evaluated the ability of six DNA barcoding sequences, one nuclear (ITS) and five chloroplast regions (trnH-psbA, matK, rbcL, trnL-trnF, psbB-psbF), to efficiently identify Dumasia species. Most single markers or their combinations identify obvious barcoding gaps between intraspecific and interspecific genetic variation. Most combined analyses including ITS showed good species resolution and identification efficiency. We therefore suggest that ITS alone or a combination of ITS with any cpDNA marker are most suitable for DNA barcoding of Dumasia. The phylogenetic analyses clearly indicated that Dumasia yunnanensis is not monophyletic and is separated as two independent branches, which may result from cryptic differentiation. Our results demonstrate that molecular data can deepen the comprehension of taxonomy of Dumasia and provide an efficient approach for identification of the species.

[Knocking down TRPC1 expression by siRNA inhibits proliferation and invasiveness of human lung adenocarcinoma cell A549 in vitro].

OBJECTIVE: To evaluate the effects of down-regulated expression of transient receptor potential canonical (TRPC1) by RNA interference (RNAi) on proliferation and invasiveness of human lung adenocarcinoma cell A549 in vitro. METHODS: A549 cells were transfected with chemically synthesized small interfering RNA (siRNA) targeting TRPC1 gene. The mRNA and protein of TRPC1 were analyzed by real-time polymerase chain reaction (PCR) and Western blot respectively. To assess malignant phenotypes of transfected A549 cells, the assays of methyl thiazolyl tetrazolium (MTT), cell cycle and cell invasion were performed. RESULTS: siRNA targeting TRPC1 dramatically suppressed TRPC1 expression. In vitro study showed that siRNA targeting TRPC1 significantly inhibited cell proliferation of A549 cells with an inhibitory rate of 34.7% while negative control siRNA had no effect on cell proliferation. Flow cytometric analysis showed that siRNA targeting TRPC1 increased the number of cells in G0/G1 phase (P < 0.05) . Moreover, a knockdown of TRPC1 expression effectively inhibited cell invasiveness in A549 cells (P < 0.05) . CONCLUSION: Knocking down TRPC1 expression can inhibit proliferation and invasiveness of A549 cells in vitro.