Antifungal Activity of Crude Extracts of <i>Tectona grandis</i> L.f. against Wood Decay Fungi

Wood is mainly made up of cellulose, hemicelluloses, lignin polymers and other organic and inorganic substances, making it susceptible to deteriorate by various biological agents. Tectona grandis L.f. (Teak) is a timber species with high resistance to biological deterioration, valued for its durability, beauty, and mechanical resistance. The purpose of this work was to evaluate the antifungal activity of crude extracts from teak on various fungi that cause wood deterioration. For this, Teak heartwood was obtained, then fragmented and pulverized until obtaining a flour which was used for compounds extraction using the Soxhlet technique coupled to a rotary evaporator through solvents of increasing polarity (hexane, dichloromethane, tetrahydrofuran, and acetone). The extracts obtained were tested against fungal organisms collected in the field, and the LC₅₀ was determined using teak crude extracts on Artemia salina as a biological model. The results obtained showed that a high flour yield was obtained with hexane (0.951 g), followed by tetrahydrofuran (0.446 g), dichloromethane (0.348 g), and acetone (0.152 g). By using nine fungal organisms that predominantly correspond to the genus Aspergillus, the extractable compounds were tested, inhibiting 25% of mycelial growth with tetrahydrofuran (T. versicolor), and 40.9% with dichloromethane (G. trabeum). Likewise, the biological model of A. salina showed an LC₅₀ of 84.9 μg/mL with hexane, 43.3 μg/mL with dichloromethane, 59.6 μg/mL with tetrahydrofuran, and 54.7 μg/mL with acetone. For this reason, it is concluded that Teak wood contains many extractable compounds in relation to its weight, besides having antimicrobial activity when extracted through polar compounds such as dichloromethane and tetrahydrofuran.     

Morphological and Phylogenetic Resolution of <i>Diplodia neojuniperi</i> Emerging <i>Diplodia</i> Top Dieback of <i>Pinus thunbergii</i> Parl. in China

In Bazhong City, Sichuan Province, China, top dieback symptoms were found on many pine trees (Pinus thunbergii Parl). The tips of old needles first turned grayish-green and then developed into brown bands in the field. Phylogenetic analysis of concatenated ITS and EF1-α indicated the pathogen of this dieback disease as Diplodia neojuniperi. Additionally, effects of temperature, pH and medium on the mycelial growth were also characterized. The most favorable temperature and pH level for mycelial growth are 25°C and 8, respectively. The optimal medium for mycelial growth is PDA medium. To our knowledge, this is the first report of D. neojuniperi causes Diplodia top dieback on Pinus thunbergii. Our results provide fundamental information for monitoring and preventing such disease in the future.     

Antibacterial Activity and Mechanisms of Ethanol Extracts from <i>Scutellaria baicalensis</i> Georgi and <i>Magnolia officinalis</i> against <i>Phytophthora nicotianae</i>

Phytophthora nicotianae causes substantial economic losses in most countries where tobacco is produced. At present, the control of P. nicotianae mainly depends on chemical methods, with considerable environmental and health issues. We investigated the effects of ethanol extracts from Scutellaria baicalensis Georgi (SBG) and Magnolia officinalis (MO). On mycelial growth, sporangium formation, and zoospore release of P. nicotianae. Both extracts inhibited the growth of P. nicotianae, with mycelial growth inhibition rates of 88.92% and 93.92%, respectively, at 40 mg/mL, and EC50 values of 5.39 and 5.74 mg/mL, respectively. The underlying mechanisms were the inhibition of sporangium formation, the reduction of zoospore number, and the destruction of the mycelium structure. At an SBG extract concentration of 16.17 mg/mL, the inhibition rates for sporangia and zoospores were 98.66% and 99.39%, respectively. At an MO extract concentration of 2.87 mg/mL, the production of sporangia and zoospores was completely inhibited. The hyphae treated with the two plant extracts showed different degrees of deformation and damage. Hyphae treated with SBG extract showed adhesion and local swelling, whereas treatment with MO extract resulted in broken hyphae. Mixture of the extracts resulted in a good synergistic effect.     

Repellent and Insecticidal Activity of Naphthoquinones from the Heartwood of <i>Tectona grandis</i> on <i>Incisitermes marginipennis</i> (Latreille)

Wood is a lignocellulosic material that, because of its organic nature, is a source of nutrients for bacteria, fungi, and insects. Incisitermes marginipennis (Latreille) is an interesting dry wood-boring termite. Because it is an extremely destructive pest, difficult to control due to its cryptic lifestyle, and for its role in the biogeochemical cycle of carbon and other elements; it is a fundamental organism. The use of less toxic and eco-friendly substances is important for protecting domestic, cultural, and historical heritage made of wood or lignocellulosic materials. The aim of this study was to evaluate the biological activity of various naphthoquinones extracted from the heartwood of T. grandis on I. marginipennis. First, heartwood flour was used for Soxhlet-type extractions to isolate and characterize the heartwood compounds by thin-layer chromatography. To identify the heartwood compounds, nuclear magnetic resonance and gas chromatography coupled to a mass spectrometer were used. The information obtained was supported using the Interactive Spectroscopy software. The identified heartwood compounds were lapachol, tectoquinone, deoxylapachol, dehydro-α-lapachone, tectol and tecomaquinone-I. Using nymphal termites of I. marginipennis as a biological model, the isolated and identified molecules were under three different tests (repellent, insecticide and protective) and their biological activity was individually evaluated. The results showed that the molecules obtained have a repellent-protective effect against I. marginipennis, although not in all cases, these molecules have high percentages of mortality and decreased the weight loss of the treated material exposed to I. marginipennis.     

<i>Aspergillus tubingensis</i> Causes Leaf Spot of Cotton (<i>Gossypium hirsutum</i> L.) in Pakistan

Cotton (Gossypium hirsutum L.) is a key fiber crop of great commercial importance. Numerous phytopathogens decimate crop production by causing various diseases. During July-August 2018, leaf spot symptoms were recurrently observed on cotton leaves in Rahim Yar Khan, Pakistan and adjacent areas. Infected leaf samples were collected and plated on potato dextrose agar (PDA) media. Causal agent of cotton leaf spot was isolated, characterized and identified as Aspergillus tubingensis based on morphological and microscopic observations. Conclusive identification of pathogen was done on the comparative molecular analysis of CaM and β-tubulin gene sequences. BLAST analysis of both sequenced genes showed 99% similarity with A. tubingensis. Koch’s postulates were followed to confirm the pathogenicity of the isolated fungus. Healthy plants were inoculated with fungus and similar disease symptoms were observed. Fungus was re-isolated and identified to be identical to the inoculated fungus. To our knowledge, this is the first report describing the involvement of A. tubingensis in causing leaf spot disease of cotton in Pakistan and around the world.     

First Report of <i>Fusarium striatum</i> Causing Root Rot Disease of <i>Panax notoginseng</i> in Yunnan,China

Panax notoginseng is a traditional Chinese medicinal plant. Root rot of P. notoginseng is one of the most serious diseases affecting P. notoginseng growth and causes wilted leaves, fewer lateral roots and rotten roots. Root rot is a soil-borne disease, and mainly occurs from June to August in Yunnan Province when the temperatures are high and the air is humid. In this study, the endophytic fungal genus Fusarium isolate E-2018.1.22-#3.2 was obtained from a P. notoginseng embryo. Fusarium isolate E-2018.1.22-#3.2 was identified as Fusarium striatum based on morphological characteristics and molecular analysis. The fungus was found to have conidiophores and macroconidia, and its ITS, LSU and TEF-1α genes shared 100%, 99.2% and 99% identities with the homologous genes of Fusarium striatum, respectively. Isolate F. striatum E-2018.1.22-#3.2 can cause root rot symptoms, including black, soft roots, fewer lateral roots and leaf wilt, in 93% of the experimental P. notoginseng plants, and could be re-isolated, fulfilling Koch’s postulates. When the P. notoginseng plants were treated with the fungicide pyraclostrobin, isolate F. striatum E-2018.1.22-#3.2 was unable to cause root rot. We have therefore demonstrated that F. striatum E-2018.1.22-#3.2 is able to cause root rot disease in P. notoginseng. This is the first report of root rot disease caused by F. striatum on P. notoginseng in China.     

Biological Control of Root-Knot Nematode <i>Meloidogyne incognita</i> in <i>Psoralea corylifolia</i> Plant by Enhancing the Biocontrol Efficacy of <i>Trichoderma harzianum</i> Using Press Mud

Meloidogyne incognita is a plant pathogen causing root-knot disease and loss of crop yield. The present study aimed to use Trichoderma harzianum as a biocontrol agent against plant-parasitic nematodes and used press mud, which is a solid waste by-product of sugarcane, as a biocontrol agent and biofertilizer. Therefore, the combined application of T. harzianum and press mud may enhance nematode control and plant growth. Elemental analysis of press mud using scanning electron microscopy (SEM) integrated with an Energy Dispersive X-ray (EDX) analyzer revealed the presence of different elements such as C, O, Mg, Si, P, K, Ca, Cu and Zn. In addition, a greenhouse study was conducted to investigate the combined effects of press mud and T. harzianum on M. incognita reproduction and growth and the biochemical features of Psoralea corylifolia. The results showed that plant length, dry biomass, leaf area, the number of seeds per plant, chlorophyll a, chl b, carotenoid content, nitrate reductase, carbonic anhydrase, and nitrogen content were significantly increased (P ≤ 0.05) in the T2 plants (plants were treated with 100 g of press mud + 50 mL T. harzianum before one week of M. incognita inoculation), over inoculated plants (IC). Antioxidant enzyme activity of ascorbate peroxidase (APX), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) in the foliage of P. corylifolia was significantly increased when plants were treated with press mud + T. harzianum. A significant reduction in the number of egg masses, nematode population, and root-knot index (RKI) was found in plants with T2 plants. These results suggest that the combined application of T. harzianum and press mud has the potential to control the M. incognita infection and can be used as an environmentally safe alternative to chemical nematicides and also help in the removal of sugarcane waste that causes environmental pollution.     

Effects of <i>Piriformospora indica</i> on the Respiration of <i>Taxus chinensis</i> var. <i>mairei</i> under Water Stress

Seedlings of Taxus chinensis var. mairei were used as experimental materials to study the adaptation of Piriformospora indica to this plant under water stress. The materials were divided into two groups, namely, with or without inoculation with P. indica. Each group was subjected to four different levels of water stress. Vitality and physiological and biochemical indexes of the roots of T. chinensis var. mairei were regularly measured. Under water stress, T. chinensis var. mairei had significantly decreased root vitality; root vitality was higher in inoculated roots than in uninoculated roots. Under intense water stress, the inoculated roots had a higher soluble sugar content than the uninoculated roots. Under water stress, T. chinensis var. mairei experienced decreased activity of aerobic respiratory metabolic enzymes. The activity of anaerobic respiratory metabolic enzymes and alcohol dehydrogenase initially increased and then decreased, whereas that of lactate dehydrogenase increased. The inoculated roots had a higher activity of respiratory metabolic enzymes than the uninoculated roots. As water stress was further intensified, the roots had significantly decreased activity of aerobic respiratory metabolic enzymes and significantly increased activity of anaerobic respiratory metabolic enzymes. The activity of respiratory metabolic enzymes decreased faster in the uninoculated roots than in the inoculated roots. This study demonstrated that Piriformospora indica plays a positive role in enhancing the antihypoxic ability of T. chinensis var. mairei, thereby alleviating plant damage due to water stress.     

Variation for Resistance to <i>Alternaria tenuissima</i> and Potential Structural Mechanism among Different Cultivars of <i>Chrysanthemum morifolium</i>

Black spot disease, caused by the necrotrophic fungus Alternaria tenuissima (Fr.) Wiltsh (A. tenuissima), is considered a highly destructive disease of Chrysanthemum (Chrysanthemum morifolium Ramat.). A set of 17 accessions of commercial chrysanthemum cultivars were evaluated for resistance to A. tenuissima by seedling artificial inoculation. It was found that the reaction of the accessions to artificial inoculation ranged from resistant to highly susceptible. Five varieties of chrysanthemum (‘Zhongshan Taogui’, ‘Jinba’, ‘Zhongshan Jinguan’, ‘Jinling Wanhuang’ and ‘Jinling Yangguang’) were resistant; two varieties of chrysanthemum (‘Zhongshan Xinggui’ and ‘Zhongshan Jinkui’) were moderately resistant; and others were susceptible to various degrees, four varieties of chrysanthemum (‘Zhongshan Zihe’, ‘Zhongshan Jiuhong’, ‘Zaoyihong’ and ‘Jinling Jiaohuang’) were highly susceptible, especially. Some leaf morphological features of two resistant and two highly susceptible cultivars were further researched. Trichome density, length, height, gland size and stomata density were found to be associated with plant passive resistance. Resistant varieties that were identified in present study will be promising germplasm for exploitation of breeding programmes aimed at developing A. tenuissima-resistant cultivars and increasing genetic diversity.     

Development of a New Cold-Tolerant Maize (<i>Zea mays</i> L.) Germplasm Using the <i>ICE1</i> Gene from <i>Arabidopsis thaliana</i>

To develop cold-tolerant maize germplasms and identify the activation of INDUCER OF CRT/DRE-BINDING FACTOR EXPRESSION (ICE1) expression in response to cold stress, RT-PCR was used to amplify the complete open reading frame sequence of the ICE1 gene and construct the plant expression vector pCAMBIA3301-ICE1-Bar. Immature maize embryos and calli were transformed with the recombinant vector using Agrobacterium tumefaciens-mediated transformations. From the regenerated plantlets, three T1 lines were screened and identified by PCR. A Southern blot analysis showed that a single copy of the ICE1 gene was integrated into the maize (Zea mays L.) genomes of the three T1 generations. Under low temperature-stress conditions (4°C), the relative conductivity levels decreased by 27.51%–31.44%, the proline concentrations increased by 12.50%–17.50%, the malondialdehyde concentrations decreased by 16.78%–18.37%, and the peroxidase activities increased by 19.60%–22.89% in the T1 lines compared with those of the control. A real-time quantitative PCR analysis showed that the ICE1 gene was ectopically expressed in the roots, stems, and leaves of the T1 lines. ICE1 positively regulates the expression of the CBF genes in response to cold stress. Thus, this study showed the successful transformation of maize with the ICE1 gene, resulting in the generation of a new maize germplasm that had increased tolerance to cold stress.     

<i>Natarajania thailandica</i> sp. nov. (Stilbosporaceae,Diaporthales) from Thailand

A fungus similar to the monotypic genus Natarajania, isolated from dead wood and collected in Thailand, is reported. Analysis of partial ribosomal LSU and a protein coding gene (RPB2) demonstrated that the new isolate belonged to Stilbosporaceae, Diaporthales and genetically different from N. indica. It is unique in producing synnematous conidiophores, smooth-walled conidiogenous cells and a flared collarette but lacks an elongated collar-canal which is distinct in the type species. Therefore, sequence data and morphological traits are used to introduce the new species, Natarajania thailandica.     

Genome-Wide Identification and Expression Profiling Suggest that Invertase Genes Function in Silique Development and the Response to <i>Sclerotinia sclerotiorum</i> in <i>Brassica napus</i>

Invertase (INV), a key enzyme in sucrose metabolism, irreversibly catalyzes the hydrolysis of sucrose to glucose and fructose, thus playing important roles in plant growth, development, and biotic and abiotic stress responses. In this study, we identified 27 members of the BnaINV family in Brassica napus. We constructed a phylogenetic tree of the family and predicted the gene structures, conserved motifs, cis-acting elements in promoters, physicochemical properties of encoded proteins, and chromosomal distribution of the BnaINVs. We also analyzed the expression of the BnaINVs in different tissues and developmental stages in the B. napus cultivar Zhongshuang 11 using qRT-PCR. In addition, we analyzed RNA-sequencing data to explore the expression patterns of the BnaINVs in four cultivars with different harvest indices and in plants inoculated with the pathogenic fungus Sclerotinia sclerotiorum. We used WGCNA (weighted coexpression network analysis) to uncover BnaINVregulatory networks. Finally, we explored the expression patterns of several BnaINV genes in cultivars with long (Zhongshuang 4) and short (Ningyou 12) siliques. Our results suggest that BnaINVs play important roles in the growth and development of rapeseed siliques and the defense response against pathogens. Our findings could facilitate the breeding of high-yielding B. napus cultivars with strong disease resistance.     

Sexual Morph of <i>Furcasterigmium furcatum</i> (Plectosphaerellaceae) from <i>Magnolia liliifera</i> Collected in Northern Thailand

We isolated an interesting fungus from dead leaves of Magnolia liliifera collected from Chiang Mai, Thailand. The novel strain is related to Plectosphaerellaceae based on the morphology of its asexual morph and the analysis of sequence data. Phylogenetic analyses using a combined gene analysis of LSU and ITS sequence data showed that this strain is clustered in the same clade with Furcasterigmium furcatum with high statistical support. The new strains produced the asexual morph in culture which is morphologically similar to F. furcatum. Thus, we identified this strain as the sexual morph of F. furcatum. This is the first record of sexual morph for the monotypic genus Furcasterigmium and the first record of this genus on Magnolia.     

Antifeedant Activity of <i>Caesalpinia coriaria</i> Essential Oil Against <i>Incisitermes marginipennis</i> (Latreille)

This study scrutinized the possibility of finding toxicant or deterrent plant metabolites against the dry wood termite Incisitermes marginipennis (Latreille). Plant deterrent agents act as repellents or antifeedants to prevent wood decay and increase its useful life. The potential of the tree Caesalpinia coriaria (Fabaceae) as a biological source of molecules with deterrent effects against the dry wood termite was assessed by a phytochemical fractionation guided by repellence and antifeedant activities. The gas chromatography-mass spectrometry analysis of the leaf essential oil showed geraniol to be one of the major components and its repellent and antifeedant effects were determined. Geraniol had only an antifeedant effect without affecting the body weight or survival of the dry wood termite. Unlike the leaf essential oil, geraniol did not exhibit a repellency effect. An in-silico approach of the activity of acetylcholinesterase in interaction with geraniol resulted in an affinity energy of −7.5 Kcal/mol. Geraniol interacted with the amino acid tyrosine 324 located in the enzyme’s active site while citronellol (negative control) interacted with tryptophan 83 located adjacent to the active site. These deterring terpenes have not been implemented for the preservation and restoration of wood products exposed to the attack of the dry wood termite. However, they are an important natural control alternative.     

Titanium Dioxide Nanoparticles Promote Root Growth by Interfering with Auxin Pathways in <i>Arabidopsis thaliana</i>

TiO₂ nanoparticles (nano-TiO₂) are widely used in the world, and a considerable amount of nano-TiO₂ is released into the environment, with toxic effects on organisms. In the various species of higher plants, growth, including seed germination, root elongation, and biomass accumulation, is affected by nano-TiO₂. However, the underlying molecular mechanisms remain to be elucidated. In this study, we observed that nano-TiO₂ promoted root elongation in a dose-dependent manner. Furthermore, we found that nano-TiO₂ elevated auxin accumulation in the root tips of the auxin marker lines DII-VENUS and DR5:: GUS, and, correspondingly, quantitative real-time PCR analysis revealed that nano-TiO₂ increased the expression levels of auxin biosynthesis- and transportrelated genes. GFP fluorescence observation using transgenic PIN2-GFP indicated that nano-TiO₂ promoted root growth by inducing PIN2 accumulation. Thus, we propose that nano-TiO₂ promote root growth in Arabidopsis thaliana by altering the expression levels of auxin biosynthesis- and transport-related genes.     

AM Fungi and <i>Piriformospora indica</i> Improve Plant Growth of <i>Pinus elliottii</i> Seedlings

Pinus elliottii is an exotic afforestation pine extensively distributed in southern parts of China. In order to understand whether endophytic fungi can affect seedling growth of P. elliottii, Piriformospora indica (Pi), Funnelifcrmis mosseae (Fm), and Diversispora tortuosa (Dt) were inoculated respectively, and the non-inoculated group was set as control. The growth indexes, the contents of soluble sugar and soluble protein, and plant endogenous hormone levels in the leaves of P. elliottii, were analyzed. The results showed that Fm, Dt and Pi colonized the P. elliottii roots to form mycorrhizal structure and chlamydospores arranged in beads respectively. Three fungal inoculants exhibited the stimulated growth responses, whilst Dt illustrated the most positive effect on plant height, single fresh weight, trunk diameter and root system structure, compared with the control. On the other hand, the soluble sugar and soluble protein contents were increased distinctively in mycorrhizal plants. The endogenous IAA, GA3, ZR contents were increased, while the ABA contents were reduced in mycorrhizal plants versus non-mycorrhizal plants. The fungi-induced endogenous hormone changes triggered plant growth improvement of P. elliottii seedlings. This research unraveled the positive effect of AM fungi and P. indica on growth of pine seedlings, while, more application of endophytic fungi to fields needs to be explored.     

Cloning and Characterization of <i>EuGID1</i> in <i>Eucommia ulmoides</i> Oliver

Gibberellic acid controlled the key developmental processes of the life cycle of landing plants, and regulated the growth and development of plants. In this study, a novel gibberellin receptor gene EuGID1 was obtained from Eucommia ulmoides Oliver. The cDNA of EuGID1 was 1556 bp, and the open reading frame was 1029 bp, which encoded 343 amino acids. EuGID1 had the homology sequence with the hormone-sensitive lipase family. Amino acid sequence alignment confirmed EuGID1 protein had the highest homology with the GID1 protein of Manihot esculenta. EuGID1 was located in the nucleus and cell membrane and had expression in four plant organs. Overexpression of EuGID1 in transgenic Arabidopsis plants promoted plant elongation and increased siliques yield.     

Phytosulfokine-α Promotes Root Growth by Repressing Expression of <i>Pectin Methylesterase Inhibitor</i> (<i>PMEI</i>) Genes in <i>Medicago truncatula</i>

Phytosulfokine-α (PSK-α), a sulfated pentapeptide with the sequence YIYTQ, is encoded by a small precursor gene family in Arabidopsis. PSK-α regulates multiple growth and developmental processes as a novel peptide hormone. Despite its importance, functions of PSK-α in M. truncatula growth remains unknown. In this study, we identified five genes to encode PSK-α precursors in M. truncatula. All of these precursors possess conserved PSK-α signature motif. Expression pattern analysis of these MtPSK genes revealed that each gene was expressed in a tissue-specific or ubiquitous pattern and three of them were remarkably expressed in root. Treatment of M. truncatula seedlings with synthetic PSK- α peptide significantly promoted root elongation. In addition, expression analysis of downstream genes by RNA-seq and qRT-PCR assays suggested that PSK-α signaling might regulate cell wall structure via PMEI-PME module to promote root cell growth. Taken together, our results shed light on the mechanism by which PSK-α promotes root growth in M. truncatula, providing a new resource for improvement of root growth in agriculture.     

Efficient Evergreen Plant Regeneration of <i>Cinnamomum japonicum</i> Sieb. through <i>in vitro</i> Organogenesis

Cinnamomum japonicum Sieb. is an excellent roadside tree and medicinal tree species with considerable ornamental and economic value. In this study, we successfully developed a large-scale micropropagation protocol for C. japonicum for the first time. Sterilized shoots were excised and used as explants for shoot induction on several basal media, supplemented with different concentrations of plant growth regulators (PGRs), such as Thidiazuron (TDZ), N⁶ -Benzyladenine (6-benzylaminopurine) (BA), α-naphthaleneacetic acid (NAA) and Gibberellic acid (GA₃). After comparison, the most efficient medium for shoot regeneration was 1/2 Murashige and Skoog (MS) medium containing 0.5 mg L^–1 BA, 0.05 mg L^–1 NAA and 0.2 mg L^–1 GA₃, which resulted in an average number of induced shoots per explant and shoot length of 5.2 and 1.62 cm at 28 d, respectively. Then, elongated adventitious shoots were transferred to induce roots. 86.7% of shoots was able to root on 1/2 MS medium supplemented with 0.5 mg L^–1 NAA and 0.1 mg L^–1 BA. The earliest rooting time observed was after 21 d and the average root length was up to 3.3 cm after 28 d. Our study shows that C. japonicum can be successfully regenerated through de novo organogenesis, which lays a foundation for future transformation research on this tree.     

Genetic Improvement in <i>Juglans mandshurica</i> and Its Uses in China: Current Status and Future Prospects

Juglans mandshurica is an economically and ecologically valuable species that is used for various construction purposes, making luxurious furniture, as food and sources of medicinal substances and landscaping because of its excellent wood, edible fruits and rich in various types of chemical compounds. In the past few decades, several genetic improvements of J. mandshurica were made, with a focus on the selection of improved varieties and on breeding technology. Many elite provenances and families were selected based on growth traits or wood properties. In recent years, with the increasing demand for high-quality seedlings in Chinese forestry production, the breeding goals of genetic improvement for J. mandshurica were redefined to include other traits, such as fruit yield and contents of medicinal component. However, the improvement processes were still slow due to the long breeding cycle and the limited use of advanced breeding technologies, resulting in the selection of fewer improved varieties. In this review, we summarized the research progresses on genetic improvements of J. mandshurica and other related works, and discussed research gaps and suggested future directions for genetic improvement of the species. The review provides valuable insight for the selection of improved varieties and production of excellent germplasms.