Genetic & Breeding · Germplasm Resources · Molecular Biology

• Identification of Peach NAC Gene Family and Role of PpNAC050 in Promoting Fruit Fructose Accumulation
• LIU Jianhao, JING Yanfu, LIU Yuexin, XU Yaoguang, YU Yang, GE Xiuxiu, XIE Hua
• Acta Horticulturae Sinica. 2024, 51(9): 1983-1996. DOI:10.16420/j.issn.0513-353x.2023-0085
• Abstract ( 335 ) HTML ( 305 ) PDF (5771KB) ( 305 ) 　　　

• The plant-specific NAC（NAM，ATAF1/2，CUC2）transcription factors play important roles in regulating fruit quality. To explore the role of the NAC in the regulation of soluble sugars in peach （Prunus persica）fruit quality，a total of 117 potential peach NAC members（PpNAC）were identified with an uneven distribution across all eight chromosomes as well as a scaffold. Phylogenetic analyses indicated that these PpNAC were classified into 13 subgroups. The NAC gene PpNAC050 that is highly expressed during later fruit development were further characterized，and it was in nucleus with transcriptional activation. Transient overexpression of PpNAC050 in peach fruits significantly increased fructose content and glucose content in peach fruit flesh. EMSA and dual-luciferase assays showed that PpNAC050，being a transcriptional repressor，directly bound to the promoters of PpERDL6-1（PpERDL16），a vacuolar membrane monosaccharide transporter gene regulating fructose content，suggesting that PpNAC050 positively regulated fructose accumulation by repressing PpERDL6-1 gene expression.

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• Cloning and Functional Analysis of Lateral Branching Regulatory Gene BoBRC1 in Broccoli
• LIU Yuxiang, HAN Fengqing, ZHAO Xinyu, LIU Yumei, LI Zhansheng, $\boxed{\hbox{FANG Zhiyuan}}$
• Acta Horticulturae Sinica. 2024, 51(9): 1997-2007. DOI:10.16420/j.issn.0513-353x.2024-0057
• Abstract ( 225 ) HTML ( 217 ) PDF (1789KB) ( 217 ) 　　　

• In this study，the BoBRC1 gene was cloned from the elite broccoli inbred line L461. Expression pattern analysis showed that BoBRC1 had the highest expression level in axillary bud tissues，and changed dynamically with axillary bud growth. According to the sequence of BoBRC1，two targets were designed on the first exon，and a CRISPR/Cas9 gene editing vector was constructed. The construct was introduced into L461 by Agrobacterium-mediated genetic transformation，and a total of 18 plants were confirmed as positive transgenic. The results showed that three plants harbored mutations in at least one of the targeted regions corresponding to an editing efficiency of 16%. Among them L461-3 was edited in both Target 1 and Target 2 while L461-1 and L461-11 were edited in Target 2. Compared with the wild type，the homologous editing mutants showed a significant increase in the number and length of lateral branches. In the bobrc1 mutant，qRT-PCR analysis of key genes downstream of lateral branch gene BoBRC1 showed a significant decrease in the expression of the BoHB21，BoHB53 and BoNCED3 genes while the expression of the BoHB40 significantly increased. This study verified the function of BoBRC1 gene in the regulation of lateral branch development in broccoli，and knocking out can promote the growth of broccoli lateral branches.

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• Fine-Mapping and KASP Marker Development for the Gene Underlying Green Fruit in Eggplant
• XIA Zhilei, YU Bingxin, YANG Meng, LIAN Zilin, GUAN Lilan, HE Yichao, YAN Shuangshuang, CAO Bihao, QIU Zhengkun
• Acta Horticulturae Sinica. 2024, 51(9): 2008-2018. DOI:10.16420/j.issn.0513-353x.2023-0567
• Abstract ( 218 ) HTML ( 128 ) PDF (2854KB) ( 128 ) 　　　

• An F₂ population developing by a white fruit eggplant line E802 and a green fruit eggplant line NY was used for the genetic analysis of the gene underlying green fruit color. The segregation ratio of green fruit and white in the 304 individuals in the F₂ population was 3︰1，indicating that the green phenotype of NY is controlled by a single dominant locus. Combing with the BSA-seq and linkage-based QTL mapping，the gene underlying green fruit color of eggplant was fine-mapped into 683.4 kb interval on chromosome 8 using F₂ and the F_2:3 population. The genetic distance of this locus is 0.17 cM. Among the 46 genes in the interval，SmAPRR2 was the best candidate gene. The 5.27 kb deletion was detected in the E802，resulting the SmAPRR2 lacking the exon 7 to 11. In addition，a tightly linked to SmAPRR2 KASP marker，22QP296，was development. The accuracies of 22QP296 for predicting the skin color（green or white）in the F₂ population and the 194 cultivars were 100% and 94.85%，respectively，indicating that this KASP marker can be used in molecular marker-assisted selection in eggplant breeding.

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• Nitrogen Allocation Characteristics and Expression of Related Genes During Corm-Forming Stage of Amorphophallus konjac
• REN Siyuan, CHEN Sen, LONG Zhijian, WANG Boya, TANG Dengguo, WANG Zhengqian, YANG Bin, HU Shanglian, CAO Ying
• Acta Horticulturae Sinica. 2024, 51(9): 2019-2030. DOI:10.16420/j.issn.0513-353x.2023-0629
• Abstract ( 113 ) HTML ( 47 ) PDF (1765KB) ( 47 ) 　　　

• Through ¹⁵N isotopic tracing and RNA-seq analysis，the N distribution in various organs and the expression of genes related to N during the development of konjac corms are systematically studied would help to understand nitrogen utilization and guide the fertilizer use. Results show that during the development of Amorphophallus konjac corms the N content per unit weight of leaves was the highest as the compared with other organs. During the expansion of corms，N content，Ndff value，¹⁵N distribution rate and ¹⁵N utilization rate in leaves showed a downward trend，whereas the N demand in corms increased，the peak of ¹⁵N utilization rate appearing right in the middle stage of corm expansion（45-75 d，day after expansion of leaves）. A. konjac reached the peak of ¹⁵N content of in a whole plant at 60 d，while the ¹⁵N utilization rate also reached the highest rate of 22.68%. Then，both the content and utilization rate of ¹⁵N were deceasing，indicating that this point was the most efficiently nitrogen use period. After 60 d，the absorbed nitrogen was distributed from leaves to corms，which also invalided that 60 d was the suitable period for N topdressing. Meanwhile，the peak of expression in N metabolism-related genes in leaves appeared between the middle and late stage of corm expansion（105 d），a range within which leaf N metabolism was strengthened，promoting the synthesis and output of N assimilation products. Among them，the expression levels in leaves of nitrate reductase gene AkNIA1 and glutamine synthetase gene AkGSR2-1 were significantly and positively correlated with the N content in leaves and roots，indicating their key role in nitrogen absorption and accumulation，and they can be used as candidate genes for genetic improvement of N utilization.

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• Identification and Expression Pattern Analysis of DUF966 Gene Family Members in Ginger
• GUO Changquan, LI Danqi, HUI Xinran, ZHENG Jingya, HOU Menglu, ZHU Yongxing
• Acta Horticulturae Sinica. 2024, 51(9): 2031-2047. DOI:10.16420/j.issn.0513-353x.2023-0422
• Abstract ( 177 ) HTML ( 107 ) PDF (5900KB) ( 107 ) 　　　

• In order to understand the function of DUF966 family genes（ZoDUF966）in ginger，the biological information method was used to systematically identify them. A total of 11 ZoDUF966 were identified and classified into groups a，b and c，including 5，4 and 2 members，respectively. All ZoDUF966 proteins were hydrophilic proteins and localized in the nucleus. Except for ZoDUF966_1b，ZoDUF966_3b and ZoDUF966_11a，the other 8 proteins were alkaline proteins. In the secondary structure of the protein，α-helix and random coil are dominant，and there are some differences in the tertiary structure. Eleven ZoDUF966 were distributed on six chromosomes，except for four and three genes on chromosomes 6 and 16，respectively，and only one gene on each of the other four chromosomes. The promoter sequence of ZoDUF966 contains cis-acting elements related to light response，stress，growth and development，and plant hormones. Gene expression analysis based on transcriptome sequencing data showed that the expression of ZoDUF966 was different in different growth periods，different tissues，biotic and abiotic stresses. Among them，ZoDUF966_6c responded to low temperature stress，and ZoDUF966_9b was highly up-regulated after inoculation with Fusarium solani. qRT-PCR results showed that ZoDUF966 responded to drought，flooding and salt stresses. Under drought stress，ZoDUF966_6c/10a/11a in roots and ZoDUF966_7a/11a in rhizomes were significantly up-regulated，while ZoDUF966_1b/4b and ZoDUF966_8a/1a in rhizomes were significantly down-regulated. Under salt stress，ZoDUF966_9b and ZoDUF966_7a were significantly up-regulated in roots，and ZoDUF966_5a was significantly down-regulated in roots. Under waterlogging stress，ZoDUF966_7a and ZoDUF966_10a were significantly up-regulated in rhizome，while ZoDUF966_1b in leaves and ZoDUF966_11a in roots were significantly down-regulated.

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• Molecular Markers Assisted Construction of Cmerecta Near-Isogenic Line of Melon Dwarfing Gene
• LIU Gangyun, DUAN Shixiang, XU Nana, GUO Yaomiao, DOU Junling, YANG Sen, NIU Huanhuan, LIU Dongming, YANG Luming, HU Jianbin, ZHU Huayu
• Acta Horticulturae Sinica. 2024, 51(9): 2048-2062. DOI:10.16420/j.issn.0513-353x.2023-0989
• Abstract ( 144 ) HTML ( 114 ) PDF (6427KB) ( 114 ) 　　　

• In the early stage，a CmERECTA gene that controls internode length was finely mapped by map cloning，and a marker Cmerecta-dCAPS2 co-separated from melon dwarf was developed. In order to further study its function，the 102 pairs of SSR markers with good polymorphism and relatively uniform distribution on chromosomes were detected by using the melon inbred line TopMark as the reincarnation parent，the dwarf inbred line M406 as the donor parent，and the Cmerecta-dCAPS2 as the foreground selection marker，the background recovery rate of the SSR markers with good polymorphism and relatively uniform distribution on the chromosomes was detected，and the Cmerecta near-isogenic line was constructed under the TopMark genetic background，and its phenotype was statistically analyzed. The results showed that the highest background response rates per plant of BC₁F₁ and BC₂F₁ generations were 80.61% and 98.57%，respectively. The phenotypes of the three BC₂F₂ generation Cmerecta pure lines with the highest background recovery rate showed that the plant height was dwarf and the leaves were rounded. The construction of this near-isogenic line can be used as a basic material for subsequent research on the regulatory mechanism and application of CmERECTA，a dwarf gene in melon.

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• Selection and Validation of Reference Genes for RT-qPCR of Flower Development in Calanthe triplicata
• WU You, JI Hongyu, DENG Shuwen, LIANG Cuiyi, WAN Zhiting, WU Shasha, ZHAI Junwen
• Acta Horticulturae Sinica. 2024, 51(9): 2063-2074. DOI:10.16420/j.issn.0513-353x.2023-0954
• Abstract ( 77 ) HTML ( 32 ) PDF (2284KB) ( 32 ) 　　　

• To facilitate studies on gene expression in Calanthe triplicata，nine candidate reference genes were identified and evaluated across three different groups（the whole flower group，the floral structures group and the mixed group）using geNorm，NormFinder，BestKeeper and RefFinder. The results showed although there were slight differences in the ranking of RGs between groups，UBQ1 and UBQ2 were the most stable. To valid the accuracy of the evaluation results，four target genes related to flower development were amplified by RT-qPCR，the results further supported that UBQ1 and UBQ2 were the most optimal for reference genes.

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• Genome-Wide Identification and Expression Analysis of CCO Gene Family in Dendrobium officinale During Flower Development
• ZHAO Jiaying, ZENG Zhouting, CEN Xinying, SHI Jiaoqi, LI Xiaoxian, SHEN Xiaoxia, YU Zhenming
• Acta Horticulturae Sinica. 2024, 51(9): 2075-2088. DOI:10.16420/j.issn.0513-353x.2023-0566
• Abstract ( 137 ) HTML ( 87 ) PDF (3681KB) ( 87 ) 　　　

• To investigate the functions of carotenoid cleavage oxygenase（CCO）gene family in Dendrobium officinale Kimura et Migo，bioinformatics methods were employed to identify the CCO family members in D. officinale. Simultaneously，their expression levels in different tissues，different stages of flower development，and after the application of methyl jasmonate（MeJA）. The results revealed that a total of 12 CCO family members were excavated，with ten belonging to the carotenoid cleavage dioxygenase（CCD）subfamily and two belonging to the 9-cis-epoxycarotenoid dioxygenase（NCED）subfamily. They were unevenly distributed on 7 chromosomes，and harbored tandem duplications. The promoter regions of these DoCCO genes contained numerous hormone and stress response elements. The expression of DoCCO genes varied across different tissues of D. officinale，with higher expression observed in pollen and roots. They were differentially expressed during flower development and in response to MeJA treatment，suggesting that their potential roles in growth，development and the MeJA response. Specifically，DoCCD1b，may play a crucial role during flower development.

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Cultivation · Physiology & Biochemistry

• Improving Physicochemical Properties and Bacterial Communities of Peach-Heavy Soils Using Biofertilizers and Organic Fertilizers
• ZHANG Fan, YANG Yang, WANG Hong, ZHANG Xuebing
• Acta Horticulturae Sinica. 2024, 51(9): 2089-2104. DOI:10.16420/j.issn.0513-353x.2023-0604
• Abstract ( 293 ) HTML ( 95 ) PDF (4538KB) ( 95 ) 　　　

• To explore the effects of different improvement measures on the soil physical and chemical properties and bacterial communities in a peach continuous cropping field. The peach seedling cultivation field planted for three years was collected and six treatments were established in the field experiment including the untreated（control），bio-organic fertilizer，ferrous sulfate，grondverbeteraar，bacillus subtilis and farmyard manure，and the effects of different improvement measures on soil physical and chemical properties and bacterial communities in the peach continuous cropping were investigated through a locational field trial. The results showed that the different treatments increased the content of nutrient elements in the soils. Compared with the control，the content of organic matter，total nitrogen，total phosphorus，total potassium，alkali-hydrolyzed nitrogen，available phosphorus，available potassium，available iron and available zinc in the soil of the treatment of bio-organic fertilizer increased by 44.30%，62.18%，58.82%，9.20%，92.97%，80.18%，93.98%，31.77% and 94.51%，respectively. Compared with the control，the soil pH decreased by 11.15%，and the soil salt content and conductivity increased by 85.71% and 89.29%，respectively. Moreover，the different treatments increased the number of bacterial OTUs and bacterial diversity in the soil. Compared with the control，the farmyard manure and bacillus subtilis treatment significantly increased the abundance and diversity of bacteria in the soils，the treatment of farmyard manure promoted the metabolism of amino acids and carbohydrates in the soil，increased the synergistic effect between bacterial communities，and improved the stability of bacterial communities in the soils. Correlation analysis showed that the soil bacterial community characteristics were mainly affected by the soil total potassium，potassium ion，chloride ion，available potassium，magnesium ion，available iron，organic matter，pH and conductivity. Generally，compared with the control，the different treatments increased the height，stem thickness，and chlorophyll content of peach seedlings，especially the bio-organic and farmyard manure treatments promoted seedling growth. The results showed that the treatments of bio-organic fertilizer and farm manure can improve the physical and chemical properties and the microbial community characteristics of the soil in peach continuous cropping field. They also accelerate the growth of peach seedlings.

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• Flowering and Fruiting Behaviour of Two South China Plum Cultivars with Different Ripening Stages in an Area Near the Northern Boundary of the Tropics
• ZHONG Yizhong, WANG Zhou, XIE Jingyao, WANG Zhengpeng, HAO Jingjing, LIU Chaoyang, ZHANG Wei, WU Jing, ZHONG Ziqin, CHEN Chengjie, HE Yehua
• Acta Horticulturae Sinica. 2024, 51(9): 2105-2119. DOI:10.16420/j.issn.0513-353x.2023-0865
• Abstract ( 135 ) HTML ( 47 ) PDF (4754KB) ( 47 ) 　　　

• Plum belongs to temperate fruit trees，and the high temperature climate in autumn and winter in southern subtropics has a serious impact on its normal growth and development. In order to explore the adaptability of plum near the northern boundary of tropical climate，two South China plum cultivars‘Congzao 1’（March plum type，early-maturing）and‘Yunkai 1’（Sanhua plum type，medium-maturing）with different maturity periods were used as materials to study their flowering and fruiting behaviours，such as bud differentiation，flowering，fruit set and fruit development in Xinyi City，Guangdong Province，China. The results showed that the morphological differentiation of flower buds commenced at the time when normal season fruits became ripe（20 April and 10 June，respectively）and lasted for about 60 d. In addition to spring shoots，summer shoots and autumn shoots can also initiate and complete the flower bud differentiation process in the current year. The earliest new shoots of‘Congzao 1’and‘Yunkai 1’first appeared to flower in mid-July and late August，respectively，and then continued to flower normally until late January of the following year，with the whole flowering period lasting about 6 months；they can be classified into five flowering periods，such as summer flowers（July）according to the flowering season，autumn flowers（August to October），winter flowers（November to December），early flowers（mid-January）and the main flowering period（late January to the end of the flowering period），the two cultivars of the secondary flowering period（July to mid-January）accounted for 18.83% and 19.36% of the amount of flowering，respectively；Summer and autumn flowers are mostly malformed and cannot set fruits normally or develop normally. The winter fruits matured in early February and early March，and although the fruits were smaller and more acidic，they still had market value. The quality of the early-flowering fruits improved significantly，and they had high commercial value，and the production of winter-flowering fruits and early-flowering fruits accounted for about 5% to 10% of the total production. Two South China plum cultivars near the northern boundary of the tropical climate showed a fast rate of bud differentiation，and the tops of the tips of the various levels that were produced by the end of September were able to complete bud differentiation，flowering and flowering. The adaptive ability of these two cultivars to the high temperature of autumn and winter may provide inspiration for the study of plum cultivation techniques and the evolution of South China plum cultivars.

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• Effects of Different Defoliants on Defoliation and Nutrient Reflux of ‘Dongzao’Jujube
• LIU Xinyue, ZHAI Zhaoci, TAO Jialin, FENG Kun, CAI Xiaoteng, LIU Zhiguo, LIU Mengjun
• Acta Horticulturae Sinica. 2024, 51(9): 2120-2130. DOI:10.16420/j.issn.0513-353x.2023-0824
• Abstract ( 253 ) HTML ( 44 ) PDF (1756KB) ( 44 ) 　　　

• The research systematically studied the effects of different types and concentrations of chemical defoliants on the defoliation and nutrient reflux of 5-year-old‘Dongzao’jujube in greenhouse via foliar spraying. The results showed that：（1）0.20% ethephon treatment had the best defoliation effect on jujube trees，with a high defoliation rate of 75.75% on 7 days after treatment；（2）The nitrogen，phosphorus，and potassium reflux caused by natural fallen leaves of jujube trees were 4.14，0.27，and 3.18 g · kg^-1，respectively；（3）Leaf nitrogen reflux occurred under all chemical defoliant treatments and 4% urea，8% urea，10% urea，0.5% zinc sulfate，and 1.0% zinc sulfate treatments significantly increased leaf nitrogen reflux. Leaves phosphorus reflux can be found under 4% urea，8% urea，10% urea，0.5% zinc sulfate，1.0% zinc sulfate，2.0% zinc sulfate，0.05% ethephon and 0.10% ethephon treatments. Potassium backflow can be detected in leaves treated with 4% urea，8% urea，10% urea，0.5% zinc sulfate，0.05% ethephon，and 0.20% ethephon. However，only 8% and 10% urea treatments significantly increased leaf nitrogen，phosphorus and potassium reflux. In conclusion，0.20% ethephon is the best treatment for rapid defoliation in production. The best treatment for the purpose of shedding leaves at a specific period without leaf nutrient waste is 8% or 10% urea，which significantly improves the backflow of nitrogen，phosphorus，and potassium.

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• Effects of Exogenous Nitric Oxide and Putrescine on Drought Resistance of Strawberry Seedlings
• LI Wenjing, SHI Shuo, ZHANG Hao, ZHANG Jiangyan, SONG Sihao, YANG Aizhen, SHEN Yuanyue, GUO Jiaxuan, GAO Fan
• Acta Horticulturae Sinica. 2024, 51(9): 2131-2142. DOI:10.16420/j.issn.0513-353x.2023-0631
• Abstract ( 235 ) HTML ( 76 ) PDF (2988KB) ( 76 ) 　　　

• The present study aimed to investigate the effects of exogenous nitric oxide（NO）and putrescine（Put）on enhancing drought resistance of strawberry seedlings.‘Benihoppe’strawberry was used as experimental material，and 10% PEG-6000 was used to simulate drought stress. The pharmacological experiments were performed by foliar application of distilled water（H₂O），Put，sodium nitroprusside （SNP）as a NO donor，DL-α-difluoromethylarginine（DFMA）as an inhibitor of arginine decarboxylase synthesis pathway of Put，and N^G-Nitro-L-arginine Methyl Ester（L-NAME）as an inhibitor of nitric oxide synthase（NOS）. The results showed that the drought stress significantly decreased the net photosynthetic rate（P_n），transpiration rate（T_r），stomatal conductance（G_s），and maximum photochemical efficiency of PSⅡ（F_v/F_m）in strawberry leaves，but led to a dramatic increase in malondialdehyde（MDA）levels in both roots and leaves of strawberry plants. Compared with drought stress alone，the hydrogen peroxide（H₂O₂）levels decreased by 25.57% and 16.62% in leaves，and by 35.38% and 40.09% in roots on the fifth day of treatment for Put and NO，respectively. Exogenous Put treatment induced a significant increase in proline（Pro）content and catalase（CAT）activity，however，exogenous NO treatment significantly boosted the activities of superoxide dismutase（SOD），peroxidase （POD），and CAT in leaves and roots. Additionally，both Put and NO treatments can markedly increase the activities of NOS and diamine oxidase（DAO），reduce polyamine oxidase（PAO）activity. As a result of increased NOS and reduced PAO activities，the application of both Put and NO on the leaves promoted the accumulation of NO，spermidine（Spd），and spermine（Spm），enhanced the levels of endogenous hormones，osmoregulation substances，and signaling molecules，as well as antioxidant enzyme activities in strawberry plants，thereby improving the drought resistance of strawberry seedlings.

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• Effects of Peat Soil and Mushroom Residue Application on the Potato Root-Associated Microbiome and Yield
• ZHONG Yang, QIN Yazhi, LUO Shuai, JING Yuling, WANG Wanxing, LI Guangcun, HU Xinxi, QIN Yuzhi, CHENG Xu, XIONG Xingyao
• Acta Horticulturae Sinica. 2024, 51(9): 2143-2154. DOI:10.16420/j.issn.0513-353x.2023-0061
• Abstract ( 179 ) HTML ( 60 ) PDF (3138KB) ( 60 ) 　　　

• Improving soil structure of the paddy-upland rotation is an important measure to enhance the efficiency of soil nutrient supply for winter potatoes. In this study，an investigation was undertaken to explore the comprehensive effects of peat soil（PS）and mushroom residue（MR）short-term application on the soil physicochemical properties and nutrient composition of paddy soils，using the potato cultivar ‘Favorita’as the experimental material. High-throughput amplicon sequencing was utilized to clarify the impact of soil improvement treatments on the structure and function of the root-associated microbiome. Results showed that PS and MR treatments have altered the proportionate distribution of soil aggregates to a certain extent；both treatments also significantly increased soil organic matter content，as well as the levels of available phosphorus and potassium. The soil improvement treatments also enhanced the diversity of the rhizosphere microbial community，with Proteobacteria，Actinobacteria，Bacteroidetes，and Firmicutes being the dominant phyla in both rhizosphere and endophytic regions. Principal coordinate analysis（PCoA）results showed that，compared to bacterial communities，fungal community compositions were relatively stable，and less impact on changes induced by soil amendments. Co-occurrence network analysis revealed that PS treatment resulted in tighter node connections and a more prominent network modularity tendency，especially among the endophytic compartment. Canonical Correspondence Analysis （CCA）indicated that soil organic carbon（TOC）and total nitrogen（TN）significantly influenced the composition of both bacterial and fungal communities. Considering the potato yield results under the combined soil improvement treatments，peat soil amendment appears to be more suitable for the amelioration of paddy field soils and has potential for application.

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• Effect of Overexpression of Robinia pseudoacacia RpACBP3 Gene on Photosynthetic Physiological Characteristics of Nicotiana tabacum
• ZHANG Songyan, DIE Pengxiang, SONG Mengting, LI Zhijian, ZHOU Jian
• Acta Horticulturae Sinica. 2024, 51(9): 2155-2167. DOI:10.16420/j.issn.0513-353x.2023-0690
• Abstract ( 92 ) HTML ( 47 ) PDF (2008KB) ( 47 ) 　　　

• To investigate the regulatory effects of RpACBP3 from Robinia pseudoacacia on the photosynthetic-physiological functions of Nicotiana tabacum，this gene was transferred into N. tabacum‘NC89’via Agrobacterium-mediated method，and the relevant indices of RpACBP3 over-expressing tobacco plants were measured using wild-type plants as the control. The results showed that seven strains of N. tabacum with RpACBP3 over-expression were obtained in this experiment. Compared to those in wild-type plants，chlorophyll a，chlorophyll b，and total chlorophyll content considerably increased and carotenoid content decreased in RpACBP3 over-expression strains. Additionally，some indices such as initial fluorescence（F_o），non-photochemical quenching coefficient（q_N）decreased，maximum photochemical efficiency（F_v/F_m），actual photochemical quantum efficiency（Φ_PSII），photosynthetic rate （P_n），and intercellular CO₂ concentration（C_i）increased，whereas others such as stomatal conductance（G_s），transpiration rate（T_r）decreased，stomatal length，and stomatal area increased in RpACBP3-over- expressing-strains. Correlation analysis revealed significant correlations between most of the indicators，and random forest regression showed that RpACBP3 overexpression had the greatest effects on tobacco indices such as chlorophyll a content，Φ_PSII，C_i，and stomatal area，respectively. In summary，the RpACBP3 over-expression enhanced the light energy utilization of tobacco plants by increasing the chlorophyll content，improving the efficiency of light absorption and transformation by the photosystem，and promoting the stomatal development.

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Plant Protection

• Expression Characteristics and Function Analysis of CsMEKK1-1 Gene in Response to Huanglongbing in Citrus
• DONG Liting, QU Rongrong, PANG Shuwei, MO Kaiqin, CHEN Shuang, SHANG Lanyue, ZOU Xiuping
• Acta Horticulturae Sinica. 2024, 51(9): 2168-2182. DOI:10.16420/j.issn.0513-353x.2023-0792
• Abstract ( 115 ) HTML ( 81 ) PDF (4276KB) ( 81 ) 　　　

• It has been shown that MAPK（mitogen-activated protein kinase）signaling pathway plays a key role in regulating citrus Huanglongbing（HLB）disease，but the key genes and mechanisms involved in this pathway need to be elucidated. Comparative transcriptome analysis of the mesophyll and midrib tissues from‘Jincheng’oranges[Citrus sinensis (L.) Osbeck]at the early stage（four months）of“CandidatusLiberibacter asiaticus”（CLas）infection revealed that differentially expressed genes（DEGs） were significantly enriched in the MAPK signaling pathway. Among these DEGs，four MEKK1 genes involved in the first cascade of the MAPK signaling pathway were up-regulated in the mesophylls，but they had no differential expression in midribs. Real-time fluorescence quantitative PCR（qRT-PCR）analysis showed that the expression of four CsMEKK1 genes were significantly different in different tissues from the HLB-susceptible‘Jincheng’orange and the HLB-tolerant‘Mafenggan’orange（Citrus hystrix）during CLas infection. CsMEKK1-1 showing the most significantly differential expression was selected for further analysis. Bioinformatics analysis showed that CsMEKK1-1 belongs to the MEKK gene family. Tobacco subcellular localization showed that CsMEKK1-1 was localized in the cell cytoplasm，nucleus and chloroplast. Expression characteristics of CsMEKK1-1 gene in response to salicylic acid（SA），jasmonic acid（JA），abscisic acid（ABA），ethylene（ETH）and CLas-flg22 in healthy‘Jincheng’leaves were analyzed by qRT-PCR. The results showed that CsMEKK1-1 expression was downregulated by SA，JA and ETH and CLas-flg22 mainly down-regulated CsMEKK1-1 expression. To evaluate CsMEKK1-1 function，MEKK1-1 overexpression and RNA interference（RNAi）vectors were constructed，and were introduced into CLas-infected‘Jincheng’branches to generate transgenic hairy roots using Agrobacterium rhizogenes-mediated citrus transformation. Quantitative PCR analysis showed that CsMEKK1-1 positively promoted CLas proliferation in hairy roots，indicating that CsMEKK1-1 is a susceptible gene for HLB disease.

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• Induction Mechanism of Methyl Jasmonate on Postharvest Navel Orange Fruit Against Blue Mold
• CHEN Ming, ZHANG Jieru, YANG Hangyun, WANG Yinbao, ZHENG Zhiyuan, ZENG Jiaoke, CHEN Jinyin, FU Yongqi, XIANG Miaolian
• Acta Horticulturae Sinica. 2024, 51(9): 2183-2194. DOI:10.16420/j.issn.0513-353x.2023-0564
• Abstract ( 98 ) HTML ( 59 ) PDF (2543KB) ( 59 ) 　　　

• In this study，‘Newhall’navel orange fruits were used as experimental material and fumigated with 50 μmol · L^-1 MeJA for 24 h，then 20 µL 1.25 × 10⁶ spores · mL^-1 blue mold pathogen Penicillium italicum spore suspension were injected，which to investigate the induced role of methyl jasmonate（MeJA）treatment on the resistance of postharvest navel orange fruit against blue mold. The results showed the blue mold lesion diameters of MeJA treatment group was significantly smaller than that of the control at 1-7 d after disease onset. The highest activities of POD，PPO，LAC，PAL，CAD，4CL and C4H and their relative gene expression levels except CsPPO in MeJA treatment group were higher than those of the control，respectively. At the same time，MeJA treatment promoted the accumulation of lignin，total phenolics，and flavonoids in navel orange fruits. Moreover，the content of phenylalanine and tryptophan in MeJA treatment group was significantly reduced. The above results indicated MeJA treatment might promote the accumulation of lignin，total phenolics and flavonoids content through regulating aromatic amino acids as well as stimulating the activities and gene expression of phenylpropanoid metabolic pathway-related enzymes，thereby inducing an enhancement in resistance of navel orange fruits against postharvest blue mold.

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New Technologies New Methods

• The Transport Activity Detection of Pitaya Sugar Transporters HpSWEET1a and HpSWEET4a by pH Indicator Method
• ZHENG Qianming, WANG Xiaoke, WANG Honglin, ZHOU Jia, XIE Pu, MA Yuhua
• Acta Horticulturae Sinica. 2024, 51(9): 2195-2206. DOI:10.16420/j.issn.0513-353x.2023-0849
• Abstract ( 190 ) HTML ( 58 ) PDF (2490KB) ( 58 ) 　　　

• Aiming at the defects of yeast growth complementation method，a new method for detecting the transport activity of candidate SWEET（sugars will eventually be exported transporter）genes was established by using pH indicator to indicate yeast extracellular acidification. In this study，using 0.006% bromocresol violet（BCP）as the pH indicator，the photoabsorption values A₅₈₉ and A₄₃₂ under the wavelength of 589 nm and 432 nm at different pH values were measured，and the correlation function equation between pH value and A₅₈₉/A₄₃₂ ratio（R_589/432）was established. HpSWEET1a and HpSWEET4a genes were isolated from pitaya（Hylocereus polyrhizus）fruit，which encoded amino acid sequences sharing identities of 66.67% and 55.36% with Arabidopsis thaliana AtSWEET1 and AtSWEET4，and belonged to the SWEET Ⅰ and Ⅱ clade，respectively. When expressed in the EBY.VW4000 yeast strain with impaired sugar uptake activity，and subjected to sugar starvation treatment followed by addition of glucose or fructose，the overexpression of HpSWEET1a，HpSWEET4a and AtSWEET1（At1g21460，positive control）caused in the extracellular BCP color from purple to yellow in 3-16 h. This change indicated the occurrence of extracellular acidification. Further calculation revealed that HpSWEET1a，HpSWEET4a and AtSWEET1 caused a decline of 1.00 in the extracellular pH value of yeast cells within 3-16 h，while the vector control only showed a decrease of 0.10. The observed extracellular acidification of yeast cells and the significant decrease in pH value demonstrated that HpSWEET1a and HpSWEET4a，similar as AtSWEET1，exhibited the glucose and fructose transport activity. To streamline the procedure and reduce time，the colorimetric method were employed based on ultra-micro spectrophotometer to measure the R_589/432 value. Following the addition of glucose for 0.5 h，the R_589/432 value reduction with HpSWEET1a was significantly higher compared to that of the vector control，indicating the method’s efficacy. The method developed in this study is superior to the commonly used yeast growth complementary detection in terms of time-consuming，accuracy，operation and flux. It also has a wide range of applications for studying the cell membrane-localized SWEET transporters.

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Review

• Progress in the Study of Glycosidealkaloids and Their Biological Activities in Solanaceae Vegetable
• LIU Yu, ZHANG Min, TAN Jie, HUANG Shuping, ZHANG Hongyuan, WANG Benqi, WANG Junliang, CHEN Huilan, CHEN Xia
• Acta Horticulturae Sinica. 2024, 51(9): 2207-2218. DOI:10.16420/j.issn.0513-353x.2023-0492
• Abstract ( 178 ) HTML ( 116 ) PDF (771KB) ( 116 ) 　　　

• Glycoalkaloid is a secondary metabolite widely present in Solanaceae plants. It has a certain impact on the quality and food safety of Solanaceae vegetables. In order to provide reference for researchers in related fields，this article analyzes and summarizes the researches about the glycoalkaloid in Solanaceae vegetables，including factors affecting their content，biological activity，and mechanism of action，etc.

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New Cultivars

• A New High-Quality Kiwifruit Cultivar with Better Storability‘Jinfu’
• LIU Yanfei, HE Xin, TIAN Ailin, LIU Zhande
• Acta Horticulturae Sinica. 2024, 51(9): 2219-2220. DOI:10.16420/j.issn.0513-353x.2021-1079
• Abstract ( 231 ) HTML ( 62 ) PDF (1293KB) ( 62 ) 　　　

• ‘Jinfu’is a new Actinidia deliciosa cultivar with better quality and storability，bred from the wild kiwifruit resource in north of Qinling Mountains. The fruit is long cylindrical in shape，with short and hard hairs rarely；the average weight of fruit is 105.89 g，and with smaller core. The flesh color is luminous green，the core color is green-white，and with tender，juicy taste and strongly aromatic. The content of soluble solids，total sugar，titratable acidity and vitamin C are 17.1%，11.2%，0.88% and 622 mg · kg^-1，respectively. The fruit is ripe in late October in Guanzhong area of Shaanxi Province，with a average yield of 30 640 kg · hm^-2 in the full fruit stage.

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• ‘Yangguang 1’-a New Monoembryonic Sterile Line of Citrus
• ZHANG Wenlong, WAN Runchu, ZHENG Ni, CHEN Yan, LAI Hengxin, YU Xin, QIAN Chun, CAO Li
• Acta Horticulturae Sinica. 2024, 51(9): 2221-2222. DOI:10.16420/j.issn.0513-353x.2021-1145
• Abstract ( 378 ) HTML ( 57 ) PDF (3065KB) ( 57 ) 　　　

• ‘Yangguang 1’（Citrus reticulata Blanco），developed by a crossing of‘Hongmeiren’（Ehime Kashi 28）as seed parent with‘Haruka’as pollen parent，is a monoembryonic and sterile line showing seedless and male-aborted. It is vigorous with high fruit-setting rate. The leaves have smooth surface with acute apex. The fruits are smooth and high flat-round in shape. The pulp is light orange in colour，crispy and tender. Single fruit weights 240-270 g in weight with 13.0%-15.0% total soluble solids，0.65% titratable acidity and 435.0 mg · L^-1 Vitamin C. In Chongqing，it matures in late November. The fruits are tolerant to storage and transportation，but tend to be suffered from high fruit cracking rate in the open field，so this cultivar is suitable for cultivation in greenhouse facilities. With annual yield of 26 300-27 500 kg · hm^-2，the major production regions include the dry-hot river valleys of Yunnan，plain/hilly area in Sichuan and western Hunan region.

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• A New Processing Pepper Cultivar‘Yanjiao 465’
• LI Yifei, YANG Xiaomiao, WANG Chunping, DUAN Minjie, HUANG Qizhong, HUANG Renzhong, ZHANG Shicai
• Acta Horticulturae Sinica. 2024, 51(9): 2223-2224. DOI:10.16420/j.issn.0513-353x.2021-1060
• Abstract ( 302 ) HTML ( 60 ) PDF (1427KB) ( 60 ) 　　　

• ‘Yanjiao 465’is a new processing pepper hybrid cultivar which was bred with the male-sterile line 481-4-1A as female parent and the restorer line 0416Y02 as the male parent. The plant height is of 100.68 cm. The average node of the first flower is 13.05. It’s with late maturing. The cultivar has strong growth vigor and high resistance to virus disease and Phytophthora blight，and resistance to anthracnose. The fruit is 10.10 cm in length，1.36 cm in width and 0.14 cm in flesh thickness. The average fruit weight is 7.38 g. The yield of fresh pepper is 30 849 kg · hm^-2. It is suitable for planting in the spring open field in the main growing areas of Southwest China，North China and Northwest China.

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• A New Muskmelon Cultivar‘Nongdatian 10’
• ZHANG Yong, MA Jianxiang, WEI Chunhua, LI Hao, YANG Jianqiang, ZHANG Xian
• Acta Horticulturae Sinica. 2024, 51(9): 2225-2226. DOI:10.16420/j.issn.0513-353x.2021-1022
• Abstract ( 84 ) HTML ( 69 ) PDF (974KB) ( 69 ) 　　　

• ‘Nongdatian 10’is a new hybrid of muskmelon. The whole growth period is 110 days and the fruit development period is about 33 days in early spring. The fruit is high-round in shape with golden and smooth peel. The flesh is orange red with crisp texture. The content of soluble solid in the center is about 16%. The average single fruit weight is 1.5 kg. The yield is about 45 200 kg · hm^-2. The cultivar is resistant to high temperature and mid-resistant to gummy stem blight and powdery mildew. It is suitable for cultivation in protection area of Shaanxi Province in spring.

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• A New Edible Crabapple Cultivar‘Jinxing’
• JIA Linguang, ZHANG He, ZHANG Xueying, SUN Jianshe, GAO Yi, LI Guofang, TAN Ming, SHAO Jianzhu
• Acta Horticulturae Sinica. 2024, 51(9): 2227-2228. DOI:10.16420/j.issn.0513-353x.2021-1051
• Abstract ( 105 ) HTML ( 52 ) PDF (3947KB) ( 52 ) 　　　

• ‘Jinxing’is derived from an open-pollinated F₁ seedling of Malus robusta Rehd. Its fruit shape is nearly oval，the average fruit weight is 38.4 g，fruit shape index is 0.95. The fruit skin covered with bright red color，and star-shaped fruit dot. The flesh is in cream white color，crisp，juicy and in good balance of sugar and acids. Its firmness is 10.62 kg · cm^-2，soluble solids content is 13.6%，titratable acid content is 0.30%. It is harvested during early October in Baoding，Hebei，and the fruit has a long storage life. The yield is 45 000-52 500 kg · hm^-2. The amount of flowers is large and compatibility is good. Because of the long flowering period，it has high degree of coincidence with Fuji and other main apple cultivars，it has good compatibility and can be used as a pollination tree specifically for apples.

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