Genetic & Breeding·Germplasm Resources·Molecular Biology

• Transcriptome Screening and Functional Analysis of Dwarf Related Genes in Pear
• LIN Ruxue, WANG Fei, ZHANG Yanjie, MA Li, LIU Xiaofeng, LI Shuran, LIU Yalong, WANG Chen, JIANG Shuling, OU Chunqing
• Acta Horticulturae Sinica. 2025, 52(3): 545-560. DOI:10.16420/j.issn.0513-353x.2024-0481
• Abstract ( 194 ) HTML ( 69 ) PDF (1622KB) ( 69 ) 　　　

• To screen the dwarf trait related genes，the shoot length and internode length of 12 pear varieties or selections with different plant architectures were measured during the new shoot growth period. The genes differentially expressed in the growth points，leaves and phloem among three pear varieties ‘Zaosu’（vigorous），‘Jinxiang’（semi-dwarf）and‘Zhongai 1’（dwarf）at different periods were screened by transcripome sequencing analysis. Combined with the expression verification in new shoot phloem of 12 varieties or selections，dwarf trait related candidate genes were obtained. One of the candidate genes PcGA2ox2 was overexpressed in tobacco to analyze its function. The results showed that the new shoot length of‘Zaosu’，‘Jinxiang’and‘Zhongai 1’had a slight difference in the early growth period，while showed a significant difference in the middle and late growth period of new shoot. The internode length of dwarf varieties were shorter than that of vigorous varieties in all test periods. The shoot length and internode length of six vigorous varieties were significantly longer than those of six dwarf or semi-dwarf varieties or selections in the middle and late growth period of new shoot. The number of differentially expressed genes between two samples ranged from 1 882 to 5 729 in different tissues，and periods of three varieties. Among them，51 differentially expressed genes showed an increase or decrease in expression levels with the decrease of new shoot length in both leaf and phloem. Nine differentially expressed genes in new shoot phloem of three varieties were selected to verify the expression levels by RT-qPCR in the phloem of 12 pear varieties or selections in the late growth period of new shoot. Among them，four genes showed a tendency of significant higher or lower expression in dwarf varieties or selections than that in vigorous varieties or selections，and were identified as candidate genes related to dwarf trait. One of the dwarf candidate genes was a member of GA2ox family genes. Total 15 members of the GA2ox gene family were further identified in the‘Zhongai 1’genome，and the expression of the candidate PcGA2ox2 gene was significantly higher in new shoot phloem of dwarf varieties or selections than that of vigorous varieties. Then PcGA2ox2 gene was overexpressed in tobacco，the transformed plants were significantly smaller than the control plants. In conclusion，PcGA2ox2 gene plays a key role in the dwarf trait of‘Zhongai 1’pear.

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• Genetic Diversity and Genetic Relationship of Local Pear Cultivars in Xinjiang
• BI Qingrui, CUI Dongsheng, MA Xinyuan, XUE Yuran, ZHANG Shikui, FAN Guoquan, NIU Yingying
• Acta Horticulturae Sinica. 2025, 52(3): 561-574. DOI:10.16420/j.issn.0513-353x.2024-0286
• Abstract ( 89 ) HTML ( 24 ) PDF (1927KB) ( 24 ) 　　　

• In this study，phenotypic，SSR and SNP markers were used to study the genetic relationship and genetic diversity of 28 Xinjiang local pear cultivars. A total of 43 310 SSR markers and 2 045 692 SNP markers were developed and used for genetic diversity and genetic relationship analysis. The Shannon-Weaver index of 10 quantitative traits of 28 Xinjiang local pear cultivars ranged from 4.145 to 5.663，and the diversity index of the number of flowers per inflorescence was the highest and the diversity was rich. The coefficient of variation of each trait was between 4.49% and 67.36%，and the stability of petal number was higher than that of other traits. The primer development polymorphism rate of SSR markers was 96.15%. The clustering results were divided into 2 groups based on SSR markers，and the pear cultivars were divided into 4 groups based on SNP markers. The average fixation index（F）of SSR markers was 0.169，and the F_st value of SNP was between 0.0538 and 0.3387，indicating that there was genetic differentiation in Xinjiang local pear cultivars. ‘Korla Fragrant Pear’，‘Kuikeamute 1’and ‘Naixiput’should be classified as Xinjiang pear system，and‘Koteamute’belongs to Western pear system.

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• Identification and Expression Analysis of Peach JMJ Histone Demethylase Gene Family
• WANG Yunyun, ZHOU Hui, QIU Keli, PAN Haifa, SHENG Yu, SHI Pei, XIE Qingmei, CHEN Hongli, ZHANG Jinyun, LI Dahui
• Acta Horticulturae Sinica. 2025, 52(3): 575-590. DOI:10.16420/j.issn.0513-353x.2024-0105
• Abstract ( 77 ) HTML ( 21 ) PDF (6500KB) ( 21 ) 　　　

• In order to understand the function of histone methylation in growth and response to abiotic stress in peach trees，genome-wide identification of histone demethylase（JMJ）family genes containing the JmjC domain was performed. Twenty-one JMJs were identified in the peach genome，which were divided into five subfamilies according to their phylogenetic relationships. There were significant differences among the members of these families，with exons ranging from 7 to 33，proteins containing 12 conserved domains，and the upstream regions of gene promoters containing different numbers of stress response，hormone response，and developmental regulatory elements. Using PpJMJ5 as bait，a potential interacting protein PpCIPK1 was found through yeast two-hybrid screening library. It was proved that the interaction between PpJMJ5 and PpCIPK1 existed，which may interfere with the interaction between calhomodin and its interacting protein CBL-CIPK to some extent. PpJMJ5 may play an important role in the abiotic stress response of peach trees.

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• CsPUB54 Negatively Regulates Cucumber Resistance to Phytophthora Melonis by Interacting with PmRXLR1 Effector
• WANG Rui, WU Hongfei, ZHANG Changyuan, CAO Haishun, TAN Delong, GUO Jinju, WANG Yunlong, WANG Rufang, YUAN Yu, WU Tingquan
• Acta Horticulturae Sinica. 2025, 52(3): 591-602. DOI:10.16420/j.issn.0513-353x.2024-0274
• Abstract ( 65 ) HTML ( 18 ) PDF (2764KB) ( 18 ) 　　　

• B80 cucumber with highly susceptible to Phytophthora blight，and Phytophthora melonis（P. melonis）were used as experimental materials. The gene that encodes a PUB protein containing the U-box domain from B80，named CsPUB54，and a RXLR effector protein gene，named PmRXLR1 from P. mellonis were cloned. Experimental results of transcriptome and qRT-PCR of cucumber leaves inoculated with P. mellonis for 24 hours both showed that the infection could induce rapid increase of gene expression levels of CsPUB54 and PmRXLR1. CsPUB54 gene silencing through transient gene silencing method could increase the resistance of cucumber cotyledons to P. melonis. In addition，the results of yeast two hybrid and Pull-down experiments confirmed that CsPUB54 could interact with PmRXLR1 both in vivo and in vitro. Using the method of base mutation，the W and Y functional domains of PmRXLR1 were mutated respectively，resulting in 7 mutants. The interaction detection between these mutants and CsPUB54 showed that the W and Y functional domains were necessary for the interaction between PmRXLR1 and CsPUB54，and the isoleucine（I）in the W functional domain was a key amino acid required for the interaction. Genetic evolution analysis of CsPUB54 and PUB proteins related to plant immune negative regulatory that have been published showed that CsPUB54 had a low genetic variation rate and the closest relationship with AtPUB22 and AtPUB23 in Arabidopsis thaliana. These research data suggest that CsPUB54 can negatively regulate cucumber resistance to P. melonis through interaction with PmRXLR1.

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• Identification and Phylogenetic Analysis of Gibberellin Oxidase Gene Family and Its Expression Pattern in Main Vine Growth in Cucurbita maxima
• SUN Tingzhen, SHU Qin, MA Wei, SHI Yuzi, ZHANG Meng, XIANG Chenggang, BO Kailiang, DUAN Ying, WANG Changlin
• Acta Horticulturae Sinica. 2025, 52(3): 603-622. DOI:10.16420/j.issn.0513-353x.2023-0974
• Abstract ( 53 ) HTML ( 10 ) PDF (5517KB) ( 10 ) 　　　

• GA2ox，GA3ox，and GA20ox are pivotal enzymes in the late stage of gibberellin synthesis，playing crucial roles in regulating plant stem elongation. In this study，the GA2ox，GA3ox，and GA20ox gene family were identified utilizing reference genomic data from Cucurbita maxima. Their physicochemical properties，gene structure，chromosome localization，phylogeny，and genomic collinearity with near-origin species were analyzed. Additionally，tissue-specific expression levels of GA2ox genes were investigated in Cucurbita maxima with varying main vine lengths. A total of 13 GA2ox，9 GA3ox，and 12 GA20ox genes were identified in the Cucurbita maxima genome. Phylogenetic analysis based on multiple amino acid sequence alignments showed these gibberellin oxidase gene family forming four major clustered branches. Promoter analysis identified numerous light-responsive，adversity stress-responsive，and hormone-responsive elements. Intragenomic analysis of GAox genes in Cucurbita maxima revealed 9 pairs of tandem duplicated genes and 10 pairs of large replicating genes. Only one gene pair（CmaGA3ox5 and CmaGA3ox6）exhibited positive selection（K_a/K_s > 1），while the rest underwent purifying selection. Genome collinearity analysis with near-origin species Cucurbita pepo and Cucurbita moschata unveiled 47 and 48 pairs of collinearity genes，respectively，between Cucurbita maxima，Cucurbita pepo，and Cucurbita moschata. CmaGAox genes were more specifically expressed in fruit，but CmaGA2ox1 and CmaGA2ox4 were more highly expressed in the main stem. The expression patterns of these two genes were significantly higher in the dwarf inbred line Cma0806 than that in the long vine inbred line Cma0807，indicates their potential roles in vine length regulation in Cucurbita maxima.

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• Functional Characterization of Carotenoid Cleavage Dioxygenases 4 Gene（RcCCD4）Involved in Biosynthetic Pathway of Floral Scent in Rosa chinensis‘Old Blush’
• FU Qi, WANG Dan, JING Weikun, ZHANG Hao, WANG Huichun, JIAN Hongying, QIU Xianqin, WANG Qigang, TANG Kaixue, YAN Huijun
• Acta Horticulturae Sinica. 2025, 52(3): 623-634. DOI:10.16420/j.issn.0513-353x.2024-0382
• Abstract ( 84 ) HTML ( 19 ) PDF (2505KB) ( 19 ) 　　　

• To reveal the role of carotenoid cleavage dioxygenases（CCDs）in biosynthetic pathway of floral scent，RcCCD4 gene were cloned from the petals of Rosa chinensis‘Old Blush’and functionally characterized. RT-qPCR showed that RcCCD4 was mainly expressed in petals，with the highest expression level at the fully opening stage and lowest at the bud stage. Subcellular localization assays showed that RcCCD4 were located in the plastid. Moreover，a prokaryotic expression protein vector for RcCCD4 were constructed and found that the RcCCD4 enzyme can specifically cleave β-carotene substrates in vitro enzymatic activity assay. Virus-induced gene silencing（VIGS）further suggested that silencing of RcCCD4 significantly reduced the content of dihydro-β-ionone in petals，and RcCCD4 overexpression led to increase in dihydro-β-ionone content. These results indicated that RcCCD4 can specifically cleave β-carotene substrates，thereby synthesizing dihydro-β-ionone.

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• Phenotypic Diversity Analysis and Ornamental Comprehensive Evaluation of Ninety-six Tree Peony Cultivars Based on Landscape Application
• ZHI Hui, YANG Jingjing, LUO Jianrang
• Acta Horticulturae Sinica. 2025, 52(3): 635-645. DOI:10.16420/j.issn.0513-353x.2024-0412
• Abstract ( 74 ) HTML ( 30 ) PDF (1913KB) ( 30 ) 　　　

• In this study，ninety-six tree peony cultivars planted in Northwest A & F University were selected as the research objects. Phenotypic diversity analysis，correlation analysis，cluster analysis and principal component analysis were used to analyze the phenotypic diversity analysis and ornamental comprehensive evaluation of tree peony growth，new branch length and flowering time. The results showed that the diversity index of 15 phenotypic traits ranged from 0.56 to 2.03，and the coefficient of variation ranged from 11.84% to 53.82%. The phenotypic diversity of flower diameter was the highest，and the coefficient of variation of flower number per plant was the highest. Plant height，growth，flower diameter，new branch thickness and population flowering time were significantly correlated with other traits；Ninety-six tree peony varieties were divided into three groups by cluster analysis，and different groups corresponded to different types of garden applications. Principal component analysis simplified phenotypic trait factors into five principal components，with a cumulative contribution rate of 64.69%. New branch thickness，plant height，population flowering time and number of flowers per plant were the main factors of phenotypic variation of tree peony. The ninety-six tree peony varieties were sorted by comprehensive scores，and the top 10 cultivars had scores ranging from 0.66 to 1.18，and the cultivars with excellent comprehensive traits such as‘Yubanbai’‘Shima Nishiki’‘High Noon’‘Okan’and‘Duohua Luohan’were selected according to the comprehensive scores.

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• The Quantitative Classification of Flower Color Phenotype and Genetic Study for Population Flower Color in Marigold
• LÜ Guifang, ZANG Yunping, TAO Zhengguo, LIU Cuicui, ZHANG Huali, BAO Manzhu, HE Yanhong
• Acta Horticulturae Sinica. 2025, 52(3): 646-654. DOI:10.16420/j.issn.0513-353x.2024-0351
• Abstract ( 70 ) HTML ( 29 ) PDF (1574KB) ( 29 ) 　　　

• In order to classify the flower color of marigold and reveal the genetic principle，the 46 marigold resources and a 390-individual F₂ population segregating for S5（orange）and MT（white）were used as experimental materials. The generating brightness value L^*，redness value a^*，and yellowness value b^* were further clustered and submitted to genetic analyses. Based on the clustering results of the L^*，a^* and b^* values，46 marigold resources were categorized into five distinct color groups: white，light yellow，yellow，orange-yellow and orange. Each group exhibited concentrated and distinct parameter distribution. Moreover，the L^*，a^* and b^* values of the 390 individuals in the F₂ population displayed continuous distribution and broad segregation. Flower color of the population adhered to the inheritance pattern of quantitative trait governed by a major gene and multiple secondary genes，and the orange color exhibited incomplete dominance over the white color.

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• Response of Ubiquitin-ligase Gene CsPUB21 to Different Abiotic Stress in Camellia sinensis
• DENG Shuqin, GAO Yingrui, LI Yutong, WANG Ying, GONG Chunmei, BAI Juan
• Acta Horticulturae Sinica. 2025, 52(3): 655-670. DOI:10.16420/j.issn.0513-353x.2024-0378
• Abstract ( 62 ) HTML ( 9 ) PDF (4961KB) ( 9 ) 　　　

• The U-box ubiquitin E3 ligase gene CsPUB21 were cloned and functionally analyzed in Camellia sinensis‘Shaancha 1’. The length of the coding sequence of CsPUB21 is 1 242 bp，encoding a total of 413 amino acids with a conserved U-box domain at the N terminus and an ARM domain at the C terminus. The encoded protein，an unstable hydrophilic protein. The promoter region contains multiple cis-acting elements in response to drought，high salt and low temperature. The subcellular localization results indicated that CsPUB21 is localized on the cell membrane and cytoplasm. Gene expression pattern analysis showed that CsPUB21 was up-regulated by drought and salt stress treatments，and down-regulated by low temperature in different cultivars of C. sinensis. Overexpression of CsPUB21 gene in Arabidopsis significantly enhanced plants resistance to drought and salt stress. The qRT-PCR results showed that the expression level of CsPUB21 was up-regulated after drought and salt stress. Compared with the wild type，overexpression of CsPUB21 in Arabidopsis resulted in higher chlorophyll content and soluble sugar content under drought and salt stress，enhanced activities of antioxidant enzymes SOD，POD，and CAT，and decreased relative conductivity and MDA content. The research results indicated that the CsPUB21 plays a positive regulatory role in tea plant response to drought and salt stress.

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Cultivation·Physiology & Biochemistry

• Influences of Trunk Heights on Leaf Photosynthesis and Fruit Qualities at Different Canopy Locations in Open-Central Canopy of Apple
• CHENG Xiaogai, WAN Yuan, LIN Lu, XIE Peng, LI Zhiqiang, LI Mi, WANG Pengpeng, NIU Zimian
• Acta Horticulturae Sinica. 2025, 52(3): 671-692. DOI:10.16420/j.issn.0513-353x.2024-0355
• Abstract ( 69 ) HTML ( 14 ) PDF (8356KB) ( 14 ) 　　　

• The current study aims to investigate the effects of trunk heights on leaf photosynthetic characteristics and fruit qualities at different canopy locations in Open-Central Canopy（OCC）of apple. By using the 36-year-old apple（Malus × domestica‘Nagafu 2’，grafted on the rootstock Malus robusta Rehd.）of OCC with trunk heights of 0.8-1.0 m（as the control，CK），1.2-1.5 m（low trunk treatment，LT），1.5-1.8 m（middle trunk treatment，MT），and 1.8-2.1 m（high trunk treatment，HT）as materials，changes of photosynthetically active radiation（PAR），diurnal changes and responses to PAR and intercellular CO₂ concentration（C_i）of leaf gas exchange，kinetics of chlorophyll fluorescence quenching and fruit quality indices at different canopy locations were measured and compared carefully. Results showed that PAR increased most significantly in different locations（at 1.5 m above ground in the east and west of outer-crown and 1.5 m and 2.5 m above ground in inner-crown）of HT with increment of 132.47%，178.29%，113.7% and 32.37% compared to those of CK，respectively. The maximum values of net photosynthetic rate（P_nmax,P）and characteristic parameters[light saturation point（LSP），light utilization range（LUR）and apparent quantum efficiency（AQE）]derived from the fitted-curves of P_n-PAR responses of HT were significantly higher than those of MT，LT and CK. In comparison with CK，maximum electron transport rate under saturated light intensity（J_max）and triose phosphate utilization rate（V_tpu）of HT & MT increased significantly. The average values of light energy capture efficiency（F_v'/F_m'），actual photochemical efficiency of PSⅡ（Φ_PSⅡ）and photochemical quenching coefficient（q_P）were different significantly among all treatments and CK with the most significant increment in HT. Comparing to CK，the nonphotochemical quenching（NPQ）in the outer-crown of HT，MT，and LT was lower significantly. There was no significant difference among the inner-crown of HT，MT and LT. At the height of 1.5 m and 2.5 m above ground，single fruit weight and chromatic value a of HT were significantly higher than those of CK. At east and west sides of 2.5 m above ground，the soluble solids content and the ratio of solid to acid of HT were significantly higher than those of CK，while fruit acidity was lower than that of CK. The chlorophyll content in peel of HT was significantly lower than that of CK among different canopy locations. The anthocyanin content，total phenol content，total flavonoid content and capacity of scavenging free radical（FRAP，ABTS⁺ and DPPH）of peel in east side of HT were significantly higher than those of CK with the ranking of east side > west side > inner-crown. In summary，the leaf photosynthetic characteristics and fruit qualities of apple showed significant spatial heterogeneity in OCC with different trunk heights. The rate，capacity and efficiency of leaf photosynthesis as well as light energy utilization efficiency were significantly enhanced，thus the fruit qualities（especially the east side）were significantly boosted in open-central canopy with high trunk.

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• Physiological Response of Shine Muscat Grape Seedlings Grafted with Different Rootstocks to Combined Stress of Salt and Low Temperature
• XING Zhigan, LEI Xiangzhao, WANG Haochen, FENG Mingxin, LI Jingwen, LIU Yujia, FANG Yulin, MENG Jiangfei
• Acta Horticulturae Sinica. 2025, 52(3): 693-704. DOI:10.16420/j.issn.0513-353x.2024-0021
• Abstract ( 86 ) HTML ( 20 ) PDF (4683KB) ( 20 ) 　　　

• ‘Shine Muscat’grape was grafted onto‘5BB’‘Kangzhen 3’‘SO4’and‘101-14’rootstocks to investigate their tolerance. The results showed that the grafted seedlings could reduce the content of MDA and relative electrical conductivity，increase the content of osmoregulatory substances（including proline，soluble sugars，and soluble proteins），and improve the antioxidant enzymes activity and photosynthetic capacity at varying degrees under salt stress compared to self rooted seedlings，among them，‘Shine Muscat/SO4’showed the best tolerance to salt stress. In addition，under low temperature stress，the changes in various physiological and biochemical indicators of grafted and self rooted seedlings are similar to those under salt stress，but the amount and degree of change was different obviously.‘Shine Muscat/5BB’exhibit stronger low temperature tolerance. Under combined stress of salt and low temperature，the MDA content of‘Shine Muscat/SO4’was significantly lower than that of other rootstock grafted seedlings and showed the least damage symptoms，while the content of soluble proteins，total soluble sugars and free proline was significantly higher than that of individual salt and low temperature stress treatment，the same as the stimulative activities of CAT and POD. Overall，comprehensive comparative analysis indicated the‘Shine Muscat’grafted onto‘SO4’has the strongest resistance to the combined salt and low temperature stress，and is most suitable for further promotion and utilization，while ‘5BB’is more suitable for improving the cold resistance of grapevines.

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• Preliminary Study on Utilization of ¹⁵N-urea Applied to Young Navel Orange Trees in Summer and Its Residual in Soil
• HU Yawei, MA Jinlong, ZHONG Balian, YAO Fengxian, LIU Guidong
• Acta Horticulturae Sinica. 2025, 52(3): 705-713. DOI:10.16420/j.issn.0513-353x.2024-0273
• Abstract ( 45 ) HTML ( 12 ) PDF (1382KB) ( 12 ) 　　　

• By measuring the absorption and utilization of nitrogen in navel orange plants，as well as their residual and loss in the soil，this provides a basis for further optimizing nitrogen management in the navel orange production system during the no-bearing stage. The experiment used 2-year-old Newhall and Gannanzao navel orange grafted on trifoliate orange as materials. ¹⁵N isotope tracing technology was used，and labeled nitrogen fertilizer was applied twice in summer. After the autumn shoots matured，plant and soil samples were collected to measure the ¹⁵N abundance of various plant organs and soil layers，and then calculate nitrogen utilization，residue，and loss. The results showed that there is a significant difference in biomass between Newhall and Gannanzao navel oranges，but the proportion of dry matter of each part in the whole plant was consistent. The proportion of dry matter of 1-year-old leaves and branches in the whole plant was over 40%，which was the growth centers of young navel orange trees，and ¹⁵N was mainly distributed to these organs. The allocation rate of ¹⁵N in Newhall is significantly higher than that in Gannanzao in 2-year-old leaves and coarse roots，and significantly lower than that in branches and trunk. The annual utilization rate，soil residual and loss percentage of ¹⁵N labeled urea for young Newhall navel orange trees were 6.45%，75.72%，and 17.83%，respectively，while for Gannanzao，they were 3.36%，54.25%，and 42.39%，respectively. The above results indicate that the utilization efficiency of nitrogen fertilizer applied in summer for young navel orange trees is relatively low，and there are significant differences in the fate of nitrogen in different varieties of navel orange orchards，which may be related to significant differences in biomass（including root architechture）between the two varieties.

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• Effect of the Salinity of Irrigation Water on Growth，Yield，and Quality of Ziziphus jujuba‘Dongzao’
• CONG Xin, HU Qianyuan, PANG Guibin, XU Lirong, XU Zhenghe, LIU Hongfei, PEI Xiangli
• Acta Horticulturae Sinica. 2025, 52(3): 714-726. DOI:10.16420/j.issn.0513-353x.2024-0404
• Abstract ( 51 ) HTML ( 11 ) PDF (2107KB) ( 11 ) 　　　

• To investigate the irrigation effects and applicability of slight saline water on natural production conditions of Ziziphus jujuba‘Dongzao’，a three-year field experiment on irrigation water salinity was conducted in Zhanhua District，Binzhou City from 2020 to 2022. The experimental variety was Ziziphus jujuba‘Zhandong 2’，with five salinity levels[1（the control），2，3，4，and 5 g · L^-1]set for irrigation water. The study revealed the effects of irrigation mineralization on the physiological characteristics，growth，yield and fruit quality of‘Dongzao’jujube. The results indicated that，physiologically，the peak values of relative chlorophyll content，net photosynthetic rate，transpiration rate，dark respiration rate，and apparent quantum efficiency in leaves occurred at salinity levels of 3 or 4 g · L^-1，and these values were significantly higher compared to the 1 g · L^-1 treatment. For the 5 g · L^-1 treatment，relative chlorophyll content，net photosynthetic rate，transpiration rate，apparent quantum efficiency，initial fluorescence，and maximum quantum yield of PSⅡ decreased significantly compared to the 3 or 4 g · L^-1 treatments，while maximum fluorescence increased significantly. Regarding quality，as irrigation water salinity increases，the content of soluble sugars，total soluble solids，titratable acidity，and vitamin C content significantly increased，with the best quality observed under the 4 g · L^-1 treatment. Correlation analysis revealed that jujube hanging length and the maximum quantum yield of PSII were the main factors affecting yield. Based on a random algorithm，the importance ranking of physiological indicators influencing fruit quality indicated that maximum net photosynthetic rate，apparent quantum efficiency，dark respiration rate，and maximum fluorescence were the primary factors influencing fruit quality. Analysis of soil salt balance after the three-year irrigation cycle showed that 3 or 4 g · L^-1 treatments had potential risks of soil salt accumulation. In‘Zhandong 2’orchards in Binzhou，Shandong，fruits can resist salt stress by adjusting its own photosynthetic and fluorescence characteristics，maintaining normal growth，and promoting quality treated with 2-3 g · L^-1 slightly saline water.

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Plant Protection

• Identification and Analysis of Viruses Infecting Flat Nectarine in Wuhan by Small RNA Sequencing
• LIU Yong, WANG Furong, WANG Huiliang, AI Xiaoyan, ZHU Wei, ZHANG Yang, GAN Zhimeng, GONG Lingzhong, HE Huaping
• Acta Horticulturae Sinica. 2025, 52(3): 727-736. DOI:10.16420/j.issn.0513-353x.2024-0086
• Abstract ( 45 ) HTML ( 8 ) PDF (1637KB) ( 8 ) 　　　

• To determine the viruses infecting flat nectarine in Wuhan，Hubei，five shoot samples with the virus-like symptoms were collected and analyzed by small RNA sequencing. The results showed that peach associated luteovirus（PaLV），peach virus D（PeVD），and peach latent mosaic viroid（PLMVd）were detected. RT-PCR with specific primers was conducted to confirm the result. Partial sequences of PaLV，PeVD and PLMVd were obtained by RT-PCR，sequenced and deposited in GenBank. Sequences of PaLV，PeVD and PLMVd（GenBank accession No. OP244073，OP244074 and OP244075）were 92.15%-98.59% identical with the corresponding nucleotide sequences of PaLV isolate T01-2（MK361479），PeVD isolate T02-1（MK361476）and PLMVd isolate HUEI-Ob166/1-1（MW046337） in GenBank. One hundred and nine flat nectarine samples were collected and detected by RT-PCR with primers specific for PaLV，PeVD，PLMVd and six other peach viruses. Only PLMVd，PaLV and PeVD were detected in these samples，with a detection rate of 33.94%，29.36% and 5.50%，respectively. The highest incidence of PLMVd indicated that it was the dominant viroid infecting flat nectarine in Wuhan. The mixed infection of viruses and viroid was 22.93%，higher than that of a single virus or viroid infection，indicating that mixed infection of virus and viroid was common in flat nectarine.

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• Identification and Biological Characteristics of the Pathogen Causing Persimmon Leaf Blight and Toxicity Test of Different Fungicides
• WANG Jie, DONG Xiaoxu, CHEN Jinxiao, YU Xianmei, GAO Rui, AI Chengxiang, SHEN Guangning
• Acta Horticulturae Sinica. 2025, 52(3): 737-748. DOI:10.16420/j.issn.0513-353x.2024-0337
• Abstract ( 48 ) HTML ( 10 ) PDF (3407KB) ( 10 ) 　　　

• To determine the primary pathogen responsible for persimmon leaf blight disease，leaves exhibiting typical symptoms of the blight were collected. The fungus was isolated and purified using the tissue separation method，and its pathogenicity was confirmed through Koch’s postulation. Based on morphological characteristics，ITS analysis，and the combined gene sequence phylogenetic analysis of TEF-CAL-HIS-TUB，the pathogen was identified as Diaporthe eres. The biological characteristics of the isolated D. eres strain DHB1 were investigated. The results showed that a culture medium containing glucose or maltose as the carbon source，along with yeast extract as the nitrogen source，significantly promoted rapid mycelium growth. The optimal conditions for mycelial growth were found to be a temperature of 28 ℃ and a pH of 6.0. In vitro toxicity tests were conducted to evaluate the effects of nine fungicides on the mycelial growth of D. eres DHB1. The results indicated that all tested fungicides had varying degrees of inhibitory effects. Among them，95% Fludioxonil had the strongest inhibitory effect with an EC₅₀ value of 0.046 mg · L^-1，followed by 95% Hexaconazole，80% Carbendazim WP and 97% Difenoconazole，with EC₅₀ values of 0.217，0.224 and 0.705 mg · L^-1，respectively.

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• Identification of Infectivity of 13 Viroid RNA and DNA Genomes of Tomato
• LU Xiuping, TANG Zhichao, TANG Wenkun, Mao Feifeng, ZHANG Wanping, LI Jingwei
• Acta Horticulturae Sinica. 2025, 52(3): 749-760. DOI:10.16420/j.issn.0513-353x.2024-0050
• Abstract ( 46 ) HTML ( 10 ) PDF (3035KB) ( 10 ) 　　　

• Thirteen types of viroids that have been widely reported in horticultural plants were selected. Their artificially synthesized cDNA was digested by Sac I and Spe I enzymes and transcribed into conventional RNA genomes in vitro by T7 enzyme. At the same time，PCR was used to synthesize full-length genomes of various viroids DNA genome. The RNA and DNA genomes were mechanically rubbed and inoculated onto Ailsa Craig tomato seedlings，and the infection efficiency of different types of viroids on tomatoes was detected by RT-PCR and RT-qPCR. Artificial inoculation of viroid genomes was conducted in both RNA and DNA forms，and the results showed that in addition to the conventional RNA genomes，the viroid DNA genomes also have infectivity，with differences in infectivity between a small amount of viral RNA and DNA genomes. Overall，all 13 types of viroids can infect tomatoes and cause diseases such as plant dwarfism，leaf shedding，leaf curling，leatheriness，and yellowing. Among them，CChMVd，ELVd-1，PSTVd，TCDVd，TPMVd，and HSVd have stronger infectivity，with higher titers in infected plants and higher disease indices. PLMVd has a lower average titer within the plant，but higher pathogenicity. The RT-PCR detection products after infection are basically consistent with the sequencing of artificially synthesized cDNA sequences.

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• Antifungal Mechanism of Isooctyl Alcohol on Botrytis cinerea Causing Tomato Gray Mold
• WANG Chunwei, WANG Yan, DUAN Tiankun, SU Yaxin, YUAN Shengnan, REN Lu, ZHAO Xiaojun, WANG Meiqin
• Acta Horticulturae Sinica. 2025, 52(3): 761-772. DOI:10.16420/j.issn.0513-353x.2024-0329
• Abstract ( 51 ) HTML ( 14 ) PDF (2369KB) ( 14 ) 　　　

• Previous findings showed that isooctyl alcohol could effectively inhibit Botrytis cinerea mycelial growth. To clarify the antifungal mechanism of isooctyl alcohol on Botrytis cinerea，the inhibition effects of isooctyl alcohol on mycelia growth，spore germination and sclerotium growth were detected by using two-sealed-base-plate method. After treatment of isooctyl alcohol，the DNA content and reactive oxygen species in B. cinerea were detected by using a laser scanning confocal microscope. The effects of isooctyl alcohol on the mycelase activity and oxalic acid production were measured using ultraviolet spectrophotometry. The control effect of isoctyl alcohol on tomato gray mold was conducted. The effects of isoctyl alcohol on the activities of defense enzymes were further detected. The results showed that isoctyl alcohol had significant inhibition effects on the mycelial growth. After treatment with isooctyl alcohol at the concentration of 20 μL · L^-1，spore germination was completely inhibited with the inhibition rate of 100%，and sclerotium was also significantly inhibited. Fluorescence intensity of DNA content in B. cinerea was dramatically reduced with the increase of reactive oxygen species level. The activities of superoxide dismutase（SOD），catalase（CAT），polygalacturonase（PG），β-1,3-glucanase（β-1,3-GA）and chitinase（CHI）were all decreased in B. cinerea. Oxalic acid（OA），an important virulence factor，was inhibited significantly in B. cinerea. In addition，the control effect of isooctyl alcohol on tomato gray mold was 77.19%. Isooctyl alcohol also enhanced SOD，CAT，CHI，peroxidase（POD）and phenylalanine aminolyase（PAL）activities in tomato. Therefore，isooctyl alcohol could effectively inhibit B. cinerea growth by interfering in the normal physiological activity，and also induce resistance to B. cinerea in tomato fruit.

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Reviews

• Research Progress on Molecular Breeding of Disease Resistance in Cucumber
• ZHANG Shengping, DONG Shaoyun, GUAN Jiantao, MIAO Han, LIU Xiaoping, GU Xingfang
• Acta Horticulturae Sinica. 2025, 52(3): 773-791. DOI:10.16420/j.issn.0513-353x.2024-0825
• Abstract ( 162 ) HTML ( 91 ) PDF (1271KB) ( 91 ) 　　　

• Cucumber is the vegetable with highest yield among all the facility-grown vegetables in China. In recent years，the main epidemic diseases have had a serious impact on cucumber production. Utilizing molecular breeding techniques to improve selection efficiency，cultivating new resistant cultivars，and promoting their application is the most economical and effective way to control diseases and of great significance for the improvement of cucumber yield and food safety. In this paper，the research on molecular breeding of cucumber disease resistance was reviewed from the aspects of germplasm resources of resistant materials，mapping of resistance genes and QTLs，gene cloning and molecular mechanism analysis，and cultivation of new disease-resistant cultivars. Besides，the existing problems were analyzed，and the future work was prospected so as to provide reference for cucumber disease resistance breeding in the future.

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• Research Progress on the Preparation Method of Biochar and Its Application Effect on Returning to Field in Facility Vegetable Fields
• REN Yi, ZHANG Yixing, HOU Saisai, NIE Lanchun, LI Qingyun, WANG Xinxin
• Acta Horticulturae Sinica. 2025, 52(3): 792-812. DOI:10.16420/j.issn.0513-353x.2024-0040
• Abstract ( 68 ) HTML ( 12 ) PDF (3195KB) ( 12 ) 　　　

• In this review，the advantages and disadvantages of different biochar preparation methods，and the effects of biochar on soil physical and chemical properties and roots and rhizosphere microorganisms of facilities vegetables，and focuses on the effects and mechanisms of biochar on water and fertilizer utilization rate，vegetable field hazards and greenhouse gas emissions，and systematically elaborates on the agricultural and eco-environment benefits of biochar application in facility vegetable were summarized. The analysis was conducted to assess the impact of biochar on enhancing vegetable yield and improving quality. The future application of biochar technology in facility agriculture in China was also prospected.

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New Cultivars

• A New Walnut Cultivar‘Jinghong 1’
• ZHANG Yunqi, CHEN Yonghao, CAI Yajun, DONG Ningguang, QI Yuanyong, LEI Yiyang, HAO Yanbin, QI Jianxun
• Acta Horticulturae Sinica. 2025, 52(3): 813-814. DOI:10.16420/j.issn.0513-353x.2023-1025
• Abstract ( 62 ) HTML ( 9 ) PDF (2913KB) ( 9 ) 　　　

• ‘Jinghong 1’is a new cultivar of red seed coat walnut introduced from the United States，which has the characteristics of late fruiting，avoiding late frost，disease and cold resistance. Nuts are of medium size，oval in shape，with a relatively smooth nutshell surface. The average weight of a single nut is 11.0 g，the average nutshell thickness is 1.40 mm，and the kernel yield is 50.8%. It is easily to take out the whole or half kernel from shell with red seed coat. The crude fat and protein content are 63.4% and 21.7%，respectively. It has a fragrant flavor and excellent nut quality. The fruit matures from late September to early October，with an average yield of 4.2 kg per plant during the full fruiting period. This cultivar has strong adaptability and could be cultivated in Beijing and ecologically similar areas in northern China.

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• A New Dendrobium officinale Cultivar‘Tiefeng 2’
• SONG Minquan, WANG Hong, YE Yuting, LI Jiawen, LIN Renan, CHEN Jialong, SONG Xianshui, ZHU Jianjun, LI Fei
• Acta Horticulturae Sinica. 2025, 52(3): 815-816. DOI:10.16420/j.issn.0513-353x.2024-1063
• Abstract ( 55 ) HTML ( 6 ) PDF (1544KB) ( 6 ) 　　　

• ‘Tiefeng 2’is a new cultivar of Dendrobium officinale originating from the wild strains of Yandang Mountain in Wenzhou，Zhejiang，with long stem internodes. A very small amount of cracking and breaking after curling makes the stem ideal for manual and mechanical processing. After 2 years of substrate cultivation，the yield（fresh stems without leaves）was 7 324.8 kg · hm^-2，the average internode length was 1.59 cm，and the average content of polysaccharides and mannose was 41.33% and 15.61%，respectively. It is suitable for planting in the southern and southwestern regions of Zhejiang Province，as well as in areas with similar environments and climates.

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• New Dendrobium Cultivars‘Yunxuetan’and‘Xinhezilong’
• JIANG Qichuan, ZHONG Hua, YANG Wei, ZHOU Bin, BI Wei, LU Zhengjiu
• Acta Horticulturae Sinica. 2025, 52(3): 817-818. DOI:10.16420/j.issn.0513-353x.2024-0648
• Abstract ( 61 ) HTML ( 17 ) PDF (1026KB) ( 17 ) 　　　

• ‘Yunxuetan’and‘Xinhezilong’are new Dendrobium cultivars developed by hybridizing Den. anosmum. Their pseudobulb are clustered，cylindrical，medium plant type，33-48 cm long，with several nodes，internode length 1.5-2.2 cm，diameter 0.4-0.9 cm，unbranched. The leaves are biserial，alternate，leathery，oblong，7.1-10.5 cm long and 1.9-3.4 cm wide. Its flowers are in racemes，each with 1-2 flowers in a bunch，with a flower transverse diameter of 6.8-8.2 cm. The flower sepals，petals and throat of‘Yunxuetan’are white（2015RHS NN155D），which ones of‘Xinhezilong’are dark purple （2015RHS 64A）. They flowering from April to June，and are suitable for greenhouse cultivation or outdoor environment in tropic and subtropic in areas.

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• A New Agapanthus praecox Cultivar‘Zijuan’
• CAO Chunyan, WANG Chengzhong, CHEN Jun, LIANG Qi, YIN Yuansen, ZHANG Yan
• Acta Horticulturae Sinica. 2025, 52(3): 819-820. DOI:10.16420/j.issn.0513-353x.2024-0399
• Abstract ( 60 ) HTML ( 10 ) PDF (1087KB) ( 10 ) 　　　

• ‘Zijuan’is a new cultivar bred from the seedlings of Agapanthus praecox‘Big Blue’. The Plant is a semi evergreen variety，and the umbel inflorescence is large and full，containing 142 to 150 florets，and pedicel lengths ranging from 5.2 to 6.1 cm. The corolla is funnel-shaped，with shortened tepals，exhibiting a length-to-width ratio of 0.84. The corolla lobes partially overlap. The RHS color chart value of the tepals is 92B，belonging to the typical blue-purple color series. There are numerous stamens slightly protruding beyond the tepals，and the stigma is positioned higher than the anthers. The flowering period occurs in mid-to-late June. This species is cold-resistant and drought-tolerant but has high fertilizer requirements. It is most suitable for cultivation in protected areas in Southern or Northern Jiangsu during autumn.

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