Abstract:In order to enrich the gene pool and the theoretical research of male sterility in cucumber, a male sterility mutant C0128 was used as material for phenotypic identification, genetic analysis and preliminary mapping of male sterility gene. The results showed that: (1) the male petals and anthers of mutant C0128 were smaller than that of wild type CCMC，and no pollen grains were produced on the anthers. (2) Genetic analysis showed that the male sterility of the mutant was controlled by a recessive nuclear gene MS4. (3) Using Gy14×C0128 F₂ population with 1 231 plants and 12 polymorphic SSR markers, the MS4 gene was initially located on cucumber Chr3, and the genetic distance and physical distance was 3.7 cM and 1.21 Mb, respectively. This study confirmed that C0128 is a new male sterile mutant in cucumber. The preliminary mapping results of MS4 can lay a foundation for further cloning of target gene and studying the mechanism of male sterility in C0128.

Abstract:MYB transcription factor family is widely involved in plant response to abiotic stresses, including drought, salinity, and chilling. To further study MYBs in okra ［Abelmoschus esculentus (L.) Moench］, in this study, we cloned a gene of AeMYB1R1 from ‘Hokkaido No.1’ of okra by PCR and characterized using bioinformatic analysis. Quantitative realtime PCR (qRTPCR) was used to analyze AeMYB1R1 expression pattern and the expression characterization under abiotic stresses. The results showed that: (1) AeMYB1R1 was successfully cloned from okra, which contained an open reading frame of 1 056 bp, encoding 352 amino acids. Sequence alignment and phylogenetic tree analysis showed that, AeMYB1R1 was evolutionarily highly conserved in plants. AeMYB1R1 had a molecular weight of 37 891.57 Da and an isoelectric point of 8.75, which contained more glutamic acid and less tryptophan, as well as more potential phosphorylation sites and glycosylation sites. (2) Structural analysis showed that AeMYB1R1 was mainly dominated by αhelix and random coil, without signal peptide and transmembrane structure, which was a hydrophobic protein. Meanwhile, its amino acid sequence contained a conserved domain from 104 to 156, indicating that it belonged to the SHAQKYF class of MYBs. (3) qRTPCR results showed that AeMYB1R1 had the highest expression level in okra leaf, followed by root and stem, which reflected its tissuespecific expression pattern. Meanwhile, compared with heat and cold stress, AeMYB1R1 was highly expressed in response to salt stress and drought stress, which suggested that AeMYB1R1 may be the key transcription factor for salt and drought resistance of okra. In summary, this study lays a theoretical basis for the functional study of the AeMYB1R1 gene in okra growth and development and in the mechanism of stress resistance.

Abstract:The Trihelix family is a specific family of transcription factors in plants, and plays an important regulatory role in plant growth, development, and stress resistance. Based on the genome database of birch, this study analyzed the expression characteristics and disease resistance function of birch Trihelix family genes, which laid the foundation for the research on the function of Trihelix family members in the disease resistance process of birch. The results showed that: (1) a total of 8 Trihelix family members (BpTrihelix1-BpTrihelix8) were distributed on 6 chromosomes; the molecular weight of amino acids is between 35 633.96-81 871.27 Da, and the isoelectric point is 5.32-8.67, all of which are hydrophobic amino acids. (2) Tissuespecific expression analysis showed that eight family members are expressed in different degrees in the roots, stems, and leaves of birch, and BpTrihelix3 have the highest expression level in roots, stems, and leaves. (3) The results of the pathogen infection test showed that BpTrihelix3, BpTrihelix4 and BpTrihelix7 were significantly upregulated when Alternaria alternata infected the leaves of birch for 48 h and Rhizoctonia solani infected roots of birch seedlings for 24 h, and the expression level of the rest of the family genes did not change significantly, indicating that among the gene members of this family, BpTrihelix3, BpTrihelix4 and BpTrihelix7 responded to the infection of pathogenic bacteria, so we speculated that they might play an important role in the disease resistance procress of birch.

Abstract:AP2/ERF transcription factor family is one of the most important transcription factor families in plants, which is involved in plant crucial biological processes such as growth and development, stress resistance and plant hormone signaling pathway. Based on PacBio sequencing database of M. sieversii upon the Valsa mali infection, MsAP2/ERF family members were screened and identified using the hidden Markov model of AP2 domain (PF00847). The MsAP2/ERF transcription factor family were identified and analyzed by MEGA6, NCBI CDD batch, MEME, ExPASY, BUSCA. The gene expression analysis based on RNAseq data and qRTPCR assay were performed to screen the potential resistant genes for Valsa canker disease. The main results are as follows: (1) in total, 106 AP2/ERF genes were identified in M. sieversii, including AP2 (17 genes), ERF (57 genes), DREB (25 genes), RAV (5 genes), and Soloist (2 genes). (2) Further detailed classification showed that the MsERF subfamily included 6 groups (B1-B6). The MsDREB subfamily contained A2, A4, A5 and A6 groups, and lacked A1 and A3 group genes. (3) Differential expression pattern analysis based on RNAseq data showed that 29 MsAP2/ERF genes were differentially expressed during the infection of V. mali. Among them, 19 DEGs were MsERF genes. (4) The qRTPCR results of 12 representative MsAP2/ERF genes showed that 8 MsERF genes were significantly upregulated after V. mali infection. Particularly, the B4 group of ERF subfamily gene (MsERF40) was remarkably upregulated with the highest fold increase at 5 d after the infection of V. mali compared with the control. Three MsDREB genes were significantly upregulated and one MsDREB gene was downregulated after V. mali infection. In addition, the MsERF gene containing TIR domain (MsERF05) was upregulated with 69fold increase at 1 d. Those results show the MsERF40 and MsERF05 play a key role during resisting V. mali in M. sieversii. In conclusion, this study laid a foundation for the further function and mechanism of MsAP2/ERF genes that respond to the V. mali infection in M. sieversii.

Abstract:The SHIrelated sequence (SRS) gene family regulates plant flowering, growth and development by mediating hormonal changes, and plays an important regulatory role in adaptation to environmental stress. Based on the apple (Malus domestica Borkh.) genome data, this study identified the members of the apple SRS gene family by bioinformatics, and analyzed the characteristics, functions and expression of the conserved domains of the SRS gene family. The results showed that: (1) the MdSRS gene family consisted of 11 members, named MdSRS1-MdSRS11, which were unevenly distributed on 9 apple chromosomes. (2) The MdSRS proteins contain 229-414 amino acid residues, and the isoelectric point distribution are between 6.38 and 9.36, and the subcellular localization results show that the MdSRS proteins are mostly distributed in the cell membrane, and also in the nucleus and chloroplast. (3) Phylogenetic analysis by introducing SRS genes from Arabidopsis, rice, tomato and poplar showed that 11 MdSRSs were divided into 5 subfamilies (A₁-A₅), with the most distribution in A4. (4) The analysis of cisacting elements showed that the 2 000 bp sequences upstream of the 11 MdSRS promoters were distributed with response elements such as hormones, environmental adaptability and stress induction. (5) The results of realtime quantitative PCR showed that the overall expression was downregulated under salt stress and drought stress, and most of them were upregulated after ABA stress. It is a potential resistance candidate gene, indicating that the SRS family is ABAregulated and other abiotic genes. Stress has a regulatory effect. The research shows that 11 members of the SRS family are involved in regulating the response to various adversities such as drought, salt and ABA stress, providing a theoretical basis for apple to withstand adverse environments.

Abstract:In order to clarify the genetic basis of rice varieties bred in the three provinces of Northeast China in recent years, 20 materials were selected as the breeding core parents by analyzing the pedigree of 256 approved rice varieties which bred in 2021. And 44 SSR polymorphic markers and 34 InDel xiangeng specific markers were used to analyze on their genetic diversity and xiangeng differentiation. The results showed that: (1) all selected markers can be applied extensively for the genetic diversity level of rice. A total of 130 alleles were detected between these varieties, and the alleles (Na) per locus ranged from 2 to 5 with the mean value of 2.95. The gene diversity indices (H) varied from 0.10 to 0.75 with an average of 0.41. The polymorphism information content (PIC) was changed from 0.09 to 0.70 with the average of 0.36. (2) Genetic diversity analysis showed that the overall diversity level of the test materials in Northeast China at a lower level, and the diversity of the core parents in Heilongjiang was slightly higher than that in Liaoning and Jilin. (3) The NJ cluster analysis indicated that all tested materials could be divided into three groups, such as Liaoning group, Jilin group and Heilongjiang group. (4) The genetic structure analysis showed that the 20 core parents could be divided into two stable groups. The core parents of Liaoning Province were in group A, and the core parents of Heilongjiang Province were in group B. (5) Analysis of xiangeng differentiation found that the 20 materials were geng type, but all of these materials contained a few number of xian loci, and the xian gene frequency (F_x) range was 0.01-0.19. Studies have shown that the possible reasons for the low level of genetic diversity of breeding varieties is the narrow genetic basis and high utilization frequency of breeding core parents in the three provinces of Northeast China. It is urgent to excavate new germplasm, introduce new resources in breeding to broaden the genetic background.

Abstract:In this experiment, ‘Saimisu 1’ Jujube and its bud ‘Saimisu 2’ fruits were used as experimental materials. Their ploidy was identified by flow cytometry, and the fruit cell omics was observed by paraffin section method. We also analyzed the internal appearance quality of both fruits and the enzyme activity related to sucrose metabolism in determining the fruit taste, so as to provide data support for the further study of the influence of bud change on the taste and quality of jujube fruits. The results showed that: (1) the cell ploidy of the two jujube varieties (strain) did not change, both are diploid. (2) ‘Saimisu 1’ jujube fruit is ovoid, while ‘Saimisu 2’ jujube fruit is flat round, and the latter fruit shape index is greater than 1, the weight of single fruit is higher than the former, core smaller, edible rate is higher, thinner skin and fruit is more crisp; (3) There are significant differences in the levels of various hormones affecting fruit cell growth, division and fruit abscission among varieties. The contents of IAA and GA₃ of ‘Saimisu 2’ are significantly higher than that of ‘Saimisu 1’, which makes the fruit shape larger. (4) In terms of internal quality, The fruits of the two jujube varieties (strain), such as soluble sugar, titrating acid, vitamin C, plant starch, soluble protein content, are consistent with the development period, but there are differences between the content levels, The ‘Saimisu 2’ has higher sugar, vitamin C, lower acid and sweeter taste. (5) The sucrose metabolismrelated enzyme activities of the two jujube fruits were significantly different in the expansion period of rapid fruit growth, which also led to the sweetness of ‘Saimisu 2’ was significantly higher than that of ‘Saimisu 1’. Research found both jujube varieties are diploid, they have obvious differences in the external shape, easy to distinguish; The product ‘Saimisu 2’ has larger fruit, smaller core, higher edible rate, thinner and crispy skin, and sweeter taste.

Abstract:Fusarium oxysporum is the pathogen of tomato fusarium wilt. In this research, a series of experiments were carried out by Trichoderma koningiopsis T51 strain against F. oxysporum to investigate the biological control mechanism of T51 strain, including confrontation culture test, the screening test of optimum temperature and pH for the prevention, and biological control effect test, where we tested the physiological and biochemical indexes of tomato seedling leaves, and tested the expression of key genes of synthesis and signaling pathways of salicylic acids and jasmonic acids. The results showed that: (1) T51 strain could inhibit the growth of F. oxysporum in confrontation culture significantly, and the inhibition rate of T51 strain against F. oxysporum increased first and decreased then, with increasing ambient temperature and pH, but the best inhibition was achieved at 20 ℃ and pH=7. (2) Tomato seedlings treated with T51 strain and F. oxysporum conidia fluid showed no conspicuous symptom, and there was no significant difference in plant growth status with the control group. Compared with F. oxysporum conidia fluid treatment group, the incidence and disease index were decreased significantly, and the relative control effect was 87.5%. (3) Compared with F. oxysporum conidia fluid treatment, chlorophyll fluorescence parameters, including maximum photochemical efficiency, photochemical quenching coefficient and apparent photosynthetic electron transport rate, and antioxidant enzymes SOD, POD, CAT activity of tomato seedlings inoculated mixed conidia fluid were increased significantly, but non photochemical quenching and the content of hydrogen peroxide were reduced significantly. (4) Compared with F. oxysporum conidia fluid treatment, the content of endogenous salicylic acid (SA) in leaves of tomato seedlings treated with mixed spore solution was decreased significantly, while jasmonic acid (JA) increased significantly. While the expression of PR1 and TGA2 genes in SA signaling pathway were downregulated significantly, and the expression of JA synthesis gene LoxD was upregulated significantly. In conclusion, T. koningiopsis T51 had a significant control effect on F. oxysporum, and the optimal control effect was obtained at 20 ℃ and pH=7. T51 strain may enhance tomato wilt resistance by inhibiting F. oxysporum infecting, enhancing antioxidant enzyme activity, improving photosynthetic efficiency of tomato leaves, regulating the expression of key genes in salicylic acid and jasmonic acid synthesis and signaling pathway, and regulating the contents of endogenous SA and JA. These results provided theoretical and research basis for the biocontrol of tomato fusarium wilt.

Abstract:To analyze the resistance mechanism of apple to Glomerella leaf spot, we analyzed 87 cultivars (lines) including ‘Gala’, ‘Mato’ and their F₁ individuals in this study. The field investigation, artificial inoculation, pathogen biomass detection, and SSR molecular marker identification were used to analyze the differences in resistance to Glomerella leaf spot in different varieties (or lines). The difference in salicylic acid resistance related genes, the defensive enzyme gene expression level, and the defensive enzyme activity were detected by the realtime fluorescent quantitative PCR and the enzyme activity methods. The results showed that: (1) there were significant differences among 87 cultivars (lines) in resistance to Glomerella leaf spot. ‘Gala’, ‘25’, ‘1919’ etc. had severe leaf disease phenotype and showed high susceptibility to Glomerella leaf spot. ‘Mato’, ‘409’ and ‘1616’ etc. had no or very few leaf spots. The content of pathogen biomass was significantly lower than that of susceptible varieties (lines). (2) The accuracy of SSR markers S0405127 and S0304673 genotypes was 93.10% and 91.95%, 91.95% and 95.40%, respectively, compared with field phenotypic investigation results and artificial inoculation results. (3) The expression patterns of SA related genes showed that MdEDS1, MdPAD4 and MdPAL were strongly induced in resistant varieties (lines) such as ‘Mato’, ‘409’ and ‘1616’ after inoculated for 4 days. Furthermore, the expression level of SA signal transduction related genes MdNPR1, MdPR1 and MdPR5 was significantly higher than those in susceptible varieties (lines) such as ‘Gala’. (4) After inoculated the pathogen for 4 days, the expression level of MdSOD and MdPOD and enzyme activities in ‘Mato’, ‘409’ and ‘1616’ and other resistant varieties (lines) were significantly higher than those in susceptible varieties (lines) such as ‘Gala’, ‘25’ and ‘1919’. These results preliminarily showed that salicylic acid synthesis, signal transduction pathway and oxidationreduction reactions process were involved in the resistance of ‘Mato’, ‘409’ and ‘1616’ and other resistant varieties to Glomerella leaf spot. This research provided important guiding significance for mining resistant genes and breeding resistant varieties by using desirable germplasm resources.

Abstract:In order to explore the effects of exogenous nitric oxide (NO) on the salt tolerance of melon seedlings under 300 mmol·L^-1 NaCl stress,we used melon variety ‘Nongda Tian No. 10’ as the tested material. In the present study, with different concentrations of spraying exogenous NO donor sodium nitroprusside (SNP) (50, 100, 150, 200, 250 μmol·L^-1), we investigated the changes of melon seedlings growth, photosynthetic pigment content, cell membrane permeability, antioxidant enzyme activities under 300 mmol·^-1 NaCl stress. The results showed that: (1) salt stress significantly inhibited the growth of melon seedlings, and significantly reduced the content of photosynthetic pigment, cell membrane permeability, antioxidant enzyme activities and osmoregulation substances in leaves. (2) Foliar spraying 150 μmol·L^-1 SNP significantly improved the plant height, stem diameter, dry and fresh weight and strong seedling index of melon seedlings under salt stress, significantly increased the photosynthetic pigment content of melon seedlings under salt stress, improving the photosynthesis of melon. (3) Spraying 150 μmol·L^-1 SNP significantly increased the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbic acid peroxidase (APX), glutathione reductase (GR), monodehydroascorbic acid reductase (MDHAR), dehydroascorbic acid reductase (DHAR) in melon seedlings under salt stress, so as to significantly reduce malondialdehyde (MDA) and Hydrogen peroxide (H₂O₂) contents and superoxide anion ( O₂^-·) production rate. (4) Spraying 150 μmol·L^-1 SNP also decreased the contents of proline (Pro) and soluble protein in the leaves of melon seedlings under salt stress. Therefore, under salt stress environment, the appropriate concentration of exogenous SNP (150 μmol·L^-1) can enhance the scavenging capacity of reactive oxygen species, reduce membrane lipid peroxidation and effectively reduce the damage of salt stress to seedlings by increasing the activities of antioxidant enzymes and the contents of photosynthetic pigments and small molecular soluble organic compounds in melon seedlings, so as to enhance their salt tolerance and promote the growth of seedlings.

Abstract:In order to explore the stress resistant physiological and biochemical mechanism of exogenous 5aminolevulinic acid (5ALA) and CaCl₂ on Paeonia lactiflora cultivated in open field under high temperature stress, to provide technical basis for alleviating the high temperature injury of P. lactiflora in summer, we investigated the plasma membrane stability, antioxidant enzyme system, chlorophyll content, photosynthetic parameters and ornamental quality of P. lactiflora ‘Dafugui’ from April to July after spraying 100 mg/L 5ALA and 4% CaCl₂ on leaves in the study. The results revealed that: (1) the flowering period, flower diameter and fresh weight of P. lactiflora in 5ALA and CaCl₂ treatment groups were significantly higher than those in the control group; (2) Compared with the control, P. lactiflora treated with 5ALA and CaCl₂ could maintain higher superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities, lower superoxide anion radical ( O₂^-·) production rate and MDA content, as well as higher cell chlorophyll content, net photosynthetic rate (P_n), transpiration rate (T_r), and stomatal conductance (G_s); (3) Compared with foliar spraying CaCl₂, spraying 5ALA had a better effect on the stress resistance physiological and biochemical indexes and ornamental quality of P. lactiflora cultivated in the open field. The results showed that exogenous 5ALA and CaCl₂ treatments could increase the chlorophyll content and antioxidant capacity of P. lactiflora, enhance the photosynthetic capacity, reduce the level of membrane lipid peroxidation, and effectively improve the ornamental quality of P. lactiflora ‘Dafugui’ cultivated in open field in summer, and the improvement effect of 100 mg·L^-1 5ALA was better.

Abstract:In order to explore the response mechanism of photosynthesis changes of millet (Setaria italica) seedlings caused by low potassium stress, we used the potassium sensitive cultivar ‘Jingu 21’ and the nonpotassium sensitive cultivar ‘Longgu 25’ as experimental materials. Normal potassium supply (K₅, 5.0 mmol·L^-1), low potassium (K₁, K_0.1, K_0.01, 1, 0.1, 0.01 mmol·L^-1) and without potassium (K₀, 0 mmol·L^-1) were set. We analyzed the effects of different degrees of low potassium stress on the growth of millet seedlings, photosynthetic gas exchange parameters, chlorophyll fluorescence characteristics and activities of key enzymes of carbon assimilation. The results showed that: (1) low potassium stress significantly inhibited the growth of millet seedlings, and the plant height, stem diameter, leaf area and dry matter decreased significantly, while the potassium content was also decreased. Compared with K₅ treatment, leaf while the potassium content of ‘Jingu21’ and ‘Longgu 25’ was significantly decreased by 48.14% and 37.85%, respectively. (2) The photosynthetic pigment content of millet seedlings under K₀ treatment was significantly lower than that under K₅ treatment, but the difference between K_0.1 and K₁ treatment was not significant compared with K₅ treatment. (3) Low potassium stress reduced the net photosynthetic rate (P_n) of millet seedlings, Compared with K₅ treatment, K₀, K_0.01 and K_0.1 treatments significantly decreased P_n, stomatal conductance (G_s), transpiration rate (T_r) and stomatal limit value (L_s), but increased intercellular CO₂ concentration (C_i), demonstrating that the photosynthetic rate reduction is mainly caused by nonstomatal limitation. (4) Low potassium stress can lead to the reduction of photochemical quantum yields of PSⅡ and PSⅠ. Under K₁ treatment, the PSⅡ actual photochemical quantum efficiency (Φ_PSⅡ) and PSⅠ photochemical quantum yield ［Y(Ⅰ)］ of leaves decreased by 5.32%-9.57% and 2.38%-5.63%, respectively. Under K₀ treatment, Φ_PSⅡ and Y(Ⅰ) significantly decreased by 17.15%-20.15% and 18.71%-21.28%, respectively. (5) Compared with K₅ treatment, the activities of ribulose 1,5biphosphate carboxylase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC)of ‘Jingu21’ were significantly decreased by 42.86% and 42.71%, respectively, under K₀ treatment, ‘Longgu 25’ were significantly decreased by 26.85% and 42.77%, respectively. The study found that under the stress of potassium deficiency, ‘Longgu 25’ had stronger absorption and utilization capacity of potassium, and the variation range of each growth physiological parameter was small, showed stronger tolerance to potassium deficiency. Potassium deficiency stress led to the decrease of the net photosynthetic rate of millet seedlings. The decrease of photosynthetic rate under K₀ and K_0.1 treatments was mainly related to the decrease of stomatal conductance, the inhibition of electron transport and energy conversion in the photosystem, and the activities of Rubisco and PEPC decreased, etc.

Abstract:Using germplasms Dracocephalum moldavica No.1, Baihua Dracocephalum moldavica L., Shandong Dracocephalum moldavica L., Gansu Dracocephalum moldavica L. and Xinjiang Dracocephalum moldavica L. seeds as materials, we explored the effects of the harvest period (flowering stage, final flowering stage, mature stage) on the growth physiological characteristics, yield of medicinal herbs and the content of pharmacodynamic components of different germplasm of D. moldavica L. in salinealkali land, to provide a reference for the popularization and planting of D. moldavica L. in salinealkali land of central Inner Mongolia. The results showed that: (1) with the delay of the harvest period, the fresh weight of all germplasms of D. moldavica L. decreased gradually, and the flowering stage was the best; while the plant height and other morphological growth indexes increased gradually, and the mature stage was the best. (2) Antioxidant enzyme activity, Osmotic regulatory substances and other physiological indexes of stress resistance decreased gradually, and the flowering stage was the best. (3) The photosynthetic gas exchange parameters decreased gradually, and the flowering stage was the best. (4) The yield increased first and then decreased, and the final flowering stage was the best; while the content of pharmacodynamic components decreased gradually, and the flowering stage was the best. Among them, the yield of Dracocephalum moldavica No.1 at the final flowering stage was the highest (4 692.32 kg·hm^-2); the content of pharmacodynamic components of Xinjiang D. moldavica L. was the highest in the flowering stage, the content of total flavonoid reached 23.40 mg·g^-1, essential oil content up to 0.59%. The research shows that, in various combinations of germplasm and harvesting period, the yield of Dracocephalum moldavica No.1 in the final flowering stage was the highest, and the flowering period of Xinjiang Dracocephalum moldavica L. had the highest growth characteristics and pharmacodynamic content. In cultivation practice, Dracocephalum moldavica No.1 can be selected for yield and harvested at the final flowering stage, and Xinjiang Dracocephalum moldavica L. can be selected for the pursuit of medical and harvested at the flowering stage.

Abstract:Juniperus przewalskii is an important part of the forest ecosystem in Qinghai Province. In order to understand the adaptability of J. przewalskii to the cold and arid environment in the plateau, we collected current year needles of J. przewalskii from Qinghai Province as research object, with paraffin section as method, measured leaf width, leaf thickness, lower cuticle thickness, lower epidermal cell thickness, xylem thickness and phloem thickness. Regression analysis and partial correlation analysis were used to study the response characteristics of needle anatomy to longitude, latitude, altitude and slope aspect. Results showed that, (1) the anatomical structure of J. przewalskii needles had no significant changes in longitude and latitude, and there was no significant correlation between anatomical structure and longitude and latitude. (2) Relationship of J. przewalskii needle anatomical structure and altitude differed according to zones and structures. In the lower zones (<3 200 m) with lower environment stress, no obvious change was found. Above 3 200 m, leaf width, leaf thickness, lower cuticle thickness and lower epidermal cell thickness increased differently with the elevation. When the elevation was higher than 3 680 m, the growth trend of needle anatomical structure became slow, especially the growth rate of leaf width and leaf thickness decreased more. The lower cuticle thickness and lower epidermal cell thickness had the strongest correlation with altitude, followed by leaf thickness and leaf width, but the thickness of xylem and phloem of leaf vascular bundle had no significant correlation with altitude. (3) In 6 regions the lower cuticle thickness was higher on shady slopes, and there was significant correlation between the lower cuticle thickness and slope aspect. This study suggested that J. przewalskii had strong adaptability to cold and arid environment of the plateau, and the environment pressure caused by the change of latitude and longitude, low altitude and sunny slope were not enough to cause the changes of anatomy; In shady slope, it can improve cold resistance by thickening the lower cuticle; While in high altitude, it can adapt to the complex environmental pressures such as extreme cold and drought by thickening the lower cuticle, lower epidermal cell layer, leaf width and leaf thickness.

Abstract:In flowering plants, male fitness and sexual reproduction are influenced by floral characteristics, floral reward, distance between pistils and stamens, pollen presentation, and pollinator efficiency. Lycium barbarum L. is a species in arid and semiarid areas, such as Ningxia, Xinjiang, and Inner Mongolia, China. We observed and analyzed the relationships between floral characteristics, pollen presentation pattern, floral reward, and pollinator behavior within the mating system of L. barbarum in Kashi, Xinjiang. Our results showed that: (1) the floral longevity was (4.07±0.15) d. The duration of the male stage (0.07±0.01 d) was shorter than that of the female stage (4±0.01 d), which was indicative of herkogamy. Additionally, the pollenpresenting pattern showed incomplete gradual presentation. (2) Floral reward differed significantly among flowering stages. (3) Apis mellifera, Bombus sp., and Syrphidae sp. were the main flower visitors; the latter two, which were the main pollinators, showed high removal and low deposition of pollen. (4) The pollination experiment and pollenovule ratio (2 448.11±448.32) revealed facultative outbreeding characteristics. The low fruit and seedsetting rate from spontaneous autogamy and manual selfpollination indicated that the species was selfincompatible. The seedsetting rate from natural pollination was lower than that from crosspollinated flowers, and the species had a high pollen limit (40.71%). In conclusion, L. barbarum floral characteristics shows herkogamy and incomplete gradual pollen presentation, which is an effective strategy for avoiding interference between male and female floral functions, reducing the synchronous removal of pollen and ensuring male fitness. However, high removallow deposition pollinators, low pollination efficiency, and selfincompatibility in natural populations are the primary reasons for pollen limitation and female reproductive success in L. barbarum.

Abstract:Based on field investigation and relevant literatures, this study has comprehensively analyzed and discussed the characteristics of the seed plants flora in Dehang Scenic spot from the aspects of family, genus and species. Meanwhile, we revealed the nature and status of the flora via comparison between plants grown in different special ecoenvironment types and those grown in adjacent regions. The results provide an important basis for management and sustainable utilization of natural resources in Dehang Scenic spot. The results showed that: (1) there was high species diversity of Spermatophyta in Dehang. Our investigation showed that there were 1 626 species of wild seed plants belonging to 154 families, 710 genera. These plants accounted for 94.48%, 83.43% and 54.00% of seed plants families, genera and species in the Wuling mountain area, and for 73.33%, 54.20% and 33.46% in Hunan Province. (2) The floristic analysis showed that the geographical element of seed plants in Dehang was complex. There are 12 areatypes of families, 14 areatypes of genera, and 15 areatypes of species in this area. The areatype of families and genera was mostly pantropic. For species, the number of endemic to China was the largest. Meanwhile, the flora of Dehang exhibited obvious endemism. The area contained 7 endemic families in East Asia, 2 Chinese endemic families, 27 Chinese endemic genera, and 588 Chinese endemic species, including 39 endemic species in central China, 29 endemic species in the Wulingshan region, and 6 endemic species in Dehang. (3) The floristic components of this area differentiated with different habitats. There were obvious differences in floristic components among three representative habitats: platform, cliff and valley. The flora of Dehang were similar to the neighboring Huping Mountain, Xiaoxi and Oolong Mountain. Overall, the flora of seed plants in Dehang Scenic spot has the characteristics of East Asian flora, and it has an important place in the flora of the Wulingshan region.

Abstract:Two species of the genus Bulbophyllum Thouars (Orchidaceae), i.e. B. kingii Hook. f. and B. pentaneurum Seidenf. found in Mêdog County, Nyingchi, Xizang are reported for the first time from China. A brief description, as well as information about phenology and distribution, and illustration, is presented to make identification easy. The voucher specimens are deposited in the Herbarium of Xishuangbanna Tropical Botanical Garden (HITBC).

Abstract:For long time it lasted of evaluation and screening of germplasm resources from different Lathyrus cultivars to get novel lines with low βNoxalylLα, βdiaminopropionicacid (βODAP) content or protease inhibitor activities. To investigate the possible relationship between βODAP content and protease inhibitor activities, we conducted several tests including sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDSPAGE), enzymatic measurement, correlation analysis etc. referring to six cultivars with two closely related species L. sativus and L. cicera included. The results suggested that: (1) SDSPAGE analysis of seed globulins and prolamins revealed significant difference in their protein profiles. (2) Kunitz trypsin inhibitor (KTi) activity in different Lathyrus cultivars ranged between 100 and 190 trypsin inhibitor unit, while BowmanBirk inhibitor (BBi) activity ranged between 5 and 9 chymotrypsin inhibitor unit. (3) The Pearsons correlation coefficient up to 0.76 suggested a significant positive correlation between βODAP content and serine acetyltransferase activity. (4) Correlation analysis of βODAP biosynthesis related genes and BBi genes expression from transcriptomic database (SRP145030) suggested a significant negative correlation between them. These results will help to further investigate the regulation of βODAP and BBi biosynthesis and improve sulfur amino acid content in Lathyrus cultivars.

Abstract:Changing the distribution of soil roots to absorb deep soil water may be an important strategy for plants to avoid drought. Lathyrus sativus is a kind of legume crop with strong stress resistance. We explored the effects of different irrigation modes (Full irrigation, FI; Partial root drying, PRD; No irrigation, NI) on soil moisture, root distribution, gas exchange, water use efficiency and yield of Lathyrus sativus at different periods after sowing. The results showed that: (1) 89.8%, 86.9% and 84.9% of the roots of L. sativus grew in 0-20 cm topsoil under FI, PRD and NI treatments, respectively. Drought stress increased the proportion of roots in deep soil to 13.05% and 15.07% under PRD and Ni treatments, which provided guarantee for roots to absorb deep soil water and avoid the influence of drought on L. sativus. (2) During the whole growth period, soil drought significantly reduced the net photosynthesis, transpiration and stomatal conductance; At 60 days after planting, PRD and NI treatment significantly improved the instantaneous water use efficiency of leaves, which was 21.4% higher than that of the control (FI treatment) and 14.9% higher than that of NI treatment. (3) The drought reduced plant height, first pod height, average pod number and seed number of L. sativus. Drought also led to a significant decrease in aboveground biomass and root system, but a significant increase in root shoot ratio; PRD treatment had no significant effect on pod length, pod weight and seed weight per pod. Drought reduced the average grain yield loss of PRD and NI reached 53% and 63%. The study found that under drought stress conditions, L. sativus could alleviate drought by increasing the proportion of roots in the deep soil, absorbing more water in the deep soil, significantly increasing the ratio of root to shoot, and significantly improving the instantaneous water use efficiency of leaves in the reproductive growth period. These results provide a reference for the cultivation of L. sativus in arid areas.