Eucalyptus grandis as material and 43 non-repeated genes beginning with AUG as objects. The results showed that the average GC content in the 3rd position was 27.97%; ENC ranged from 39.49 to 61.00 with an average of 47.04; there were 31 codons whose RSCU were more than 1.00 in the chloroplast genome; of which, 29 codons ended with A/U; neutral plot analysis showed correction and regression analysis between GC12 and GC3 were not significant; ENC-plot revealed most genes were located along or near the standard curve; correspondence analysis indicated the 1st axis accounted for 17.68% contribution, the 2nd axis 11.49%, the rest axes accounted for 8.00% and 5.76% and the first four axes accounted for 42.93% in total; the correction between the 1st axis and the parameters such as GC, ENC and CAI was extremely significant. The results mentioned above revealed that the codon bias level was low in the chloroplast genome and the 3 rd codons always end with A/U and codon bias might be determined by both mutation and selection nearly equally. Finally, twelve codons that were not only highly expressed but frequently were determined as the optimal codons including UUG, CUU, GUU, UCC, UCA, ACA, UAU, UAA, CAU, AAU, AGA and GGA. This study will provide a solid foundation for codon optimization of the genes transformed into chloroplast genome and future increasing the expression efficiency for improvement of important traits.]]> 2019/12/27 10:09:49 1,2, WU Shuangcheng², YANG Liping³, WANG Huayu², CHEN Naiming³, ZHANG Zhaoyuan^1*]]> WANG Pengliang^1,2, WU Shuangcheng², YANG Liping³, WANG Huayu², CHEN Naiming³, ZHANG Zhaoyuan^1* 9true Ulmus pumila were used as explants, 75% alcohol and 0.1% HgCl₂ were used for disinfection. After initiation culture, the multiple shoots were first induced in the enrichment medium, and then cut into individual plants for rooting induction, and finally a tissue culture and rapid propagation system was established. The results showed that the optimal disinfection treatment combination of explants was 75% alcohol treatment for 50 s + 0.1% HgCl₂ treatment for 8 min, the contamination rate of explants was 17.3% and the survival rate was 78%. The sterilized explants were inoculated into the initiation medium and cultured for 25 d, and the most suitable medium for start-up of the explants was found to be MS + 1.0 mg L^-1 6-BA + 0.1 mg L^-1 IBA + 30 g L^-1 sucrose + 6.5 g L^-1 AGAR, with initiation rate up to 87.5%. After the initial culture, axillary buds of the explants were cut off and inoculated into the enrichment medium for multiple shoots induction. Finally, the optimal enrichment medium was selected as MS + 0.5 mg·L^-1 6-BA + 0.1 mg·L^-1 KT + 0.1 mg·L^-1 IBA + 30 g·L^-1 sucrose + 6.5 g·L^-1 AGAR, and the subculture cycle was 25 d with the increment coefficient as high as 6.2. The best rooting medium was 1/2 MS + 0.1 mg·L^-1 IBA + 0.1 mg·L^-1 IAA+ 30 g·L^-1 sucrose + 6.5 g·L^-1 AGAR, and rooting was induced for 30 d with a rooting rate of 97%. After seedling adaptation, the tissue culture seedlings of U. pumila were transplanted to mixed matrix with perlite:vermiculite:peat(volume ratio 1:1:1), and the survival rate reached above 90%. Higher increment coefficient, rooting rate and transplant survival rate can reduce production cost and realize factory seedling breeding.]]> 2019/12/27 10:09:49 1, 2*, XIN Quanwei², LUO Hailing¹, MA Zhihui², YAN Shaojuan^1,3]]> SUN Hongying^{1, 2*}, XIN Quanwei², LUO Hailing¹, MA Zhihui², YAN Shaojuan^1,3 8true Camellia oleifera as test materials. The results were as follows: Under the light intensity of 100 μmol·m^-2·s^-1, ZR content and POD activity of oil-tea camellia seedlings were the highest, while MDA content was the lowest, but the content of soluble sugar, IAA and GA were also the lowest; Under the light intensity of 150 μmol·m^-2·s^-1, ABA content of oil-tea camellia seedlings was the highest, furthermore, the soluble protein content and SOD activity were the lowest; Under the light intensity of 200 μmol·m^-2·s^-1, SOD activity of oil-tea camellia seedlings was the highest, but POD activity was the lowest, furthermore, the MDA content was the highest; Under the light intensity of 250 μmol·m^-2·s^-1, the soluble protein content, soluble sugar content, free amino acid content, IAA content, GA content and CAT activity of oil-tea camellia seedlings were all the highest; Under the light intensity of 300 μmol·m^-2·s^-1, the free amino acid content, ABA content, ZR content and CAT activity of oil-tea camellia seedlings were all the lowest. Compared with other treatments, 250 μmol·m^-2·s^-1 LED composite light(10% red lights + 90% blue lights), which is more conductive to improve the physiological and biochemical indexes of ‘Changlin-4' C. oleifera seedlings, is the ideal light intensity to cultivate seedlings of oil-tea camellia.]]> 2019/12/27 10:09:49 1,2, YAO Xiaohua^2*, WU Pengfei², WANG Kailiang², YE Sicheng², CHENG Guiwen¹]]> GONG Hongen^1,2, YAO Xiaohua^2*, WU Pengfei², WANG Kailiang², YE Sicheng², CHENG Guiwen¹ 7true Camellia, nine populations of eight yellow Camellia species with different petal colors in Chrysantha sect. of genus Camellia were used as experimental materials to measure their petal color, total flavonoids content, water content, cell pH as well as seven kinds of metal ion contents. The results showed that the average value of lightness L^*, hue a^*, hue b^*, saturation C^*, hue angle h was 80.82, -2.88, 53.97, 54.10, 93.19°, respectively, and the petal color of yellow Camellia was regarded as a kind of color of bright yellow in flowers, and the species could be divided into three categories in terms of hue b^* value as the major index of measurement of yellow color, golden yellow, yellow and light yellow. The contents of total flavonoids and water in petals were 20.17% and 88.14% respectively. Both of them were significant among different species and not closely related to petal color, and thus they were not be regarded as the fatal factors in determining color of yellow Camellia. The pH in petal cells was 6.19 in average and significant among the species. But the pH in petal cells was found to be positively correlated with petal colors, which indicates that the slightly weak acidic environment may be helpful to phenotypic expression of yellow color in these Camellia flowers. The metal ion concentration of K⁺ was found to be the highest(12.61 mg·g^-1), and then ranked by Ca²⁺(3.91 mg·g^-1), Mg²⁺(1.28 mg·g^-1), Al³⁺(0.98 mg·g^-1), Na⁺(0.17 mg·g^-1), Fe³⁺(0.07 mg·g^-1), the lowest value was Cu²⁺(0.003 8 mg·g^-1). There were significant differences for seven kinds of metal ions among these species. Besides the three kinds of Al³⁺, Fe³⁺ and Ca²⁺ interfere with petal colors to some extent, and it seems that the higher the concentration, the lighter the yellow color in high concentration. Therefore, low concentration of Al³⁺, Fe³⁺ and Ca²⁺ may be beneficial for the color appearance of yellow Camellia.]]> 2019/12/27 10:09:49 1, LI Jiyuan^1*, TONG Ran¹, HE Libo^1,3, ZHANG Lei^1,2, LI Zhihui⁴, HUANG Xiaona⁴]]> JIANG Lina¹, LI Jiyuan^1*, TONG Ran¹, HE Libo^1,3, ZHANG Lei^1,2, LI Zhihui⁴, HUANG Xiaona⁴ 6true Sorghum bicolor immature embryos. The differences of physiological and biochemical parameters between different types of callus in S. bicolor somatic embryogenesis were compared by variance analysis. The results were as follows:(1)The contents of soluble protein, free proline and soluble sugar in two kinds of embryogenic callus were significantly higher than that of non-embryogenic callus, which indicates that the metabolic activity in embryogenic callus is higher than that in non-embryonic callus, and embryogenic callus can provide more material energy basis for somatic embryogenesis.(2)The physiological and biochemical differences between the two types of embryogenic callus were also significant. Among them, the contents of soluble protein and free proline in Type Ⅱ embryogenic callus were significantly higher than that of Type I embryogenic callus. In contrast, the content of soluble sugar in Type Ⅱ embryogenic callus was significantly lower than that of Type I embryogenic callus. We draw a conclusion that the differences of physiological and biochemical affect the differentiation on a certain degree. This study provides a theoretical basis for the relationship between embryogenic ability and biochemical metabolism of callus.]]> 2019/12/27 10:09:49 *]]> JI Yanli, CHENG Yunwei, CHEN Faju, ZHANG Dechun, ZHOU Chao^* 5true Prunella vulgaris. The full-length nucleotide sequence of PvDXS was obtained by reverse transcription PCR and the bioinformatics analysis of the gene was conducted. The expression levels of PvDXS in different tissues and exogenous substances were detected by real-time quantitative PCR. The results showed the cDNA sequence of PvDXS contained the open reading frame which had 2 181 bp and encoded a predicted protein of 726 amino acids with a theoretical molecular weight of 78 040.47 D and a isoelectric point of 6.75. The protein had Transketolase_C domain and Transket_pyr domain. Phylogenetic tree results showed that PvDXS protein was closely related to DXS(SmDXS2, CrDXS2)from Salvia miltiorrhiza and Catharanthus roseus, and it was inferred that PvDXS belonged to the Class Ⅱ DXS protein type. Tissue expression pattern analysis revealed that PvDXS gene in leaves was higher than that in ears and stems. After treated with seven exogenous substances for 24 h, the expression of the gene increased in GA₃ treatment group and decreased after treatment with the others. The expression level of the gene decreased significantly after CaCl₂, SNP and SA treatments. The expressions of PvDXS were variant in different tissues and varied greatly after treatment of exogenous substances, which laid a foundation for further study on the function and expression regulation of PvDXS in the synthesis pathway of terpenoid components of Prunella vulgaris.]]> 2019/12/27 10:09:49 1, DONG Chengming^1,2, ZHANG Mengjia¹, ZHU Yunhao^1,2*]]> LI Lu¹, DONG Chengming^1,2, ZHANG Mengjia¹, ZHU Yunhao^1,2* 4true Anoectochilus roxburghii as the study object, single factor comparison was carried out to determine the effects of phytohormone(NAA, IBA, 6-BA, GA₃, KT, ZT, TDZ, 2-IP)and inoculation method(vertical inoculation and horizontal inoculation)on cultivating strong seedling and inducing root. The results showed that compared to control treatment, NAA was better than IBA in cultivating strong seedling and inducing root. And the effects of cytokinins were as 6-BA >TDZ>KT=ZT> 2-IP >CK. The average height of seedlings in 6-BA treatment was 8.4 cm, the average root number was 3.6, the stem diameter was 2.84 mm, all seedlings grown vigorously with the best inducing effect. Gibberellin GA₃ could induced seedlings tall and straight, but it could not make seedling strong and it inhibited the growth of roots. The combination of 6-BA 0.5 mg·L^-1 and NAA 1.0 mg·L^-1 generated a good effect, which could induce strong seedlings and numerous roots. Horizontal inoculation could induce numerous roots, and it was convenient for operation and saved time of inoculation. Therefore, it can be concluded that during the strong plant culture and root inducing of Guangxi Anoectochilus roxburghii, the optimum medium is 1/2MS+6-BA 0.5 mg·L^-1 +NAA 1.0 mg·L^-1+banana mud 100 g·L^-1+ AC 1.0 g·L^-1+ sugar 20 g·L^-1, and the best inoculating method is to inoculate horizontally.]]> 2019/12/27 10:09:50 *]]> FU Chuanming, XIAN Kanghua, SU Jiang, HE Jinxiang, HUANG Ningzhen^* 3true Erigeron breviscapus collected from Yunnan in spring were used as the test materials, the effects of storage humidity, storage temperature, storage duration and illumination, temperature, imbibitional condition on seed germination rate were studied. The results were as follows:(1)Reducing the storage humidity(15%RH)and the storage temperature(-20, 4 ℃)of the seeds was beneficial to the seed preservation, which could prolong the seed life to more than two years, and the germination rate could reach more than 80%; High temperatures(35, 45 ℃)and high humidity(60% RH)accelerated the aging of seeds, which was not conducive to preservation, so the seeds were short-lived seed.(2)There was no significance of germination rate in either light or dark, so the seeds were light-neutral, but light was beneficial to the seedling formation after seed germination.(3)The optimum temperature for the seed germination was 25 ℃, and the germination rate was 84.37%.(4)The low temperature(4 ℃)and high temperatures(30, 35 ℃)must be avoided for seed germination in production, which was beneficial to increase the emergence rate.(5)The seeds were insensitive to imbibitional damage, so the seeds were cold-resistant. Therefore, in seed research and production of medicinal materials, mature seeds should be dried and sealed in low temperature immediately after harvest, and sown early in spring; In seedling production, suitable lighting condition is necessary, a separate constant temperature(25 ℃)culture room should be set, and cold season sowing should also be avoided. This paper studying the suitable storage conditions and germination characteristics for the seeds of E. breviscapus, will provide effective guidance for the reasonable storage of the rare medicinal species and high yield planting in future studies.]]> 2019/12/27 10:09:50 1,2, LI Weiqi¹, WANG Dandan^1*]]> ZHAO Luyan^1,2, LI Weiqi¹, WANG Dandan^1* 2true Calotropis gigantea was studied by using stem segments as explants in this paper. The results showed that the optimal sterilization method of explants was to treat 7 min with 0.1% HgCl₂, and the survival rate of explants was 32.3%. The suitable primary induction medium was MS+ sucrose 30 g·L^-1+ ager 3.5 g·L^-1. And after 20 d culture, 3-4 cm high regenerative buds were formed. Pre-multiplication culture test showed that MS+ 6-BA 1.5 mg·L^-1+ NAA 0.05 mg·L^-1+ sucrose 30 g·L^-1+ ager 3.5 g·L^-1 was a suitable multiplication medium, and proliferation coefficient was 4.6. However, during the subsequent culture process, the seedlings were easy to vitrify by using this method. With the change of generation, the vitrification rate increased, and it nearly reached 100% on the fourth generation. Therefore, inhibition of vitrification was the key to succeed. Based on the above multiplication culture treatment, with AgNO₃ as a vitrification inhibitor, the suitable multiplication culture medium of MS+6-BA 1.5 mg·L^-1+ NAA 0.05 mg·L^-1+ AgNO₃ 1.0 g·L^-1+ sucrose 30 g·L^-1+ ager 3.5 g·L^-1 was verified. With this method, 25 d later, seedling height was 5-8 cm, and proliferation coefficient was higher than 5.8 and vitrification rate of multiple shoots was lower than 10%. The optimal medium for rooting was 1/2MS+ NAA 1.0 mg·L^-1+ sucrose 20 g·L^-1 + ager 3.6 g·L^-1, and 14 d later, the rooting rate was 98%. The rooting seedlings were transplanted in the 70% shading greenhouse. And 30 d later, they were about 20 cm high, with 85% survival rate. This method can be used for the large-scale production of excellent clonal seedlings of Calotropis gigantea.]]> 2019/12/27 10:09:50 *]]> SU Jiang, HE Jinxiang, XIAN Kanghua, FU Chuanming, HUANG Huijin, HUANG Ningzhen^* 1true