Research Papars

• Study on Expression and Anthocyanin Accumulation of Solute Carrier Gene MdSLC35F2-like in Apple
• WANG Zhiyu, CHANG Beibei, LIU Qi, CHENG Xiaofan, DU Xiaoyun, YU Xiaoli, SONG Laiqing, ZHAO Lingling
• Acta Horticulturae Sinica. 2022, 49(11): 2293-2303. DOI:10.16420/j.issn.0513-353x.2021-0764
• Abstract ( 668 ) HTML ( 439 ) PDF (3169KB) ( 439 ) 　　　

• Anthocyanin is the main pigment affecting the skin color of apple fruit. In our previous study，MdSLC35F2-like was expressed at higher levels in the‘Nagafu 2’apple red bud mutant than in the wild-type. The open reading frame（ORF）of MdSLC35F2-like was cloned，it is 1 041bp，encoding 346 amino acids，which was predicted to be a hydrophobic α helix transmembrane protein with the highest homology to the PbSLC35F1-like of Pyrus × bretschneideri. Phylogenetic analysis showed that it had the closest evolutionary relationship with P. × bretschneideri，and the furthest evolutionary relationship with Theobroma cacao and Eucalyptus grandis. MdSLC35F2-like sequence and its expression rules before and after the fruit bagging were analyzed. After unbagging，the expression level of MdSLC35F2-like increased firstly，and then decreased with a peak on the third day. The expression level of MdSLC35F2-like in the two kinds of buds was significantly higher than that of‘Nagafu 2’. The above results indicated that the expression level of MdSLC35F2-like gene is positively correlated with anthocyanine content. Meanwhile，its expression levels in different color apple cultivars were compared. The expression of MdSLC35F2-like in red peel cultivars was significantly higher than that in green peel cultivars，and the expression level in red pulp cultivars was higher than that in non-red pulp cultivars. It suggests that MdSLC35F2-like may participate in the anthocyanine accumulation process.

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• Dynamic Changes of Browning Degree，Phenolics Contents and Related Enzyme Activities During Pear Fruit Development
• SU Yanli, GAO Xiaoming, YANG Jian, WANG Long, WANG Suke, ZHANG Xiangzhan, XUE Huabai
• Acta Horticulturae Sinica. 2022, 49(11): 2304-2312. DOI:10.16420/j.issn.0513-353x.2021-0703
• Abstract ( 1134 ) HTML ( 299 ) PDF (822KB) ( 299 ) 　　　

• Browning of pear flesh is an important problem affecting its quality. In this experiment，Browning varieties‘Baozhu’，‘Pingguoli’and non-browning varieties‘Fengshui’，‘Honghuada’were used to study the physiological mechanism of pear flesh browning，by measuring the changes of browning degree，phenolics and related enzyme activities during fruit development. The results showed that the browning degree，phenolic content and some enzyme activities of pear flesh decreased gradually with The growth and development of the fruit. Arbutin，chlorogenic acid and epicatechin were the main phenolic compounds in pear fruit from young fruit stage to mature fruit stage，accounting for more than 90% of the total phenolic content. The contents of arbutin and chlorogenic acid in the fruits of the two browning varieties were higher than those of the two non-browning varieties. According to the correlation analysis between fruit browning degree and phenolic substance content，single phenolic substance had little effect on fruit browning in young fruit stage，and phenolic substance strongly correlated with fruit browning in late fruit growth were arbutin，catechin，chlorogenic acid and caffeic acid. In the process of fruit growth and development，the PPO，PAL activities and total phenol content of browning varieties were higher than those of non-browning varieties. The PPO activity of the browning varieties was significantly different from that of the non-browning varieties at young fruit stage（P < 0.05），and it was not significantly different at mature fruit stage. The activities of PPO and PAL were significantly correlated with the contents of most phenolic substances in the fruits of the four varieties. The study on fruit browning at different development stages should take PPO activity and total phenolic content into consideration.

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• Construction of DNA Fingerprint Map and Analysis of Genetic Diversity for Chinese Chestnut Cultivars（Lines）
• NIE Xinghua, LI Yiran, TIAN Shoule, WANG Xuefeng, SU Shuchai, CAO Qingqin, XING Yu, QIN Ling
• Acta Horticulturae Sinica. 2022, 49(11): 2313-2324. DOI:10.16420/j.issn.0513-353x.2021-0863
• Abstract ( 459 ) HTML ( 207 ) PDF (1889KB) ( 207 ) 　　　

• The DNA fingerprint map of 342 chestnut cultivars（lines）was constructed using SSR fluorescent molecular markers as well as the genetic relationship and genetic differentiation were further illuminated among the cultivar groups in the current investigation. The results showed that：（1）The PI and and PIsibs values of all the markers combined were 4.960 × 10^-20 and 2.395 × 10^-8，respectively，indicating that the 21 markers used in this study had excellent potential for fingerprint recognition. A total of 338 unique corresponding fingerprint information were obtained from 342 cultivars（lines）. Among them，‘Shucheng Dahongpao’shared only one fingerprint information with‘Jiaoza’，similarly for ‘Shuanghe Dahongpao’and‘CSB-1’. Combined with the main botanical traits，these cultivars（lines） were finally speculated to be synonym. Simultaneously，19 same-named cultivars（lines）with more than ten loci differences were identified as homonym. （2）The average F_st of each pairwise of chestnut cultivar groups was 0.0224（F_st < 0.05），which demonstrated that there was low genetic differentiation among cultivar groups. Subsequently，gene flow（N_m）and AMOVA were carried out on the five cultivar groups. The genetic variation of chestnut cultivars（lines）mainly was found in individuals，accounting for 84% of the total variation. The average gene flow among cultivar groups was 6.592，revealing extensive gene exchange and restricting differentiation among chestnut cultivar groups.（3）From analyzing the population structure，principal coordinates and cluster tree via the site data，it could be seen that all chestnut cultivars （lines）were mainly divided into two major groups，the north and the south. Meanwhile，a region of northeastern Hubei，southern Henan，and north-central Anhui along the Dabie Mountains and the southern Shandong，the northern Jiangsu constituted the boundary zone（mixed zone）of two groups.

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• Preliminary Study on Mechanisms of Resistance to Citrus Canker of Kumquat FcRGA1
• DAI Wenshan, WU Yue, WANG Min
• Acta Horticulturae Sinica. 2022, 49(11): 2325-233. DOI:10.16420/j.issn.0513-353x.2021-0940
• Abstract ( 397 ) HTML ( 155 ) PDF (1439KB) ( 155 ) 　　　

• NBS-LRR resistant proteins are the most abundant R protein members in plants. This family contains typical NB-ARC domains and LRR domains，which are mainly involved in the defense process of plants against pathogen’s invasion. In this study，an R gene containing the NB-ARC domain was cloned from kumquat（Fortunella crassifolia）and named FcRGA1. This gene contained a complete open reading frame（ORF）of 3 954 bp and encoded 1 317 amino acids. qRT-PCR analysis showed that the FcRGA1 gene was expressed in the roots，stems and leaves of kumquat，with the highest expression level in the leaves and the lowest in the roots. Furthermore，the expression of FcRGA1 gene was up-regulated by infection with canker bacteria and reached the highest value at 12 h，which was 12.3 times higher than that of the control. After silencing the FcRGA1 gene by VIGS（Virus-induced Gene Silencing），kumquat leaves in the silenced group showed more severe chlorosis symptom than those in control group after inoculated by Xcc（Xanthomonas citri subsp. citri），concurrent with significantly higher lesion area，bacterial growth and relative electrolytic leakage. Whereas，the chlorophyll content and hydrogen peroxide content were significantly lower in comparison with the control group，indicating that FcRGA1 might affect the resistance of kumquat to citrus canker through the regulation of reactive oxygen species.

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• The Neutral Interaction of Co-infection Papaya Between Papaya Ringspot Virus and Papaya Leaf Distortion Mosaic Virus
• MO Cuiping, WU Zilin, GUO Yongyi, ZHANG Shuguang, LI Pengfei, LI Huaping
• Acta Horticulturae Sinica. 2022, 49(11): 2336-2346. DOI:10.16420/j.issn.0513-353x.2021-0804
• Abstract ( 362 ) HTML ( 95 ) PDF (3412KB) ( 95 ) 　　　

• The commercialized transgenic papaya‘Huanong 1’has been utilized to successfully control the destructive virus-papaya ringspot virus（PRSV）in South China. However，another new emerging virus，papaya leaf distortion mosaic virus（PLDMV）was found in some PRSV-resistant transgenic and other non-transgenic plants in Guangdong and Hainan Provinces through a field investigation. The survey results indicated that the two viruses had co-infections on some papaya plants. To clarify the interrelationship between the two viruses on papaya，the characteristics of both virus incidence，symptoms and cellular pathology，and virus accumulation on transgenic and non-transgenic papaya were analyzed by artificial inoculation. The results showed that the transgenic papaya‘Huanong 1’was still strong resistant to PRSV，but highly susceptible to PLDMV，and PLDMV could not help PRSV overcome its resistance to transgenic papaya. In addition，it was not observed significant symptomatic difference on the transgenic and non-transgenic papaya by the single- or co-infection of two viruses. The virions of the two viruses mostly existed in different mesophyll cells，which were not more seriously damaged with co-infection of two viruses compared with single viral infection. Moreover，the accumulation of PRSV gradually decreased until it was undetectable 15 days post inoculation on the transgenic papaya，while the accumulation of PLDMV gradually increased and remained at a higher level. On transgenic or non-transgenic papaya，the accumulation of PRSV virus was lower than that of PLDMV，but the two viruses co-existed for a long time and each maintained the corresponding viral contents on the non-transgenic papaya. These results indicate that transgenic papaya‘Huanong 1’is highly susceptible to PLDMV，and PRSV and PLDMV were shown as neutral with no synergistic infected in papaya plants.

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• Expression Analysis of Genes Related to Photosensitive Color Under the Caylx in Eggplant Based on Transcriptome Sequencing
• QIAO Jun, WANG Liying, LIU Jing, LI Suweng
• Acta Horticulturae Sinica. 2022, 49(11): 2347-2356. DOI:10.16420/j.issn.0513-353x.2021-0665
• Abstract ( 386 ) HTML ( 179 ) PDF (1161KB) ( 179 ) 　　　

• In order to explore the different genes related to low light tolerance between the the photosensitive and non-photosensitive varieties，stable genetic purple under the calyx，round eggplant inbred line Y₅ and green under the calyx，round eggplant inbred line Y₇₃ were sequenced at three-time points（0，4 and 8 h）. The total effective data of 75.61 Gb was obtained，and the percentage of Q30 base reached 93.97%. 11 812 differential expression genes were obtained by sequencing and comparing two inbred lines at three-time points，including 5 277 up-regulated genes and 6 535 down-regulated genes. KEGG enrichment analysis of data at three time points shows three same pathways of phenylpropane biosynthesis，flavonoids biosynthesisand carbon fixation of photosynthetic organisms. There are four genes in the biosynthesis pathway of phenylpropane and flavonoids，named FAOMT，CCOAOMT，CYP73A4 and HST. The CHI，ANS，F3H，PAL genes and the transcription factor MYB113 gene related to anthocyanin synthesis were screened to express significantly in the peel under the calyx.

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• Evaluation of Steroidal Glycoalkaloids and Analysis of Related Gene Expression in Potato Resources
• YE Guangji, ZHENG Zhenzhen, NA Tiancang, WANG Jian
• Acta Horticulturae Sinica. 2022, 49(11): 2357-2366. DOI:10.16420/j.issn.0513-353x.2021-0811
• Abstract ( 311 ) HTML ( 103 ) PDF (1447KB) ( 103 ) 　　　

• The content of SGAs（Steroidal glycoalkaloids）was evaluated in the leaf and peel tissue of 11 potato resources，the resources with relatively low level of SGAs were selected. The gene expression related to the SGAs biosynthesis was determined in Xiazhai 65，LZ111，Q072625，Longshu 7，Qingshu 9，and Qingshu 11，which would help confirm the key genes in SGAs biosynthesis of potato and provide the potential to create the low SGAs potato resources in the future. These results showed that SGAs content in the leaves of 11 cultivars was 0.08600-1.58066 mg · g^-1 FW;the SGAs content in the peel tissue of potato tubers was 0.01415-0.18450 mg · g^-1 FW and lower than 0.20 mg · g^-1 FW（the safety level）. The genes of StSQS1，StCAS，StSSR2 and StGAME4 played key roles in SGAs biosynthesis.

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• Cloning and Functional Analysis of Peony PlSVP Gene in Regulating Flowering
• JI Fengjiao, MA Yan, QI Shuai, GUO Xianfeng, CHEN Junqiang
• Acta Horticulturae Sinica. 2022, 49(11): 2367-2376. DOI:10.16420/j.issn.0513-353x.2021-1253
• Abstract ( 456 ) HTML ( 160 ) PDF (1619KB) ( 160 ) 　　　

• Cloning SHORT VEGETATIVE PHASE（SVP）gene from peony and exploring its function in regulating flowering will provide gene resource for molecular breeding of peony. In this study，PlSVP gene was isolated from Paeonia lactiflora‘Da Fugui’by RT-PCR method. The open reading frame of PlSVP gene was 687 bp in length，encoding 228 amino acids. Phylogenetic analysis indicated that PlSVP protein had the closest relationship with the homologue from P. suffruticosa. The qRT-PCR results showed that the expression of PlSVP gene was generally confined to vegetative organs. The highest expression was detected in roots，followed by in leaves，and the expression level in the basal leaves was higher than that in the top leaves. Overexpression of PlSVP gene in Arabidopsis Col-0 indicated that both bolting and flowering of the transgenic plants were delayed，by 7 and 15 d，respectively. And the complementary overexpression study in Arabidopsis svp-41 verified the inhibition effect of PlSVP gene. Further study that the expression of the floral promotors FT，SOC1，LFY and AP1 in transgenic plants was significantly down-regulated. These results suggested that PlSVP gene distinctively and negatively control flowering time，and possibly via inhibiting the expression of FT，SOC1，LFY and AP1.

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• Characterization of CmMYC2 in Formation of Green Color in Ray Florets of Chrysanthemum
• CHEN Sijia, WANG Huan, LI Ruirui, WANG Zhuoyi, LUO Jing, WANG Caiyun
• Acta Horticulturae Sinica. 2022, 49(11): 2377-2387. DOI:10.16420/j.issn.0513-353x.2021-0524
• Abstract ( 394 ) HTML ( 154 ) PDF (2394KB) ( 154 ) 　　　

• White Chrysanthemum vestitum and light green C. morifolium‘Chunxiao’，dark green C. morifolium‘Green anna’，as well as cut flower variety C. morifolium‘Lükou’were used to investigate the expression pattern and gene function of chlorophyll synthesis-related bHLH transcription factor gene CmMYC2. In addition，the regulation of chlorophyll synthesis-related genes by CmMYC2 was also studied. The results showed that the expression of CmMYC2 was gradually increased in ray florets and leaves of C. vestitum，C. morifolium‘Chunxiao’and‘Green Anna’，which was highly correlated with chlorophyll accumulation in these materials. Abscisic acid（ABA）treatment inhibited the accumulation of chlorophyll in ray florets and leaves of‘Lükou’and the expression of CmMYC2 and chlorophyll synthesis-related genes. The cluster heat map showed that there was a significant correlation between the expression pattern of CmMYC2 and chlorophyll synthesis-related genes in ray florets and leaves of ‘Lükou’under ABA treatment and in leaves of C. vestitum，C. morifolium‘Chunxiao’and ‘Green Anna’. Transient over-expression of CmMYC2 in leaves of‘Lükou’significantly promoted the accumulation of chlorophyll，and the chlorophyll synthesis-related genes，including HEMA1，CRD1，CHLG1 and PORA1 were notably induced by CmMYC2. The transient trans-activation assay in leaves of tobacco（Nicotiana benthamiana）showed the promoter activity of HEMA1 and CHLI1 was significantly enhanced by CmMYC2.

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• Identification and Analysis of the Type of Leaf Variegation of Primulina pungentisepala
• LI Yueya, HE Dong, CHEN Jiancun, LI Bo, BAI Meng, LUO Le, Zhang Qixiang
• Acta Horticulturae Sinica. 2022, 49(11): 2388-2394. DOI:10.16420/j.issn.0513-353x.2021-1038
• Abstract ( 343 ) HTML ( 142 ) PDF (3000KB) ( 142 ) 　　　

• Several features of Primulina pungentisepala leaf to determine the type of leaf variegation were analyzed. These features include：the morphological characteristics of leaf epidermis，the optical characteristics of leaf adaxial epidermis，the anatomical structure of leaf，and chlorophyll content and chlorophyll fluorescence parameters（F_v/F_m） of leaf. The results indicated relatively stable leaf variegation，showing fishbone-like characteristics. The variegated areas presented two reflection modes：spot reflection（spotted pattern）and polygon reflection（polygonal pattern）. Boundaries between tissues were blurry in variegated areas. Conspicuous intercellular spaces existed between the epidermal and palisade cells，and among palisade cells. In non-variegated areas，intercellular spaces were not observed between palisade cells. In variegated areas，the stacking degree was low and chloroplasts were sparse，but profuse and dense osmiophilic were presented. On the contrary，the stacking degree of chloroplast was high with fewer osmiophilic droplets in non-variegated areas. Between the variegated and non-variegated areas，the chlorophyll a content did not differ significantly，while the chlorophyll b content and the total chlorophyll content differed remarkably. The chlorophyll fluorescence parameters（F_v/F_m）showed no significant differences between the variegated and non-variegated areas. Collectively，these results indicate that the formation of silver-white leaf variegation of P. pungentisepala is mainly related to the conspicuous intercellular spaces between the epidermal and palisade cells，and among palisade cells，but is also affected by the reduction of chlorophyll contents.

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• Analysis of Free Aromatic Components of Different Osmanthus fragrans Cultivars
• ZHU Linlin, ZHOU Wanfei, NING Xuan, ZHU Jun, XI Wan, ZENG Xumei, XIONG Kangshun, WANG Caiyun, LUO Jing, ZHENG Riru
• Acta Horticulturae Sinica. 2022, 49(11): 2395-2406. DOI:10.16420/j.issn.0513-353x.2021-0773
• Abstract ( 737 ) HTML ( 166 ) PDF (2661KB) ( 166 ) 　　　

• In this study，methyl tert-butyl ether（MTBE）solvent extraction combined with gas chromatography-mass spectrometry（GC-MS）was applied to detect the free aroma components in petals of 20 common cultivars of Osmanthus fragrans. The results showed that 125 kinds of free components were identified in 20 cultivars，which were significantly more than the corresponding volatile aroma components. The aroma components mainly included terpenoids，benzenoids，alkanes，aldehydes，alcohols and esters. Terpenoids were the dominant aroma active components. Among the 20 cultivars，‘Yulian Yinsi’and‘Rixianggui’contained the maximum contents of free aroma components.‘Juye Sijigui’and‘Rixianggui’contained the high contents of terpenoids and were rich in aroma. Luteus Group generally had low aroma components and hardly tended to browning‘Xiaoye Zhushagui’and‘Mantiaohong’had the highest contents of terpenoids in Luteus Group，thus they were recommended as characteristic cultivars for industrial application.‘Rixianggui’was a potential cultivar because it had considerably high contents of β-ionone，γ-decalactone and linalool.‘Juye Sijigui’was also an ideal cultivar with high contents of linalool oxide.

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• Cloning and Function Analysis of Chalcone Isomerase Gene RdCHI1 in Rhododendron delavayi
• SUN Wei, SUN Shiyu, CHEN Yiran, WANG Yuhan, ZHANG Yan, JU Zhigang, YI Yin
• Acta Horticulturae Sinica. 2022, 49(11): 2407-2418. DOI:10.16420/j.issn.0513-353x.2021-0988
• Abstract ( 302 ) HTML ( 150 ) PDF (5533KB) ( 150 ) 　　　

• In order to investigate the function of Chalcone Isomerase（CHI）from Rhododendron delavayi，the flower of R.delavayi was used as study material to clone RdCHI1 gene. Multiple sequence alignment，phylogenetic analysis，qRT-PCR，genetic transformation of Arabidopsis thaliana and stress assay were employed to study the function of RdCHI1 on anthocyanin synthesis and stress resistance. The results showed that CDS sequence length of RdCHI1 is 663 bp，encoding 220 amino acids，and the predicted molecular weight of the protein is 23.78 kD. Analysis of multiple sequence alignment revealed that RdCHI1 shares 56.52% and 56.07% similarity with CHI of Arabidopsis thaliana and Medicago. The expression levels of RdCHI1 showed a trend of rising first and then decreasing during flower development，and the transcripts were the highest in pistil，but relatively lower in petal and root. Transformation of Arabidopsis found RdCHI1 could restore the biosynthesis of anthocyanins and flavonols which missed in CHI mutant（tt5），and turn the color of cotyledons and hypocotyls of seedlings from green back to purple. Meanwhile，stress assay indicated that Arabidopsis overexpressed RdCHI1 showed better adaptability and survival rate than the wild type when under NaCl and mannitol stresses，suggesting RdCHI1 playing a potential role to stress resistance in plants.

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Research Notes

• Effects of Film Mulching on Improving Fruit Quality of Ponkan and Possible Mechanisms
• ZENG Yike, SHI Ying, CHEN Siyi, LI Guojing, HUANG Xianbiao, XIE Zongzhou, LI Chunlong, GUO Dayong, LIU Jihong
• Acta Horticulturae Sinica. 2022, 49(11): 2419-2430. DOI:10.16420/j.issn.0513-353x.2021-0720
• Abstract ( 345 ) HTML ( 136 ) PDF (4488KB) ( 136 ) 　　　

• In the current study the effects of film mulching above the soil on sugar and acid content and peel color of Citrus reticulata‘Egan 1’ fruit and the possible molecular mechanisms were investigated. The results showed that film mulching could significantly increase the content of total soluble solids in the fruits，with the most prominent increase being detected in sucrose content. Film mulching promoted coloring of Ponkan fruits at an earlier stage，leading to more reddish peel at ripening. However，the contents of titratable acid and citric acid were not dramatically altered by film mulching. Six sucrose synthetase genes（CrSUS1-CrSUS6）and five sucrose phosphate synthetase genes（CrSPS1-CrSPS4a/b）were identified by analyzing the released genome of C. reticulata. Gene expression analysis showed that film mulching significantly up-regulated some of the CrSUS and CrSPS genes. In addition，film mulching increased activity of the SUS enzyme involved in sucrose synthesis，but decreased the one associated with sucrose decomposition. In conclusion，film mulching enhanced the synthesis of soluble sugars and increased the content of sugars by inducing the expression of SUS and SPS genes in Ponkan fruits. Meanwhile，film mulching effectively elevated the ratio of total soluble solids/titratable acid，leading to better flavor，and stimulated fruit coloring，which demonstrated that it has an obviously positive effect on improving fruit quality.

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• Detection and Genetic Diversity Analysis of Apple Necrotic Mosaic Virus in Gansu Province
• LI Shifan, SHAO Yuchun, QI Haonan, YANG Lan, LI Xiaowei, XU Bingliang, CHEN Yahan
• Acta Horticulturae Sinica. 2022, 49(11): 2431-2438. DOI:10.16420/j.issn.0513-353x.2021-0886
• Abstract ( 363 ) HTML ( 87 ) PDF (1681KB) ( 87 ) 　　　

• In order to clarify the incidence and genetic variation of apple necrotic mosaic virus （ApNMV）in Gansu Province，a total of 93 apple leaf samples with mosaic or without obvious symptoms were tested by reverse transcription-polymerase chain reaction（RT-PCR）. The results showed that the average incidence of ApNMV among the collected samples was 66.67%，which indicated that this virus spread widely around the surveyed regions of Gansu Province. The full-length coat protein（CP）genes generated from mine samples were cloned and sequenced. The similarity of nucleotide and amino acid sequence identities of ApNMV CP genes of the nine isolates ranged from 92.3%-99.7%，and 93.6%-99.1%，respectively，while they shared that of the available 18 ApNMV isolates from NCBI database of China，India and Japan，which ranged from 86.7%-99.7%，and 87.1%-99.7%，respectively. The phylogenetic tree were constructed based on the complete CP gene，and the ApNMV isolates clustered into five groups，among which，nine ApNMV isolates from Gansu and other ApNMV isolates to form GroupⅠ，GroupⅡand GroupⅤ，respectively. Finally，a potential recombination event was tested among the nine complete nucleotide sequences of ApNMV CP genes.

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• Cloning of Mulberry MaERF105-Like Gene and Its Expression Under Drought Stress
• HUANG Renwei, REN Yinghong, QI Weiliang, ZENG Rui, LIU Xinyu, DENG Binyan
• Acta Horticulturae Sinica. 2022, 49(11): 2439-2448. DOI:10.16420/j.issn.0513-353x.2021-0543
• Abstract ( 307 ) HTML ( 112 ) PDF (2437KB) ( 112 ) 　　　

• MaERF105-Like gene and its promoter were cloned from‘Deguo 1’. Sequence analysis showed that the length of MaERF105-Like cDNA was 1 131 bp with an ORF of 882 bp，encoding 293 amino acids with molecular weight 32.43 kD and isoelectric point 8.71. MaERF105-Like has one AP2/ERF domain，belongs to B3 group of ERF family and shares a close relationship with tomato SlERF5. Subcellular localization prediction showed that MaERF105-Like might be located in nucleus. Promoter analysis showed that MaERF105-Like promoter possesses cis-acting elements involved in ABA，MeJA，ethylene and defense and stress responsiveness. qRT-PCR result showed that the expression level of MaERF105-Like was up-regulated by drought，and its expression was significantly down-regulated after rewatering treatment. The results of this study showed that MaERF105-Like might play an important role

  in the resistance to drought in mulberry.

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• Isolation of Phenotypic Traits from Wild Cordyceps militaris Fruitbody
• XIAO Jun, CHEN Xun, ZHAO Ying, MA Xiaoying, GONG Na, LIU Guoli
• Acta Horticulturae Sinica. 2022, 49(11): 2449-2454. DOI:10.16420/j.issn.0513-353x.2021-0683
• Abstract ( 328 ) HTML ( 53 ) PDF (1865KB) ( 53 ) 　　　

• Six Cordyceps militaris（C5-1，C5-2，D1-1，D1-2，D1-2，D5-1，D5-2）which were the offspring of three（C5，D1，D5）wild C. militaris which were collected from Xifeng and Dashiqiao of Liaoning Province were compared in terms of colony morphology，agronomic traits and nutritional composition. Then，the genetic differences were analyzed by ISSR molecular markers. The results showed that there were significant differences in growth rate，fruiting body height and density among the differentiated strains from the same wild cordyceps militaris fruiting body. It can be seen from the ISSR marker analysis of the differentiated strains that the genotypes of D1-1 and D1-2，D5-1 and D5-2 from the same wild cordyceps militaris were significantly different. Moreover，there were significant differences in the content of cordycepin and adenosine among the differentiated cordyceps militaris strains from the same wild cordyceps militaris strains.

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• Genetic Relationship Analysis of the Population Germplasms of Section Thea with Unstable Ovary Locule Number Based on SLAF-seq
• WU Zhijun, LI Wei, WANG Xinghua, ZHANG Cheng, JIANG Xun, LI Sheng, LUO Liyong, SUN Kang, ZENG Liang
• Acta Horticulturae Sinica. 2022, 49(11): 2455-2470. DOI:10.16420/j.issn.0513-353x.2021-0876
• Abstract ( 329 ) HTML ( 76 ) PDF (6416KB) ( 76 ) 　　　

• In order to further explore the genetic relationship of the population germplasms of section Thea with unstable ovary locule number（ovary glabrous，3-5 loculed，style 3-5 lobed）（UONG），and to clarify whether the variation of individuals in the population caused interspecific variation，the simplified genome sequencing and molecular marker analysis of 87 germplasms of section Thea and other sections（outgroup comparison）of genus Camellia from Chongqing，Yunnan，and other provinces of China were carried out by SLAF-seq technology. A total of 2 804 071 SLAF labels were obtained by sequencing，and the average sequencing depth was 11.73×. A total of 25 069 219 SNP molecular markers were obtained by comparing the reference genome with SALF labels. Based on high consistency SNP data，using the methods of phylogenetic tree，genetic structure，and PCA analysis，the investigated germplasms were basically divided into three types，namely，the germplasms of section Thea and other sections of genus Camellia from Yunnan and other provinces（ClassⅠ），the population germplasms of big tea tree in Chongqing（ClassⅡ），and the Ser. Sinenses germplasms（common cultivated varieties and‘Chuanxiaozhong’）from multiple provinces（Class Ⅲ）. The section Thea germplasms of ClassⅠwere composed of Ser. Guinquelocularis，Ser. Pentastyla，Ser. Gymnogynae，and Ser. Sinenses. ClassⅡ included UONG and Ser. Sinenses（morphological characteristics are between UONG and common Ser. Sinenses）. Moreover，the F_ST values of genetic differentiation coefficient showed that the degree of genetic differentiation between ClassⅡgermplasms and other types of germplasms was the highest（> 0.3），and there was also high genetic differentiation between ClassⅠand Class Ⅲgermplasms（> 0.2）. The classification results and F_ST values of simplified genome sequencing showed that the investigated UONG are relatively independent and the variation of individuals within the population did not cause interspecific variation. Therefore，it is reasonable to classify these germplasms into one species. Moreover，there is a type of Ser. Sinenses germplasms with cross genetic structure of UONG in Chongqing，which may be the offspring of natural distant hybridization.

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New Technology and New Methods

• Studies on Detection of Cucumis Melo Endornavirus Using TaqMan RT-qPCR Method
• ZHAO Liqun, ZHANG Xiaofei, QIU Yanhong, LIU Hui, ZHANG Jian, YANG Jingjing, ZHANG Haijun, XU Xiulan, WEN Changlong
• Acta Horticulturae Sinica. 2022, 49(11): 2471-2478. DOI:10.16420/j.issn.0513-353x.2021-0620
• Abstract ( 263 ) HTML ( 99 ) PDF (1458KB) ( 99 ) 　　　

• Cucumis melo endornavirus is an important plant virus that infects a wide range of hosts，occurs popularly and transmits highly in seeds. One set of specific primers and probes were designed according to the conserved sequence of CmEV genome，and a detecting method of CmEV was established using the Real-Time Fluorescent Quantitative PCR with TaqMan probes（TaqMan RT-qPCR）. This detection method could detect the virus in 1 × 10^-2 ng · μL^-1 RNA samples and 1.8 × 10³ copies · μL^-1 plasmids，the sensitivity of which was about one hundred times higher than traditional RT-PCR. We used the CmEV TaqMan RT-qPCR technique to detect 11 seedling lots of Cucumis melo，Citrullus lanatus，Cucumis sativus，Cucurbita moschata stock that randomly sampled from the main cucurbit industries of Beijing，Shandong，Liaoning and Hainan provinces. It was found that Cucumis melo seedling from Shandong and Hainan industries carried CmEV. The novel TaqMan RT-qPCR method was proved to be efficient in testing CmEV，which could be a technical support for precisely detecting and scientific controlling of this virus，and could help preventing the virus spread from the source.

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• Establishment and Application of Real-Time PCR for Quantitative Detection of Fusarium oxysporum f. sp. lycopersici
• MENG Zhen, ZHANG Weiping, WANG Ying, LI Long, JI Xiaoxue, DONG Bei, QIAO Kang
• Acta Horticulturae Sinica. 2022, 49(11): 2479-2488. DOI:10.16420/j.issn.0513-353x.2021-0606
• Abstract ( 394 ) HTML ( 128 ) PDF (963KB) ( 128 ) 　　　

• In this study，a pair of specific primers，209F/361R，were designed to establish a real-time PCR（RT-PCR）reaction system of Fusarium oxysporum f. sp. lycopersici（FOL）based on the protein kinase gene sequences of FOL. FOL was detected at the base of tomato stems using this assay. Results of RT-PCR assays showed that only one absorption peak was detected with the primers for F. oxysporum and no absorption peak was produced for other tested strains. The RT-PCR detection system established with the primers showed a good linear relationship. The detection sensitivity was 5.76 × 10³ copies · μL^-1，which was 10 times more sensitive than the conventional PCR. Moreover，FOL was detected at the base of the tomato stems at the 7th day after artificial inoculation. Twenty-four naturally infected tomato samples were collected from field condition and the RT-PCR results showed that FOL was detected in 16 samples. The established RT-PCR detection system for F. oxysporum was fast，highly specific，sensitive，and reproducible，providing scientific tools for epidemic monitoring and early diagnosis of Fusarium wilt of tomato.

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• Selection and Validation of Reference Genes for RT-qPCR in Phalaenopsis- type Dendrobium Hybrid
• HOU Tianze, YI Shuangshuang, ZHANG Zhiqun, WANG Jian, LI Chonghui
• Acta Horticulturae Sinica. 2022, 49(11): 2489-2501. DOI:10.16420/j.issn.0513-353x.2021-0763
• Abstract ( 593 ) HTML ( 146 ) PDF (2663KB) ( 146 ) 　　　

• In order to screen reference genes stably expressing in Phalaenopsis-type Dendrobium hybrid for analysis of real-time fluorescent quantitative PCR，the whole floral buds，including the sepals，petals and labellums，from various cultivars and the floral bud at different development stages of dendrobium were used as materials. The expression stability of seven candidate gene was calculated by three commonly used software（geNorm，NormFinder and BestKeeper），comprehensive stability rankings were merged by RefFinder and the selected reference genes were verified. The results suggested that the expression stability of each reference gene in dendrobium differed greatly. In floral buds of different cultivars at the same developmental stage，β-actin，TUA，and GADPH were the most stable reference genes. The expression of β-actin，TUA，and CYP were the most stable during the development of the floral buds. For different tissues of floral organ，β-actin，TUA，and GADPH were the most stable reference genes in the sepals，β-actin，CYP，and PGK were in the petals and CYP，TUA，and PGK were in the labellum.

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Review

• Light Regulation of Ascorbic Acid Biosynthesis in Horticultural Crops
• PENG Yinxia, ZHANG Ying, ZHU Kangyou, SUN Xin, ZHANG Kemin, SUN Zhouping, QI Mingfang, LI Tianlai, WANG Feng
• Acta Horticulturae Sinica. 2022, 49(11): 2502-2518. DOI:10.16420/j.issn.0513-353x.2022-0486
• Abstract ( 488 ) HTML ( 250 ) PDF (1849KB) ( 250 ) 　　　

• This review summarized the regulation of light on ascorbic acid biosynthesis and metabolism in horticultural plants，analyzed the interaction between photosynthesis and respiration on ascorbic acid biosynthesis and metabolism，and focused on elucidating the regulation mechanism and signaling network of key light-regulated factors on ascorbic acid biosynthesis in horticultural plants. It is expected to lay a theoretical foundation for analyzing the molecular mechanism and regulatory network of light regulation of plant ascorbic acid biosynthesis and metabolism，and provide theoretical and practical guidance for increasing the content of ascorbic acid inhorticultural crops，and cultivating functional horticultural products by using genetic engineering and LED light supplement technology.

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New Cultivars

• A New Apple Dwarf Rootstock Cultivar‘Sc5’
• YU Lu, NIU Zimian, LI Quan, LIN Lu, WANG Hongning, LI Zhiqiang, LI Hongyan
• Acta Horticulturae Sinica. 2022, 49(11): 2519-2520. DOI:10.16420/j.issn.0513-353x.2020-1047
• Abstract ( 588 ) HTML ( 131 ) PDF (1350KB) ( 131 ) 　　　

• ‘Sc5’is a new cultivar of dwarf apple rootstock derived from Malus spectabilis × M. honanensis SH5. Its conopy size was small and the vigor was moderate. The length of internode was 2.1 cm on average. The‘Red Fuji’cultivar in its adult stage on the interstock had a tree height of 3.27 m and a canopy diameter of 2.83 m. Its grafting position was smooth without air root. The ratio of trunk circumferences of scion and interstock was 0.97. There was 65.3% of‘Nagafu 2’on the interstock started fruiting in the second year. Mean yield of the‘Nagafu 2’from the 6th to 9th year was 43 290-57 330 kg · hm^-2 and the soluble solids content of fruit was 16.8%，the fruit hardness was 9.34 kg · cm^-2. Compared to those of‘M26’，the degree of dwarfing of‘Sc5’was similar and the cold hardness was greater.‘Sc5’is suitable for apple production in the Loess Plateau and regions with similar climate.

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• A New Early-ripening Grape Cultivar‘Huangjinmi’with Muscat Flavor
• GUO Zijuan, HAN Bin, LIU Changjiang, YUAN Junwei, LI Minmin, YIN Yonggang, SUN Yan, JIA Nan, ZHAO Shengjian
• Acta Horticulturae Sinica. 2022, 49(11): 2521-2522. DOI:10.16420/j.issn.0513-353x.2020-0648
• Abstract ( 2227 ) HTML ( 128 ) PDF (1554KB) ( 128 ) 　　　

• ‘Huangjinmi’，a new early-ripening table grape cultivar with muscat flavor，is derived from the cross of‘Red Globe’and‘Xiangfei’. The average cluster weight is 703.5 g，and the average single berry weight is 9.5 g. The berry is round，yellow-green or golden yellow，crisp and hard. The soluble solids content is 19.0%，and the titratable acid content is 0.58%. It had a high yield（26 300 kg · hm^-2），early bearing，and long shelf life. It is suitable for open field and protected cultivation in the Beijing，Tianjin，Hebei and other areas with similar ecological conditions，and for rain shelter cultivation in the rainy regions of the South.

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• A New Anthurium andraeanum Cultivar‘Mingnong Baifeng’
• ZHOU Huiming, MO Zhilong, CHEN Changming, LIN Huifeng
• Acta Horticulturae Sinica. 2022, 49(11): 2523-2524. DOI:10.16420/j.issn.0513-353x.2020-0408
• Abstract ( 239 ) HTML ( 96 ) PDF (783KB) ( 96 ) 　　　

• Anthurium andraeanum‘Mingnong Baifeng’is a new potted cultivar with plant height of 46.8 cm and width of 35.6 cm，which was derived from the variation of seedlings during the tissue culture of‘Sharade’. The leaves are medium，ovate. The spathes，being 9.0 cm in length and 7.7 cm in width，are white in color and above the leaves. The spadixes are curved inwards，with length of 4.7 cm，and the bases are milky，the apexes are yellow in color. It takes 540 days from tissue culture seedlings to the potted product.

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• A New Dendrobium Cultivar‘Lüying’
• GONG Jianying, WANG Huaxin, WANG Xiaoyu, LONG Dingjian, TANG Qiuming, CHEN Baoling, SHU Lihua
• Acta Horticulturae Sinica. 2022, 49(11): 2525-2526. DOI:10.16420/j.issn.0513-353x.2020-1056
• Abstract ( 615 ) HTML ( 92 ) PDF (1311KB) ( 92 ) 　　　

• ‘Lüying’is a new Dendrobium cultivar developed by crossing female parent Den. densiflorum and male parent Den. thyrsiflorum.It has medium size，white petals and sepals，golden yellow lips，distinguish flower colour，large number of flowers，pleasant aroma，evergreen in all seasons and strong adaptability. It was adopt to pot culture in green house and epiphytic culture outdoor.

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• A New Schlumbergera truncata Cultivar‘Tongyun’
• ZHAO Tianrong, XU Zhihao, REN Xiliang, SHI Yongtai, ZHAN Chai
• Acta Horticulturae Sinica. 2022, 49(11): 2527-2528. DOI:10.16420/j.issn.0513-353x.2020-0671
• Abstract ( 706 ) HTML ( 100 ) PDF (1206KB) ( 100 ) 　　　

• Schlumbergera truncata‘Tongyun’is a hybrid of‘Super Kenya’בDenmark’. The cultivar has early flowering，dark pink red flower color，high ornamental value，strong growth potential，strong resistance to disease，high temperature and cold.

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