Abstract:Two squalene epoxidase (SE) genes were cloned by reverse transcription polymerase chain reaction (RTPCR) from Tripterygium wilfordii hairy root. The genes are named as TwSE1 (GenBank accession MG717395) and TwSE2 (GenBank accession MG717396). Sequence analysis indicates that the open reading frame of TwSE1 and TwSE2 genes were 1 578 bp and 1 584 bp, which encoding 525 and 527 amino acids. Two amino acid sequences from TwSE1 and TwSE2 shared 76.18% similarity, but were highly divergent in Nterminal regions. Further, gene expression pattern in different tissues and the expression level of TwSE in T. wilfordii hairy root after treatment by methyl jasmonate (MeJA) was detected by realtime PCR. TwSE1 and TwSE2 genes were expressed in roots, stems, young leaves, old leaves and flowers of T. wilfordii. TwSE1 expressed the highest in flowers and lowest in roots, but TwSE2 expressed the highest in flowers and lowest in old leaves. The expression of TwSE2 was lower than that of TwSE1 in all tissues. MeJA treatment enhanced the TwSE1 and TwSE2 expression in hairy roots. The expression level of TwSE1 and TwSE2 has a increasing tendency in the early stage, then decreased in the middle stage and increased in the late time. The highest expression was reached after the treatment of 3 h, then decreased, and the expression level increased rapidly after 12 h. In same treatment condition, the increase of TwSE2 gene expression level was less than that of TwSE1 gene.

Abstract:In the present study, a pair of homologous genes BrrHMA2.1 (GenBank is MG_283237) and BrrHMA2.2 (GenBank is MG_283238) of the heavy metal ATPase (HMA) family in turnip (Brassica rapa var. rapa) was cloned and their protein sequence characteristics and gene expression patterns were analyzed. (1) The fulllength open reading frames of these two genes were 2 619 and 2 724 bp and they encoded 872 and 907 amino acids, respectively. Sequence structure analysis showed that both BrrHMA2.1 and BrrHMA2.2 proteins included six transmembrane regions and conserved domains of HMA family. Phylogenetic tree analysis showed that BrrHMA2.1 and BrrHMA2.2 proteins had the closest evolutionary homology with AtHMA2. (2) The results of subcellular localization indicated that both BrrHMA2.1 and BrrHMA2.2 proteins were localized in the plasma membrane. (3) qRTPCR analysis showed that the expression levels of BrrHMA2.1 and BrrHMA2.2 genes were much higher in leaves at the early stage of turnip. However, the expression levels of these two genes in leaves gradually decreased whereas those in roots gradually increased with the increasing growth time. In addition, the results also found that BrrHMA2.1 gene was induced by Cd²⁺, Zn²⁺, Na⁺ and Mg²⁺ while BrrHMA2.2 gene was induced by Cd²⁺, Na⁺ and Cu²⁺ stresses, indicating these two genes may play roles in coping with these metal ions. This study provides foundation for further functional studies on plant HMA genes in heavy metal tolerance or transport.

Abstract:Based on the tea plant transcriptome database, we cloned two fulllength cDNAs of the isopentenyl diphosphate isomerases (CsIDI1 and CsIDI2) using RTPCR method from the tea plant cultivar of Tieguanyin. CsIDI1 was 1 378 bp in length and contained a 894 bp ORF encoding 297 amino acids, which shared 95% similarity with Vitis vinifera IDI. Subcellular localization prediction showed that CsIDI1 was localized to the chloroplast. Additionally,the length of CsIDI2 was 1 216 bp and contained a 717 bp ORF encoding 238 amino acids, CsIDI2 had similarity with 96% homologous to Sesamum indicum IDI and predicted to was located on the cytoplasm. Both CsIDI1 and CsIDI2 contained a typical NUDIX hydrolase domain. The results of realtime quantitative PCR showed that CsIDI1 and CsIDI2 were expressed in different tissues of tea plant，wherease the expression of CsIDI2 was relatively higher, The expression of CsIDI1 and CsIDI2 was significantly higher in female parent Huangdan and high scent hybrids than that in male parent Tieguanyin, showing the heterosis of aroma. During the greenmaking procedure of Oolong tea , the expression level of CsIDI2 was significantly higher than that of CsIDI, indicating that CsIDIs play an important role in the formation of tea terpenoids aroma.

Abstract:In order to discuss the etiolation mechanism and provide a theoretical basis in citrus breeding programs, we studied the relationship among photosynthetic characteristics, photosynthetic pigment content and the relative level of CgSGR expression of three graft combinations. Citrus grandis (L.) Osbeck. cv. ‘Hongmian miyou’ （Hm/Pt） and ‘Guanxi miyou’ grafted on Poncirus trifoliata （Gx/Pt）, and ‘Hongmian miyou’ grafted on C. junos (Hm/Cj) were used as the experimental materials. The results were showed as follows. (1) The photosynthetic rate, stomatal conductance, transpiration rate and mesophyll carboxylation efficiency of Hm/Pt were significantly lower than that of Gx/Pt and Hm/Cj; (2) The three graft combinations had similar change trend of chlorophyll content, while the chlorophyll a, b and total chlorophyll in Hm/Pt were significantly lower than that of control groups; (3) The open reading frame (ORF) of CgSGR was 816 bp, encoding 271 amino acids (GenBank accession number: MF945620). The deduced protein molecular weight was 30.62 kD, which was a stable alkaline hydrophilic protein. According to multiple sequence alignment analysis, the sequence of ‘Hongmian miyou’ and ‘Guanxi miyou’ were high consistency with C. grandis, C. sinensis and C. clementina. Based on phylogenetic tree analysis, CgSGR keep closest genetic relationship with C. grandis, C. sinensis and C. clementina, and relatively close with Litchi chinensis; (4) RTqPCR results showed that CgSGR expression levels were upregulated in Hm/Pt when the plants initiated etiolation. The CgSGR transcripts reached the highest level grafted after 404 days; (5) With the growth of the grafted seedlings, the trend of expression level of CgSGR was opposite with the net photosynthetic rate and chlorophyll content. The results indicated that CgSGR might be involved in transcriptional regulation during the seedling etiolation of C. grandis ‘Hongmian miyou’ grafted to P. trifoliata.

Abstract:In this study, the fulllength sequence of fructokinase gene (LbFRK7) was obtained by using RTPCR from wolfberry (Lycium barbarum Linn.) ‘Ningqi No.1’ fruit based on TR28373|c0_g1 transcriptome sequencing. The fulllength sequence of LbFRK7 was 1 060 bp （ORF length 1 044 bp）and encoding a polypeptide of 348 amino acids. The relative molecular weight was 37.44 kD and the theoretical isoelectric point (pI) was 5.05. The amino acid sequence of LbFRK7 contained three highly conserved specific regions interent to the pfkB family of carbohydrate kinases, two substrates recognition locus and four ATP binding locus. Homologous genes comparison indicated that LbFRK7 had more high similarity with tobacco and pepper fructokinase genes（90% homology）. The change of LbFRK7 expression was founded in different plant tissues by quantitative realtime PCR. LbFRK7 expressed in the highest in fruits and in the lowest in roots. LbFRK7 expression of fruits showed a trend on firstly rising and then falling during fruit ripening, and reached on the highest level at 15 days after full bloom. LbFRK7 expression had a similar trend with fructose content at the early stage of fruit development, while there was an opposite change between LbFRK7 expression and fructose content at the mid and late stages. LbFRK7 expression was not significantly correlation with fructose and sucrose contents by correlation analysis (r₁=-0.326, r₂=-0.339). Therefore, LbFRK7 played a role on converting fructose during wolfberry fruit development, particularly on increasing of fructose content during the process of fruit ripening. This study provided a reference basis on researching into function of LbFRK7 and metabolism of fructose.

Abstract:Two red pomegranate cultivars ‘Hongbaoshi’ and ‘Moshiliu’ were sampled as plant materials. The transcriptional characterizations of CHS, CHI, F3H, DFR, ANS, and UFGT involved in anthocyanin biosynthesis were monitored by qRTPCR during fruit development. The relationships between contents of total anthocyanins in fruit peels and transcription abundance of these genes were also analyzed. Results showed that: (1) during fruit development, the content of total anthocyanins in ‘Moshiliu’ was much higher than that in ‘Hongbaoshi’ pomegranate. The content of total anthocyanins in ‘Hongbaoshi’ increased gradually with fruit development, while in ‘Moshiliu’, the content of total anthocyanins was high at early stages and then decreased at later periods. (2) In ‘Hongbaoshi’ pomegranate, transcripts of CHS, CHI, F3H, DFR, and UFGT were most abundant at early and late stages in fruit development. The transcription level of ANS in ‘Hongbaoshi’ increased gradually and reached the highest amounts at the late phases. In ‘Moshiliu’ cultivar, the transcription levels of all detected genes except UFGT remained high at early stages, and then showed a declining trend afterwards. The expression level of UFGT gene in ‘Moshiliu’ reached peak at middle stage. (3) The correlation analysis results showed that a significant positive correlation between ANS abundance and anthocyanins content in ‘Hongbaoshi’ cultivar, while ‘Moshiliu’ cultivar, there was strong positive correlation between CHS and ANS levels and anthocyanins content. It might be concluded that the different red coloration between two pomegranate cultivars was due to the differential expression of the anthocyanin biosynthetic genes at initial and final phases. ANS gene played a key role in ‘Hongbaoshi’ coloration, CHS and ANS played important roles in anthocyanin accumulation of ‘Moshiliu’ pomegranate.

Abstract:Gastrodia elata Bl. is a rare and endangered traditional medicinal plant in China.The difference among germplasms is tiny in morphological characteristics, while is prominent in medical components, which results in its germplasm confusion in both cultivation and pharmacy. With the aim to construct DNA fingerprinting for G. elata germplasm, we used simple sequence repeat (SSR) molecular markers in this study to analyze the population genetic structure for G. elata with its 120 samples collected from 12 populations of its 3 forms (G. elata Bl. f.glauca S. Chow, G. elata Bl. f.elata, G. elata Bl. f. viridis Makino). As the results shows: (1) seven pairs of SSR primer were successfully used in the PCR amplification, and performed abundant polymorphism, the number of allele per primer pair (N_a) ranged from 5 to 7 with the average of 6.43, while the polymorphism information content (PIC) ranged from 0.626 2 to 0.823 5 with the average of 0.759 5. (2) Genetic diversity analysis of all samples of G. elata showed that the genetic diversity was high (species level: A=6.428 6, H=0.789 0, I=1.682 9; form level: A=2.666 6, H=0.523 9, I=0.812 3). (3) Analysis of molecular variance (AMOVA) analysis revealed strong genetic differentiation was happened among both populations and the forms (F_st=0.558 6, F_ct=0.381 8). (4) Cluster analysis showed that the populations of the same form clustered together firstly, 3 forms were separated completely. SSR fingerprinting had a good identification effect at the form level; 106 genotypes were detected from the 120 samples in total. The Simpson index (D) was 0.998, indicating the SSR fingerprinting has good ability of identification on the individual level. The study revealed the genetic background of G. elate, which provided scientific and technical basement for its conversation,germplasm selection and identification.

Abstract:In order to reveal the genetic variation and relationship of large old poplars, we collected 226 samples on 7 Populus species from 15 populations that distributed in southwest China, and molecular marker of the large old poplars was conducted by SSR technology, which will provide the basis for reasonable protection and utilization of large old poplars in this area. The results showed that: (1) 80 polymorphic loci were amplified by 7 pairs of primers. According to the values of the number of effective alleles, the genetic diversity among the large old poplars of 7 Populus species was in the order of P. schneideri > P. qamdoensis > P. kangdingensis > P. szechuanica var. tibetica > P. xiangchengensis > P. szechuanica > P. haoana, and the genetic diversity among populations within 5 Populus species were Daocheng population > Xiangcheng population > Yajiang population in P. xiangchengensis, Litang population > Xiangcheng population > Daocheng population in P. schneideri, Shangrila population > Deqen population in P. haoana, Markam population > Gonjo population > Qamdo population in P. qamdoensis, and Deqen population > Markam population in P. szechuanica var. tibetica, respectively. (2) The inbreeding coefficient (F_is) within population of P. xiangchengensis, P. schneideri, P. szechuanica var. tibetica, P. haoana and P. qamdoensis was -0.024 6, -0.253 5, 0.205 4, 0.240 1 and 0.029 2, respectively. The coefficient of genetic differentiation (Fst) was 0.156 1, 0.253 5, 0.128 8, 0.182 0 and 0.177 3, respectively, among the populations of P. xiangchengensis, P. schneideri, P. szechuanica var. tibetica, P. haoana and P. qamdoensis. Gene flow (N_m) among populations of P. xiangchengensis, P. szechuanica var. tibetica, P. haoana and P. qamdoensis was more than 1, except P. schneideri. (3) The genetic similarity coefficient among the 7 Populus species was ranged from 0.089 0 to 0.691 0, with the average of 0.402 0. The UPGMA clustering and Bayesian analysis both indicated that the 7 Populus species was divided into three groups. P. schneideri and P. kangdingensis comprised the first group, the second group consists of P. xiangchengensis and P. schneideri, while P. szechuanica var. tibetica, P. haoana and P. qamdoensis were at the third group. The UPGMA cluster result among populations revealed that the Litang population of P. schneideri was clustered with P. xiangchengensis, while the populations of other species were clustered closely. These results demonstrated that the large old poplars held high level of genetic variation, and the genetic variation mainly existed in different individuals within population, which means that the genetic diversity of large old poplars will decrease or loss results from the loss of individuals. Thus, it is essential to protect the large old poplar resources distributed in these areas.

Abstract:The study set of simple sequence repeat (SSR) markers were developed using Restriction site Associated DNA (RAD) approach and Illumina pairedend sequencing to the whole genome of endangered plants Rhododendron molle G. Don. And it would provide technical support for further investigation of population structure and diversity of R. molle and other congener species from the evaluation of 63 individuals from three different populations. The results showed that: (1) the sequencing output generated a FASTQ file size of raw reads 7.653G bp, and the clean reads was to 7.513G bp. About 171.534 M bp of R. molle genome distributed over 498 252 contigs were obtained upon assembly of sequencing data. (2) After filtering and SSR detection, a final set of 11 687 simple sequence repeats with primers were obtained from 11 961 microsatellite loci. The dinucleotides motif unit were the most abundant (51.76%) repeat sequences. (3) 128 microsatellite markers were selected randomly to detect the polymorphism in 6 different individuals of R. molle, from which 20 polymorphic primers were identified. (4) Then the characteristics and availability of polymorphic primers were further evaluated in 63 individuals from three different populations. The number of alleles per locus ranged from 4 to 16, expected heterozygosity (H_e) values ranged from 0.489 to 0.908, respectively. Our result showed that the abundance of SSR existed in R. molle was moderate and the dinucleotides were the most abundan repeat sequences. It further confirms that the RADseq method is an efficient and costeffective means for SSR discovery, and these polymorphic microsatellite markers developed in this study will be useful for further investigation of population structure and diversity of R. molle and other congener species.

Abstract:This paper used SEM to observe the flower organ ontogeny process, in order to know the flower base number of Phytolacca and whether or not its stamen and pistil derived from leave, than to clarify the model of Phytolacca flower ontogeny. The results show that: (1) after flower primordia initiated, two bractlets of two species initiated one by one. Than the perianths initiated one by one, the bractlets and perianths initiated can be clockwise or counterclockwise, and they are with the same direction. They all initiated by 2/5 circumference spiral. (2) When the perianths had initiated over, the stamens initiated on ring meristem of flower top meristem, and the stamens ontogeny almost at same time, and there is no any order; and while the flower has two rounds of stamen, the inner round first initiate, in some time, the out stamen alternate with perianths, out round stamens also did not opposite to perianths. (3) Carpels of two species initiate alternate with stamen (or inner stamen), and carpel initiates almost at same time, no order. Phytolacca flower is 5 base number flower, but the stamen and carpel were not fit with 5 base number, because they all initiated on ring meristem. (4) The flower of Phytolacca ontogeny is no any relation with 3 base number flower. When stamens are multiround, the out round initiate lately. At the end, the flower of Phytolacca is 5 base number, and the results did not support the flower of Phytolacca is 3 base number ontogeny model.

Abstract:To explore the effects of DELLA protein deficiency on drought tolerance in Arabidopsis, we treated DELLA proteins deficient mutant della by drought stress. The survival rate, germination rate, water loss rate, and contents of proline, soluble sugar, and malondialdehyde were measured. Meanwhile, the gene expression patterns of the late embryogenesis abundant protein coding genes LEAs, which play important roles in dehydration protection of plant cell, and ABA responsive genes, such as LOX3, COR15b, and COR413, were investigated by qPCR. The results showed that: (1) after 21 days of drought stress and rewatering treatment, the survival rate of della mutant was significantly higher than that of wild type Ler; (2) the germination rate of della mutant was markedly higher than that of Ler on 1/2 MS with mannitol; (3) the water loss speed of leaves detached from della mutant was distinctly slower than that of Ler; (4) the contents of proline, soluble sugar, and malondialdehyde in della mutant were lower than that of Ler; (5) the upregulated expression of LEA genes in della mutant was higher than that of Ler, while the upregulated expression of ABA responsive genes was lower. These results suggest that the deficiency of DELLA proteins improves the drought resistance in Arabidopsis.

Abstract:The objective of the present study is exploring the effect of exogenous GA₃ and 6BA on biennial bearing, flowering and branching in “Fuji”. Using 4yearold “Fuji” trees, we sprayed 75 mg/mL GA₃ or 6BA at several different growth periods. we also sprayed 50 mg/mL and 100 mg/mL GA₃ or 6BA at different spraying repeat (single spraying or multiple spraying). The flowering rate, branching rate and endogenous hormones (GA₃, IAA, ABA, ZT) in different types of tree branches were tested. The results showed that: (1) at all growth periods, GA₃ treatment promoted the accumulation of endogenous GA₃ and ABA in terminal buds, but inhibited the synthesis of ZT in all types of branches and IAA in short branches, decreased the flowering rate of different types of branches , promoted branching rate in short branches. 6BA treatment promotes the synthesis of GA₃, ABA, IAA , ZT and flowering rate in all terminal buds of different branches, the branching rate of short shoots, the elongation of long branches also increased. (2) Single spraying of GA₃ inhibited the synthesis of IAA, promoted the accumulation of GA₃, ABA in all branches terminal buds and ZT in short branches. The flowering rate and the elongation of branch were inhibited, the shoot forming rate was promoted by this treatment. the effect of GA₃ on ZT increased with the increase of GA₃ concentration. Multiple spraying of GA₃ increased the accumulation of GA₃ and IAA in all terminal buds, but decreased the content of ABA in the short branches, had no effect on ZT. The long branch increased, the flowering rate and the branch forming rate decreased by this treatment. (3) Single application of 6BA increased the contents of GA₃ and ABA in short terminal buds and ZT content in all branches, but inhibited the synthesis of GA₃ and ABA in long branches and IAA synthesis in all terminal buds. It inhibited the elongation of short branches and promoted the elongation of long branches. Multiple spraying of 6BA increased the contents of GA₃ and IAA in all terminal buds and ZT in short branches, decreased the contents of ABA in all branches and ZT in long branches, and inhibited the flowering rate and elongation of all branches. There was no significant effect on the branching rate and the elongation of long branch. In conclusion, the use of exogenous hormones at different growth stages can promote the synthesis of GA₃ and ABA in the top buds, but the effects of the contents of IAA, ZT, the rate of flower formation, the branching rate and the length of the branches vary with the treatment period. The spraying times and concentrations had different effects on endogenous hormones synthesis, shoot forming rate and branch elongation, but they all inhibited flower bud differentiation and flowering rate.

Abstract:Using the main rose cultivars in Yunnan Province， ‘Carola’(red)，‘Movie Star’ (pink) and ‘Tineke’ (white) as the experimental materials, we researched the effects of drought stress on the petals relative moisture content, soluble protein content, membrane peroxidation and antioxidant enzyme activities. Our results showed that: （1）relative moisture content and soluble protein content of the pedals decreased during the drought stress, while the malondialdehyde (MDA) content kept increasing and reached the peak at the fifth day and Tinekes MDA content was the highest. （2）The activities of the petals superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) and glutathione reductase (GR), ascorbic acid peroxidase (APX) declined after rising. CAT, POD, APX and GR reached the maximum on the third day, which illustrated the petal cells had the highest abilities of removing reactive oxygen species(ROS). Then the pedals antioxidant capacity decreased sharply and the pedals began to senescence and die. The APX activities of three rose varieties did not decline significantly in the later period of drought stress, which indicated that APX played a more important role in drought resistance in the later treatment. The SOD activity of Corolla had the largest increase under the drought stress, and its average activity was also the highest among the three varieties. The POD activity of Corolla reached the maximum at the third day, which was 9.2 times of that of Tineke, indicating that the Corollas droughttolerant was stronger. （3）According to the average value of membership function, the drought resistance ability of rose is sorted, following as: Carola> Movie Star>Tineke. In conclusion, our results suggest that the three cut rose varieties enhance their droughttolerant ability by increasing the activities of antioxidant enzymes and the degree of peroxidation of petal membranes is aggravated by drought stress. Different varieties show different drought resistance, especially Carola displays higher droughttolerant ability.

Abstract:In this study, salicylic acid (SA), methyl jasmonate (MeJA), Ca²⁺, and sterile water as a control were used as exogenous inducers to pretreat the melons for resistance and susceptibility to fusarium wilt. Two days after the induction of pretreatment, they were inoculated with F. melilocarpa, and the incidence was observed on the 5, 7 and 9 d after inoculation. The disease status was investigated, and melon leaves were taken at 1, 3, 5, 7 and 9 d after inoculation. Expression changes of Fom2 and CHT in resistant melon (MR1) and susceptible melon (M115) leaves were evaluated in order to check the wilt in control wilt with the technical way of dyeing. The results showed that: (1) the disease indexes of the two varieties after inoculation with exogenous MeJA and SA were significantly lower than that of the control and there was no significant difference between the condition index after Ca²⁺ treatment and the control. (2) After inoculated with exogenously induced pretreatment, the expression of Fom2 and CHT genes in leaves of MR1 and M115 cultivars was different but the effect of Ca²⁺ on upregulation was not strong. (3) After inoculated with SA and MeJA, the expression of Fom2 and CHT genes in the leaves of the two cultivars were significantly higher than those of the control, but the expression level of Fom2 for resistant melon MR1, the peaks were reached at 5 d and 7 d and all susceptible melon M115 were peaked at 9 d after inoculation. The expression of CHT gene for resistant melon MR1 peaked at 7 d after inoculation. M115 showed peak at 7 and 9 days after inoculation, respectively. (4) There was no significant effect of Ca²⁺ treatment on the expression of Fom2 and CHT genes in muskmelon leaves. (5) The correlation analysis showed that the disease index of Fusarium wilt was correlated with the expression levels of Fom2 and CHT genes after SA and MeJA induced pretreatment inoculation. The effect of Ca²⁺ treatment is not significant.

Abstract:Twoyearold potted Malus baccata seedlings was used as experiment materials. Normal watering was used as the control CK, different concentrations of ALA (0/25/50/75 mg/L) were sprayed under drought stress. The physiological indexes of drought resistance and photosynthetic fluorescence parameters in leaves at different periods of continuous stress (day 0/4/8/12) were measured. The effects of ALA on chlorophyll fluorescence, physiological and biochemical characteristics of chlorophyll fluorescence and its regulation mechanism under drought stress were studied. The results showed that: (1) exogenous ALA increased the contents of osmolytes (SS, SP, Pro) and promoted the activities of antioxidant enzymes (SOD, POD and APX), while reduced the accumulation of malondialdehyde (MDA) in M. baccata under continuous drought stress conditions; (2) exogenous ALA increased the stomatal opening in leaves of M. baccata, promoted the synthesis of chlorophyll, and significantly alleviated the decrease of the maximum photochemical rate of chlorophyll fluorescence parameters (F_v/F_m), the actual photochemical efficiency (Y_Ⅱ), the photochemical quenching coefficient (qP) and the photosynthetic electron transport rate (ETR), as well as the increase of the quantum yield of PSⅡ regulated energy dissipation (Y_NPQ), quantum yield of nonregulated energy dissipation (Y_NO) and nonphotochemical quenching coefficient (NPQ/4) induced by drought. The results showed that the application of ALA could relieve the damage of the physiological and metabolic function of M. baccata under drought stress. However, there was a difference in response to different concentrations of ALA in M. baccata, of which 75 mg/L ALA had the most significant effect.

Abstract:A pot experiment was conducted to study the effects of different water treatments (normal irrigation，light drough，moderate drought，and severe drought) on the quality，gas exchange and chlorophyll fluorescence characteristics of purple cabbage(Brassica campestris ssp. chinensis var. communis Tsen et Lee). The result showed that: (1) with the increasing extent and duration of drought stress，the maximal anthocyanin content, the soluble sugar, soluble protein and vitamin C contents of the purple cabbage leaves increased gradually under light drought stress, while decreased rapidly under both moderate and severe drought stress. (2) As compared with those under normal irrigation, the chlorophyll a, chlorophyll b, chlorophyll (a+b) and carotenoid contents all increased gradually under light drought stress, while decreased rapidly under both moderate and severe drought stress. (3) With the degree of drought treatment, the net photosynthetic rate (P_n), stomatal conductance (G_s) and transpiration rate (T_r) all decreased gradually under light drought, moderate and severe drought stress, while water use efficiency (WUE) increased firstly and then decreased. (4) With the degree of drought treatment, performance index on absorption basis (PI_ABS) decreased rapidly under all drought stress, while absorption per active reaction centers(ABS/RC), trapping per active reaction centers(TR_O/RC), electron transport per active reaction center(ET_O/RC), dissipation per active reaction centers(DI_O/RC)all increased gradually under drought stress, trapping per excited crosssection(TR_O/CS), dissipation per excited crosssection (DI_O/CS) both decreased rapidly under all drought treatments. The maximum quantum yield of PSⅡ (ψ_PO), efficiency that a trapped exciton can move an electron into the electron transport chain beyond Q_A^-（ψ_O）, probability that an absorbed photon will move an electron into the electron transport chain beyond Q_A^-(ψ_EO) all decreased rapidly under all drought treatments. The value of relative variable fluorescence at Jstep (V_J) increased more than the value of the ration of fluorescence F_K to the amplitude F_JF_O (W_K), while the increasing of the maximum rate of reduction(M_O) stated that Q_A be restored. Those results suggest that under light drought treatment, the anthocyanin and photosynthetic pigment contents increased. Moreover, the photosynthetic rate and the quality of plant nutrition improved. It is worth popularizing and applying in the dry production of purple cabbages.

Abstract:We explored the response mechanism of photosynthetic physiological parameters of wild Ziziphus jujuba var. spinosa to soil drought under the natural condition in the area of central and southern Shandong Province, and the quantitative relationship between the change process, mechanism and soil moisture under different water gradients. This paper studied wild Z. jujuba var. spinosa seedlings of 2 years old, and by artificial water supply and natural water consumption to simulate the soil drought under natural condition, studied the response process and mechanism of photosynthesis and fluorescence parameters of wild Z. jujuba var. spinosa leaves to the soil moisture (RWC). The results showed the following. (1) The gas exchange parameters in leaves of wild Z. jujuba var. spinosa which is the net photosynthetic rate (P_n), transpiration rate (T_r) and water use efficiency (WUE) were increased firstly and then decreased with the increase in soil water content. When the RWC <38.5%, the net photosynthetic rate (P_n) and the stomatal limitation (L_s) were both decreased, while, the intercellular CO₂ concentration (C_i) was increased, which indicated that the decline of the photosynthetic rate of the leaves was mainly caused by nonstomatal limitation. When RWC = 38.5%-65.1%, the net photosynthetic rate (P_n) was decreased, the intercellular CO₂ concentration (C_i) and stomatal conductance (G_s) were both decreased, and the photosynthetic rate of the leaves was also decreased in leaves of Z. jujuba var. spinosa at stomatal limitation stage. Therefore, the decline of the photosynthetic rate of wild Z. jujuba var. spinosa is about RWC=38.5% from the stomatal limit to the non stomatal limit. (2) The soil water content in leaves of wild jujube leaves with high photosynthetic productivity was 46.0%-80.5% by threshold simulation of P_n and WUE, and that of higher water use efficiency was 56.3%-73.9%. (3) In the process of soil drought (RWC range of 29.9%-86.5%) , the maximum fluorescence (F_m), the maximum photochemical efficiency of PSⅡ (F_v/F_m), and the PSⅡ actual photochemical efficiency (Φ_PSⅡ) gradually decreased, the initial fluorescence (F_o) was significantly increased, the photochemical quenching (qP) was increased first and then decreased, the Nonphotochemical quenching (NPQ) was exhibited higher values with the excess or low of the soil moisture (RWC> 83.7%; RWC <38.5%), which showed that the heat dissipation of Z. jujuba var. spinosa was increased. The results showed that the parameters of gas exchange and chlorophyll fluorescence in leaves of wild Z. jujuba var. spinosa have obvious threshold response to soil moisture, and the RWC was about 38.5% at the threshold point. When RWC <38.5%, the photosynthetic rate of the leaves changed from stomatal limitation to nonstomatal limitation, the PSⅡof wild Z. jujuba var. spinosa was damaged, the electron transport was blocked and the photosynthetic mechanism was destroyed.

Abstract:In order to study the effects of exogenous 5aminoacetyl propionic acid (ALA) on the growth and chlorophyll fluorescence induction kinetics of Scenedesmus obliquus, we spiked ALA to cultured S. obliquus, using two methods onetime spike (ALA) or everythreeday spike (CALA) and tested its growth response at 5, 15, and 25 ℃, respectively. The chlorophyll fluorescence parameters were measured in the logarithmic phase. The results illustrated: (1) A consistent pattern at 5 and 15 ℃ for ALA treatment, which had the greatest maximum growth rate (μ_max) and we tested a 122.7% and 126.8% increase of μ_max related to the control. (2) The μ_max of CALA was higher than that of control, suggesting that adding ALA can promote the growth of S. obliquus, particularly at 5 ℃ where a more evident significance observed. Furthermore, the decline of the maximum quantum yield of primary photochemistry (F_v/F_m) and the performance index on absorption basis (PI_ABS) were significantly lower with ALA treatment than that of control. Besides, the parameter of F_ok, F_kj, F_ji, and F_ip were significantly higher than that of CK. (3) By analyzing the JIPtest parameter, we observed a reduced light energy absorbed by the active reaction center of S. obliquus with ALA treatment in addition to a declined heat dissipation, indicating that more energy can pass through the electron transport chain and participate in photochemical reactions. Visible, these evidences support the view that exogenous ALA can promote the growth of S. obliquus to some extent, and the promoting effect is more obvious in 5 ℃ low temperature; ALA treatment can boost the photosynthetic efficiency, improving the Q_A, Q_B, and PQ significantly (P<0.05); the ALA significantly protect PSⅡ with the environmental temperature decreasing within a certain temperature range

Abstract:The dynamic variation of ultraweak luminescence (UWL)and energy level, and their relationship under stress of 20% PEG treatment and drought stress with regulating of reactive oxygen by carrying out four treatments of PEG, PEG+hydrogen (H₂O₂), PEG+sodium benzoate and distilled water（CK）in Sedum hybridumseedling to supply theoretical basis for understanding the generation of UWL. The results showed: (1) in process of drought stress by PEG treatment, ATP content, energy charge and UWL intensity all decreased; above energy index and UWL intensity of PEG treatment decreased more rapidly and showed a bigger drop. (2) Under drought stress with regulating by H₂O₂ and sodium benzoate, ATP content, energy charge and UWL intensity of treatments of PEG+H₂O₂ and PEG+sodium benzoate all decreased along with stress time as well as PEG treatment; However, above energy index and UWL intensity of PEG+H₂O₂ were lower than those of PEG treatment, while above energy index and UWL intensity of PEG+ sodium benzoate were higher than those of PEG treatment. (3) Correlation analysis also showed that UWL intensity was positively correlated with ATP content and energy charge both under drought stress and under drought stress with regulation of reactive oxygen. Above results indicated: under drought stress and drought stress with regulation of reactive oxygen, energy level represented by ATP content decreased more rapidly than that of CK, UWL intensity decreased more rapidly than that of CK too; UWL intensity decreased along with the decline of ATP content. which indicated that the generation of UWL in plants positively related to ATP level.

Abstract:In order to provide theoretical basis for high yield and good quality cultivation of Fagopyrum tataricum in the Loess Plateau, we determined the effects of combining different nitrogen (N application rates of 0 g/kg, 0.1 g/kg and 0.2 g/kg) and phosphorus fertilizer (P₂O₅ application rates of 0.1 g/kg and 0.2 g/kg) conditions on the root physioecological indices and yield during the growing period of F. tataricum under experimental pot conditions. The results showed that: (1) under equal phosphorus fertilizer treatments, plant height, stem diameter, shoot dry weight, main root length, root surface area, root volume, root average diameter, root dry weight and seedling index initially increased and then decreased with increasing nitrogen application rate while root shoot ratio decreased initially and then increased with increasing nitrogen application rate. Chlorophyll content, root activity, acid phosphatase activity, soluble protein content, plant N accumulation show the parabola changes with the increase of nitrogen application rate. Root NR activity and plant N content increased with increasing nitrogen rate while SOD, POD activities and MDA content in root, soluble sugar content and free proline content decreased initially and then increased with increasing nitrogen application rate. Weights per plant and 100seed weight initially increased and then decreased with increasing nitrogen application rate. (2) Under equal nitrogen fertilizer treatments, root Apase, SOD and POD activities, soluble sugar, soluble protein and MDA contents decreased with increasing phosphorus application rate. The other above indices increased under high phosphorus treatment compared with low phosphorus treatment. (3) Among the three nitrogen levels, yield of F. tataricum was the highest under 0.1 g/kg nitrogen application. It increased respectively by 7.04% and 37.40% compared with 0 g/kg and 0.2 g/kg nitrogen treatments under low phosphorus condition. It also increased respectively by 14.73% and 68.26% compared with 0 g/kg and 0.2 g/kg nitrogen treatments under high phosphorus condition. In addition, the yield of F. tataricum was higher in high phosphorus treatment. It also increased, respectively by 15.96% and 42.00% compared with low phosphorus treatment under equally nitrogen fertilizer treatment. (4) In this study, reasonable application of nitrogen and phosphorus fertilizer showed a positive additive effect, but overapplication of fertilizer could reduce yield. F. tataricum was more suitable for production at suitable nitrogen fertilizer (0.1 g/kg N application) and high phosphorus fertilizer condition (0.2 g/kg P₂O₅ application).

Abstract:Using ¹⁵N tracer technique, we quantify the characteristics of nitrogen absorption and distribution by organs of seven plant species in the Kobresia humilis alpine meadow, in order to reveal the ecological adaptability, competitiveness and position in the community of the main plants. The results showed: (1) the leaf and stem of K. humilis, the leaf of Elymus nutans, the leaf and stem and root of Scirpus distigmaticus and Pedicularis kansuensis can effectively accumulate nitrate nitrogen. The ear and leaf of Poa annua, the root of P. kansuensis and Lagotis brachystachya Maxim can effectively accumulate ammonium nitrogen. (2) Glycine and nitrate nitrogen absorbed by K. humilis mainly allocated in leaf and ammonium nitrogen allocated in stem. Glycine and nitrate nitrogen absorbed by S. distigmaticus mainly allocated in stem, ammonium nitrogen allocated in leaf. Inorganic nitrogen absorbed by E. nutans and P. annua allocated mainly in leaf. The glycine absorbed by E. nutans mainly allocated in root and by P. annua allocated in ear. Nitrate nitrogen mainly allocated in leaf and ammonium nitrogen allocated in root absorbed by P. kansuensis. The glycine and inorganic nitrogen absorbed by P. anserina mainly allocated in leaf. Glycine absorbed by L. brachystachya mainly allocated in leaf, while nitrate nitrogen and ammonium nitrogen mainly allocated in root. (3) Organic nitrogen and inorganic nitrogen in soil of K. humilis meadow mainly contributed to the flower of P. kansuensis, the ear of P. annua, the root of E.nutans and shoot of P. anserina at herbage growth stage. Absorption and distribution of nitrogen has diversified characteristics in different organs of the main plants in K. humilis meadow, that differed in the biological characteristics and ecological habits of different plant species.

Abstract:We studied leaf functional traits, namely, leaf dry matter content (LDMC), specific leaf area (SLA), leaf nitrogen content (LNC), leaf phosphorus content (LPC), and leaf nitrogen/phosphorus ratio (N/P) of three plants, which were Populus koreana, Artemisia sacrorum and Patrinia rupestris from 13 stablel plant communities in lava plateau of new volcano of Wudalianchi. We analyzed the variation among the functional traits to discuss the relationship and the adaption strategy of leaf function for the environment in lava plateau of new volcano. The results showed that:（1）LDMC was between 0.294‐0.359 g·g^-1, SLA was between 9.082-22.347 m²·kg^-1, LDMC was larger, and SLA was low in lava plateau of new volcano than that in other regions, which indicated that the higher LDMC and the lower SLA of plant were adjusted to adapt to the poor environment in lava plateau of new volcano of Wudalianchi.（2）LNC was between 9.690-15.710 g·kg^-1, LPC was between 0.669-1.078 g·kg^-1, LKC was between 10.410-29.830 g·kg^-1, N/P was between 9.781-20.990, LNC and LPC was low, LKC and N/P was larger in lava plateau of new volcano than that in other regions, which indicated that development of plant is mainly restricted by phosphorin in lava plateau of new volcano in Wudalianchi. while low LNC and greater LKC were related to soil N and K contents in lava plateau of new volcano;（3）Oneway ANOVA analysis revealed that varied leaf traits were low among community, and varied N/P, LDMC and SLA were low among the three plants also, which indicated that the similar adaptation strategies of plant to the dry and poor nutrient in lava plateau;（4）Pearson analysis revealed that N/P was significant negative correlated with LDMC and SLA.

Abstract:During a survey of freshwater algal diversity from streams in the Mount Maoshan, Jiangsu Province, China, a newly recorded diatom, Brachysira irawanae (Podzorski & Hkansson) LangeBertalot & Podzorski has been recorded. B. irawanae was previously reported in the Philippines and Japan with relatively simple description. In this paper, taxonomic characteristics of B. irawanae under light microscope (LM) were described in details, and the scanning electron microscope (SEM) characteristics were firstly presented in details. Morphological features differences among some resembling gomphonemoid species belonging to Brachysira genus were discussed. In addition, a short review of taxonomic studies on Latin names of Brachysira and a checklist of Brachysira genus reported from China (contains seven species and one variant) is given.