Chestnut Cultivars Research Articles

Comparative Analysis of Photosynthetic Traits, Yield, and Fruit Quality Among Different Chestnut Cultivars

This study aimed to compare the photosynthetic physiological traits, fruiting characteristics, and fruit quality of four different chestnut cultivars. The cultivars studied were ‘Yanshanzaofeng’ (YS), ‘Guangdedahongpao’ (GD), ‘Chang’anhuijianli’ (CA), and ‘Guizhouyouli’ (GZ). Leaf functional traits, photosynthetic activity, fruit setting characteristics, and both external and internal fruit quality indicators were measured. The results indicated significant differences in leaf traits among cultivars. Cultivar GD exhibited the largest leaf area and dry matter content, while cultivar GZ had the smallest. The photosynthetic rate (Pn) followed a bimodal curve, with an obvious ‘lunch break’ caused by stomatal limitations. Cultivar GD had the highest Pn, followed by CA, YS, and GZ. The water use efficiency (WUE) and CO2 utilization of cultivar CA were notably superior, indicating its suitability for arid conditions. In terms of yield, cultivar GD had the highest bur, nut weight, and plant yield, followed by CA, YS, and GZ. The phenotypic quality of the fruit was also superior in cultivar GD. However, cultivar YS had the highest amylopectin and soluble sugar content, and cultivar GD had the greatest amylose, total starch, and fat content. Cultivars CA and YS exhibited better overall fruit quality than GZ. Correlation analysis revealed that single bur weight, single nut weight, and single plant yield all exhibited highly significant or significant positive correlations with Pn, stomatal conductance (Gs), intercellular CO2 concentration (Ci), and the transpiration rate (Tr). The longitudinal diameter of burs showed a significant positive correlation with vitamin C (Vc), Pn, and Gs, with a correlation coefficient of 0.99. Additionally, both the transverse and longitudinal diameters of nuts were significantly positively associated with Pn and Ci. Furthermore, the total starch content and water content of nuts demonstrated a significant positive correlation with Pn. In conclusion, cultivar GD was found to be ideal for high-yield starch production, while cultivar YS offers superior sweet and waxy nut qualities. Cultivar CA presents a balance of photosynthetic capacity, yield, and quality, making it the second-best candidate. Cultivar GZ is unsuitable for large-scale cultivation.

Variations on the chemical compositions of chestnut fruits collected at different locations

Chestnut is an essential food source in many countries. Nutritional quality and potential health benefits of Anatolian chestnut trees (Castanea sativa Mill.) have led to increased concern and interest in chestnut production. However, knowledge of the factors that influence the chemical content of chestnut fruits still needs to be improved. Thus, the chemical compositions were evaluated for Anatolian chestnut fruits collected at 14 different locations in northern Türkiye, which is one of the biggest chestnut producers in the world. The effects of latitude, longitude, altitude, aspect, mean annual temperature (°C) (TMA), and mean annual precipitation (mm) (PMA) of the study locations on the chemical compositions of chestnut fruits were monitored. The effects of these parameters on several chestnut characteristics were examined using a mixed-effects multiple regression model. Latitude, longitude, TMA, and PMA were correlated with the mean concentrations of sucrose, free amino acid, glycine betaine, nitrogen (N) (%), and total carbon (C) (%) of the chestnut samples. The moisture content of the fruits was affected by longitude. The antioxidant and mineral content of the chestnut samples also varied by location. These findings may be helpful in site selection, production, and conservation of chestnut cultivars.

Genetic differences in susceptibility of Japanese chestnut cultivars to infestation by chestnut weevil (Cuculio sikkimensis)

Genetic differences in susceptibility of Japanese chestnut cultivars to infestation by chestnut weevil (Cuculio sikkimensis)

Protocols for the micropropagation of several chestnut cultivars

Protocols for the micropropagation of several chestnut cultivars

Predicting the behavior of chestnut cultivars grafted on ColUTAD under different edaphoclimatic conditions

Predicting the behavior of chestnut cultivars grafted on ColUTAD under different edaphoclimatic conditions

Gall wasp susceptibility of chestnut cultivars in an organic South Carolina orchard

Gall wasp susceptibility of chestnut cultivars in an organic South Carolina orchard

Hot Water Treatment Preserves Chinese Chestnut (Castanea mollissima Blume) Quality during Storage by Increasing Its Sugar Accumulation and ROS-Scavenging Ability

Heat treatment is a widely used physical technology for postharvest fruit and crops. The Chinese chestnut cultivar “Kuili” has high sugar and amylose contents, and is popular among people. However, the chestnut quality decreases quickly after harvest. In order to maintain the chestnuts’ quality during storage, this study explores five hot water treatments for chestnuts: T1 (control, no treatment), T2 (50 °C), T3 (65 °C), T4 (75 °C), and T5 (90 °C) for 45 min. T1 was dried at ambient temperature, while the other heat treatments were dried at 30 °C for 30 min. After treatment, chestnuts were placed in plastic trays, covered with a 15 μm thick PVC film, and stored at 4 °C with 70% relative humidity; they remained in the same air for 120 days. Results indicated that T3 and T4 showed slight color changes while maintaining shell and kernel firmness, and their weight loss was reduced (+5–8%), as well as their decay rate (limited to within 20%). The T3, T4, and T5 treatments (from days 60 to 120) decreased their pest survival rates to <2%. Additionally, heat treatments facilitated the accumulation of total soluble sugar and increased the expression of sugar biosynthesis-related genes. Meanwhile, T3 and T4 delayed starch reduction (they maintained relatively higher contents, from 288 to ~320 mg g−1 DW) and altered some starch biosynthesis genes. Furthermore, T2, T3, and T4 exhibited higher antioxidant activity and lower hydrogen peroxide (H2O2) and superoxide anions (O2−) contents than T1. At the end of storage, the scores of T3 and T4 treatments were 55.1 and 52.3, and they ranked first and second among the five treatments, respectively. Therefore, these findings provide valuable insights for controlling postharvest losses in chestnuts.

Identifying the sensory profile and fatty acid composition for quality valorization of Marrone chestnut cultivars

Identifying the sensory profile and fatty acid composition for quality valorization of Marrone chestnut cultivars

Insights into multiscale structure and digestive characteristic of starch from two cultivars of chestnut during kernel development

Multiscale structure and digestive characteristic of starch during kernel development of Castanea henryi (‘Jinzhui’ (YS) and ‘Baiyan No.1’ (WS)) were investigated in this study. Structural analysis revealed that the surface of starch granules became smooth, the amylopectin content decreased (from 71.32 % to 70.47 %, from 71.44 % to 68.37 %, respectively), the chain length distribution of amylopectin reduced (the proportion of B1 chain decreased from 52.35 % to 50.60 %, from 52.22 % to 50.59 %, respectively) while the amorphous and semi-crystalline lamellae of starch increased during development, which was consistent with the decreasing relative crystallinity (from 28.79 % to 24.11 %, from 29.57 % to 23.66 %, respectively) and short-range ordering degree. The degradation of ordered structure further resulted in the increase of digestibility, especially in the late developmental stage, supported by a significant decrease of resistant starch content (from 70.21 % to 61.70 % and from 73.58 % to 58.86 %, respectively). Transcriptome analysis and RT-qPCR were performed to explore the possible molecular mechanisms affecting starch structure. The high expression of several key genes including AGPase, GBSS, SBE, SSS, ISA and PUL in late development stage might be the reason of structural changes during development. The results provided valuable information for starch accumulation during kernel development of Castanea henryi.

Classification of hybrid chestnut cultivars (Castanea sativa) registered in Türkiye with artificial neural networks, based on some physical properties of their nuts

Classification of hybrid chestnut cultivars (Castanea sativa) registered in Türkiye with artificial neural networks, based on some physical properties of their nuts

Better selection of chestnut cultivars: experimenting the sensory characterization of the Marrone chestnuts compared to the “Chataigne” chestnuts

Better selection of chestnut cultivars: experimenting the sensory characterization of the Marrone chestnuts compared to the “Chataigne” chestnuts

GWAS identifies two important genes involved in Chinese chestnut weight and leaf length regulation.

There are many factors that affect the yield of Chinese chestnut (Castanea mollissima), with single nut weight (SNW) being one of the most important. Leaf length is also related to Chinese chestnut yield. However, the genetic architecture and gene function associated with Chinese chestnut nut yield have not been fully explored. In this study, we performed genotyping by sequencing 151 Chinese chestnut cultivars, followed by a genome-wide association study (GWAS) on six horticultural traits. First, we analyzed the phylogeny of the Chinese chestnut and found that the Chinese chestnut cultivars divided into two ecotypes, a northern and southern cultivar group. Differences between the cultivated populations were found in the pathways of plant growth and adaptation to the environment. In the selected regions, we also found interesting tandemly arrayed genes that may influence Chinese chestnut traits and environmental adaptability. To further investigate which horticultural traits were selected, we performed a GWAS using six horticultural traits from 151 cultivars. Forty-five loci that strongly associated with horticultural traits were identified, and six genes highly associated with these traits were screened. In addition, a candidate gene associated with SNW, APETALA2 (CmAP2), and another candidate gene associated with leaf length (LL), CRYPTOCHROME INTERACTING BASIC HELIX-LOOP-HELIX 1 (CmCIB1), were verified in Chinese chestnut and Arabidopsis (Arabidopsis thaliana). Our results showed that CmAP2 affected SNW by negatively regulating cell size. CmCIB1 regulated the elongation of new shoots and leaves by inducing cell elongation, potentially affecting photosynthesis. This study provided valuable information and insights for Chinese chestnut breeding research.

Tolerance evaluation and genetic relationship analysis among some economically important chestnut cultivars in Türkiye using drought-associated SSR and EST-SSR markers.

The aim of this study was to evaluate drought tolerance and genetic relationships among some important chestnut cultivars for Türkiye by using drought-related genomic simple sequence repeat (SSR) markers and genic expressed sequence tag-simple sequence repeat (EST-SSR) markers. Using five SSR markers, the average number of alleles (avNa), mean heterozygosity (Havp) and polymorphism information content (PIC) were determined to be 9.22, 0.395 and 0.375, respectively. In addition, using eight EST-SSR markers, the values of avNa, Havp and PIC were determined to be 7.75, 0.309 and 0.262, respectively. All microsatellite markers used in this study showed 100% polymorphism among chestnut cultivars. In UPGMA dendrograms obtained with both SSR and EST-SSR markers, the Erfelek and Hacıömer chestnut cultivars were determined to be the most similar cultivars. Some assessments are discussed regarding drought tolerance for specific alleles obtained from the EST-SSR markers GOT045, GOT021, GOT004, FIR094 and VIT033 in chestnut cultivars. Some preliminary results regarding drought tolerance in chestnut cultivars were obtained in our study with the help of these markers. Our study also characterized the genetic relationships among chestnut cultivars of great importance using drought-related character-specific markers.

Use of retrotransposon based iPBS markers for determination of genetic relationship among some Chestnut Cultivars (Castanea sativa Mill.) in Türkiye.

The aim of this study was to reveal the genetic relationships among some economically important chestnut cultivars for Türkiye by using retrotransposon-based inter primer binding site (iPBS) markers. In this study, a total of 19 iPBS markers were used to determine the genetic relationships among 11 chestnut cultivars (Castanea sativa Mill.). In the study, chestnut cultivars named Hacıömer, Osmanoğlu, Sarıaşlama, Erfelek, Kemer, Işıklar, Şekerci, Siyah Bursa, Tülü, Bouche De Betizac and Marigoule were the preferred cultivars utilised. Using the online marker efficiency calculator (iMEC), some indices of polymorphism, such as the mean heterozygosity, polymorphism information content, marker index and discriminating power, were determined. In addition, the size ranges of alleles, number of average alleles, number of total alleles, number of polymorphic alleles, and polymorphism rate were determined at a successful level. The chestnut cultivars of Hacıömer and Şekerci were determined to be the most similar cultivars with a similarity coefficient value of 0.924, and they formed a subgroup together with the chestnut cultivars Osmanoğlu and Erfelek, showing close similarity with these two cultivars. The use of iPBS markers in chestnuts in Türkiye was carried out for the first time in this study. The power of iPBS markers to evaluate the genetic relationship for our preferred chestnut cultivars was revealed. For this reason, it has emerged that it will be useful in the molecular characterization of both genotypes in natural chestnut populations and chestnut breeding materials such as varieties and cultivars in chestnut breeding programs.

Influence of the cooking system, chemical composition, and α-amylase activity on the sensory profile of chestnut cultivars - longal and judia - and their consequence on consumer's acceptability

The chestnut (Castanea sativa Mill) is a nut with single nutritional and sensory properties that play an essential role in human nutrition, especially in celiac patients, where it is highly recommended for that diet. This study aims to understand the influence of the chestnut cooking process, chemical composition, and tasters α-amylase activity on the sensory profile of Castanea sativa Mill chestnut cultivars. - Longal and Judia - and their consequence on consumer acceptance. The methodology focuses on enzymatic kits for measuring α-amylase enzyme activity, quantifying crude protein, starch, and crude fat by analytical methods, and evaluating consumer perception through sensory descriptive tests.After analysis of the chemical composition, it was possible to verify that chestnuts of both cultivars have a high starch concentration, influencing the taster's α-amylase activity, and at the same time, are low in sugar and fat. These characteristics make chestnuts a high-energy food. The results also showed chemical correlations between the amount of starch and soluble sugars and crude fat and protein content. In addition, the analysis of the CATA test (Check-All-That-Apply), applied to consumers, and a QDA test (Quantitative Descriptive Analysis), applied to a trained tasting panel, denoted that roasted Judia and Longal are chestnuts with sensory attributes highly appreciated. Moreover, the higher α-amylase activity detected when tasting chestnuts from the Judia cultivar may not necessarily result in a sweeter or more dissoluble chestnut.

Composition analysis of free and bound phenolics in chestnut rose (Rosa roxburghii Tratt.) fruit by UHPLC-IM-QTOF and UPLC-QQQ

Chestnut rose (Rosa roxburghii Tratt.) is an underutilized plant in the Rosaceae family that originates from southwest of China. This study used UHPLC-IM-QTOF and UPLC-QQQ to analyze the free and bound phenolic fractions in three cultivars of chestnut rose fruit from different producing areas. The optimization of IM feature acquisition was conducted firstly. Then, 23 phenolics were reported in chestnut rose fruit for the first time. Differential phenolics profiles were observed between cultivars and fractions, with 24 phenolics further quantified. Catechin, procyanidin B1, gallic acid, ellagic acid and isoquercitrin were the five most abundant phenolics. Most of the phenolics were more abundant in the free fraction than in the bound fraction. As many phenolics were reported with functions such as antioxidant, antidiabetic and anti-cancer, the chestnut rose fruit could serve as a healthy functional supplement foods in the form of juice, oral solution and powder, as well as an ingredient for functional foods.

Transcriptome analysis of differential sugar accumulation in the developing embryo of contrasting two Castanea mollissima cultivars.

Chinese chestnut (Castanea mollissima) is an important nut tree species, and its embryo is rich in sugar. We combined metabolomic and transcriptomic data to analyze metabolites and genes related to sugar in two Chinese chestnut cultivars at 60, 70, 80, 90 and 100 days after flowering (DAF). The soluble sugar content of high-sugar cultivar at maturity is 1.5 times that of low-sugar cultivar. Thirty sugar metabolites were identified in embryo, with the most dominant being sucrose. Analysis of the gene expression patterns revealed that the high-sugar cultivar promoted the conversion of starch to sucrose by up-regulating genes related to starch degradation and sucrose synthesis at 90-100 DAF. It also strongly increased the enzyme activity of SUS-synthetic, which may promote sucrose synthesis. Gene co-expression network analysis showed that ABA and peroxide were related to starch decomposition during Chinese chestnut ripening. Our study analyzed the composition and molecular synthesis mechanism of sugar in Chinese chestnut embryos, and provided a new insight into the regulation pattern of high sugar accumulation in Chinese chestnut nuts.

First Report of Chestnut Blight Caused by Cryphonectria parasitica on Chestnut (Castanea seguinii) in Gansu Province, China.

In China, chestnut blight usually causes insignificant damage to fruit production of Chinese chestnut (Castanea mollissima Blume) and no serious disease epidemics occur, due to the high resistance to Cryphonectria parasitica (Huang et al. 1998). According to recent surveys, chestnut blight was mainly found in sixteen provinces including Shandong, Hebei, Anhui, Hunan, Jiangxi, Beijing, and Fujian, with severe cases occurring occasionally (Guo et al. 2005). The disease incidence has been aggravated with increasing monoculture of newly improved chestnut cultivars in chestnut-producing areas (Yan et al. 2007), though it was not detected in Gansu Province. In September 2021, some chestnut trees (Castanea seguinii) showing symptoms of crown dieback and diffuse sunken cankers on the trunk with swelled margins and subsequent cracking of the outer bark, were collected in mountains of Hui County in Longnan City, Gansu Province (E 104° 15' 5.76″ ，N 35° 11' 30.84″). Symptomatic branches were washed using tap water and dried on sterilized tissue paper. The Junction between diseased and healthy tissue was cut from the bark and sterilized with NaClO (2.5 %) for 2 minutes, then plated on potato dextrose agar (PDA) and incubated at 25 ℃ for 3 to 4 days. After fungal colonies formed, mycelia were transferred and subcultured onto new PDA media and then purified using single spore culture. After 7 days, colonies turned yellow white. Uninucleate conidia were formed in orange pycnidia and the orange pigments could turn purple if in 2% KOH. Conidia were straight or slightly curved, hyaline, with 2.5-3.5 × 1.2-1.5 μm in size. The characteristics of the culture and morphology were similar with those of C. parasitica (Tziros et al. 2016). Perithecia were not found on culture medium. In accordance with previous findings, the sexual stage of C. parasitica appears on diseased trees in late October. For molecular identification, genomic DNA was extracted from mycelium using a Fungal Genomic DNA Extraction Kit (Tsingke Biotech Co. Ltd, Xi'an, China), the ITS region was amplified with primers ITS1/ITS4 (Sorrentino et al. 2019), and the TEF1-α region was amplified with primers TEF-1H/TEF-2T (O'Donnel et al. 1998). Cloning and sequencing of PCR products were carried out by Tsingke Biotech Co. Ltd, Xi'an, China. The resulting sequences were deposited in GenBank (ITS sequence accession number: OM033734, TEF sequence accession number: OM12254). BLAST results revealed that the sequences of ITS and TEF shared identity over 99% with those of C. parasitica strains (GenBank accession number: AY308953, KP524763, KP824756 and KF220299). Based on morphological and molecular characteristic, the fungal isolates were identified as C. parasitica. To verify pathogenicity, thirty 3-year-old chestnut seeding (70 cm high, 1 cm diameter) of Castanea seguinii were used for inoculation. Chestnut branches were wounded (five wounds per sapling) using a hole punch and inoculated with a mycelial plug (5 mm in diameter) from the edge of 7-day-old, actively growing colonies. Pathogen-free PDA plugs were used as controls. To prevent desiccation, inoculated wounds were sealed with parafilm, and saplings were incubated in a greenhouse at 25℃. Each treatment consisted of 5 seedling and the pathogenicity tests were repeated three times. After inoculation for 5 weeks, symptoms of bark cankers were observed on branches similar to those of diseased chestnut trees in the field. Control saplings with sterile PDA discs did not display symptoms. C. parasitica was reisolated from inoculated branches. To our knowledge, this is the first report of C. parasitica causing chestnut blight in Gansu Province, one of the few areas in the China thought to be free of the disease. The specimens were found in the westernmost part of the natural distribution of chestnuts in China. There are more than 2.6 million chestnut trees, which constitute one of the most important economic forests in Hui County Gansu Province (Yang et al. 2005). The occurrence of chestnut blight could be a restricting factor for chestnut forests.

Genetic Diversity and Population Structure of Chinese Chestnut (Castanea mollissima Blume) Cultivars Revealed by GBS Resequencing.

Chinese chestnut (Castanea mollissima Bl.) is one of the earliest domesticated and cultivated fruit trees, and it is widely distributed in China. Because of the high quality of its nuts and its high resistance to abiotic and biotic stresses, Chinese chestnut could be used to improve edible chestnut varieties worldwide. However, the unclear domestication history and highly complex genetic background of Chinese chestnut have prevented the efficiency of breeding efforts. To explore the genetic diversity and structure of Chinese chestnut populations and generate new insights that could aid chestnut breeding, heterozygosity statistics, molecular variance analysis, ADMIXTURE analysis, principal component analysis, and phylogenetic analysis were conducted to analyze single nucleotide polymorphism data from 185 Chinese chestnut landraces from five geographical regions in China via genotyping by sequencing. Results showed that the genetic diversity level of the five populations from different regions was relatively high, with an observed heterozygosity of 0.2796-0.3427. The genetic diversity level of the population in the mid-western regions was the highest, while the population north of the Yellow River was the lowest. Molecular variance analysis showed that the variation among different populations was only 2.07%, while the intra-group variation reached 97.93%. The Chinese chestnut samples could be divided into two groups: a northern and southern population, separated by the Yellow River; however, some samples from the southern population were genetically closer to samples from the northern population. We speculate that this might be related to the migration of humans during the Han dynasty due to the frequent wars that took place during this period, which might have led to the introduction of chestnut to southern regions. Some samples from Shandong Province and Beijing City were outliers that did not cluster with their respective groups, and this might be caused by the special geographical, political, and economic significance of these two regions. The findings of our study showed the complex genetic relationships among Chinese chestnut landraces and the high genetic diversity of these resources.

Chromosome-level genome assembly provides new insights into Japanese chestnut (Castanea crenata) genomes.

Japanese chestnut (Castanea crenata Sieb. et Zucc) is an economically and ecologically important chestnut species in East Asia. Here, we presented a high-quality chromosome-level reference genome of the Japanese chestnut cultivar 'Tsukuba' by combining Nanopore long reads and Hi-C sequencing. The final assembly has a size of 718.30 Mb and consists of 12 pseudochromosomes ranging from 41.03 to 92.03 Mb, with a BUSCO complete gene percentage of 97.6%. A total of 421.37 Mb repetitive sequences and 46,744 gene models encoding 46,463 proteins were predicted in the genome. Genome evolution analysis showed that Japanese chestnut is closely related to Chinese chestnut and these species shared a common ancestor ~6.5 million years ago. This high-quality Japanese chestnut genome represents an important resource for the chestnut genomics community and will improve our understanding of chestnut biology and evolution.