Abstract:To classify the role of ferredoxin NADP⁺ oxidoreductase (FNR) in the process of soft rot resistance in Oncidium, we cloned a OnFNR gene (Genbank accession No. KX461907) from ‘Little Cherry’ Oncidium by using RACEPCR. Bioinformatics analysis and subcellular localization analysis of OnFNR were performed, and qRTPCR was used to analyze the expression pattern of OnFNR in different organs and different soft rot infection stages. Moreover, the overexpression vector of OnFNR was constructed and transformed into protocormlike bodies (PLBs) to investigate its function in Oncidium soft rot resistance. The results showed that: (1) the OnFNR gene contains an open reading frame of 1 080 bp that encodes 359 amino acids. The predicted molecular mass is 40 066.14 Da, and the isoelectric point is 8.72. OnFNR contains two typical domains: FAD binding domain and NADP⁺ binding domain, and it is subcellularly located in the chloroplast. (2) Multiple sequence alignment and phylogenetic tree analysis revealed that OnFNR is clustered with other plant LFNRs, and is close to Phalaenopsis equestris LFNR (89.1%). (3) qRTPCR results showed that the expression level of OnFNR was significantly higher in the leaf than that in flower and pseudobulb, and the lowest expression was found in root. Moreover, after the plants were inoculated with the soft rot pathogen, the expression of OnFNR was significant downregulated in pseudobulb and leaf at only 1 day post pathogen inoculation (dpi) (P<0.01), and the expression levels of the five susceptible stages were all lower than that of the healthy plants. (4) The overexpression vector pCAMBIA1301OnFNR was successfully constructed, and it was successfully transformed into Oncidium PLBs by agrobacterium EHA105 infection, and 16 transgenic PLBs overexpressing OnFNR were obtained. In the overexpressed OnFNR PLBs of Oncidium, both OnFNR and Fd gene expression were significantly upregulated, especially the expression of Fd was increased to 3.67 times of the control (nontransgenic PLBs). Moreover, the survival rate of PLBs overexpressing OnFNR was 48.88% on the 4th day of soft rot pathogen infection, while the control was only 6.66%. This study shown that: OnFNR is a photosynthetic ferridoxin NADP+ oxidoreductase located in chloroplast, and overexpression of OnFNR can significantly improve the disease resistance of plants. It is speculated that OnFNR plays an important role in plant resistance to virus and ROS outbreak, and overexpression of OnFNR may promote signal transduction of MAPK pathway by improving electron transfer efficiency of LET and increasing Fd expression.

Abstract:MYB transcription factors are involved in the formation of plant cell morphology and pattern, the regulation of secondary metabolism and the response to biological and abiotic stress, while the expression of tomato MYB (SlMYB86) under nitrogen deficiency stress has not been reported. In this study, the tomato SlMYB86 gene was amplified by RTPCR, cluster analysis and conserved domain sequence analysis were carried out, prokaryotic expression vector and induced purified protein were constructed, and the expression level of SlMYB86 under nitrogen deficiency and nitrogen resupply was detected by qRTPCR and Western blot, which laid a foundation for further exploring the function of tomato MYB86 transcription factor under nitrogen deficiency stress. The results show that: (1) tomato SlMYB86 and tomato SlMYB26 belong to the same branch in the evolutionary tree, with close genetic relationship, and SlMYB86 contained two Myb_DNAbinding conserved domains, belonging to R2R3MYB transcription factor. (2) qRTPCR analysis showed that SlMYB86 gene was expressed in tomato roots and leaves, and the expression of SlMYB86 was significantly higher than that of the control under nitrogen deficiency stress. (3) The prokaryotic expression vector pET28aSlMYB86 was constructed and transformed into E. coli BL21 (DE3). The results of SDSPAGE and Western blot showed that the best induction conditions of SlMYB86 protein were 0.5 mmol/L IPTG and 37 ℃ for 8 hours. The relative molecular weight of the target protein is about 41 kD, which is consistent with the expected size, and SlMYB86 prokaryotic protein with high purity is obtained. (4) Mice were immunized with the purified SlMYB86 protein to obtain the antibody. Western blot showed that the expression of SlMYB86 protein in tomato was upregulated after nitrogen deficiency stress, indicating that tomato SlMYB86 gene was involved in the response to nitrogen deficiency stress.

Abstract:SAUR (small auxin up RNA) is one of the main auxin inducing genes in plants, which plays an important regulatory role in promoting plant cell division and cell elongation. In this study, Impatiens uliginosa Franch. was used as material, and the SAUR gene was cloned by RTPCR and analyzed by bioinformatics and gene expression. The results showed that the cDNA sequences of the six SAUR genes were 351, 534, 396, 333, 309 and 411 bp, encoding 116, 177, 131, 110, 102 and 136 amino acids, respectively. Bioinformatics analysis showed that SAUR3 was stable, and the other five proteins were unstable. All the proteins were hydrophilic except SAUR5 which was hydrophobic. All proteins are nonsecretory proteins. The amino acid sequences encoded by these six SAUR genes had higher homology with other plants, and showed certain conserved characteristics of species. It is speculated that SAUR4 and SAUR5 are paratellate relatives, and SAUR1, SAUR2, SAUR3 and SAUR6 are direct relatives.RtPCR analysis showed that the relative expression levels of the six SAUR genes were the highest at the initial flowering stage, followed by the full flowering stage, and the lowest at the bud stage. SAUR3 gene was highly expressed in both spur and blade. SAUR4, SAUR5 and SAUR6 genes were highly expressed in the basel and blade of p. I. uliginosa Franch, while the other three SAUR genes were not significantly expressed in the tip and camber of I. uliginosa Franch. This study provided some basic data and scientific basis for the regulation mechanism of flower spacing, flower pattern improvement and new variety breeding of Impatiens.

Abstract:In this study, a UVB photoreceptor gene (MsUVR8) of alfalfa was cloned by RACE amplification. On the basis of bioinformatics analysis, Agrobacterium mediated method was used to obtain the overexpressed callus of MsUVR8. The contents of flavonoids, flavonols, anthocyanins, hydrogen peroxide (H₂O₂), superoxide anion (O₂^-·) and UVB signaling pathway related genes in MsUVR8 overexpressed callus and wild type after UVB radiation treatment were detected and analyzed. The purpose of this study is to supply a theoretical foundation for revealing the molecular mechanism of plant response to UVB stress. The results showed that: (1) the CDS sequence of MsUVR8 in alfalfa was 834 bp, and the similarity between MsUVR8 and MtUVR8 gene of Medicago truncatula was more than 95%. The MsUVR8 protein formed an incomplete βfolded structure, and phylogenetic analysis showed that it belongs to the same branch as chickpea. (2) It was found that the content of flavonoids in MsUVR8 overexpressed callus (UVR8OE) of alfalfa was significantly higher than that of wildtype callus (WT), and the content of flavonoids in UVR8OE after UVB radiation was further significantly higher than that of WT. (3) DPBA fluorescence labeling showed that UVB radiation greatly promoted the synthesis of flavonols, and UVR8OE had the highest flavonols content after UVB radiation. (4) DAB and NBT staining showed that the accumulation of reactive oxygen species (H₂O₂ and O₂^-·) in WT increased after UVB treatment, but there was no significant difference between UVBtreated and untreated UVR8OE, indicating that MsUVR8 could enhance the antioxidant capacity of plant tissues and cells and reduce the oxidative damage caused by UVB stress. (5) After UVB irradiation, the expression of PAL, CHS and FLS in WT was activated and significantly increased, and the expression of four genes in UVR8OE reached the maximum, which was significantly increased compared with the other three treatment groups. The results showed that alfalfa MsUVR8 activated by UVB promoted the expression of genes related to flavonoid synthesis and activated the activities of key enzymes in flavonoid synthesis, thus improving the efficiency of flavonoid synthesis and enhancing the antioxidant capacity of plant callus under UVB stress.

Abstract:In this study, the tuber mustard cultivar ‘Yongan Xiaoye’ was selected as experimental material, and the isopentenyl transferases (IPT) family genes were identified in its genome. The fluorescent quantitative PCR were used to test the IPT gene expression patterns in different organs and under salt and Plasmodiophora brassicae treatments. The results showed: (1) twentyseven IPT genes were identified in the genome of tuber mustard, which were located on 14 of 18 chromosomes, the IPT proteins attributed to 7 clades in the phylogenetic tree. (2) The majority of IPT genes were highly expressed in roots and stems, little genes were expressed in leaves, flowers and pods. BjuB006281 were highly expressed in stems, and BjuA027211, BjuB010173, BjuB010174 and BjuA001839 were expressed higher in roots than the other organs. (3) Most of the IPT genes were downregulated by salt stress treatment, the expression of BjuB006281, BjuA036403, BjuB010173 and BjuB026254 were reduced between 12-48 h after salt stress treatment, while BjuB022918 and BjuB007352 were reduced between 24-48 h. (4) The majority of IPT genes were induced by P. brassicae treatment at 12 h, for example, the expression levels of BjuB006281, BjuA014415 and BjuB022918 were increased more than 15 folds comparing to the 0 h control. In together, several salt and P. brassicae responsive genes were identified in this study, which could provide a basis for further studying their functions.

Abstract:SQUAMOSA promoterbinding protein like (SPL) gene family plays an important regulatory role in floral transition and flower development. In this study, we used bioinformatics method to identify 15 CsSPLs with SBP conserved domain from the whole genome of Citrus sinensis, and the relative expression specificity in flower buds and leaves in C. sinensis of different flowering and varieties by using qRTPCR method, which laid a foundation for further exploring the function of CsSPLs during flowering induction. The results show that: (1) these genes distributed on 6 chromosomes and they were named CsSPL1-CsSPL15. (2) Analysis of physicochemical properties showed that the length of the CsSPLs proteins ranged from 130 to 1 075 aa with molecular mass of 14.73 to 118.75 kD. Phylogenetic analysis showed that 15 CsSPLs were divided into 8 subfamilies, and most CsSPLs were clustered with AtSPLs, except for CsSPL4. (3) The predictive analysis of cisacting elements showed that CsSPLs promoter contained a large number of light responsiveness elements, indicating that they might play an important role in the regulation of C. sinensis. (4) Transcriptome data analysis showed that CsSPLs expressed in callus, flowers, leaves and fruits of C. sinensis. The expression of CsSPL3, CsSPL4, CsSPL7, CsSPL8, CsSPL12, CsSPL13, CsSPL14 and CsSPL15 were high in flowers and leaves. (5) The qRTPCR results showed that the relative expression levels of CsSPLs were significantly upregulated in flower buds and leaves of two C. sinensis varieties. And CsSPLs in ‘Gannan Zao’ cultivars were higher than that in flower buds and leaves of ‘Newhall’ cultivars at 5 sampling time points. These results showed that the high expression of CsSPLs in flower buds and leaves led to the early flowering of C. sinensis.

Abstract:Stearoylacyl carrier protein desaturase (SAD) catalyzes the dehydrogenation of stearic acid to oleic acid, which is the key enzyme to form unsaturated fatty acids. The Perilla frutescens stearoylacyl carrier protein dehydrogenase (PfSAD) family genes were screened and identified from the transcriptome database of perilla, and bioinformatics analysis and conserved functional domain analysis were carried out. The expression characteristic of each member of PfSADs in different tissues were detected by qRTPCR. So as to explore the role of PfSAD family genes in regulating seed fatty acid components, and provide gene elements for the genetic improvement of fatty acid components of P. frutescens. The results showed that: (1) six PfSAD family genes were detected from P. frutescens transcriptome database tested by our research group in the early stage, and the amino acid lengths of the encoded proteins were between 367 and 396 amino acids. They all had the conserved domain and diiron center of SAD, and the encoded proteins were all located in the chloroplast. (2) The results of multiple sequence alignment showed that the protein sequences of PfSADs had more than 50% homology with the SAD protein sequence of Arabidopsis thaliana, Ricinus communis and Theobroma cacao L.; Phylogenetic tree analysis showed that six PfSADs proteins belonged to three subgroups, respectively, among which the first subgroup contained PfSAD1, the second subgroup contained PfSAD2 and PfSAD3, and the third subgroup contained PfSAD4, PfSAD5 and PfSAD6. (3) Real time quantitative PCR analysis showed that there were significant differences of the expression levels of PfSAD members in different tissues of ‘JinZisu 1’, in which PfSAD1 is mainly expressed in leaves, the expression levels of PfSAD2, PfSAD3, PfSAD4 and PfSASD5 were higher in seeds, and PfSAD6 has a significant expression advantage in flowers. The results show that PfSADs have typical conserved motifs and active center that catalyze SAD, and their members are highly expressed in different tissues, It suggested that all these 6 genes involved in the formation of oleoylACP derived from the dehydrogenation of stearoylACP and play a key role in the process of P. frutescens oil synthesis and metabolism. The study provides an important reference for further exploring the role of PfSAD family genes in regulating seed fatty acid components.

Abstract:The morphological description of Aster procerus Hemsley was not complete enough in the original literature when compared with the specimen which we collected from its type locality. Additionally, there is a lack of reports from cytology and molecular phylogeny in recent studies. We made a detailed description of A. procerus and did some studied about cytology and molecular phylogenetic on this species, and provided new evidences for the revision of Aster. The results reveal that: (1) there are some new characteristics for A. procerus that basal leaves pinnatilobed, larger when matured, up to 26 cm in length and 8 cm in width, and receptacle convex. (2) The cytology evidence showed that the number of chromosome was 2n = 18 and the karyotype formulae was 2n = 2x = 16 m + 2 M, belongs to 1A. (3) The molecular phylogenetic analysis which based on ITS and ETS showed that these two populations of A. procerus formed a highly supported clade (LP = 100, PP = 1.00) and was nested within the core Aster clade (LP=100, PP=1.00). Furthermore, phylogenetic analysis indicated that A. procerus was sister to Turczaninovia fastigiata (Fischer) Candolle. Our results supported A. procerus belongs to Aster and suggested transferring T. fastigiata to Aster.

Abstract:The sexual reproduction of Orchidaceae is special, each flower has only a anther and pollens have aggregated into pollinium is one of its characteristics. In this study, the anthers of wild Dendrobium officinale at different stages are used as materials, the anatomical observation of anther development were carried out by semithin section and plant histochemical methods. The mature pollinium is cultured in vitro to observe the germination of pollen tubes. The results show that: (1) the anther wall of D. officinale is composed of one layer of epidermis cells, two layers of endothecium cells, one layer of middle layer cells and one layer of tapetal cells. At anthesis, the tapetal cells degenerate, while layer of middle layer cells do not, and the endothecium cells form fibrous bands in its cell wall. The microspore mother cells have no obvious callose wall structure. (2) Its microsporogenesis is simultaneous type. After meiosis, four microspores in tetrad do not disperse and sequentially develop as pollen tetrads, which stick together to form pollinia. (3) During microspore development, sporopollen covers the surface of whole pollinium and forms the extine of the pollinium, while the pollen tetrads inside the pollinium have no extine structure. No pollen germpore was observed in the extine of pollinium. (4) When pollen germinates in vitro, pollen grains with extine on the surface of pollinium do not germinate, and pollen tubes are mainly produced in pollen grains inside the pollinium.

Abstract:WJS01A is a stable cytoplasmic male sterility (CMS) line originated from Brassica juncea (B. juncea) with complete pollen abortion that is rarely affected by environmental conditions. The present study identified WJS01A based on its morphological, cytological, genetical and molecular biological characteristics to reveal its mechanism of pollen abortion and provide a theoretical basis for its application in rapeseed breeding. The results are as follows: (1) the inflorescence structures of WJS01A are similar to those of normal B. juncea. However, its flower bud size, flower opening angles and petal size are slightly smaller than those of B. juncea. The anthers and filaments of WJS01A are shorter than those of normal B. juncea, thus its stamen heights are dramatically less than the stigma. Meanwhile, its anthers are albino without producing pollens; (2) Through testing the restorer and maintainer relationship of sterile line WNJ01A in Brassica napus (B. napus) derived from WJS01A, Polima (Pol), Ogura (Ogu) and Kosena (Kos) CMS types, the results showed that that of WNJ01A is significantly different from those of Pol, Ogu and Kos. Only Hui01 could restore the fertility of WNJ01A; (3) WJS01A is a nonpollen sactype sterile line, and its pollen abortions occurred from the anther primordial stage to the archesporial cell stage; (4) Multiplex PCR analysis of mitochondrial sterility genes showed that WJS01A and WNJ01A could be clearly distinguished from Pol, Ogu and Kos. But the current primers cannot distinguish WJS01A from normal B. juncea; (5) Restriction fragment length polymorphism (RFLP) analysis of the mitochondrial genome indicated that all of the eight probe/enzyme combinations could distinguish WJS01A from the other four sterile lines. It revealed that WJS01A is a CMS type significantly different from Pol, Ogu and Kos. Exploiting WJS01A will broaden the current genetic basis of heterosis utilization in B. napus. Furthermore, it will provide new germplasm to solve the current issue of cytoplasmic simplification in heterosis utilization in B. napus.

Abstract:In order to clarify the protective effect of epidermal wax in the physiological response to nonheading Chinese cabbage under high temperature stress, we used waxy (Q28) and waxless (Q1202) varieties of nonheading Chinese cabbage as experimental materials under high temperature stress in this study. The experiment set the high temperature stress group (day/night temperature of 37 ℃/30 ℃) and control group (day/night temperature of 25 ℃/18 ℃) to observe the morphology of leaf epidermal cells of different materials. Measure and compare the differences in physiological and photosynthetic index changes in different periods of high temperature stress. The results showed that: (1) the biomass of the two nonheading Chinese cabbage seedlings was inhibited from varying degrees under high temperature stress, and the decline in the waxy material was smaller; the leaf epidermal cell morphology also had a big difference. The shrinkage of epidermal cells of the material leaves was significantly lower than that of the waxfree material. (2) The contents of proline, soluble sugar and soluble protein in the waxed material leaf was significantly higher than that of the waxfree material at 9 days of high temperature stress. (3) The antioxidant enzyme activities of the two materials showed a dynamic change that first increased and then decreased, and the activities of the waxy material were greater; the malondialdehyde content and relative conductivity of the two materials showed an upward trend, and the waxy material increasedless. (4) The chlorophyll content of the leaves of the two materials showed a downward trend, but the waxy material was still higher; compared with the waxfree material, the waxy material leaves had a lower transpiration rate and a higher net photosynthetic rate. Studies have revealed that under high temperature stress, leaf wax can improve leaf osmotic adjustment ability, protect the normal morphology of leaf epidermal cells, and enhance plant antioxidant capacity.

Abstract:In order to provide a theoretical basis for introduction and cultivation of Koelreuteria paniculata in saline alkali areas, this paper studied effects of mixed salt stress on the photosynthesis and chlorophyll fluorescence characteristics of K. paniculata seedlings and its adaptation mechanism. The paper performed pot experiment at the six gradients of 0 (CK), 100 (S₁₀₀), 200 (S₂₀₀), 300 (S₃₀₀), 400 (S₄₀₀) and 500 (S₅₀₀) mmol·L^-1 , which were prepared by mixing NaCl and NaHCO₃ at molar mass ratio of 1∶1, and 2yearold K. paniculata cuttings were used in the pot experiment. The results showed that: (1) with the increase of stress degree, K. paniculata seedlings showed some apparent symptoms, such as yellowing, scorching, curling, root reduction, plant death and so on. (2) With the increase of stress degree, leaf length increment and leaf width incremen of K. paniculata seedling increased. The leaf length increment and leaf width increment of K. paniculata seedling were no difference with the control group when mixed salt concentration was 100 and 200 mmol·L^-1 , but the leaf length increment began to decrease significantly when mixed salt concentration reached 300 mmol·L^-1 ，and the leaf width increment began to decrease significantly compared with control group when mixed salt concentration reached 400 mmol·L^-1 . (3) The chlorophyll, PSⅡ actual quantum (Yield), photochemical quenching coefficient (qP) and maximum quantum yield of PSⅡ(F_v/F_m) of K. paniculata seedling leaves were no difference with the control group when mixed salt concentration was 100 mmol·L^-1 , but the indexes except maximum quantum yield of PSⅡ(F_v/F_m) began to decrease significantly when mixed salt concentration reached 200 mmol·L^-1 , and the indexes except maximum quantum yield of PSⅡ (F_v/F_m) began to decrease significantly compared with control group when mixed salt concentration reached 300 mmol·L^-1 . (4) With the increase of mixed salt stress, net photosynthetic rate (P_n), stomatal conductance (G_s) and transpiration rate (T_r) of K. paniculata seedlings decreased as a whole; When mixed salt stress was 0-30 days, and mixed salt concentration was 100-300 mmol·L^-1 , changes of net photosynthetic rate (P_n), intercellular CO₂ concentration (C_i) and stomatal conductance (G_s) of K. paniculata seedling leaves were same. With the increase of stress degree, net photosynthetic rate (P_n) and stomatal conductance (G_s) decreased, and intercellular CO₂ concentration (C_i) increased. These results showed that: when the mixed salt concentration was 100 mmol·L^-1 , the growth indexes and physiological indexes of K. paniculata did not change significantly, showing a certain ability to tolerate mixed salt stress. At this time, stomatal restriction was the main factor. The growth indexes, chlorophyll content and photosynthetic physiological indexes of K. paniculata seedling leaves decreased significantly as a whole when mixed salt concentration reached 200 mmol·L^-1 , resulting in the inhibition of plant growth. At this time, nonstomatal restriction and photochemical activity inactivation were main factors affecting photosynthesis.

Abstract:The content and proportion of sugar and acid substances in tomato fruits directly affect its flavor quality. Previous studies have shown that appropriate concentration of exogenous 5aminolevulinic acid (ALA) can promote the ripening of fruits and improve their aroma quality. We conducted this experiment to explore the effects of different concentrations of exogenous ALA (0, 100, 200 mg·L^-1 ) on the development of tomato fruits and their sugar and acid qualities. Tomato fruits (Solanum lycopersicum cv. Yuanwei No. 1) grown in greenhouse were used as test material, ALA solution was sprayed on the surface of the fourth ear fruit at the fruit setting stage. 10 d after pollination and the fruit morphology, peel color, sugar and acid contents in different fruit tissues were determined. The results showed that: (1) the exogenous ALA solution significantly promoted the increase of tomato fruit transverse and longitudinal diameters and the increase of fruit weight per fruit; the exogenous ALA treatment also significantly reduced fruit hardness, promoted fruit softening and improved fruit taste; the exogenous ALA treatment also increased fruit V_C and soluble solids content. (2) The results of sugar fractions in different parts of fruit tissues (including flesh, columella and septum) showed that exogenous ALA treatment significantly increased the total soluble sugar content (including fructose, glucose and sucrose) and facilitated the accumulation of sugar into the fruit flesh. (3) Among the organic acids, except for the increase of tartaric acid content, exogenous ALA could reduce the contents of other acid components in the tissues of various parts of the fruit. Therefore, the ratio of sugar to acid could be significantly improved in the pulp parts of tomato fruits, and the fruit flavor quality was promoted. It was found that exogenous application of 200 mg·L^-1 ALA during the development process of tomato fruits can not only promote fruit development, fruit weight and coloration, but also improve the formation of fruit sugar and acid quality, which enhance the appearance quality.

Abstract:In order to clarify the influence mechanism of light quality on the growth of Loropetalum chinense var. rubrum callus and the synthesis and accumulation of secondary metabolites flavonoids, to provide a theoretical basis for manmade regulation of the yield and quality of its cell products, we used, the callus induced by L. chinense var. rubrum leaves as the test material in this experiment with the darkness (CK) as control. White light (W), red light (R), blue light (B), blueviolet light (BP), and blue light + UVA (B+UVA) and UVA treat for 15 and 30 d, respectively. Through comparative analysis of callus growth, physiological indicators, anthocyanin and total flavonoids content, we explored the effect of light quality on L. chinense var. rubrum callus growth and flavonoid content. The results show that: (1) compared with CK, several different light quality treatments can increase the dry and fresh weight of callus. Among them, R is more conducive to the increase of callus fresh weight, B+UVA and UVA are more conducive to the increase of dry weight, and there are some genotypic differences in the influence of light quality on the dry weight of callus. (2) R, B and W treatments can significantly increase the solubility of L. chinense var. rubrum callus sugar content, among which R treatment has the highest valueadded, B and W treatments second, and other shortwave treatments slightly increase or decrease compared with 0 d. (3) Shortwavelength light quality treatment significantly improves the callus of L. chinense var. rubrum. Among them, B+UVA treatment has the highest valueadded content. (4) Shortwavelength light quality treatment is more conducive to increasing the PAL activity of L. chinense var. rubrum callus. Among them, BP and B+UVA treatments are the most significant. (5) Shortwavelength light quality (B, BP, B+UVA and UVA) can promote the synthesis of anthocyanins and flavonoids in the callus of L. chinense var. rubrum, while R treatment play an inhibitory role. It was shown that shortwave light quality B, BP, B+UVA and UVA treatments can promote the synthesis of anthocyanins in the callus of L. chinense, B+UVA and B treatments are more conducive to the increase of total flavonoids content; Moreover, there are certain genotypic differences in the influence of light quality on the dry weight of callus, anthocyanin and total flavonoids.

Abstract:A total of 23 local tea variety resources from Xiaomaoshan, Liangshan and Nanwushan in Yunxiao County, Fujian Province were used as test materials. The contents of catechins, purine alkaloids and amino acid components detected by high performance liquid chromatography (HPLC) and ultra performance liquid chromatographymass spectrometry (UPLCMS/MS), and descriptive statistics, difference analysis and cluster analysis were performed for screening tea varieties with specific biochemical components. The results showed that: (1) the total catechin content of 23 tea variety resources ranged from 73.54-260.31 mg·g^-1 , with an average of 160.48 mg·g^-1 . Epigallocatechin3Omethylgallate (EGCG3″Me) was detected in all resources, and the highest content was Xiaomaoshan 3 (X03), up to 33.65 mg·g^-1 . (2) The total purine alkaloids in 23 tea variety resources ranged from 15.28-70.42 mg·g^-1 , with an average of 40.95 mg·g^-1 . The theacrine (TC) was detected in tea variety resources (LS01LS07) in Liangshan, and the theacrine content of Liangshan 6(L06) and Liangshan 7(L07) were higher than their caffeine contents. (3) The total amino acid content of 23 tea variety resources ranged from 6.40-47.57 mg·g^-1 , with an average of 20.83 mg·g^-1 . Amino acid composition is rich, a total of 20 amino acids were detected. (4) The results of difference analysis and cluster analysis showed that the biochemical components of tea variety resources in three regions of Yunxiao County had obvious regional characteristics. Among them, tea resources in Liangshan are rich in theacrine (TC). The contents of epigallocatechin gallate (EGCG) and epigallocatechin3Omethylgallate (EGCG3″Me) were higher in Xiaomaoshan resources. The contents of alanine (Ala), glutamic acid (Glu) and glutamine (Gln) in Nanwushan tea variety resources were slightly higher than those in other two places. Our data suggested that the catechins, purine alkaloids and amino acids of Yunxiao local tea variety resources were significantly different, rich genetic diversity and obvious regional characteristics. 18 specific germplasms including high catechin, high EGCG3″Me, high theacrine and high theanine were screened, which laid the foundation for the systematic development and utilization of Yunxiao local tea variety resources.

Abstract:Altitude change is the gradient effect of multienvironmental factors. The fine root is an important organ for plants to absorb water and nutrients, and its characteristics are of great significance in indicating plant growth and distribution. In this study, the fine roots of spruce (Picea asperata) in the Gonggang Mountains at 2 500-3 300 m were taken as the research object. We used the root order classification method to determine the biomass and fine root morphology (average diameter, specific root length, root length density, specific surface area) of spruce to clarify the response of fine root biomass and morphological characters of spruce to altitude changes and the tradeoff between fine root functions. The purpose of this study is to provide a basis for explaining the structure and functional characteristics of a forest ecosystem. The results showed that: (1) the fine root biomass of spruce at different elevations increased with the increase of root order, and the biomass of 0-10 cm soil layer was significantly higher than that of 10-20 cm soil layer. (2) At different elevations and different soil layers, the diameter of 1-5 fine roots increased with the increase of root order, and the specific root length, root length density, and specific surface area decreased with the increase of root order. (3) Altitude had extremely significant effects on specific root length, root length density, and specific surface area, and among fine root traits, diameter had an extremely significant negative correlation with specific root length, root length density, and specific surface area, while had a significant positive correlation with biomass. The study shows that the effects of soil depth and spruce root order on diameter, specific root length, root length density, specific surface area, and biomass are not consistent, that is, there is heterogeneity in the response of root functional traits to environmental conditions.

Abstract:In this study, Illumina Miseq sequencing technology was used to determine the diversity and community structure of arbuscular mycorrhizal (AM) fungi in the rhizosphere of Ophiopogon japonicus in both cultivated and wild habitats, and the correlation analysis was carried out in combination with soil physical and chemical factors, in order to clarify the distribution characteristics of AM fungi in the rhizosphere soil of O. japonicus in the two habitats and the distribution characteristics of dominant communities, explore the driving factors of the differences in the distribution of AM fungi communities, and provide theoretical basis and technical support for the application of AM fungi in the production of O. japonicus. The results showed that: (1) 10 species of AM fungi were identified from the rhizosphere soil of O. japonicus in different habitats. Among them, 7 species of AM fungi were identified from the rhizosphere soil of wild O. japonicus in 3 genera, belonging to the genera Acaulospora, Diversispora, and Glomus, respectively. 1 genus and 6 species of AM fungi were identified under the cultivation environment, belonging to the genus Glomus, and the dominant genus in both habitat were Glomus. (2) There were significant differences between the AM fungi in the rhizosphere of O. japonicus in different habitats. The AM fungi diversity index of the rhizosphere soil of O. japonicus in the wild habitat, ACE and Shannon, were both greater than those in the artificial habitat, while the Simpson index was the opposite. (3) Correlation analysis shows that AM fungal diversity index and community structure related to soil physical and chemical factors. Among them, total potassium (TK), total phosphorus (TP), and total nitrogen (TN) contributed to the differentiation of the AM fungal diversity index and community structure under different habitats. This study demonstrated that there are significant differences in the rhizosphere AM fungal community of O. japonicus in different habitats. Glomus is the key genus of O. japonicus mutually beneficial symbiosis. TK, TP and TN are the main driving factors for the differences in the rhizosphere AM fungal community of O. japonicus in different habitats.

Abstract:The transient transformation system plays an important role for initially and rapidly verifying gene functions and identifying related phenotypes. To improve the transformation efficiency and stability of transient transformation system of the Chinese chestnut callus and to identify the function of the Chinese chestnut starch synthase gene (CmSSⅠ), we optimized the transient transformation system of Chinese chestnut callus through different states of callus tissues and expression vectors by using the callus tissues induced from young embryos of Chinese chestnut ‘Yanshanhongli’. The results showed that: (1) callus was divided into an embryogenic callus (EC_E) and early stage of embryogenic callus (EC_D Ⅰ, Ⅱ and Ⅲ) based on the difficulty level of initiating somatic embryo. The early stage of embryogenic callus with white and relatively dispersed texture (EC_D Ⅲ) were more suitable for the transient transformation system of Chinese chestnut callus. (2) The transient transformation efficiency of RNAi silencing vector pK7GWIWG2 (Ⅱ) RR277 was the highest at 87.67% when the transformed material was at the early stage of embryonic callus (EC_D Ⅲ). (3) The expression of CmSSⅠ gene was significantly downregulated in the transgenic callus tissues by the optimal callus transient transformation system, and the contents of total starch and amylopectin of the CmSSⅠsilenced positive callus were significantly reduced, and amylose content was not significant differences. In this study, the efficiency and stability of the transient transformation system of Chinese chestnut callus tissues were improved, and it was demonstrated that the gene CmSSⅠ was regulating the synthesis of Chinese chestnut starch. This laid a foundation for the study of Chinese chestnut gene function and further provided a technical platform for molecular assisted breeding.

Abstract:Picea meyeri was listed as Ⅱ protected rare and endangered species in Inner Mongolia in 1989. Based on the records of 50 effective distribution points and 12 environmental factor variables of P. meyeri in China, this study used MaxEnt model and ArcGIS software to analyze the potential geographical distribution of P. meyeri in China in four periods of midHolocene, modern, 2050 and 2070. The contribution rate of environmental factors and the knifecut test were used to determine the dominant factors limiting the modern potential geographical distribution, and the response curve was used to determine the appropriate range of environmental factor variables, so as to clarify the potential geographical distribution area and area of P. meyeri in different periods, and provide the basis for the introduction and protection management of P. meyeri. The results showed that: (1) the area of receiver operating curve (AUC) predicted by MaxEnt model was 0.979, indicating that the prediction accuracy of the model was accurate and the reliability of the prediction results was high. (2) The main climatic factors affecting the potential distribution of P. meyeri and their suitable growth ranges are: altitude (1 200-2 300 m), the ratio of diurnal temperature difference to annual temperature difference (25%-28%), the wettest monthly rainfall (90-145 mm) and the annual average temperature (0-5 ℃). (3) The potential geographical distribution of P. meyeri which is mainly located in the middle and western part of Inner Mongolia (Jiufeng Mountain, Zhenglan Banner, Duolun County), most of Shanxi Province (Dashidong, Wutai Mountain) and part of Hebei Province (Wuling Mountain, Saihanba) in China has total area of 1.0356×10⁶ km². (4) From the middle Holocene to modern climate conditions, the potential distribution area of P. meyeri in the northern high latitudes of Inner Mongolia decreased, the survival suitability decreased, and most of the most suitable areas in central Inner Mongolia lost; under the RCP2.6 emission scenario in 2070, the suitable areas of P. meyeri in low latitude areas such as Shanxi Province and Hebei Province were also basically lost. Compared with the modern distribution area, the suitable areas of P. meyeri under future climatic conditions were reduced and migrated to the northeast of Inner Mongolia. Studies have shown that from the middle Holocene to 2070, the potential distribution area of P. meyeri gradually narrowed, and there was a trend of migration to high latitude and high altitude areas, and its most suitable area also moved to northeast Inner Mongolia.

Abstract:Based on literature review and field investigation, the seed plants flora of Xilin Gol Grassland National Nature Reserve were investigated and analyzed. Meanwhile, the species composition, water ecotypes and geography elements of seed plants in this area were counted by statistic method. The results showed that there are 856 species wild seed plants which belong to 345 genera and 87 families. Of which, there are 11 Gymnosperms species which belong to 5 genera and 3 families; 845 Angiosperm species which belong to 340 genera and 84 families. There are 559 species of mesophytes, accounting for 65.30% of the total species of the flora; and 213 species of xerophytes, accounting for 24.88% of the total species of the flora. The lifestyle is mainly herbaceous plants, accounting for 88.67% of the total species of the flora. The types of floristic geographical elements are complex, which reflects not only the strong regional characteristics of plants in the reserve, but also the characteristics of diverse habitat types and high plant richness in the region.