Abstract:Caragana intermedia is an important sandfixing shrub in northwest arid area with drought, cold and salinealkali resistance. Excellent stress resistant candidate genes screened from it could provide good gene resources for genetic engineering of forest and forage species. In this study, the full length cDNA sequence of CiPUB22 (plant Ubox 22) had been mined from the transcriptome library constructed in our laboratory using drought stressed seedlings of C. intermedia. The CiPUB22 gene contained 1 260 bp open reading frame (ORF) which encoding 419 amino acids. Quantitative real time PCR analysis showed that the expression levels of CiPUB22 were significantly increased and reached the highest level, which was 12, 35 and 7 times of the control at 1 h after dehydration, NaCl and ABA treatments, respectively. After drought treatment, the relative expression of CiPUB22 was significantly increased and reached the highest level at 12 d, which was 2.5 times more than that of the control. The results indicated that the transcription of CiPUB22 was induced by abiotic stress. Furthermore, expression vector pCanGCiPUB22 was constructed and transformed into the wildtype Arabidopsis. Homozygous transgenic Arabidopsis overexpressing CiPUB22 were generated for further analysis. Seed germination assay showed that CiPUB22 transgenic lines germinated slower than that of wildtype on medium containing 150 mmol/L NaCl, 400 mmol/L mannitol or 1 μmol/L ABA. These results indicated that CiPUB22 decreased tolerance of the transgenic Arabidopsis to salt and osmotic treatments during seed germination.

Abstract:Microbial lignin peroxidase is considered one of the key enzymes for lignin degradation. The lignin peroxidase gene (PcLIPH8) from Phanerochaete chrysosporium was introduced into plant binary expression vector for wildtype rice (Kitaake) transformation. Transgenic rice lines were confirmed by molecular identification. Enzymatic activity, lignin content determination and phenotypic changes were analyzed. The results showed that: (1) 35S∷PcLIPH8 plant binary expression vector was successfully transformed and three independent homozygous transgenic lines of rice were obtained. At seedling stage, there is no significant difference between transgenic rice lines and wildtype control. (2) Enzymatic activity and lignin content determination showed that lignin peroxidase activity increased 3.06%-5.07% and the lignin content decreased 11.44%-14.97% at seedling stage and 13.83%-20.05% at mature stage in transgenic rice lines compared with the wildtype control. (3) Phenotypic analysis at harvest showed that the plant height increased 28.37%-39.78%, panicle grain number increased 110%-120%, and biomass increased 18.61%-22.97% compared with the wildtype control. However, the grain weight decreased 12.86%-13.34%, and the grain length decreased 6.67%-7.15%. The research laid a foundation for the further use of the PcLIPH8 gene to reduce lignin content and increase biological production for improving plant quality.

Abstract:In this study, we used the new species Narcissus tazetta‘Yunxiang’ as the experimental material. A NAC gene was cloned by RTPCR and named NtNAC2， which contains 936 bp open reading frame encoding 311 amino acids. Bioinformatics analysis showed that NtNAC2 gene is a member of NAC family， which contains a typical NAM conserved domain located in the Nterminal region and a close evolutionary relationship grouped with monocotyledonous Asparagus officinalis， Crocus sativus， Dendrobium catenatum. The quantitative realtime PCR detection showed that the relative expression level of NtNAC2 gene in petal and corona increased gradually with the development of floral organs, and reached the peak in the senescence period. The expression profiles of NtNAC2 in root and leaf were analyzed， it was inducible under ABA， MeJA， SA， H₂O₂， 50 ℃， PEG and NaCl treatments， and the spatiotemporal and tissue expression difference of root and leaf was reflected．In order to further identify its abiotic stress function， we successfully constructed the plant overexpression vector and finally obtained 10 strains of transgenic tobacco by GUS and molecular detection. The overexpression of NtNAC2 in transgenic tobacco was detected by semiquantitative RTPCR. The roots of transgenic plants are 2 to 3 times that of wild type， the water loss rate of leaves is less than 30% and the survival rate is higher than 60% under the salt and drought stress. These results showed that the expression of NtNAC2 gene can increase the tolerance of tobacco to high salt and drought， so it can be used as an effective candidate gene for N. tazetta resistance molecular breeding.

Abstract:In order to understand the basic properties of the longan ERF family and the expression of early embryogenesis, this study identified 108 ERF family members for basic physicochemical properties and phylogenetic tree construction in the longan genome. The relationship between DlERF family members and lncRNA and miRNA was predicted and expressed in combination with longan transcriptome, miRNA and lncRNA database. The results showed that: (1) the physicochemical properties and phylogenetic tree analysis of the family indicated that the AP2/ERF domain is relatively the most conservative in longan, and DlERF may play an important role in the longterm stress resistance and defense ability of the pathogen. (2) Analysis of expression levels in RNASeq revealed that 95 ERF genes were detected in the transcriptome, and there were 31, 11 and 53 ERF genes highly expressed in the callus, incomplete embryonic compact structure and globular embryo stage, respectively. (3) qRTPCR results showed that among the five ERF genes that were significantly expressed early in the longan somatic embryo, the expression levels of Dlo_008317.1ERF152, Dlo_022310.1ERF11 and Dlo_009939.1ERF98 in GE stage were significantly higher than those of EC and ICpEC, Dlo_009070.1ERF1063 and Dlo_022634.1ERF221 were highly expressed in the EC and ICpEC phases, respectively. (4) Analysis of DlERF family members and related lncRNA and miRNA expression levels showed that LTCONS_00013739 has a positive regulatory relationship with the target gene Dlo_008317.1ERF152; Dlo_miR413 and Dlo_miR1510a target Dlo_009070.1ERF1063 together, showing a significant negative regulatory relationship from EC to GE, while Dlo_miR413 and Dlo_008317.1ERF152 expression were positively correlated, presumably compared to Dlo_008317.1ERF152 Dlo_miR413 is more inclined to regulate Dlo_009070.1ERF1063; Dlo_miR408 and Dlo_miR774b regulate Dlo_009939.1ERF98. From the expression trend, Dlo_miR774b can negatively regulate Dlo_009939.1ERF98 in the early stage of longan somatic embryogenesis; Dlo_miR399c and Dlo_022310.1ERF11 may have negative regulation relationship in EC to GE stage. (5) Ethylene treatment with different gradient concentrations significantly downregulated DlERF gene expression. These findings provide important insights into DlERF during somatic embryogenesis in longan, and lay a foundation for further functional analysis of DlERF during somatic embryogenesis in longan.

Abstract:The cDNA of okra (flowers and fruits) were sequenced based on Illumina Hiseq 2500 and were analyzed by using the bioinformatics methods subsequently, such as sequencing assess and gene function annotation. The result of research shows that: (1) 7.12 Gb and 8.14 Gb Clean Data were obtained respectively from the flowers and fruits and the base ratios with quality values higher than 30 in reads (Q30) were more than 91.0% from both. (2) Compared the transcriptome of the flowers and fruits, 1 131 differentially expressed genes (DEGs) were found, including 319 upregulated genes and 1 017 downregulated genes. (3) Annotation analysis indicated that 1 131 genes were annotated. With GO function annotation classification, 455 functional annotations of these DEGs were divided into 41 function categories, in which many function categories were mainly involved, such as metabolic process, catalytic activity, singleorganism process, cellular process. Through KOG analysis, there were 472 functional annotations of DEGs, involving 23 functional classifications. KEGG analysis showed that 372 DEGs were annotated to 80 metabolic pathways, and obtained 10 key DEGs, F3H, F3′5′H, DFR, ANR, ANS, GT, LAR. F3H and DFR showed upregulated effect in okra flowers; F3′5′H, ANR and LAR showed downregulated effect in okra fruits; ANS and GT showed up/downregulated effects in flowers and fruits. (4) The relative expression levels of 7 DEGS wasin line with that of the transcriptional group by qRTPCR. (5) Through the flavonoid metabolic pathway, the research showed that anthocyanin were catalyzed by F3H, DFR, ANS(c83240), GT (c82265/c82004) from NAR in okra flowers; The formation of DHM was initiated by F3′5′H, then produced flavonols by FLS; Partly NAR was catalyzed by F3H and DFR to dephinidin, then ultimately went into anthocyanins and proanthocyanidins synthesis pathways. This study enriched transcriptome information of okra and provided reference for the purification and functional utilization of flavonoids in okra.

Abstract:Based on the 16S rRNA gene sequence of chloroplasts, this study constructed the phylogenetic tree of green euglenophyte and reconstructed their ancestor on the base of 8 morphological characters, which will clarify the phylogenetic relationships of green euglenophyte and provide theoretical basis for the study of the origin of these plants. The results indicated: (1) the phylogenetic tree of green euglenophyte constructed by Bayesian showed that Eutreptia and Eutreptiella are sister groups, and Phacus, Lepocinclis and Discoplastis are close relatives. We also can see that Trachelomonas and Strombomonas are close relatives, and Euglena, Cryptoglena, Colacium and Monomorphina have close genetic relationships. It is showed that Euglena is not a monophyletic group. (2) The results of ancestral reconstruction based on morphological characters showed that 7 relatively original characters of green euglenophyte included: cuticula soft and easy deformation, spirally striated, posterior end slightly narrowing or sharp elongated cauda, without lorica, chloroplasts show sheet, shield, or plate, pyrenoid without sheath, with many small grains are primitive traits, but the length of flagella can not infer possible ancestral states. (3) The results of ancestral reconstruction based on 8 morphological characters showed that Euglena and Euglenaria which have original characters may be the ancestor of green euglenophytes who appear earliest.

Abstract:Epimedium pubescens Maxim. is a species widely distributed in China and abundant in morphological variation. There are still many voices in the classification of E. pubescens and its related species. This study chose 31 populations of E.pubescens Maxim.and its related species including 3 populations of E.stellulatum Stearn, 1 population of E.zhenbaense sp.nov. and 1 population of E.wanyuanense sp.nov. and observed nonglandular hairs on the back of their leaves, so as to study the variation law of E.pubescens and its related species and their intraspecific division. The results are as follows. (1) the nonglandular hairs from what we saw are divided into 7 large classes and 19 small classes, namely straight hair, curved hair, appressed curly hair, long appressed hair, pseudo short appressed hair, short appressed hair and single cell hair, and found that each population or individual was composed of many types of nonglandular hairs. (2) Mastoid were found in 13 populations and the population which has nonglandular hair under 50/mm², accounting 69.2%, and 27 populations has single cell hair, accounting 75%. (3) Based on nonglandular hair density and major types, we come to conclusion of 36 populations classification. 21 populations of E.pubescens are straight hair group (A) and 7 populations are curly hair group (B). Long appressed hair group (D) contains 2 populations of E.pubescens, 3 population of E.stellulatum and 1 population of E.zhenbaense. One population of E.pubescens is pseudo short appressed hair group (E) and one population of E.wanyuanense is short appressed hair group (F). All populations have straight hair, showing that the core type in E.pubescens and its related species is straight hair. (4) From the angle of nonglandular hairs type, the evolutionary relationship between populations is combed, namely is AⅠ→AⅡ→AⅢ→AⅣ→AⅤ, BⅠ→BⅡ→BⅢ→BⅣ, DⅠ→DⅡ→DⅢ, straight hair group→curly hair group, short straight hair group→short appressed hair or pseudo short appressed hair, and it shows a good correlation with geographical distribution as well. (5) Single cell hair has been found for the first time in Epimedium and considered to have some relation to the main hair type (straight hair and curly hair) and geographical distribution. However, there is a negative correlation between the mastoid and nonglandular hairs density on back of the leaves. The results of this study support the classification treatment that E.stellulatum Stearn is under the species of E. pubescens Maxim.

Abstract:In order to explore the preference of Cunninghamia lanceolata for different nitrogen forms, unravel the response characteristics of the lateral roots development and photosynthetic physiology of C. lanceolata seedlings under different forms of nitrogen, and thus provide a theoretical basis for rational management of nitrogen fertilizer for C. lanceolata, we investigated the effects of NO₃^-N, NH₄⁺N, and NH₄NO₃ (3 mmol·L^-1 nitrogen) on the lateral roots growth, CO2 exchange parameters and chlorophyll fluorescence characteristic of C. lanceolata by using 3monthold C. lanceolata seedlings. The results showed that: (1) different forms of nitrogen significantly influence the biomass of shoots and lateral roots, and the most higher biomass both for shoots and lateral roots were observed in NH₄⁺N treatment, follows by NO₃^-N treatment, NH₄NO₃ treatment was the lowest. (2) Under NH₄⁺N and NO₃^-N treatments, the biomass of shoots and lateral roots in total roots length, total roots surface, and total roots volume were significantly higher than that of NH₄NO₃ treatment (P＜0.05), and the above root morphology parameters in NH₄⁺N treatment were significantly higher than that in NO₃^-N treatment as well (P＜0.05), while no significant differences were noted in lateral roots number among different nitrogen form treatments (P＞0.05). (3) The photosynthetic rate, stomatal conductance, and transpiration rate in leaves of C. lanceolata seedlings were obviously higher in NH₄⁺N treatment than that in NO₃^-N and NH₄NO₃ treatments, while no difference was observed between NO₃^-N and NH₄NO₃ treatments. (4) NH₄⁺N treatment significantly decreased the initial fluorescence, while increased the maximal fluorescence, variable fluorescence, and PSⅡpotential efficiency as compared with NO₃^-N treatment. The above results indicated that NH₄⁺N treatment not only increased the stability of PSⅡ reaction center, but also maintained a higher photochemical activity and electron transfer rate in PSⅡ reaction center，which ultimately improved the growth of C. lanceolata. Therefore，from the growth of lateral roots and photosynthetic characteristics in leaves of C. lanceolata under different nitrogen forms, it can be deduced that among different forms of nitrogen, C. lanceolata seedlings was much preferences for NH₄⁺N.

Abstract:7 Begonia species (cultivars) were used as materials. The leaf tissue structure, chlorophyll contents and chlorophyll fluorescence parameter F_v/F_m were observed to analyze the causes of leaf variegation formation and silver spots genetic characteristics by hybridization test. The results showed: (1) there were intercellular spaces between the abaxial epidermis cells and palisade tissue cells in variegated areas of B. deliciosa, B. handelii var. prostrata, B. pseudodryadis, ‘Oeympica’ and ‘African Jungle’, while no intercellular spaces in nonvariegated areas, the abaxial epidermis cells and palisade tissue cells were linked tightly in B. masoniana var. maculata and‘Tiger’. (2) Chloroplasts in both variegated areas and nonvariegated areas were intact of 7 Begonia species (cultivars), the thylakoid membrane was rich, and the stroma lamella and grana lamella were clear. The chlorophyll a, b and total chlorophyll contents in the variegated areas were lower than the nonvariegated areas’ in B. deliciosa, B. pseudodryadis, ‘Oeympica’and ‘African Jungle’, while in B. handelii var. prostrata there were no differences. The fluorescence parameter F_v/F_m were higher in the variegated areas than that in the nonvariegated areas of 6 Begonia species (cultivars) except B. pseudodryadis. (3) B. deliciosa hybridized with other species without variegation, the ratio of plants with variegation and without variegation was nearly 3∶1, while the ratio of plants was close to 1∶1 in its selfhybrid offsprings. The research found that the variegations of B. deliciosa, B.handelii var. prostrata, B. pseudodryadis, ‘Oeympica’ and ‘African Jungle’ were belonged to structure variegation, the variegations of B. masoniana var. maculata and ‘Tiger’ were belonged to pigment variegation. The leaf with silver spots and without silver spots were a pair of characters which can be heritable, silver spots was a dominant character.

Abstract:A resource survey from 2013 to 2015 found white berries in Qinghai Province. The phenotype and main active compounds were determined in the two berries at three stages (Ⅰ～Ⅲ) to compare the differences. The results showed that: (1) the shape of white fruit and black fruit were the same, and there was no significant difference in volume and mass. (2) Anthocyanin content in black fruit at the second period up to 17.18 mg/g fresh weight and in white fruit was extremely low in all three periods. The lack of anthocyanin caused the appearance of white fruits. (3) The total polyphenol, polysaccharides and vitamin E were found in black and white fruits, and the content all of them reached the highest at stage Ⅱ, Ⅲ. Although the content of these active substances in white fruits was considerable, they were significantly lower than that of black fruits in all developmental stages. (4) Ten of the seventeen mineral elements (B, Ca, Li, Mg, Mn, Na, Si, K, Zn and Al) are dominant in the white fruit. This study provided basic data for the variety selection, nutrition value evaluation and adaptability of white fruit from Lycium ruthenicum Murr.

Abstract:We investigated the growth and physiological effects of Ni²⁺ at 3 concentrations (0 mg·L^-1, 0.1 mg·L^-1, 1 mg·L^-1) with 22.4 mg·L^-1 N on nitrogen uptake in the seedling stage of Lactuca sativa L. using hydroponic. The results showed: (1) the root and shoot biomass of the lettuce increased with the increase of treatment time. Compared with the control T₁ (0 mg·L^-1 Ni²⁺ and 112 mg·L^-1 N), T² treatment (0 mg·L^-1 Ni²⁺ and 22.4 mg·L^-1 N) had certain inhibitory effects on the root growth and leaf growth of the lettuce; the fresh weight of the plant, dry weight, root to shoot ratio, root length, mean diameter, surface area, volume, number of root tips, number of roots, leaf surface area and volume were significantly higher under T₃ (0.1 mg·L^-1 Ni²⁺ and 22.4 mg·L^-1 N) treatment for comparison, T₄ treatment (1 mg·L^-1 Ni²⁺ and 22.4 mg·L^-1 N) promoted the growth of roots and leaves of the lettuce, but showed some inhibition on the number of root tips and roots. (2) With the increase of Ni²⁺ concentration, the contents of chlorophyll a, chlorophyll b and total chlorophyll in the leaves of the lettuce showed a first increase and then decrease, and both of them significantly increased under T₃ (0.1 mg·L^-1 Ni²⁺ and 22.4 mg·L^-1 N) treatment. (3) With the increase of treatment time, the net photosynthetic rate (P_n), stomatal conductance (G_s) and transpiration rate (T_r) of the leaf lettuce gradually increased, and the intercellular CO₂ concentration (C_i) gradually decreased. The stomatal conductance (G_s) of leaves with T₃ (0.1 mg·L^-1 Ni²⁺ and 22.4 mg·L^-1 N) treatment was significantly higher than that of the control, the intercellular CO₂ concentration (C_i) was the lowest, and the net photosynthetic rate (P_n) was the largest. (4) Applying Ni²⁺ to pointed leaf lettuce, organic acid, soluble protein, soluble sugar content, POD and SOD activities had significant effect. With T₃ (0.1 mg·L^-1 Ni²⁺ and 22.4 mg·L^-1 N) treatment, organic acid content decreased, while soluble sugar and soluble protein contents increased significantly,SOD and POD activities were significantly improved. (5) With T₃ treatment, the contents of B and Ca in roots and N in leaves were higher; the Ni content in roots was higher than that in leaves, the Ni content in leaves was lower, and the Mg content was higher; Cu content in plants decreased with the increase of Ni²⁺ concentration. Research shows that exogenous Ni²⁺ treatment can affect the growth and physiological status of rapeseed lettuce seedlings under low nitrogen conditions (22.4 mg·L^-1 N). The appropriate concentration (0.1 mg·L^-1) Ni²⁺ can effectively improve the nitrogen absorption and utilization efficiency of the root system of rapeseed lettuce, reduce the amount of nitrogen application, promote the growth of the root system and aboveground leaf of rapeseed lettuce, increase the photosynthetic pigment content, and improve the net photosynthetic rate, thus improve the yield and nutritional quality of the plant.

Abstract:The aim of the study was to investigate the effect of exogenous salicylic acid (SA) pretreatment on the growth, chlorophyll contents, osmotic adjustment substance contents and antioxidant system of melon seedlings under chilling stress (12 ℃/ 6 ℃) and 7 days’ recovery condition (28 ℃/ 22 ℃). Cultivar ‘Hongyou’ seedlings were treated with different concentrations of SA (including 0.1, 0.5, 1.0 and 2.0 mmol·L^-1) in climate chambers. The results showed that： (1) chilling stress significantly inhibited the growth of melon seedlings, different concentrations of exogenous SA pretreatment could alleviate the damage induced by chilling stress, and 1.0 mmol·L^-1 SA has the most notable effect. 1.0 mmol·L^-1 SA significantly increased plant height, stem thickness, and fresh weight of melon seedlings.(2) Suitable exogenous SA pretreatment also increased soluble sugar, soluble protein and proline contents, promoted osmotic adjustment.(3)In addition, exogenous SA pretreatment could strengthen the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR) and dehydroascorbate reductase (DHAR), increase the contents of ascorbic acid (AsA) and glutathione (GSH), improve the ratios of ASA/DHA and GSH/GSSG, so the electrolyte leakage, malondialdehyde (MDA) content and reactive oxygen species (ROS) greatly reduced. Overall, appropriate concentration of exogenous SA pretreatment could promote the growth and chilling tolerance of melon seedlings, through increasing osmotic adjustment substance contents, enhancing antioxidant enzyme activities and activating AsAGSH cycle.

Abstract:By using etiolated bean (Phaseolus vulgaris) seedlings, the present work studied the effects of alternative respiratory pathway on chlorophyll content and chlorophyll fluorescence characteristics during greening of etiolated bean seedlings under Pb (lead) or PEG (polyethylene glycol) stresses, to elucidate the physiological role of alternate respiratory pathway of plants under environmental stress. The results showed that: (1) during greening of etiolated bean seedlings, Pb or PEG stress caused significant decreases of the chlorophyll content, F_v/F_m (the potential maximal photochemical efficiency of PSⅡ), F_v′/F_m′ (the maximum quantum efficiency of PSⅡ photochemistry at illumination), Y(Ⅱ) (effective photochemical quantum yield of PSⅡ photosynthetic), and qP (photochemical quenching coefficient), while Pb or PEG stresses increased the levels of NPQ (nonphotochemical quenching), compared to the controls (greening of etiolated bean seedlings without environmental stress). (2) During greening of etiolated bean seedlings, the capacity of the alternative respiratory pathway was increased significantly, compared to the controls. (3) During greening of etiolated bean seedlings under Pb (lead) or PEG stresses, the leaves pretreated with salicylhydroxamic acid (the specific inhibitor of the alternative respiratory pathway, SHAM) exhibited lower levels of chlorophyll content, F_v/F_m, F_v′/F_m′, Y(Ⅱ) and qP, but higher levels of NPQ than the leaves without SHAM treatment. This indicate that inhibition of alternate respiratory pathways will aggravate the inhibition of PSⅡ reaction center activity by Pb or PEG stress and further increase the accumulation of reducing power and increase of heat dissipation. These results suggested that, during greening of etiolated bean seedlings, Pb or PEG stress can significantly reduce the utilization of light energy by PSⅡ and hinder the greening process of etiolated bean seedlings, while the alternate respiratory pathway could alleviate the excessive reduction of PSⅡ under stress conditions, thus alleviating the inhibition of Pb or PEG stress on the greening process to some extent.

Abstract:The tomato variety ‘Yingshi Dahong’ was used as the material to carry out the cultivation experiment in the greenhouse under drip irrigation and fertilization conditions; The upper limit of irrigation is set at three levels, that is, the relative water content of the soil is 70% (W₁), 80% (W₂), and 90% (W₃) of the maximum water holding capacity in the field, respectively, and the lower irrigation limit is uniformly set to 50% of the maximum water holding capacity in the field. N, P, K fertilization set three levels, low fertility F₁ ［N (228 kg/hm²), P₂O₅ (132 kg/hm²), K₂O (300 kg/hm²)］, medium fertilizer F₂ ［N (285 kg/hm²), P₂O₅ (165 kg/hm²), K₂O (375 kg/hm²)］ and highfertilizer F₃ ［N (342 kg/hm²), P₂O₅ (198 kg/hm²), K₂O (450 kg/hm²)］, with flood irrigation large water (8 165 m³/hm²) and local recommended fertilization amount (342 kg/hm² N, 198 kg/hm² P₂O₅, 450 kg/hm² K₂O) as common waterfertilizer control (CK). To explore the effects of different irrigation upper limit and fertilization treatment combinations on tomato yield quality and dry matter quality, in order to screen the optimal irrigation limit and fertilization amount of tomato cultivation in greenhouse. The results showed that: (1) Under the condition of integrated water and fertilizer, the dry weight of the above ground parts of the tomato plants, the dry weight of the shoots, and the rootshoot ratio were significantly higher than those of the traditional water and fertilizer treatments except F₃W₁. (2) The yield of tomato fruit was different under different irrigation upper limits and fertilization amounts. Among them, the fruit weight, economic yield and biological yield of tomato fruit reached the highest under F₂W₂ treatment, and the difference was significant with CK. (3) Under the same irrigation limit, increasing the amount of fertilizer in a certain range can significantly increase the content of soluble sugar, vitamin C, soluble protein and lycopene in tomato fruit. However, the organic acid and nitrate contents of tomato fruit increased with the increase of fertilizer application; Under the same fertilization amount, the organic acid content of tomato fruit decreased with the upper limit of irrigation, while the nitrate content of tomato fruit increased with the upper limit of irrigation. The study found that under the condition of drip irrigation and fertilization, the irrigation amount and fertilization amount of greenhouse tomato can significantly increase the yield of tomato and the contents of soluble sugar, vitamin C, soluble protein, lycopene and organic acid in tomato fruit, reduce the nitrate content and increase the accumulation of dry matter. The best water and fertilizer treatment combination is the upper limit of irrigation with 80% of the maximum water holding capacity in the field, the irrigation amount with 3 686.691 m³/hm², the fertilization amount is 285 kg/hm² N, 165 kg/hm² P₂O₅, 375 kg/hm² K₂O. The tomato yield increased significantly by 15.03% compared with the traditional water and fertilizer treatment, and the fruit quality was also effectively improved.

Abstract:Based on observation of soil moisture in deep soil layers in Elaeagnus angustifolia, Caragana korshinskii, Citrullus lanatus, Lycium chinense and grassland on the gravelsand mulched field in the arid zone of central Ningxia, we calculated, analyzed and compared soil moisture content, soil water overuse rate, soil desiccation indexes and thickness of desiccated soil layer in different vegetation zones, to provide the theory basis for improving the utilization on the gravelsand mulched field in the arid zone of central Ningxia. Results show as follows: (1) mean soil moisture content, water storage and available soil water storage were 7.163%, 591.978 mm and 187.088 mm of different vegetation zones on the gravelsand mulched field. The average soil water overuse rate was 274.942 mm. (2) The soil moisture of different vegetation types show the overall trend was reduced，then increased from the depth of the surface to 600 cm. In addition to watermelon，the water moisture content of other vegetation was significantly lower than soil stable moisture. (3) The soil desiccation index of different vegetation zones was in the range of 2.152%~85.026%,and mean soil desiccation index was 37.674%, falling into the category of severely desiccated. The C. korshinskii and E. angustifolia land were extreme desiccated. The average thickness of the desiccated soil layer in different vegetation zones was 500 cm. The order of soil moisture content is: C. korshinskii land> E. angustifolia land>L. chinense land> grassland >C. lanatus land. (4) The canonical correlation analysis showed that environmental factors such as latitude, longitude, elevation,vegetation type, silt content and sand content were significantly factors affecting soil desiccated index and soil water content in the inner of dried soil layer.

Abstract:This article takes the dominant species Castanopsis eyrei population in three sample plots (Diaoqiaoan, Yungusi and Wangpulou) for monitoring forest plant diversity in Mount Huangshan as the research object. Using population size structure analysis, static life table, survival curve, population growth model and point pattern analysis, we studied the population size dynamics and spatial distribution pattern. Results showed that: (1) Castanopsis eyrei population in three sample plots showed a large number of seedlings, abundant saplings, and the number of individuals in each sample plot gradually decreased with the increase of age class, indicating that C. eyrei population was in the growth stage, with strong renewal ability, belonging to a stable population. (2) The survival curves in Diaoqiaoan and Wangpulou plots were similar to Deevey Ⅱ type. The mortality rates at different age levels were similar in the two plots. The three death peaks were in juvenile stage, early maturity stage and old age. (3) the survival curve of Yungusi plot was Deevey Ⅲ type, the mortality rate was higher at the young stage than the mature and aging stage. (4) C. eyrei population in forest plants of Mount Huangshan was contagious distribution in small scale and it turned to be uniform distribution or random distribution at large scale.

Abstract:Based on the field survey of species composition and diversities in six typical plant communities of Songshan Nature Reserve, Beijing in 2017, we selected the diversity indices of α and β to describe the plant diversity characteristics of arborous, shrub and herbal layers and their main dominants. (1) The standard plots surveyed in Songshan Nature Reserve were composed of 75 species which belongs to 58 genera and 40 families. Major dominent species in arborous layer were Pinus tabulaeformis Carr., Quercus mongolica, Populus tomentosa Carr. and Populus davidiana. Spiraea pubescens Turcz. and Grewia biloba G Don were dominant or subdominant species in the shrub layer. Compositae species were widely distributed in herbal layer. (2) ShannonWiener and richness indices were sized as herbal, shrub and arborous layer. The indices of α diversity in herbal layer increased with elevation, of which layer the richness and evenness influenced α diversity significantly. (3) Considering the variation of β diversity along the altitudinal gradient, herbaceous common species decreased at first and then increased, while turnover rates of species were gradually increased first and then decreased. Therefore, the synthetic regulation of stand structure and microtopography should be considered on biodiversity conservation which followed the law of natural succession, formulating reasonable and feasible conservation experience and technology to provide scientific support for the protection of forest community diversity and its ecological function.

Abstract:The spatial distribution and correlation of population is an important means to study population diffusion, community succession and the interaction between biological and environmental factors. The study takes Reaumuria songarica and Stipa sareptana var. krylovii as the main species in Laohutai arid desert area of Gaolan County, Gansu Province. The spatial distribution characteristics and their association of R. songarica and S. sareptana var. krylovii on different slopes were analyzed by using Ripleys k function, revealing the competitive relationship, survival, and reproduction strategies among dominant populations in the process of plant succession in arid desert areas. The results showed that: (1) there were significant differences in the distribution of R. songarica and S. sareptana var. krylovii in the four slopes. With the change of slope aspect from northwest to south, the plant number, coverage and important value of R. songarica population increased first and then decreased, while the population of S. sareptana var. krylovii increased continuously. In the northwest slope, the R. songarica population showed aggregation distribution on the scale of 0-2.1 m, with the increase of the scale, the aggregation intensity weakened and tended to random distribution, and the population of S. sareptana var. krylovii was mainly aggregation distribution; In the west slope, the R. songarica population showed random distribution on the whole scale, and the S. sareptana var. krylovii population showed aggregate distribution; In the southwest slope, the population of R. songarica showed aggregation distribution on the scale of 0-3.7 m and random distribution on the scale of 3.7-5 m, the S. sareptana var. krylovii population showed a random distribution on the scale of 0-1 m and 4.2-5 m, an aggregate distribution on the scale of 1-4.2 m; In the south slope, the R. songarica population showed aggregate distribution on the whole scale, and the S. sareptana var. krylovii population showed random distribution. (2) In the northwest slope and west slope, the R. songarica and the S. sareptana var. krylovii showed negative correlation on the small scale, with the increase of the scale, the interspecific correlation of the species tended to be unrelated; In the southwestern and southern slopes, the two species showed no correlation in the whole scale.

Abstract:The method of loading Ca²⁺ fluorescent probe (Fluo4/AM) in pollen tube under vacuum infiltration was studied with Fengshui pear pollens which were cultured for 2 h. The results showed that: (1) pollen germination rate and activity of pollen tube were not affected by vacuum infiltration treatment for 2 hours. (2) The pollen tubes cultured for 2 h were subjected to vacuum infiltration under different conditions to assist Fluo4/AM probe to enter the pollen tubes. Laser confocal microscopy showed that Ca²⁺ gradient could be observed at the tip of pollen tube at low temperature (4 ℃) under vacuum infiltration (-80 kPa) loading for 30 min. (3) The fluorescence density of pollen tube was also significantly decreased by inhibiting the external Ca²⁺ influx or decreasing the external Ca²⁺ concentration of pollen tube. The study suggests that the method of vacuum infiltration auxiliary loading can effectively promote the entry of fluorescent probes into pollen tube cells and the binding of Ca²⁺.

Abstract:As provincial new distributions, one genus and two species and one variety of dicotyledon from Hunan are reported in this paper. They are Tinospora sinensis (Loureiro) Merrill, Machilus salicina Hance, Mallotus apelta var. kwangsiensis F. P. Metcalf and Malvastrum coromandelianum (Linnaeus) Garcke. Among these species, M. coromandelianum (Linnaeus) Garcke belongs to Malvastrum A. Gray, which is a newly recorded genus in Hunan. M. coromandelianum (Linnaeus) Garcke, an invasive species, may cause damage to local agricultural production and ecological environment.

Abstract:Peltigera occidentalis (.E. Dahl) Kristinsson is reported new to China based on the specimen collected from Heilongjiang Province. The morphology, anatomy and chemistry analysis, and a phylogentic analysis of nrDNA ITS sequence were carried out. The new record species can be distinguished by the smooth and shiny upper surface, no tomenta, phyllidia and isidia; the marginal pale brown and central dark brown lower surface, flat and distinct veins, simple to fasciculate rhizines. Detailed description of P. occidentalis basing on the Chinese specimen and discussion with allied species, i.e. P. scabrosa, P. ploydactylon and P. canina and a key to them were provided.