Actinidia, nine species distributed in Guizhou Province, including A. polygama, A. rubricaulis var. coriacea, and A. callosa var. henryi, were selected in this study. Based on next-generation sequencing data, we performed chloroplast genome assembly, annotation, and comparative genomic analysis to systematically investigate their genomic characteristics and phylogenetic relationships. The results were as follows:(1)The chloroplast genomes of all nine Actinidia species were double-stranded circular molecules with a typical quadripartite structure. Their full lengths ranged from 155 660 to 156 770 bp, and the overall GC content varied from 37.21% to 37.33%, indicating high similarity in genome size.(2)A total of 130 genes were annotated in most species, including 83 protein-coding genes, 39 tRNA genes, and 8 rRNA genes, except that 129 genes were annotated in A. fulvicoma and A. fortunatii.(3)Codon usage bias was similar among species, with a preference for A/U at the third codon position. A total of 491 simple sequence repeat(SSR)loci were identified, encompassing six repeat types ranging from mononucleotide to hexanucleotide.(4)Comparative genomic analysis revealed that sequence variation was higher in the large single copy(LSC)and small single copy(SSC)regions than in the inverted repeat(IR)region, and that non-coding regions exhibited more pronounced variation than coding regions. Nine divergent gene fragments were identified, including intergenic spacers such as rps16-trnQ-UUG, ndhC-trnV-UAC, and the rbcL-accD region.(5)Phylogenetic analysis resolved the nine species into four clades: A. polygama was phylogenetically distant from the others; A. chinensis and A. chinensis var. deliciosa clustered together; A. callosa var. henryi, A. rubricaulis var. coriacea, A. fortunatii, and A. fulvicoma formed a distinct clade; and A. latifolia showed the closest relationship with A. eriantha. This study has provided an important basis at the chloroplast genome level for the identification and conservation of kiwifruit germplasm resources in Guizhou Province, and has also accumulated key data and a theoretical basis for the taxonomy, phylogeny and molecular identification of this genus.]]> 2026/5/9 21:51:38 1, SHI Binbin¹, LIU Qing¹, ZHONG Weimin¹, QI Yong¹, TANG Dongmei^1*, ZHOU Jia^1,2*]]> ZHANG Sheng¹, SHI Binbin¹, LIU Qing¹, ZHONG Weimin¹, QI Yong¹, TANG Dongmei^1*, ZHOU Jia^1,2* 9true AcPAL gene family in kiwifruit(Actinidia chinensis)and their expression profiles during fruit ripening, a genome-wide identification of AcPAL genes was performed, followed by analyses of their sequence characteristics, encoded protein properties, promoter cis-acting elements, gene structures, and phylogenetic relationships. Quantitative real-time PCR(qRT-PCR)was employed to detect the expression patterns of these genes in different tissues and during fruit ripening. The results were as follows:(1)A total of seven kiwifruit AcPAL genes were identified and designated as AcPAL1-AcPAL7, respectively. The proteins encoded by the AcPAL family genes consisted of 706-722 amino acids, and all of them were stable acidic proteins. These proteins possess the conserved domain(PLN02457)and active site motif(GTITASGDLVPLSYIA).(2)Chromosomal localization and collinearity analyses revealed that one tandem duplication event and ten segmental duplication events were the major driving forces for the expansion of the AcPAL family members.(3)Phylogenetic tree analysis indicated that all AcPAL family members clustered within the dicotyledon clade and showed a close genetic relationship with CsPAL proteins from Camellia sinensis.(4)The promoters of AcPAL family genes contain a various cis-acting elements involving light response, stress response, hormone response, as well as growth and development regulation.(5)qRT-PCR results showed that different AcPAL members exhibited differential expression patterns in roots, stems, leaves, flowers and fruits of kiwifruit. Notably, four members(AcPAL2, AcPAL3, AcPAL4 and AcPAL5)were significantly up-regulated during postharvest fruit ripening. This expression pattern was consistent with the marked increase in PAL enzyme activity, and their expression was induced by abscisic acid(ABA). These findings provide candidate genes and a theoretical basis for further investigation into the functions of AcPAL genes in the formation of postharvest fruit quality in kiwifruit.]]> 2026/5/9 21:51:38 1,2, HUANG Qingqing¹, GAO Minxia^1,2, CHEN Yiting^1,2*]]> FENG Xin^1,2, HUANG Qingqing¹, GAO Minxia^1,2, CHEN Yiting^1,2* 8true AvHMGR gene family and its function under waterlogging stress, a genome-wide identification of the AvHMGR gene family in Actinidia valvata was performed using bioinformatics approaches. Comprehensive analyses were conducted on their chromosomal localization, gene structures, conserved protein domains, and cis-acting elements in promoter regions, etc. The results were as follows:(1)A total of 12 AvHMGR family members were identified in the A. valvata genome and were located across 12 different chromosomes. These AvHMGR genes encoded proteins ranging from 514 to 597 amino acids in length, all of which were predicted to be localized in the endoplasmic reticulum. Based on the phylogenetic analysis, AvHMGR members were grouped into three clusters.(2)Promoter analysis revealed abundant hormone-responsive elements and stress-responsive elements within the AvHMGR promoters.(3)Expression profiling showed that AvHMGR6b and AvHMGR9a/b exhibiting relatively high expression levels at different tissues and fruit developmental stages; AvHMGR5a/b were up-regulated after 12 h of salt stress, suggesting their involvement in short-term salt stress response.(4)Under waterlogging stress, multiple AvHMGR genes including AvHMGR5b, AvHMGR6a/b, AvHMGR9a/b, and AvHMGR21a were significantly up-regulated in both leaves and roots, suggesting that AvHMGRs played a critical role in plant responses to waterlogging stress. The sults of this study provides a theoretical foundation for further research on the functional characterization of HMGR in plant responses to waterlogging stress and lays a fundamental basis for future breeding efforts aimed at enhancing kiwifruit tolerance to waterlogging stress.]]> 2026/5/9 21:51:38 1, CHANG Zirui¹, LI Jinling¹, LIU Ruonan^2,3, GAO Jianyou², LIU Cuixia², LI Jiewei², WANG Faming^2*]]> ZHANG Meijuan¹, CHANG Zirui¹, LI Jinling¹, LIU Ruonan^2,3, GAO Jianyou², LIU Cuixia², LI Jiewei², WANG Faming^2* 7true Actinidia rubricaulis var. coriacea as the research subject, systematically measuring chilling requirements and integrating physiological-biochemical assays with high-throughput transcriptome sequencing to elucidate dynamic changes in bud carbohydrate metabolism, endogenous hormone balance, and antioxidant enzyme systems during the process from the dormancy initiation to the dormancy release. The results were as follows:(1)With chilling accumulation, bud soluble sugar content significantly increased(approximately two fold of initial stage)while starch content markedly decreased(to about half of initial level)by dormancy release, indicating a dynamic metabolic shift from starch degradation to soluble sugar accumulation.(2)Endogenous hormone levels exhibited stage-specific changes, with abscisic acid(ABA)content decreasing from 486.75 μg·L^-1 at initial stage to 218.45 μg·L^-1 at dormancy release stage, and gibberellin(GA)content increasing from 214.23 pg·mL^-1 to 614.75 pg·mL^-1, resulting in an ABA/GA ratio decline from 2.27 to 0.36, suggesting a hormonal shift toward germination promotion.(3)Antioxidant enzyme system(SOD, POD, etc.)activities peaked at 192 h of chilling accumulation, indicating enhanced antioxidant capacity as a response to cold stress.(4)Transcriptome analysis identified 12 685 differentially expressed genes(DEGs), with 6 067 genes up-regulated and 6 618 genes down-regulated, enriched in plant hormone signal transduction, starch and sucrose metabolism, and environmental response pathways, revealing a multi-gene coordinated regulatory mechanism. This work, for the first time at the systems level, elucidates the physiological-transcriptomic coordinated regulatory mechanism of chilling requirement accumulation in A. rubricaulis var. coriacea, providing a foundation for addressing climate warming-induced dormancy disorders and related breeding research.]]> 2026/5/9 21:51:38 *]]> XIA Liming, YE Kaiyu, JIANG Qiaosheng, GAO Jianyou, LI Jiewei, LIU Cuixia, ZHU Rongxiang, GONG Hongjuan, QI Beibei, WANG Faming^* 6true Actinidia spp.). Insufficient accumulation of low temperatures in winter will lead to abnormal flower bud development, which in turn impairs the yield in the subsequent year. Determining the CR of the Actinidia chinensis cv. ‘Zhonghe Hongyang' remains an unresolved issue to date.In this study, potted seedlings of the ‘Zhonghe Hongyang' were used as experimental materials. To determine the CR of this cultivar, the seedlings were exposed to cold treatments of different durations under controlled artificial low-temperature conditions. Meanwhile, the flowering performance of the kiwifruit plants in the second year after cold treatment was monitored to verify the existence of “chilling treatment memory”. An artificial climate chamber was employed to simulate the cold accumulation pattern in natural environments. Specifically, five cold treatment groups were set with 4 ℃ low temperature for durations of 2, 4, 6, 8, 10 d, respectively; a control group was established concurrently. The effects of different cold accumulation levels on the growth and development of kiwifruit were analyzed based on the flowering and fruiting parameters. The results were as follows:(1)Different durations of cold treatment had a significant effect on the flowering and fruiting of ‘Zhonghe Hongyang' plants. The optimal cold treatment duration was 6 d at 4 ℃, under which the plants produced 49 flowers and 17 fruits, significantly higher than those in other treatment groups.(2)Follow-up observations in the second year showed that the cold-treated plants could flower normally. Among these, the group treated with 4 ℃ for 6 d still exhibited significantly better flowering performance than other groups, and could achieve normal fruit set after artificial pollination. The minimum CR of ‘Zhonghe Hongyang' when cultivated in Guangdong Province was 576 h, and the plants could retain the chilling treatment memory in the second year. Based on the CR results and the influence of terrain conditions, the suitable planting areas for this cultivar in Guangdong are Meizhou, Heyuan, Shaoguan, Qingyuan, and Yunfu. In all, the ‘Zhonghe Hongyang' variety has a low CR, which is suitable for cultivation in South China.]]> 2026/5/9 21:51:38 *]]> ZHENG Jiasheng, YAO Shuqin, LIANG Hong, ZHANG Xianzhi^* 5true Pseudomonas syringae pv. actinidiae, is a devastating disease. Compared with chemical control methods, microbial-based disease control offers significant advantages, including exceptional environmental compatibility, robust sustainability, and a reduced likelihood of developing pathogen resistance. Through literature review, this article systematically summarizes the disease characteristics, pathogenic bacterium, and transmission routes, as well as the main microorganism species used in biological control, core biocontrol mechanisms, and practical applications of microorganisms in the biocontrol of KBC. The aim of this study is to provide theoretical support and practical guidance for the sustainable biocontrol of KBC. The results are as follows:(1)Biocontrol microorganisms are highly diverse. The microorganisms with control effects on KBC mainly included four categories: bacteria, actinomycetes, fungi, and bacteriophages. Among these, Bacillus and Pseudomonas(bacteria)and Streptomyces(actinomycetes)are the most widely used and exhibit significant efficacy.(2)The biocontrol mechanisms involve both direct and indirect pathways. Direct mechanisms include the secretion of antimicrobial peptides, antibiotics and other antimicrobial substances to dissolve pathogenic bacterial cell walls, blocking infection sites through nutritional competition and spatial occupation, as well as direct disruption of pathogen structure via parasitism; indirect mechanisms primarily involve the induction of systemic resistance in host plants to enhance resistance to KBC. Most highly effective biocontrol strains employ both mechanisms, demonstrating superior efficacy compared with strains relying on a single mechanism.(3)In the same study, the control efficacies and stability of composite microorganism agents are generally superior to those of single microorganisms. The synergistic effects among different strains not only broaden the antimicrobial spectrum but also enhance the colonization rate and stress tolerance of the strains on plant surfaces. In summary, this article clearly identifies the core issues in the current field of KBC biocontrol and puts forward targeted recommendations.]]> 2026/5/9 0:00:00 1,2, ZHAO Yue¹, TANG Qianli¹, LIU Jingwen¹, WANG Jialiang¹, LIU Dejiang^1,2*]]> DU Chunmei^1,2, ZHAO Yue¹, TANG Qianli¹, LIU Jingwen¹, WANG Jialiang¹, LIU Dejiang^1,2* 4true Pseudomonas syringae pv. actinidiae(Psa)infection in kiwifruit, this study used the highly susceptible cultivar ‘Hongyang' with two relative humidity treatments: 60%±2%(water deficit group)and 90%±2%(high humidity group). Colony counting, fluorescence observation, and scanning electron microscopy were employed to investigate the effects and mechanisms of moderate water deficit treatment on bacterial canker. The results were as follows:(1)Plants under early water deficit treatment exhibited higher initial activities of catalase(CAT), superoxide dismutase(SOD), glutathione reductase(GR)and phenylalanine ammonia-lyase(PAL), lower stomatal aperture, and had only about 1/5 of the pathogen load in leaves compared to the high humidity group after 12 days inoculation.(2)When infected plants from the high humidity group were transferred to water deficit conditions, leaf fluorescence showed diffuse patterns after 7 days, and pathogen mortality reached 99.38% after 12 days of treatment; this treatment effectively induced a decrease in leaf water potential, stomatal closure, and significantly enhanced antioxidant enzyme activities. In conclusion, water deficit reduces pathogen invasion by decreasing leaf water potential and promoting stomatal closure, while enhancing plant resistance through antioxidant enzyme regulation, not only inhibiting Psa infection and proliferation but also eliminating established pathogens. This study confirms that moderate water deficit effectively controls kiwifruit bacterial canker, enriches the “water-plant-pathogen” interaction framework. It provides new ideas and theoretical references for the prevention and control of bacterial canker in kiwifruit, and also lays a theoretical foundation for the popularization of field water management strategies such as rain-sheltered cultivation.]]> 2026/5/9 0:00:00 1, ZHU Rongxiang¹, YUAN Ping², JANG Qiaosheng¹, LIU Cuixia¹, XIA Liming¹, YE Kaiyu¹, WANG Faming^1*]]> GAO Jianyou¹, ZHU Rongxiang¹, YUAN Ping², JANG Qiaosheng¹, LIU Cuixia¹, XIA Liming¹, YE Kaiyu¹, WANG Faming^1* 3true 2026/5/9 21:51:38 *]]> HUANG Wenjun, YANG Jie, ZHANG Qi, HAN Fei, LV Haiyan, ZHONG Caihong^* 2true Actinidia arguta, ‘Jiuyue' and ‘Huanyou No.1'. Fruits at different growth stages were taken as test materials, and measurements were conducted according to methods specified in national standards, encompassing three dimensions(length, width, thickness), single fruit weight, total sugars, total acids, 17 amino acids, 4 vitamins, mineral elements, and total dietary fiber content. The results were as follows:(1)The fruit development for both ‘Jiuyue' and ‘Huanyou No.1' could be divided into four distinct growth stages: young fruit stage, fruit expansion stage I, fruit expansion stage II, and maturation stage, with both cultivars exhibiting a fruit shape index exceeding 1.(2)In ‘Jiuyue' fruits, only the contents of glutamic acid, arginine, and methionine increased, while in ‘Huanyou No.1' fruits, only glutamic acid showed an increasing trend; all other amino acids decreased. The tyrosine content decreased significantly to(342.06±1.13)mg·kg^-1(an 88.52% reduction)in ‘Jiuyue' and(245.18±0.44)mg·kg^-1(a 94.32% reduction)in ‘Huanyou No.1'. Glutamic acid became the most abundant amino acid during the fruit expansion II and maturation stages, reaching levels of(1 971.11±1.18)mg·kg^-1 in ‘Jiuyue' and(1 397.68±0.23)mg·kg^-1 in ‘Huanyou No.1'.(3)Both cultivars were rich in vitamin C, showing a consistent trend of an initial increase followed by a subsequent decrease.(4)Mineral element contents exhibited considerable fluctuation during the early growth stages. The potassium content increased, while the contents of other measured minerals decreased, with calcium showing the most pronounced decline(75.00%).(5)The total acid content increased initially and then decreased, while the total sugar contents increased rapidly upon entry into the maturation stage.(6)The dietary fiber contents of both cultivars displayed a significant decreasing trend after the fruit reached maturity. The results of this study indicate that fruits of both ‘Jiuyue' and ‘Huanyou No.1' possess a favorable fruit shape, are rich in vitamins, mineral elements, and dietary fiber, and have a moderate sweetness, indicating high potential for promotion and commercialization. The differential accumulation patterns of various compounds throughout fruit development provide valuable insights for assessing the nutritional and potential medicinal value of the fruits. Furthermore, these findings offer crucial guidance for optimizing agricultural practices to enhance fruit quality and nutrient content.]]> 2026/5/9 21:51:38 1,2, ZHANG Yuming^1,2, YANG Chengjun⁴, SHEN Jian^1,2, N. V. Skrypchenko^2,3, LIU Dejiang^1,2, CAO Manjun^1,2*]]> LI Lili^1,2, ZHANG Yuming^1,2, YANG Chengjun⁴, SHEN Jian^1,2, N. V. Skrypchenko^2,3, LIU Dejiang^1,2, CAO Manjun^1,2* 1true