Effects of Ambient Temperature and Available Sugar on Bacterial Community of \u3cem\u3ePennisetum sinese\u3c/em\u3e Leaf: An \u3cem\u3ein vitro\u3c/em\u3e Study

The present in vitro study investigated the effects of temperature and available sugar on the bacterial community of Pennisetum sinese leaf during fermentation. P. sinese leaves were cultured in MRS broth containing 0.4 and 1.6 g sugar and incubated at 25°C and 45°C for 9, 18, and 36 h. The results showed that the dominant phyla during sugar fermentation were Firmicutes, followed by Proteobacteria and Bacteroidetes. Compared to a low incubation temperature (25°C), a high incubation temperature (45°C) decreased the relative abundances of Exiguobacterium and Acinetobacter and increased those of Bacillus and Paenibacillus. Leaf samples incubated at 25°C showed higher bacterial alpha diversity indices than those incubated at 45°C. Principal coordinate analysis revealed that the bacterial community structure was altered by the high incubation temperature. Sugar concentration of 1.6g/50ml increased the relative abundances of Bacillus and Klebsiella but decreased those of Paenibacillus and Serratia as compared to sugar concentration of 0.4g/50ml. pH was the primary factor that influenced the succession of bacterial communities during sugar fermentation in P. sinese leaves. In conclusion, ambient temperatures(25°C and 45°C)and high sugar concentration restructured the bacterial communities on P. sinese leaves by facilitating the dominance of Bacillus and Paenibacillus. This study provided insight into the mechanisms by which bacterial communities on P. sinese leaves are enriched

Effects of Lactic Acid Bacteria Inoculants and Stage-Increased Storage Temperature on Silage Fermentation of Oat on the Qinghai–Tibet Plateau

Ensiling is a simple and effective method of alleviating a shortage of forage for ruminants. This study aimed to investigate the effects of lactic acid bacteria (LAB) inoculants and stage-increased temperature on the fermentation characteristics and chemical composition of oat silage on the Qinghai– Tibet Plateau. The silage was treated with local laboratory inoculant (I) and commercial inoculant (S) and stored at ambient temperature (\u3c10 °C) or stage-increased (5, 10 and 15 days) temperatures of 10 °C and 15 °C for 60 days. The results showed that stage-increased storage temperature can improve silage fermentation. Compared with 10 °C, a stage-increased storage temperature of 15 °C effectively (p \u3c 0.05) promoted the fermentation rate of silage by increasing the dominance of Lactiplantibacillus plantarum, with higher lactic, acetic and propionic acid contents and a lower ammonia-N ratio of the total N and final pH value. Compared with S, treatment with I increased the water-soluble carbohydrate and lactic acid contents and decreased the ammonia-N ratio of the total N and final pH value. This work demonstrated that increasing the storage temperature in stages using a warming infrastructure facilitates the preservation of oat silage in cold regions, and the inoculation of lactic acid bacteria could advance silage fermentation on the Qinghai–Tibet Plateau

Response of Fertile Tiller Characters and Seed Yield of \u3cem\u3eElymus sibiricus\u3c/em\u3e L. to Row Space Alteration

Elymus sibiricus L. cv chuancao NO.2 is widely planted in the eastern Tibetan Plateau of China. At present, the study about E. sibiricus L. seed yield has focused on the influence of fertilizing and harvest time on seed yield and its components. The response of fertile tiller characters and seed yield of E. sibiricus L. to different row space still has not been reported. This experiment analyzed the response of fertile tiller characters and seed yield to different row spaces, and presents the optimal spacing to increase seed yield and quality in the Northwest Plateau of Sichuan. The objective was to provide a scientific basis for large-scale seed production

Study on differentially expressed genes related to defoliation traits in two alfalfa varieties based on RNA-Seq

Abstract Background Alfalfa (Medicago sativa) is a widely cultivated, essential commercial forage crop. The protein content in its leaves is the critical factor in determining the quality of alfalfa. Thus far, the understanding of the molecular mechanism of alfalfa defoliation traits remains unclear. The transcriptome database created by RNA-Seq is used to identify critical genes related to defoliation traits. Results In this study, we sequenced the transcriptomes of the Zhungeer variety (with easy leaf abscission) and WL319HQ variety (without easy leaf abscission). Among the identified 66,734 unigenes, 706 differentially expressed genes (DEGs) upregulated, and 392 unigenes downregulated in the Zhungeer vs WL319HQ leaf. KEGG pathway annotations showed that 8,414 unigenes were annotated to 87 pathways and contained 281 DEGs. Six DEGs belonging to the “Carotenoid biosynthesis”, “Plant hormone signal transduction” and “Circadian rhythm-plant” pathways involved in defoliation traits were identified and validated by RT-qPCR analyses. Conclusions This study used RNA-Seq to discover genes associated with defoliation traits between two alfalfa varieties. Our transcriptome data dramatically enriches alfalfa functional genomic studies. In addition, these data provide theoretical guidance for field production practice and genetic breeding, as well as references for future study of defoliation traits in alfalfa