Fruits are an important source of a healthy diet due to their essential nutrients for daily intake. Melon is known as a significant fruit crop of the Cucurbitaceae family based on its various dietary benefits, but its shelf life needs to be maintained for long-term usage. 1-Methylcyclopropene (1-MCP) is a cyclopropene-derived synthetic plant growth regulator (PGR) that is used for significantly delaying the ripening process and maintaining the shelf life of climacteric fruits during storage. In this study, freshly harvested melon fruits were fumigated with various concentrations (1.0 µL·L−1, 2.0 µL·L−1, and 3.0 µL·L−1) of 1-MCP treatment for 12 h (h) and stored at low temperature (8 ± 1 °C) for 30 days (d). The obtained results showed that 1-MCP fumigation coupled with low-temperature treatment maintains the postharvest shelf life of melon fruit. It was noticed that the increase in color hue (a* (red/green), b* (blue/yellow), L* (lightness)) was slowed down and the external fresh color was effectively maintained. At the same time, the firmness, soluble solids, titratable acids (TAs), and vitamin C (VC) content seemed to be maintained at a high level; weight loss and cell permeability were reduced; respiratory intensity and ethylene emission were inhibited; and the accumulation of superoxide anions and malondialdehyde (MDA) was also reduced. In addition, an upsurge in the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) was noticed in melon fruits under the combined treatment of 1-MCP and low-temperature storage as compared with the control group (CK, without treatment), indicating that 1-MCP treatment can effectively enhance the antioxidant metabolism of melon fruits during storage. Overall, we can recommend that the 3.0 µL·L−1 concentration of 1-MCP had the best effect on maintaining the internal and external quality of sweet melon fruit during storage.
The stripe color of watermelon is a vital commercial trait and is the focus of attention of consumers and researchers. However, the genetic determinants of watermelon stripe color are incompletely understood. Based on the results of preliminary localization studies, we constructed a large-capacity F2 generation population (710 plants) using light-green striped ZXG1555 and green-striped Cream of Saskatchewan (COS) watermelon strains as parental lines for fine mapping. Genes controlling stripe color were located in an 85.284kb region on chromosome 9, which contained five candidate genes. Combined with parental phenotypes, chlorophyll contents of rinds and stripes were assayed. Gene sequence alignment and transcriptional level analysis of parental lines predicted Cla97C09G175170 (encoding a two-component response regulator-like protein, APRR2) as the best candidate gene for stripe color trait. Two SNPs in the ClAPRR2 coding region caused amino acid substitutions, but were not located in the conserved domain, while a 12bp insertion caused premature translation termination and a 35 amino acid deletion in the conserved domain and may have affected ClAPRR2 function in ZXG1555. Subcellular localization analysis showed that ClAPRR2 was expressed in the ZXG1555 cell membrane but was located in the nucleus and cell membrane of COS. Nucleotide polymorphisms and deletions were also detected in the promoter region between parental lines and caused cis-acting element variations. Luciferase activity suggested that promoter variations may not be the main factor in the regulation of ClAPRR2 expression.
Petal size is a key agronomic trait for plant reproduction. However, the genetic basis and developmental regulation of melon petal size remain unexplored. In this study, the examination of F2 populations derived from M1-15 (large-petaled) and PI 614174 (small-petaled) melon lines suggested that petal size is a quantitative trait. Microscopic observation revealed that the difference in petal size between parental lines was due mainly to the cell number and size. Bulk segregant analysis sequencing (BSA-seq) and genetic mapping of data from 2023 to 2024 identified a major effective stable QTL Cmqps8.1 for petal size in a 1.42 Mb region on chromosome 8. MELO3C024520.2 (annotated as ethylene-responsive transcription factor ERF024) was preliminarily predicted as the candidate gene for melon petal size through in silico BSA, gene expression analysis, and the cloning of promoter and coding region sequences in the parental lines and a natural melon panel with different petal sizes. The InDel marker Chr08_9521560 located in the mapping region, co-segregated with large and small petals in F2 individuals and 19 melon germplasms, and could serve as the marker in marker-assisted selection. These results provide a theoretical basis for further fine mapping and functional analysis of key genes related to melon petal size.
Background As an important global agricultural cash crop, melon has a long history of cultivation and a wide planting area. The physiological metabolism of melon after harvest is relatively strong; if not properly stored, melon is easily invaded by external pathogens during transportation, resulting in economic losses and greatly limiting its production, development and market supply. Therefore, the storage and freshness of melon are the main challenges in realizing the annual supply of melon, so postharvest storage has received increasing amounts of attention from researchers. Methods This study used academic, PubMed, and Web of Science resources to retrieve keywords related to postharvest storage and melon quality; read, refined, classified, and sorted the retrieved literature; sorted and summarized the relevant research results; and finally completed this article. Results This article reviews the mechanism and effects of physical, chemical and biological preservation techniques on the sensory quality, compound contents and respiratory physiological activities of different varieties of melon fruits. When maintaining normal metabolism and not producing physiological disorders, melon inhibits cell wall metabolism, reactive oxygen species metabolism and the ethylene biosynthesis pathway, etc., to the greatest extent during postharvest storage, thereby reducing the material consumption of fruits, delaying the ripening and senescence process, and prolonging the postharvest life and shelf life. Conclusion The literature provides a theoretical basis for postharvest preservation technology in the melon industry in the future and provides corresponding guidance for the development of the melon industry.
The gene controlling pink flesh in watermelon was finely mapped to a 55.26-kb region on chromosome 6. The prime candidate gene, Cla97C06G122120 (ClPPR5), was identified through forward genetics. Carotenoids offer numerous health benefits; while, they cannot be synthesized by the human body. Watermelon stands out as one of the richest sources of carotenoids. In this study, genetic generations derived from parental lines W15-059 (red flesh) and JQ13-3 (pink flesh) revealed the presence of the recessive gene Clpf responsible for the pink flesh (pf) trait in watermelon. Comparative analysis of pigment components and microstructure indicated that the disparity in flesh color between the parental lines primarily stemmed from variations in lycopene content, as well as differences in chromoplast number and size. Subsequent bulk segregant analysis (BSA-seq) and genetic mapping successfully narrowed down the Clpf locus to a 55.26-kb region on chromosome 6, harboring two candidate genes. Through sequence comparison and gene expression analysis, Cla97C06G122120 (annotated as a pentatricopeptide repeat, PPR) was predicted as the prime candidate gene related to pink flesh trait. To further investigate the role of the PPR gene, its homologous gene in tomato was silenced using a virus-induced system. The resulting silenced fruit lines displayed diminished carotenoid accumulation compared with the wild-type, indicating the potential regulatory function of the PPR gene in pigment accumulation. This study significantly contributes to our understanding of the forward genetics underlying watermelon flesh traits, particularly in relation to carotenoid accumulation. The findings lay essential groundwork for elucidating mechanisms governing pigment synthesis and deposition in watermelon flesh, thereby providing valuable insights for future breeding strategies aimed at enhancing fruit quality and nutritional value.
Pectin is a structural polysaccharide and a major component of plant cell walls. Pectate lyases are a class of enzymes that degrade demethylated pectin by cleaving the α-1,4-glycosidic bond, and they play an important role in plant growth and development. Currently, little is known about the PL gene family members and their involvement in salt stress in potato. In this study, we utilized bioinformatics to identify members of the potato pectate lyase gene family and analyzed their gene and amino acid sequence characteristics. The results showed that a total of 27 members of the pectate lyase gene family were identified in potato. Phylogenetic tree analysis revealed that these genes were divided into eight groups. Analysis of their promoters indicated that several members’ promoter regions contained a significant number of hormone and stress response elements. Further, we found that several members responded positively to salt treatment under single salt and mixed salt stress. Since StPL18 exhibited a consistent expression pattern under both single and mixed salt stress conditions, its subcellular localization was determined. The results indicated that StPL18 is localized in the endoplasmic reticulum membrane. The results will establish a foundation for analyzing the functions of potato pectate lyase family members and their expression under salt stress.
WRKY transcription factors (TFs) can participate in plant biological stress responses and play important roles. SlWRKY80 was found to be differentially expressed in the Mi-1- and Mi-3-resistant tomato lines by RNA-seq and may serve as a key node for disease resistance regulation. This study used RNAi to determine whether SlWRKY80 silencing could influence the sensitivity of ‘M82’ (mi-1/mi-1)-susceptible lines to M. incognita. Further overexpression of this gene revealed a significant increase in tomato disease resistance, ranging from highly susceptible to susceptible, combined with the identification of growth (plant height, stem diameter, and leaf area) and physiological (soluble sugars and proteins; root activity) indicators, clarifying the role of SlWRKY80 as a positive regulatory factor in tomato defense against M. incognita. Based on this phenomenon, a preliminary exploration of its metabolic signals revealed that SlWRKY80 stimulates different degrees of signaling, such as salicylic acid (SA), jasmonic acid (JA), and ethylene (ETH), and may synergistically regulate reactive oxygen species (ROS) accumulation and scavenging enzyme activity, hindering the formation of feeding sites and ultimately leading to the reduction of root gall growth. To our knowledge, SlWRKY80 has an extremely high utilization value for improving tomato resistance to root-knot nematodes and breeding.
The species degeneration caused by traditional potato cultivation methods is becoming increasingly evident, and it is particularly important to study new potato cultivation methods. Sprout planting technology has the advantages of large reproductive capacity, fast growth speed, and simplified maintenance of cultivated crops. In this study, four disease-free potato varieties (‘Fujin’, ‘Youjin’, ‘Zhongshu 4’, and ‘Feiwuruita’) were treated with different parts (top bud, middle bud, and tail bud) and different bud lengths (10 cm, 15 cm, and 20 cm), and then potato sprout planting was carried out. A nutrient pot experiment was performed following a randomized complete block design (RCBD) with various replicates and a natural control (CK) treatment. By comprehensively measuring the emergence, chlorophyll content, net photosynthetic rate, dry matter distribution during the bulking period of blocks, and effect of growth and quality with bud direct seeding under both treatments, it was found that potato block top bud direct seeding cultivation is significantly superior to other parts. In terms of early maturity and yield statistics, the advantage of top bud cultivation in ‘zhongshu 4’ is most obvious; it reaches maturity an average of 14 days earlier, and the yield can be increased by 38.05%. Therefore, top bud direct seeding is more suitable for potato sprout planting technology. On this basis, the 20 cm and 15 cm bud length treatments of top buds were used for direct cultivation, and all the above indicators performed well. Among them, in the zhongshu 4 variety, the yields of 15 cm and 20 cm bud length treatments increased by 41.78% and 38.05%, the growth rates of commercial potatoes increased by 6% and 6.9%, respectively, and the effects were the most obvious. In conclusion, the deep research and application of potato sprouting technology has high utilization value for improving potato yield and quality and has guiding significance for greenhouse potato cultivation in early spring.
Root-knot nematode (RKN) infections are among the most serious soil-borne diseases in the world, and tomato is a common host of RKNs. WRKY transcription factors are involved in complex, diverse biological processes in plants. In a previous study, a resistant variety, LA3858 (Mi-3/Mi-3), was treated at different soil temperatures before RNA-seq, and six differentially expressed genes (DEGs) encoding WRKY proteins were screened. In this study, cloning and sequencing were used to identify six target DEGs encoding SlWRKY1, SlWRKY13, SlWRKY30, SlWRKY41, SlWRKY46, and SlWRKY80. Conserved domain identification and phylogenetic tree analysis showed that SlWRKY1, SlWRKY13, and SlWRKY46 have similar functions and are mainly involved in plant growth and development and abiotic stress responses. SlWRKY30 and SlWRKY41 share high homology, while AtWRKY46 and AtWRKY70, which are highly homologous to SlWRKY80, play an important role in the disease resistance of A. thaliana. Considering these findings combined with the high level of SlWRKY80 expression observed in the roots and leaves of the resistant variety Motelle (Mi-1/Mi-1) and the continuous upregulation of SlWRKY80 expression in the roots after inoculation of Motelle with M. incognita, it is speculated that SlWRKY80 plays an important role in the Mi-1-mediated disease resistance pathway. Further study revealed that SlWRKY80 is a typical nuclear-localized protein, and a virus-induced gene silencing (VIGS) assay verified that SlWRKY80 is involved in tomato resistance to RKNs as a positive regulator. SA and JA signals play an important role in Mi-1-mediated resistance to RKNs. SlWRKY80 was able to respond rapidly to treatment with both plant hormones, which indicated that SlWRKY80 might be involved in disease resistance regulation through various immune pathways.
Background Potato, a vegetable crop grown worldwide, has many uses, a short growth period, a large market demand and high economic benefits. The loss of potato seediness due to traditional potato growing methods is becoming increasingly evident, and research on new ways of growing potatoes is particularly important. Bud planting technology has the advantages of more reproduction, faster growth, and simplified maintenance of crop plants under cultivation. Methods In this study, a bud planting method was adopted for the cultivation of potato seedlings. Specifically, we assessed different types of treatments for the production of high-quality buds and seedlings of potato. A total of four disease-free potato varieties (Fujin, Youjin, Zhongshu 4, and Feiwuruita) were selected, potato buds with three different lengths (3 cm, 5 cm, and 7 cm) were considered the T 1 , T 2 , and T 3 treatments, and terminal buds, middle buds, and tail buds were used as the T 4 , T 5 , and T 6 treatments. A nutrient pot experiment was performed following a randomized complete block design (RCBD) with three replicates and a natural control (CK) treatment. Cultivation was performed with the common horticultural practices of weeding and hoeing applied as needed. The photosynthetic indices, physiological indices, growth indices and quality of potato seedlings and quality of potato buds were measured at two-week intervals, and yield indices were measured when the final crop was harvested 14 weeks after planting. Results and Conclusions Cultivation of seedlings from potato buds of different lengths increased the reproduction coefficient and reduced the number of seed potatoes needed for cultivation. All morphological, physiological, and yield indices showed positive trends. A potato bud length of 7 cm was optimal for raising seedlings. Moreover, buds located at the terminal of the potato yielded seedlings with the best quality. In conclusion, we recommend that our proven bud planting technique be adopted at the commercial level, which could support good crop production with maximum yield.
碱性螺旋-环-螺旋(bHLH)转录因子是植物中最大的转录因子家族之一,为了分析其在Mi-3介导热稳定抗性过程中的相关功能,本研究根据番茄转录组测序结果,筛选出了抗感比较组中5个编码bHLH的高差异表达基因,通过克隆并与数据库比对,确定目标基因分别是SlbHLH100,SlbHLH100-like,SlbHLH35,SlbHLH68和SlbHLH130,随后对其进行生信分析与根部表达模式验证。结果发现,目标基因编码氨基酸结构域含有高度保守的motif 1和motif 2,且二者共同构成bHLH结构,除了SlbHLH130,其余SlbHLHs启动子区均包括G-box结合位点;进化树功能预测显示,SlbHLH100,SlbHLH100-like和SlbHLH35被归类到一组,该组大部分基因参与植物的抗逆抗病反应。而SlbHLH130与SlbHLH68所在分组的众多基因参与植物的生长发育进程;抗感比较组中,相比较其他SlbHLHs,SlbHLH130在根部差异表达量较低,而启动子顺式作用元件注释与共表达分析结果进一步说明,SlbHLH130很大可能不参与Mi-3常温下(25℃)的抗病调控;而在SlbHLH100和SlbHLH100-like的共表达网络中,其调控的差异表达基因主要参与抗病中PTI(PAMP-triggered immunity, PTI)、ETI(Effector-triggered immunity, ETI)反应以及活性氧(reactive oxygen species, ROS)信号途径,并且这些基因经常在植物的抗病过程中积极响应。结合抗感比较组根部的高差异表达量,综合推测,SlbHLH100和SlbHLH100-like在Mi-3介导热稳定抗病进程中发挥重要的作用。本研究为后续其具体调节机制挖掘,培育番茄抗根结线虫病新材料提供参考和理论依据。
以厚皮甜瓜高代自交系M625、M44为试验材料,采用浸种和叶面喷施铜制剂的方法,研究了不同时期喷施铜制剂对甜瓜主蔓长、茎粗、最大功能叶叶面积、最大功能叶节位、最大功能叶叶绿素含量、单瓜质量、中心糖含量、病叶率和铜害指数的影响,以期为探究甜瓜不同时期铜敏感性差异提供参考依据.结果表明:不同时期喷施铜制剂均不同程度降低了 2个甜瓜材料的主蔓长、茎粗、叶面积、叶绿素含量,以及产量和品质,其中苗期处理的各项指标下降幅度最大;不同时期喷施铜制剂均不同程度升高了甜瓜的最大功能叶节位、病叶率和铜害指数,且铜制剂喷施时间越早铜害表现越明显.M625和M44在苗期对铜制剂表现最为敏感,铜害程度最严重,坐瓜期次之,浸种处理与CK差异不显著,M625与M44相比之下,M625对铜制剂表现更敏感.综上所述,不同时期喷施铜制剂处理对2个甜瓜材料各项生长指标、产量、品质以及铜害指标的影响差异表现基本一致,铜敏感性排序依次是苗期>伸蔓期>坐瓜期>浸种.
The color of watermelon flesh is an important trait determined by a series of carotenoids. Herein, we used Cream of Saskatchewan (pale yellow flesh) and PI 186490 (white flesh) as parental materials for an F2 segregation and initial mapping using the bulked segregant analysis sequencing (BSA-seq) strategy. The BSA results revealed a flesh color-related QTL that spans approximately 2.45 Mb on chromosome 6. This region was preliminarily positioned in a 382-kb segment, and then narrowed down into a 66.8-kb segment with 1260 F2 individuals. A total of nine candidate genes were in the fine mapping interval, but only Cla007528 (encoding chlorophyllase) had non-synonymous mutations and was significantly expressed between the parental materials throughout flesh development. We also checked the expression patterns of the carotenoid metabolic pathway genes based on RNA-seq data and qRT-PCR validation. Three genes in the xanthophyll cycle (CICHYB, CINCED-1 and CINCED-7) exhibited differential expression patterns between the two parental lines at different flesh color formation stages. ClPSY1, CIPDS, CIZDS, CICHXE, CICRTISO and CILCYB also exhibited clearly different expression patterns accompanied by carotenoid accumulation.
Watermelon fruit texture and quality are determined by flesh firmness. As a quality trait, flesh firmness is controlled by multigenes. Defining the key regulatory factors of watermelon flesh firmness is of great significance for watermelon genetic breeding. In this study, the hard-flesh egusi seed watermelon PI186490 was used as the male parent, the soft-flesh cultivated watermelon W1-1 was used as the female parent, and 175 F2 generations were obtained from selfing F1. Primary mapping of the major genes controlling center flesh firmness was achieved by bulked-segregant analysis (BSA)-Seq analysis and molecular marker technology. Finally, major genes were delimited in the physical interval between 6,210,787 and 7,742,559 bp on chromosome 2 and between 207,553 and 403,137 bp on chromosome 8. The content of each cell wall component and hormone was measured, and comparative transcriptome analysis was performed during fruit development in watermelon. The protopectin, cellulose, hemicellulose, indole-3-acetic acid (IAA) and abscisic acid (ABA) contents were measured, and paraffin sections were made during the three fruit developmental stages. The results revealed that protopectin, celluloses, and hemicelluloses exhibited similar trends for flesh firmness, while the IAA and ABA concentrations continued to decrease with fruit ripening. Paraffin sections showed that PI186490 cells were more numerous, were more tightly packed, had clearer cell wall edges and had thicker cell walls than W1-1 cells at every developmental stage. Comparative transcriptome analysis was conducted on RNA samples of flesh during fruit development and ripening in W1-1 and PI186490. The results from the localization interval transcriptome analysis showed that Cla016033 (DUF579 family member), which may influence the cell wall component contents to adjust the flesh firmness in watermelon fruit, was different in W1-1 and PI186490 and that Cla012507 (MADS-box transcription factor) may be involved in the regulation of fruit ripening and affect the hardness of watermelon fruit.
Lycopene content and flesh color are important traits determined by a network of carotenoid metabolic pathways in watermelon. Based on our previous study of genetic inheritance and initial mapping using F2 populations of LSW-177 (red flesh) × cream of Saskatchewan (pale yellow flesh), red flesh color was controlled by one recessive gene regulating red and pale yellow pigmentation, and a candidate region related to lycopene content was detected spanning a 392,077-bp region on chromosome 4. To obtain a more precise result for further study, three genetic populations and a natural panel of 81 watermelon accessions with different flesh colors were used in this research. Herein, we narrowed the preliminary mapping region to 41,233 bp with the linkage map generated from F2 populations of LSW-177 (red flesh) × cream of Saskatchewan (pale yellow flesh) with 1,202 individuals. Two candidate genes, Cla005011 and Cla005012, were found in the fine mapping region; therein Cla005011 was a key locus annotated as a lycopene β-cyclase gene. Phylogenetic tree analysis showed that Cla005011 was the closest relative gene in gourd. LSW-177 × PI 186490 (white flesh) and another BC1 population derived from garden female (red flesh) × PI 186490 were generated to verify the accuracy of the red flesh candidate gene region. By analyzing the expression levels of candidate genes in different developmental stages of different color watermelon varieties, Cla005011 for the expression differences was not the main reason for the flesh color variation between COS and LSW-177. This indicated that the LCYB gene might regulate fruit color changes at the protein level. A new marker-assisted selection system to identify red and yellow flesh colors in watermelon was developed with flesh color–specific CAPS markers and tested in 81 watermelon accessions.
随着当前社会对人才需求的逐渐提高,对现阶段高校学生教育和培养也提出了新要求,为了打造高要求、高素质、全面发展的高质量人才,各高校在专业课程设置及建设过程中对实践环节重视程度不断提升,园艺专业更是重中之重.本文在园艺专业实践教学过程管理情况、目前面临的问题以及需要改进的方向进行了探讨,以期为今后园艺课程设置优化提供一定参考.