Deciduous Fruit Research Articles

First detection of fungal diversity associated with Prunus salicina Lindl malformation syndrome

The Chinese deciduous fruit Prunus salicina Lindl is loved by people because of its distinctive flavor and significant industrial worth. This study presents the first report of abnormal leaf bud in Prunus salicina Lindl. Malformation of Prunus salicina Lindl leaf buds leads to abnormal development and growth, causing deformities and a decrease in fruit yield. Identifying the underlying causes and causative pathogens is essential for effective disease management. In this experiment, we observed the Malformation Syndrome in Prunus salicina Lindl and used the internal transcribed spacer (ITS) to compare fungal diversity between malformed and healthy leaf buds. These results show a higher level of fungal diversity in diseased leaf buds. Alternaria, Curvibasidium, Symmetrospora, Fonsecazyma, and other genera among the identified fungi are suspected to induce the malformations. Potential contributors to these malformations include Endophyte-plant_Pathogen and Plant_pathogen-Undefined_saprotroph. These findings provide valuable insights for further research on the etiology of plum bud diseases, identifying potential pathogens, and formulating control strategies.

Deciphering the genetic mechanisms of chilling requirement for bud endodormancy release in deciduous fruit trees.

Bud endodormancy in deciduous fruit trees is an adaptive trait evolved by selection for the capacity to survive unfavorable environmental conditions. Deciduous trees require a certain amount of winter chill named chilling requirement (CR) to promote bud endodormancy release. In recent decades, global warming has endangered the chill accumulation in deciduous fruit trees. Developing low-CR cultivars is a practical way to neutralize the effect of climate changes on the cultivation and distribution of deciduous fruit trees. In this review, we focus on the effect of chilling accumulation on bud endodormancy release and the genetic mechanisms underlying the chilling requirement in deciduous fruit trees. Additionally, we put forth a regulatory model for bud endodormancy and provide prospective directions for future research in deciduous fruit trees.

Deciduous fruit trees and grapevines as alternative crops in Demathophora necatrix (syn. Rosellinia necatrix) infested soils

White root rot, caused by Dematophora necatrix (syn. Rosellinia necatrix), affects deciduous trees. A D. necatrix infection-distribution survey found widespread disease in apple and cherry orchards in northern Israel bordering a Mediterranean forest, although the forest trees were unaffected. Because cherry and apple orchards must be abandoned due to long fungal survival in infested soils, alternative deciduous fruit trees and grapevines were assessed for growth in these D. necatrix-infested orchards. In the field, grapevine rootstocks and the almond–peach rootstock GF-677 were most tolerant to D. necatrix-infested soil. Apple was the most sensitive crop, with the rootstock Hashabi being more tolerant than PI80 or MM104. The Mediterranean forest tree Pistacia atlantica, which can serve as a rootstock for pistachio, was as sensitive as kiwifruit and apple, and persimmon rootstock sensitivity was not different from grapevine. Those results show that beside the above mentioned crops, vineyards can also replace apple orchards in D. necatrix-infested soils and so broadens the list of possible crops for the local farmers in a Mediterranean climate at altitudes above 440 m above sea level. This has also been observed in a commercial 10-year-old vineyard of ‘Shiraz’ grapevines grafted on SO4 rootstock. The almond-peach rootstock GF-677 can also be grown in infested soil, but in commercial orchards requires additional treatment for adequate disease control.

Crop type classification, trends, and patterns of central California agricultural fields from 2005 to 2020

AbstractCalifornia produces many key agricultural products in the United States. Current geospatial agricultural datasets are limited in mapping accuracy, spatial context, or observation period. This study uses machine learning and high‐resolution imagery to produce a time series of crop maps to assess crop type trends and patterns across central California from 2005 to 2020. National Agriculture Imagery Program and Landsat imagery were used to classify nine crop types that are common in the study region: grain crops, field crops, rice, citrus and subtropical, deciduous fruit and nut, vineyard, berry and vegetable, pasture, and fallow/young perennial crop types. To create labeled data, we sampled 1253 fields and manually identified crop types for each examined year using high‐resolution imagery and Landsat normalized difference vegetation index time series. We applied a random forest machine learning algorithm in Google Earth Engine. Results show that the mean overall classification accuracy of the nine‐class map was 93.1%, with individual accuracies ranging from 99.3% (rice) to 89.5% (fallow/young perennial). Mann–Kendall trend tests showed significant (p < 0.05) declines in field crop and pasture area during the study period, while deciduous fruit and nut, citrus and subtropical, and fallow/young perennial crop types experienced significant increases. At an aggregate level, there was a general shift from annual crop types to perennial crop types. These data provide a 16‐year time span of spatially explicit crop type classifications, trends, and patterns in central California that can be used to aid managers and decision makers for resource planning or hazard mitigation.

Prediction of potential suitable distribution for sweet cherry (Prunus avium) based on the MaxEnt model.

The sweet cherry (Prunus avium) is among deciduous fruit trees with high economic value and its planting area is gradually expanding. However, little was known about its accurately suitable area in China. Herein, the potential distributions were modeled based on the MaxEnt model under the current conditions. Its performance was excellent, with AUCs >0.9 for model training and testing. The key environmental factors were the thermal factors (minimum temperature of the coldest month (bio06) from -14.5 to 4.5°C, the mean temperature of the warmest quarter (bio10) from 21.0 to 28.0°C), followed by the water factor (the annual precipitation (bio12) from 500 to 1200 mm), indicating that it is not resistant to cold and heat, nor is it resistant to drought or floods. The suitable area in China mainly is found in seven geographical regions including southwest China (eastern Sichuan, northeast and main urban areas of Chongqing, mid-western Guizhou and mid-northern Yunnan), northwest China (mid-southern Shaanxi, southern Ningxia mid-southern and eastern Gansu), northeast China (Coastal region of Liaoning), central China (most of Henan, mid-northern Hubei and central Hunan), north China (Beijing, Tianjing, mid-southern Shanxi), east China (Shanghai, Jiangsu, Shandong, central Zhejiang, central and northern Anhui and eastern Jiangxi) and south China (western Guangxi). Based on statistical analysis, these fourteen provinces or cities, namely, Shaanxi, Beijing, Tianjing, Shanxi, Hebei, Henan, Shanghai, Jiangsu, Shandong, Sichuan, Guizhou, Yunnan, Liaoning and Hubei were the main regions for current development and utilization while for the twelve provinces with higher moderate suitable areas, namely, Chongqing, Guizhou, Yunnan, Shaanxi, Ningxia, Liaoning, Hubei, Hunan, Zhejiang, Anhui, Jiangxi and Guangxi, we should supplement the appropriate irrigation and winter insulation facilities etc. Additionally, Hubei, Hunan, Anhui, also have been identified to have some potentially suitable areas. These information will help avoid the loss of human labor, material, and financial resources and provide a scientific basis for its current introduction, cultivation, and management.

Effect of organic fertilizer and amino acids on the vegetative growth of young pomegranate trees Punica granatum L. c.v. “Wonderful”

The experiment was conducted on a pomegranate field located in a deciduous fruit orchard at the Agricultural Research and Experimentation Station, which is associated with the College of Agriculture at the University of Kirkuk in the Republic of Iraq. The experiment took place during the 2023 season. The study incorporated 2 variables. The experiment consisted of 2 factors: the first factor included 5 levels of organic fertilization (0, 250 and 500 g tree-1 of residue poultry and 15 and 30 g tree-1 of humic acid) and the second factor involved spraying with 3 concentrations of amino acids (0-, 5- and 10- mL L-1). The experimental design used was a Randomized Complete Block Design (RCBD) within factorial experiments, with 2 factors and 3 replicates. The study involved a total of 90 young pomegranate trees, with 2 trees assigned to each experimental unit. The data were analyzed using Duncan's multinomial test at a significance level of 0.05. Applying 500 g of chicken waste per tree resulted in a notable enhancement in vegetative development, namely in stem length. The leaf area and dry weight of the leaves were measured at 6.45 cm2 and 54.67 % respectively. The level of 30 g tree-1 of humic acid resulted in a significant increase in the stem diameter, branch length and branch diameter, which was recorded at 23.16 mm, 39.98 cm and 6.30 mm respectively, compared to the control treatment. The application of a 10 mL L-1 concentration of amino acids led to a notable enhancement in the observed traits (stem length and branches, their diameters, leaf area and dry weight of leaves) in comparison to the control treatment. The mutual influence of organic fertilizer and spraying with amino acids resulted in a noticeable and statistically significant effect. This effect was particularly evident when using a level of 500 g tree-1 of chicken waste for fertilization and a concentration of 10 mL L-1 of amino acids for spraying, as it positively impacted most parameters.

Bacterial Community Composition and Functions In Rhizosphere Soil of Four Deciduous Fruit Trees

The purpose of this study was to explore the composition of bacterial communities in the rhizosphere soil of four deciduous fruit trees (pomegranate, peach, cherry, and ginkgo) and to study the bacterial community structure and metabolic function of them. 16S rRNA sequencing technology was adopted to analyze the bacterial community structure, and Tax4Fun was employed to predict the metabolic profiles of the bacterial community. The results showed that the Shannon index, Ace index, and Chao1 index values of the ginkgo rhizosphere soil samples were the largest, indicating that the bacterial diversity of ginkgo rhizosphere soil is the highest. 4764 OTUs were identified for bacteria and were classified as 46 phylums, 113 classes, 175 orders, 247 families, 339 genera, and 504 species. Whether at the phylum level, at the order level, or at the genus level, no significant differences in the composition of bacterial communities were detected among the rhizosphere soils of the four deciduous fruit trees. Proteobacteria, Actinobacteria, Bacteroidota, and Acidobacteriota were the most abundant phyla, and Gammaproteobacteria, Bacteroidota, Alphaproteobacteria, and Alphaproteobacteria were the most abundant orders across all samples. The KOs (KEGG orthology) were mainly involved in 6 KEGG level 1 pathways and 35 KEGG level 2 pathways. The relative abundance of these six pathways was not significantly different in rhizosphere soils among the four deciduous fruit trees at the first KEGG level. The main enrichment pathways of microorganism metabolism at the second KEGG level are consistent, mainly in carbohydrate metabolism, amino acid metabolism, energy metabolism, lipid metabolism, nucleotide metabolism, and the metabolism of cofactors and vitamins. Bangladesh J. Bot. 53(2): 287-295, 2024 (June)

How to Build a Blackberry Trellis System: A Complete Guide

Blackberry (Rubus spp.) is a deciduous fruit crop. The fruit are usually small, round, and dark purple to black. Blackberry fruit is comprised of multiple drupelets that cluster together to form a berry, which has a glossy appearance when matured. Blackberries have a complex flavor profile that blends sweetness and acidity, and taste may vary depending on the variety and maturity stage. They are rich in nutrients, vitamins, minerals, and antioxidants. Blackberries are best grown in sub-tropical to temperate climates. Blackberry is a new emerging fruit crop in Florida, where they are harvested in May-June. There are several varieties, some of which are native to Florida. This publication aims to provide a general overview of the importance of trellis, different types of trellis, and their installation in blackberry production for county and state Extension faculty, growers, homeowners, and students interested in growing blackberries in Florida.

Early impact assessment of the paninvasive polyphagous shot hole borer beetle on commercial pear production

AbstractThe polyphagous shot hole borer (PSHB) beetle, Euwallacea fornicatus (Eichhoff) (Coleoptera: Curculionidae, Scolytinae), and its phytopathogenic fungal symbiont (Fusarium euwallaceae Freeman et al.) threaten commercial and urban tree species worldwide. This pest–fungus complex has been newly discovered in the commercial deciduous fruit industry (Western Cape, South Africa), where its effect is still unknown. This study explored the impact of PSHB infestation on fruit quality and plant water‐use efficiency (WUE) – as indicated by carbon and nitrogen stable isotope ratios – of commercially cultivated Packham's Triumph pear trees within the first year of invasion, as well as changes in phenotypic plasticity (trait expression range). The impact of PSHB infestation is currently most evident in fruit quality traits, with a clear distinction between the control and most densely attacked tree categories. Fruit and leaf traits showed high variation and a significant change in phenotypic plasticity. Increased PSHB attack density was associated with smaller, duller‐toned, sweeter fruit at the time of harvest and data tended towards reduced plant WUE. Producers can expect significant variation in fruit quality and plant WUE even in hosts without branch dieback, visible plant stress or extensive beetle breeding, especially in orchards where infestations persist beyond the first year. These findings necessitate additional research to describe the long‐term impact, examine the threat to other deciduous fruit crops and cultivars and assess the need for adapted management or harvesting methods.

Using eDNA to play whack-a-mole with invasive species in green yard waste.

As large cities begin to overrun their landfill capacities, they begin to look for alternative locations to handle the waste stream. Seeing an opportunity to bring in revenue, rural communities offer to handle municipal waste in their landfills. However, many rural communities are also places of agricultural production, which are vulnerable to attacks by invasive insect species, which could be present in green yard waste, the component of municipal waste most likely to contain agriculturally harmful insect species. We used environmental DNA (eDNA) to determine whether green yard waste could be a pathway for invasive insect species to enter and establish in the landfill-receiving agricultural community. We identified several target species that could be in green yard waste coming from Vancouver, BC, Canada, to Central Washington State, USA. We sampled green yard waste from 3 sites every 2 weeks from June to October in 2019 and 2020. DNA was extracted from the nearly 400 samples and subjected to amplification with COI barcoding primers followed by sequencing to identify target insects in the samples. Sequence analyses identified 3 species from the target list: 2 species that are pests of deciduous tree fruits and a generalist root-feeding crop pest. This eDNA technique was useful in identifying potential invasive species in green yard waste and may prove to be an important tool informing policy on the movement of biological material across borders and stemming the spread of invasive species.

Genetic and molecular regulation of chilling requirements in pear: breeding for climate change resilience.

Pear (Pyrus spp.) is a deciduous fruit tree that requires exposure to sufficient chilling hours during the winter to establish dormancy, followed by favorable heat conditions during the spring for normal vegetative and floral budbreak. In contrast to most temperate woody species, apples and pears of the Rosaceae family are insensitive to photoperiod, and low temperature is the major factor that induces growth cessation and dormancy. Most European pear (Pyrus Communis L.) cultivars need to be grown in regions with high chilling unit (CU) accumulation to ensure early vegetative budbreak. Adequate vegetative budbreak time will ensure suitable metabolite accumulation, such as sugars, to support fruit set and vegetative development, providing the necessary metabolites for optimal fruit set and development. Many regions that were suitable for pear production suffer from a reduction in CU accumulation. According to climate prediction models, many temperate regions currently suitable for pear cultivation will experience a similar accumulation of CUs as observed in Mediterranean regions. Consequently, the Mediterranean region can serve as a suitable location for conducting pear breeding trials aimed at developing cultivars that will thrive in temperate regions in the decades to come. Due to recent climatic changes, bud dormancy attracts more attention, and several studies have been carried out aiming to discover the genetic and physiological factors associated with dormancy in deciduous fruit trees, including pears, along with their related biosynthetic pathways. In this review, current knowledge of the genetic mechanisms associated with bud dormancy in European pear and other Pyrus species is summarized, along with metabolites and physiological factors affecting dormancy establishment and release and chilling requirement determination. The genetic and physiological insights gained into the factors regulating pear dormancy phase transition and determining chilling requirements can accelerate the development of new pear cultivars better suited to both current and predicted future climatic conditions.

Mineral elements in peach cultivars from Beijing, China: Profiling and health risk assessment

Peach fruits, recognized as one of the primary deciduous fruit trees grown globally, are renowned for their abundant mineral nutrients. This study delves into the comprehensive analysis of mineral elements in 20 distinct peach cultivars, including 12 nutrients (NEs), 6 toxic elements (TEs), and 16 rare earth elements (REEs). Inductively coupled plasma-mass spectrometry was utilized. The average contents of 12 NEs ranked as follows: K > Mg > Ca > B > Fe > Na > Zn > Cu > Mn > Sr > Mo > Se. TEs were identified as potential health hazards, particularly for children, with arsenic emerging as the primary source of dietary risk across diverse populations. Moreover, the presence of 16 REEs was noted across most peach cultivars, with cerium being the most abundant. Principal component analysis revealed seven principal components, contributing to a cumulative variance of 87.4 %. Cluster analysis was used to categorize the 20 peach cultivars into four groups. Excepting the 4th group, the remaining three groups exhibited the highest values for 22, 9, and 3 elements, respectively. These results contribute to a foundational understanding for the nutritional assessment of peaches and their cultivar breeding strategies.

EuAP2a, a key gene that regulates flowering time in peach (Prunus persica) by modulating Thermo-responsive transcription programming

Abstract Frequent spring frost damage threatens temperate fruit production, and the breeding of late-flowering cultivars is an effective strategy for preventing such damage, but the lack of specific genes and markers and a lack of understanding of the mechanisms make it difficult. We examined a Late-Flowering Peach (LFP) germplasm and found that its floral buds require a longer chilling period to release from their dormancy and a longer warming period to bloom than the control cultivar, two key characteristics associated with flowering time. We discovered that a 983-bp deletion in euAP2a, an APETALA2 (AP2)-related gene with known roles in regulating floral organ identity and flowering time, was primarily responsible for late flowering in LFP. This deletion disrupts an miR172 binding site, resulting in a gain-of-function mutation in euAP2a. Transcriptomic analyses revealed that at different stages of floral development, two chilling-responsive modules and four warm-responsive modules, comprising approximately 600 genes, were sequentially activated, forming a unique transcription programming. Furthermore, we found that euAP2a was transiently downregulated during the activation of these thermal-responsive modules at various stages. However, the loss of such transient, stage-specific downregulation of euAP2a caused by the deletion of miR172 binding sites resulted in the deactivation or delay of these modules in the LFP flower buds, suggesting that euAP2a acts as a transcription repressor to control floral developmental pace in peaches by modulating the thermo-responsive transcription programming. The findings shed light on the mechanisms behind late flowering in deciduous fruit trees, which is instrumental for breeding frost-tolerant cultivars.

First Report of Botryosphaeria dothidea Causing Postharvest Fruit Rot of Plum in China.

The Nai plum (Prunus salicina var. cordata cv. Younai) holds significance as an important deciduous fruit crop in China. In July 2023, symptoms of postharvest fruit rot were observed on Nai plum with a 10% disease incidence of harvested fruits in three supermarkets, located in Nanchang City, Jiangxi Province, China. Infected fruits displayed brown, circular lesions, accompanied by a transition in the surrounding peel color from cyan to red. To investigate the causal agent, small sections (3 to 4 mm2) from the periphery of ten infected fruits were subjected to surface sterilization using 75% ethanol for 30 seconds. Following sterilization, the samples were rinsed three times with sterilized distilled water, air-dried, and aseptically placed on potato dextrose agar (PDA) at 25 ℃ for 3 days. Isolated colonies were subcultured by hyphal tiptransfer. Ten of the resulting 12 fungal isolates showed similar morphological characteristics. The colonies exhibited an initial white hue, gradually transitioning to gray, and featured short and thick aerial hyphae with an irregular colony margin. Microscopic examination revealed conidiogenous cells that were hyaline, aseptate, and narrowly fusiform. The conidia were measured 11.0 to 15.6 × 3.2 to 4.9 µm (x̅ = 13.5 ± 1.4 × 4.0 ± 0.4 µm, n = 30), and were hyaline and subcylindrical. The morphological characteristics were in accordance with those of the Botryosphaeria species (Crous et al. 2006). To identify the strain, two representative isolates, JFRL03-1792 and JFRL03-1793, were selected for further characterization. Amplification of nucleotide sequences from three regions (ITS, TEF1-a and TUB2) was conducted using the primer sets ITS5/ITS4, EF1-728F/EF1-986R, and BT2A/BT2B, respectively (Guo et al. 2023). The resulting sequences were deposited in GenBank under the accession numbers: OR418373 and OR418374 for ITS; OR424405 and OR424405 for TEF1-a; OR424411 and OR424412 for TUB2. A BLASTN homology search of the obtained sequences revealed a high similarity of 99%-100% to the ITS (AY236949, 511/513 nucleotides), TEF1-a (AY236898, 282/282 nucleotides), and TUB2 (AY236927, 431/431 nucleotides) sequences of Botryosphaeria dothidea CWM8000 (ex-type). Maximum likelihood analyses were performed for the combined ITS, TEF1-a, and TUB2 dataset using Phylosuite V1.2.2 (Zhang et al. 2020). The resulting phylogenetic tree indicated that the two representative isolates were clustered together with Botryosphaeria dothidea in a clade with 95% bootstrap support. Based on the comprehensive assessment of morphological and molecular data, the two isolates were conclusively identified as B. dothidea. To confirm pathogenicity, six healthy Nai plum fruits were surface sterilized with 75% ethanol and were subsequently wounded with a sterile needle. A 5-mm-diameter mycelial plug of the isolate JFRL03-1792, cultured on PDA at 25 ℃ for three days, was applied to the wound. Another set of six fruits was inoculated with sterile agar plugs as control. Following incubation in a climatic chamber at 25 ℃ and 80% relative humidity, the fruits were examined after 5 days. The experiment was repeated twice. The fruits inoculated with B. dothidea displayed typical rot symptoms, while the control fruits remained asymptomatic. In adherence to Koch's postulates, the fungus was successfully re-isolated from the inoculated fruits and confirmed as B. dothidea through morphological and molecular analysis. B. dothidea has previously been reported causing fruit rot on kiwifruit, winter jujube, and apple (Tang et al. 2012; Zhou et al. 2015; Marsberg et al. 2017; Xu et al. 2023). In addition, B. dothidea also reported causing Botryosphaeria canker disease on plum (Lin et al. 1994). But to our knowledge, this is the first documentation of B. dothidea causing postharvest fruit rot on plum in China. This discovery imparts critical insights into the management of this high-risk disease affecting plum in China.

Comparing apples and pears: Linking capitals and capacities to assess the resilience of commercial farming operations

CONTEXTAs the concept of social-ecological resilience gains increasing policy attention, there is growing demand for approaches that operationalise it. Amongst these demands is the need to empirically assess absorptive, adaptive and transformative capacities that underpin resilience to better understand the ways in which social-ecological systems can navigate change and uncertainty. OBJECTIVEWe explore the application of a capitals approach for assessing resilience capacities, using an example of deciduous fruit farming operations in the Western Cape region of South Africa. METHODSSemi-structured interviews were conducted, thematically coded, and analysed using causal loop diagrams and co-occurrence analyses to identify changes experienced by farming operations, their responses to these changes, and the effects of both on capital resources. We then apply the criteria developed for the classification of resilience capacities. RESULTS AND CONCLUSIONSA variety of changes affect farming operations at multiple points across the value chain, and have effects across capital resources. Most significant to farmers are changes which impact the amount of water available and the cashflow they require to sustain their operations. The most common responses employed by farmers consisted of activities which either increase the availability of an affected resource, or decrease its demand in order to maintain the same functions (adaptive capacity). In fewer cases, farming operations were able to absorb the depletion of their capital resources due to pre-emptive management (absorptive capacity). In similarly few cases, the potential or realised resource deficiencies caused by changes were either corrected or decoupled from the farming operation through structural reorganisation towards a different or additional function and types of output being delivered (transformative capacity). Evidence of changes being anticipated prior to their onset were also identified, leading to responses which are used in conjunction with the preceding three capacities. SIGNIFICANCEOur findings suggest that the criteria we developed for classifying resilience capacities offer a useful means of operationalising resilience. In particular, the approach we pilot in this paper enables the application of a systems perspective to identify interactions between changes and responses, which broadens the options for identifying management strategies and interventions. The approach we propose can be used to identify key leverage points to strengthen the capacities of vulnerable farmers. Further work is required to integrate consideration of cross-scale effects of farm-scale resilience strategies on the broader social-ecological system.

Haplotype-resolved T2T reference genomes for wild and domesticated accessions shed new insights into the domestication of jujube

Abstract Chinese jujube (Ziziphus jujuba Mill.) is one of the most important deciduous tree fruits in China, with substantial economic and nutritional value. Jujube was domesticated from its wild progenitor, wild jujube (Z. jujuba var. spinosa), and both have high medicinal value. Here we report the 767.81- and 759.24-Mb haplotype-resolved assemblies of a dry-eating ‘Junzao’ jujube (JZ) and a wild jujube accession (SZ), using a combination of multiple sequencing strategies. Each assembly yielded two complete haplotype-resolved genomes at the telomere-to-telomere (T2T) level, and ~81.60 and 69.07 Mb of structural variations were found between the two haplotypes within JZ and SZ, respectively. Comparative genomic analysis revealed a large inversion on each of chromosomes 3 and 4 between JZ and SZ, and numerous genes were affected by structural variations, some of which were associated with starch and sucrose metabolism. A large-scale population analysis of 672 accessions revealed that wild jujube originated from the lower reaches of the Yellow River and was initially domesticated at local sites. It spread widely and was then independently domesticated at the Shanxi–Shaanxi Gorge of the middle Yellow River. In addition, we identified some new selection signals regions on genomes, which are involved in the tissue development, pollination, and other aspects of jujube tree morphology and fertilization domestication. In conclusion, our study provides high-quality reference genomes of jujube and wild jujube and new insights into the domestication history of jujube.

New data on an old pest complex: The status of Phlyctinus callosus Schönherr and Phlyctinus xerophilus Haran (Coleoptera: Curculionidae) in South Africa

Phlyctinus is an endemic weevil genus of the Cape Floristic Region that comprises eight to ten species, previously classified under the monotypic P. callosus sensu lato concept. Two species of this genus, Phlyctinus callosus and P. xerophilus, are of economic concern to the deciduous fruit and grapevine industry in the Western Cape province of South Africa, causing primary damages and being of phytosanitary concern at the adult stage. The taxonomic revision conducted in 2020 raised doubts whether one of the two species was a newly emerging pest and/or what species was considered in studies before the clarification of species boundaries. Also unclear is whether these species can be controlled similarly using current control measures. The aim of this study therefore is to review the pest status of the two species over time based on museum records, field collections and historical publications, and to clarify how control measure(s) are impacted. We infer that neither species appear to be emerging pests in the region, both being of agricultural significance for at least 80 years. Phlyctinus callosus is mostly distributed along the southern coast, while P. xerophilus is distributed in inland valleys. The two species show similar biology, physiology and ecology in agro-ecosystems, and can be excluded from the host plant canopy using stem-barriers, adults being flightless. As such, it is shown that the naming of P. xerophilus as a pest is mainly a taxonomical clarification within a pre-existing species complex.

Allelic variation of PmCBF03 contributes to the altitude and temperature adaptability in Japanese apricot (Prunus mume Sieb. et Zucc.).

Japanese apricot is an important subtropical deciduous fruit tree in China, widely distributed in different altitude areas. How does it adapt to the different temperature environments in these areas? In this study, we identified a low-temperature transcription factor PmCBF03 on chromosome 7 through adaptive analysis of populations at different altitudes, which has an early termination single nucleotide polymorphism mutation. There were two different types of variation, PmCBF03A type in high-altitude areas and PmCBF03T type in low-altitude areas. PmCBF03A gene increased the survival rate, Fv/Fm values, antioxidant enzyme activity, and expression levels of antioxidant enzyme genes, and reducing electrolyte leakage and accumulation of reactive oxygen species in transgenic Arabidopsis under low temperature and freezing stress. Simultaneously, PmCBF03A gene promoted the dormancy of transgenic Arabidopsis seeds than wild-type. Biochemical analysis demonstrated that PmCBF03A directly bound to the DRE/CRT element in the promoters of the PmCOR413, PmDAM6 and PmABI5 genes, promoting their transcription and enhanced the cold resistance and dormancy of the overexpressing PmCBF03A lines. While PmCBF03T gene is unable to bind to the promoters of PmDAM6 and PmABI5 genes, leading to early release of dormancy to adapt to the problem of insufficient chilling requirement in low-altitude areas.

High-quality production of red plum apricot in semiarid Loess Hilly region of China

Red plum apricot is a deciduous fruit tree and the best cash forest in semi-arid Loess hilly regions of China. Since 1995, the distribution area of the apricot has spread in most of the water-limited regions, in China, and the yield and benefits of red plum apricot increase dramatically. Since 2017, China put forward high-quality development, and red plum apricot must carry out high-quality production. But, as the red plum apricot tree grows, low temperatures and frost, hazards of heart-eating insects and soil drying will appear, which seriously influence the yield, quality, and benefits of red plum apricot in turn. However, there are few reports on the method for High-quality production of red plum apricot. In this study, the effectiveness of different methods of controlling low temperature and frost and hazards of heart-eating insects and soil drying was estimated. The results show that the greenhouse method is the better method for controlling Low temperature and frost, spraying Beta-cypermethrin still is the better method for controlling Hazards of heart-eating insects. When the soil water resource in the maximal infiltration depth is lower than the soil water resource use limitation by red plum apricot, the plant water relationship enters the key period of plant water relationship regulation. The ending time of the critical period of plant water relation regulation is the failure time of plant water relation regulation. When the current plant density is more than the soil water vegetation carrying capacity, the plant-water relation should be regulated, and then the vegetative growth and reproductive growth on the appropriate leaf quantity when the current plant density is equal to the soil water vegetation carrying capacity and the leaf fruit relation.

Steinernema yirgalemense (Steinernematidae) to control Phlyctinus callosus and Phlyctinus xerophilus (Curculionidae)

Summary Considerable progress has been made in the surveying, taxonomy, screening, mass production and formulation of entomopathogenic nematodes (EPN) and their associated symbiotic bacteria in South Africa. Steinernema yirgalemense isolate 157-C is one of the most promising native EPN candidates with regards to virulence, its broad insect-host spectrum, and can be readily mass-produced and formulated into a commercial product. The banded fruit weevils, Phlyctinus callosus sensu stricto and Phlyctinus xerophilus, previously grouped together under the Phlyctinus callosus sensu lato species concept, are native entimine weevils of economic importance to deciduous fruit, grapevine and berries in the Western Cape province of South Africa. This study investigated potential differences in baseline susceptibility of larvae and pupae of the two weevil species to S. yirgalemense in laboratory screenings. The test arena used was 24-well bioassay plates, with an inoculation concentration of 200 infective juveniles (IJ) insect−1 for larvae and 100 IJ insect−1 for pupae. Infection was determined 48 h and 96 h after inoculation. Field-efficacy of S. yirgalemense, applied at a concentration of 60 IJ cm−2, against larvae of the two weevil species was determined in an ecologically relevant semi-field trial. In all cases in vitro mass-produced IJ of S. yirgalemense were used. No baseline differential susceptibility between P. callosus and P. xerophilus larvae was obtained in laboratory screenings. Phlyctinus pupae were approximately twice as susceptible compared to larvae, with significant differences between bioassay batches. Approximately 45% control of P. xerophilus larvae was obtained after 96 h of exposure to S. yirgalemense in the field, differing significantly from the control and P. callosus treatment. Low levels of Phlyctinus larval infection by native EPN (confirmed as Heterorhabditis bacteriophora from one P. xerophilus cadaver) occurred in both control and EPN treatment groups under field conditions.