In this paper, a 3-factor fertilization experiment with N, P and K in an incomplete orthogonal design of "3414" was conducted to validate the optimal fertilization effect model, and the dry weight of single fruit and hesperidin content of Citrus medica 'Fingered' (CM) were used as the indicators for statistical analysis. The results showed that nitrogen, phosphorus and potassium fertilizers had effects on the dry weight of single fruit and hesperidin content in CM and N₂P₂K₂ (40g/plant for N, 40g/plant for P and 45g/plant for K) had the best effect among the different fertilization treatments, and no or less fertilization led to the decrease of quality of CM in Wanzhou to different degrees. The two-factor interaction analysis showed that when any of the N, P and K fertilizers were at the level of 2, with the increase of the other two factors, the single fruit dry weight and hesperidin content of CM showed a trend of increasing and then decreasing, indicating that any two factors interacted with each other within a certain range, and two of the N, P and K factors had an interaction effect. The optimization results of the fertilization model indicated that the suitable fertilization rates of N, P and K for cultivation of CM in Wanzhou ranged from 38.78 g to 51.25 g per plant, 35.67 g to 42.35 g per plant and 48.17 g to 60.37 g per plant, respectively. The results of the validation experiments under the intermediate conditions of the optimal fertilizer application effect model showed that the dry weight yield of single fruit of CM was 8.14% higher than that of the highest group of "3414", and the hesperidin content was 1.94% higher than that of the highest group of "3414". This indicates that the optimal formulation fertilization model is reasonable which has some practical guidance for the field cultivation of C. Sarcodactylis Fructus.

Pteris minor is one of the rare pteridophytes in the coastal zone. Because its morphology is similar to that of P. fauriei, it has been wrongly identified as P. fauriei for a long time and lacks attention. In fact, there are obvious differences between them in habitat, plant morphology, spore morphology and chromosome ploidy. Therefore, P. minor was upgraded from a variety of P. fauriei to a species. In order to clarify the distribution area and survival status of P. minor, ArcGIS 10.7 software was used to construct the geographical distribution information maps of different geographical ranges of P. minor, by sorting out the previous collection records and research results, combined with the findings of the authors' field investigation, and its protection value was evaluated according to the standard of IUCN 3.1. The results show that: (1) In terms of the world geographical distribution pattern, P. minor is mainly distributed in Asia; In terms of the geographical distribution pattern in Asia, it is mainly distributed in China, Japan and Philippines; In terms of the geographical distribution pattern of China, it is mainly distributed in Zhejiang, Fujian, Macao, Hong Kong and Taiwan; In terms of the geographical distribution pattern of Japan, it is mainly distributed in the Ryukyu Islands; In terms of the geographical distribution pattern of Philippines, it is mainly distributed in the northern islands. (2) According to the IUCN 3.1 standard, the protection level of P. minor is temporarily set as near threatened (NT). According to the current data, the distribution range of P. minor is narrow, and its habitat is vulnerable to human activities, but it lacks protection for a long time. Therefore, corresponding protection suggestions were put forward finally.

Harvested cucumber is sensitive to low temperature, which is subjected to chilling injury during cold storage and causes heavy postharvest losses. In this study, the method of RNA sequencing combined with bioinformatics analysis was used to analyze the transcriptomic changes of harvested cucumber when subjected to a short-term of cold treatment. The chilling injury index (CII) and relative electrical conductivity (REC) gradually increased but the chlorophyll fluorescence (F_v/F_m) decreased with increasing time when stored at 5℃, indicating that the chilling injury was obviously occurred. Compared with that before treatment (0 h), treatment at 5℃ for 12 h resulted in 2679 differentially expressed genes (DEGs), of which 1194 DEGs were up-regulated and 1485 DEGs were down regulated. Compared with treatment for 0 h, treatment for 72 h resulted in 9494 DEGs, of which 4807 DEGs were up-regulated and 4687 DEGs were down regulated. The results of KEGG enrichment analysis showed that the DEGs caused by cold treatment were most significantly enriched in the pathways of plant hormone signal transduction, phenylalanine metabolism, plant pathway interaction and phenylpropanoid biosynthesis. The results of GO enrichment analysis showed that DEGs were mainly involved in regulation of transcription DNA templated, protein phosphorylation and transmembrane transport in biological process. In cellular component, most enriched DEGs were related to organelle components such as membrane and nucleus. In molecular function, the enriched DEGs were mainly involved in ATP binding, protein serine/threonine kinase activity, DNA binding and transcription factor activity. DEGs related to hormone signal were significantly expressed when cucumber fruits were cold-treated for 12 h. However, the DEGs related to plant pathogen interaction and phenylpropanoid synthesis were significantly induced following 72 h of cold treatment. The results showed that plant hormone participated in the transmission of low temperature signals, the induced pathogenesis-related gene and phenylpropanoid biosynthesis might be important mechanisms for harvested cucumbers to improve chilling tolerance and cope with chilling stress. The results would provide new insights into the molecular mechanisms of harvested cucumber adaptation and resistance to chilling stress, and identify a lot of key gene resources for breeding cold-tolerant cucumber.

Rucheng Baimaocha (Camellia sinensis var. pubilimba Chang) is one of the four tea plants native to Hunan Province, China. Previous studies have shown that Rucheng Baimaocha is different from other three local population resources in Hunan in evolutionary status, and has distinctive characteristics in botanical characteristics, biochemical components and tea making quality. However, there are few studies on the differences of secondary metabolites of Rucheng Baimaocha germplasm resources. Using UPLC-MS/MS analysis technology, taking Anhua population (AHQT, C. sinensis var. sinensis), Chengbu Dongcha [CBDC, C. sinensis var. assamica (Masters) Kitamura], and Jianghua Kucha [JHKC, C. sinensis var. assamica (Masters) Kitamura] of typical local tea resources in Hunan as controls, the significantly different metabolites in Rucheng Baimaocha were screened and clustered by K-means analysis and differential metabolite enrichment pathway analysis. Compared with the control, 189, 180 and 162 significantly different metabolites were screened in Rucheng Baimaotea, the most species were flavonoids (69, 51 and 60 respectively), followed by phenolic acids (31, 40 and 25 respectively), and the least were lignans and coumarins (5, 4 and 4 respectively). Compared with the other three populations, Rucheng Baimaotea increased the content of 15 metabolites. The content of flavonoids and phenolic acids increased the most in Rucheng Baimaocha, and the highest increase was pinocembrin, followed by 1,2,3,6-tetra-o-galloyl-d-glucose. The differential metabolites were analyzed by K-means clustering. The metabolites with the same change trend in the four groups could be divided into nine categories. Among the four populations, there were 32 metabolites with the same change trend and the highest content in Rucheng Baimaotea, mainly flavonoids and tannins. The results of KEGG pathway enrichment of differential metabolites showed that the differential metabolites of Rucheng Baimaotea were mainly enriched in flavonoid biosynthesis pathway, flavonoid and flavonol biosynthesis pathway, phenylpropane biosynthesis pathway and so on. In addition to the differential metabolites reported in some tea, some differential metabolites less concerned in tea research were detected, such as pinocembrin, ellagic acid, kaempferol, etc. The substances would provide an important reference for the excavation and breeding of characteristic tea germplasm resources of Rucheng white tea in the later stage.

To investigate the effects of different coating treatments on the quality of betel nut fresh fruits during storage, three groups of coating agents, aseptic distilled water (CK), chitosan (T₁), and chitosan-chitosan-thymol (T₂), were used to coat the surface of betel nut fresh fruits and then packed in PE bags with perforations to determine the quality changes of fresh fruits stored at 13℃ and 65% relative humidity for 40 days. The results showed that the T₁ and T₂ film treatments effectively delayed and inhibited fruit decay and softening, kernel browning, yellowing, water loss and shrinkage, and extended the shelf life from 5 days to 35 days. Compared with the CK group, the T₁ treatment effectively inhibited fruit yellowing, but the T₂ treatment had the best overall preservation effect, which not only enhanced the initial antioxidant capacity of fresh fruits, but also significantly inhibited the increase of weight loss and decay rate, and the decay rate was only 8% at the 35th day. At the same time, the color of fresh fruits was more stable and the browning of kernels was not obvious in T₂ treatment. In addition, the changes of respiratory intensity, hardness, cellulose and lignin content had showed that the T₂ coating treatment could maintain the physiological and metabolic capacity of fresh fruits during the storage period after 25 days, and the freshness preservation effect was significantly better than that of the CK group, so the T₂ coating treatment can be used as a green, safe, economic and effective method to preserve fresh fruits of betel nut.

Passion fruit (Passiflora edulia Sims), as an emerging tropical fruit tree, plays a very important role in tropical agriculture. However, abiotic stresses such as drought and high temperature seriously affect its normal growth and development. Relevant studies have shown that aquaporin (AQP) can improve the stress resistance of plants. In this study, Passiflora 'Tainong' was used as the material, an aquaporin gene PePIP2 was cloned using the genome data of passion fruit. The open reading frame (ORF) was 861 bp, encoding 286 amino acids. The molecular formula was C₁₄₁₇H₂₁₅₆N₃₆₀O₃₇₃S₈, the molecular weight was 30 459.37 Da, the isoelectric point was 8.84, and the subcellular localization was on the cell membrane. Analysis of the promoter region revealed that it contained cis-acting elements involved in stress response. The expression analysis showed that PePIP2 could be induced by drought, high temperature and low temperature stress. Among them, the expression level was the highest when the soil water content was 50%, treated at 45℃ for 4 h and at 0℃ for 48 h. Transiently expressed in tobacco, the expression of PePIP2 was also induced to varying degrees under drought stress at different times. The results of this study would lay the foundation for the analysis of the stress resistance mechanism and molecular breeding of the passion fruit.

With the rapid development of the livestock industry, the demand for forage is increasing, and it is urgent to screen new forage crop varieties. In this study, two national forage sugarcane varieties were used as the control. The biological yield of 15 sugarcane varieties and the routine nutritional components of 10 green fodder were measured and analyzed to explore the principal component variation of sugarcane at different cutting stages, and evaluate the feeding value of sugarcane, so as to provide scientific basis for more than one year of sugarcane harvest and whole plant feeding. Crude protein (CP), acid detergent fiber (ADF), water-soluble carbohydrate (WSC) and crude fat (EE) were selected by factor principal component analysis, which basically contained all the information of the indexes measured. Among the 15 sugarcane varieties, 'Yunzhe 12-201' had the highest CP content, which was 8.80 %, 'ROC22' with the lowest ADF content, 35.25 %. The highest WSC content was from 'Yunzhe 00-290', 6.16 %. The highest EE content was from 'Yunzhe 01-286', 1.40 %. The CP content of 'ROC22' and 'Yunzhe 12-201' was higher than that of CK1 and CK2. The ADF content of 'Q27','ROC22','Yunzhe 01-286', 'Yunzhe 06-160','Yunzhe 12-142-1-J', 'Dianzhe 11-728' was lower than that of CK1 and CK2. The WSC content of 'Q27', 'Yunzhe 00-290', 'Yunzhe 12-142-1-J', 'Yunzhe 16-16', 'Dianzhe 11-726' and 'Dianzhe 11-728' was higher than that of CK1 and CK2. There was no significant difference in EE content between 15 sugarcane varieties and CK1 (P>0.05), except 'Yunzhe 06-160'. There was no significant difference in EE content between 14 sugarcane varieties and CK2. Except for 'Dianzhe 11-726', there was no significant difference in Ca content between 14 varieties and CK1 and CK2. The CP content of all sugarcane varieties in the first cutting period was higher than that in the second cutting period, and the ADF, WSC, EE and Ca content in the first cutting period was higher than that in the second cutting period, with 12, 5, 4 and 14 sugarcane varieties, respectively. The total yield of 15 sugarcane was 71.40-163.95 t/hm², higher than that of CK1 and CK2. The yield of CP, ADF, WSC and EE per unit area of 15 sugarcane varieties exceeded that of CK1 and CK2, and the Ca yield of 15 sugarcane varieties exceeded that of CK2. Comprehensive evaluation showed that sugarcane could be used as ruminant feed with high nutritional value and economic benefit. In this study, five varieties 'Q27', 'ROC22', 'Yunzhe 01-286', 'Yunzhe 12-201', 'Dianzhe 11-728' were selected as the sources of forage sugarcane, which could not only meet the raw material needs of forage animals, but also form an industrial development model of sugar-animal linkage..

Youjiang River Valley in Baise is one of the famous dry and hot river valleys in China. Drought is the most serious meteorological disaster in the region. It has a unique suitable environment for mango and is the main mango producing area in China. However, the research on the water use strategy of Mango in Baise dry-hot river valley region is still lacking. Based on based on the measuring of hydrogen and oxygen stable isotope of precipitation, soil water at different layers, groundwater, and mango xylem water, the variation characteristics of hydrogen-oxygen isotope an its influencing factors of precipitation were analyzed, and the water absorption sources of mango roots at different growth stages were quantified. The hydrogen-oxygen stable isotopes and d-excess had obvious seasonal changes in the year, which were low in rainy season and high in dry season. The local meteoric water line was δD=8.2587δ¹⁸O+12.308 (r=0.9968, n=35, P<0.001) for the area. Under the influence of monsoon climate, the stable isotope value of precipitation had a significantly negative linear relationship with precipitation amounts and air temperature (P<0.05). During mango flowering stage, young fruit stage, fruit expansion stage, and mature stage, the stable isotopes of soil water became poor with the increase of soil depth. In the flowering stage and young fruit stage, mango trees used a relatively uniform proportion of soil water at different depths and groundwater, while in the expansion stage and maturity stage, mango trees mainly used deep soil water and groundwater, indicating that mango trees in this area mainly use deep soil water and groundwater as water sources, as mango trees' roots are mainly distributed in deep layers, and reveals its conservative water use strategies. The variation of hydrogen-oxygen stable isotopes of precipitation indicates the xerothermic environment of Baise dry-hot river valley region, and mango mainly uses deeper soil water and groundwater, the above results are expected to provide a basis for the sustainable development of mango industry in this area.

To investigate the characteristics of plant diversity in the understory of eucalyptus plantations in Hainan, vegetation surveys were conducted in different areas of eucalyptus plantations, and the biomass of the upper part of the interior of the sample plots was measured by combining the standard wood method and the harvesting method, then theα-diversity index of the irrigation and grass layers was combined with the biomass of the above-ground part to construct a comprehensive functional index, and the new index was compared with the α diversity index. There were 101 species of understory plants in eucalyptus plantation, among which 49 species appeared in shrub layer, belonging to 45 genera of 31 families, and 52 species appeared in herb layer, belonging to 48 genera of 28 families. There was no significant difference in the diversity index of understory shrub layer in different regions of eucalyptus plantations. The α diversity index of herbaceous layer in Lingao was significantly higher than that of other areas. It means the diversity level of shrub layer was similar, while the diversity level of herb layer was more affected by environment. There were significant differences in aboveground biomass allocation between shrub layer and grass layer in different regions. Although shrub layer was larger than herb layer, the distribution ratio fluctuated widely. Yd indices of shrub layer of eucalyptus plantations in different areas had no significant difference, and Yd indices of herb layer in Lingao and Ding'an were significantly higher than those in Tunchang and Dongfang. It means that the ecological functions of shrub layer in different areas were similar, while the ecological functions of herbaceous layer were obviously stronger than those of Lingao and Ding'an. The Yd index of the shrub layer was strongly correlated with the α-diversity index; the Yd index of the herb layer was generally correlated with the α diversity index and strongly correlated with above-ground biomass. The results show that the plant diversity characteristics of the eucalyptus understory are influenced by the regional environment, with the herbaceous layer being more susceptible than the shrub layer; the α-diversity index of the shrub layer has a greater influence on the Yd index, while the above-ground biomass of the herbaceous layer has a greater influence on the Yd index. The Yd index can reflect both the α-diversity level and biomass of the understory, and is a good complement to evaluate the ecological functions of the understory vegetation of eucalyptus plantations.

Cassava is an important cash crop in Southern China, which is enriched with starch in the tuber roots. The analysis of the regulation mechanism of starch synthesis in cassava root would contribute to the improvement of yield and high starch molecular in cassava. AGPase is composed of large subunit and small subunit, and it catalyzes G-1-P and ATP to form ADPG and PPi, in which ADPG is the substrate of starch biosynthesis. Therefore, AGPase is a rate-limiting enzyme in plant starch synthesis, and improving the activity of AGPase is beneficial for the accumulation of crop starch and the improvement of yield. The small subunit encoded by MeAGPS1a is the catalytic center of AGPase in cassava. Previous studies have shown that the growth response factor MeSAUR1 as a transcription factor positively regulates the expression of MeAGPS1a gene, and yeast two-hybrid screening of a cassava cDNA library revealed that the calmodulin-like (CML) member MeCML24 is a candidate interacting protein of MeSAUR1. To determine the interaction between MeCML24 and MeSAUR1, and MeCML24 was cloned from the genome of SC8 cassava variety in this study. The length of CDS region of MeCML24 was 492 bp, encoding 163 amino acids. The physicochemical properties and secondary structure analysis of MeCML24 showed that the value of theoretical pI was 4.38, which belonging to hydrophilic protein with α-helix accounting for 52.76%, random coil accounting for 30.06%, and beta turn accounting for 11.04%. Yeast two-hybrid vector BD-MeCML24 was constructed, and the self-activation experiment showed that MeCML24 had no self-activation. Yeast two-hybrid point-to-point experiment revealed that yeast strains co-transfected with AD-MeSAUR1 and BD-MeCML24 plasmids turned blue on nutrient medium with SD/TLHA+x-α-gal, indicating that MeCML24 interacted with MeSAUR1. The fusion protein MeSAUR1-nEYFP and MeCML24-cEYFP were co-expressed in tobacco leaves by bimolecular fluorescence complementation (BiFC) experiment, and the fluorescence signal of yellow fluorescent protein EYFP was detected under laser confocal microscope, which further proved the interaction between MeCML24 and MeSAUR1. Finally, the interaction between MeCML24 and MeSAUR1 negatively regulated the expression of MeAGPS1a by double luciferase experiment. The study revealed the mechanism of MeSAUR1 and MeCML24 synergistically regulating MeAGPS1a gene expression in cassava, and found that the calmodulin-like protein MeCML24 regulating the expression of MeAGPS1a, a key gene for starch synthesis in cassava root. This study would provide a theoretical basis for cultivating excellent cassava varieties by molecular biology technology.