Zucchini Cultivars Research Articles

Proteome Profiling of Cucurbita pepo Phyllosphere After Infection by Podosphaera xanthii and Application of Reynoutria sachalinensis Extract

Podosphaera xanthii is the main causal agent of powdery mildew (PM) disease for Cucurbita pepo. Disease control is attained principally by applications of chemical fungicides, along with parallel use of tolerant crop varieties and alternate application of elicitors to control development of disease resistance. To get insight into C. pepo molecular responses to P. xanthii infection and elicitor treatment we studied the proteomic profile differences at the phyllosphere of a zucchini cultivar susceptible to PM, at the onset of P. xanthii (PX) infection and after application of Reynoutria sachalinensis (RS) plant extract, respectively, using a nano-LC-HRMS/MS, Q-Exactive-Orbitrap approach. Analysis of peptide sequences regarding four treatment groups (Control; PX; RS; and RSPX (PX-infected priorly treated with RS)) resulted in 2070 CuGenDB annotations. Three comparisons (treatments vs. Control) encompassed most of the Differentially Expressed Proteins (DEPs). In these three comparisons, KEGG and Gene Ontology functional analyses highlighted unique differentially enriched pathways—some of which included highly expressed proteins—in PX-related (proteasome, pentose phosphate pathway, and carbon fixation), RS-related (biosynthesis of secondary metabolites, flavonoids, and starch and sucrose metabolism), and RSPX-related (pyruvate metabolism and polycomb repressive complex) comparisons, respectively, suggesting distinct mechanisms of early plant responses modulated by PX and RS. Furthermore, in four out of six comparisons the thiamine metabolism pathway was found to be enriched, suggesting a pivotal role in PX-induced responses.

Assessment of Certain Zucchini Cultivars Response to Infection with Papaya Ringspot Virus (PRSV) and Watermelon Mosaic Virus (WMV) Under Greenhouse and Field Conditions

Assessment of Certain Zucchini Cultivars Response to Infection with Papaya Ringspot Virus (PRSV) and Watermelon Mosaic Virus (WMV) Under Greenhouse and Field Conditions

Susceptibility of Zucchini Cultivars to Powdery Mildew (Podosphaera xanthii) Under High- and Low-Nitrogen Regimes

Powdery mildew, primarily caused by Podosphaera xanthii, threatens cucurbit crop yield and longevity. Fungicides and resistant cultivars cannot fully manage or prevent the disease. Previous work has shown that powdery mildew incidence and severity can increase under high soil nitrogen. This study was conducted in Kentucky to determine disease severity and yield using a split plot design with nitrogen fertility (high: 140 kg/ha; low: 84 kg/ha) and zucchini cultivar (Cash Machine, Cue Ball, Desert, Dunja, Eight Ball, Emerald Delight, Golden Glory, Mexicana, and Spineless Perfection) as the main plot and subplot factors, respectively. In year 1, powdery mildew severity was significantly higher in high soil nitrogen and varied significantly among cultivars. Yield was significantly lower in high soil nitrogen. Significant differences in fruit count, but not fruit weight, were observed among the cultivars. In year 2, nitrogen did not significantly affect disease severity, but fruit weight and count were significantly lower in the high soil nitrogen treatment. Golden Glory had significantly higher powdery mildew severity, while Mexicana and Eight Ball had significantly lower severity compared to all other cultivars. Spineless Perfection had the highest fruit weight and was significantly higher than all other cultivars except for Cue Ball and Eight Ball. Golden Glory had the highest fruit count and was significantly higher than all others except for Dunja. Nitrogen did not consistently affect disease severity throughout the study. The effects of powdery mildew on yield should be explored further, as heavily diseased plants did not always have low yield.

Susceptibility of Yellow Squash and Zucchini Cultivars to the Sweetpotato Whitefly, Bemisia tabaci Gennadius (MEAM1), in the Southeastern United States.

The sweetpotato whitefly, Bemisia tabaci (Gennadius) Middle East-Asia Minor 1 (MEAM1), causes significant losses to vegetable crops directly by sap-feeding, inducing plant physiological disorders, and elevating the build-up of sooty mold, and indirectly by transmitting plant viruses. In this study, we evaluated the susceptibility of 20 yellow squash and zucchini (Cucurbita pepo) cultivars to MEAM1, across three growing seasons in the southeastern United States. Weekly sampling of the numbers of MEAM1 adults, nymphs, and eggs were conducted from the fourth week after seed sowing and across 6 weeks during the summer and fall of 2021 and five weeks during the fall of 2022. In general, adult whitefly populations were high during the first week of sampling but decreased as the seasons progressed. The zucchini cultivar 'Black Beauty' harbored the most adults, while 'Green Eclipse Zucchini' was the least attractive zucchini cultivar to the adults in fall 2022. For yellow squash, 'Early Summer' (summer 2021) and 'Amberpic 8455' (summer 2021 and fall 2022) were the cultivars with the highest adult populations, while 'Lioness' (summer 2021) and 'Gourmet Gold Hybrid' (fall 2022) harbored the lowest adult counts. The whitefly egg counts across both vegetables trailed those of adults and peaked in the second week of sampling. The counts of nymphs increased as the seasons progressed, but there was a decline after the second week during fall 2021. For the yellow squash cultivars, 'Gourmet Gold Hybrid', (summer 2021 and fall 2022), 'Lioness', and 'Fortune' (summer 2021) recorded the highest yields. For zucchini, 'Golden Glory' (summer 2021) was the top performer. These results provide valuable information for whitefly management in yellow squash and zucchini based on host plant susceptibility and yield.

Worm castings and naphthaleneacetic acid in the growth and yield of zucchini in shade houses

The cultivation of zucchini (Cucurbita pepo L.) under protected conditions has limitations, such as low fruit set due to poor pollination, which affect the commercial yield and profitability of the crop. The investigation was carried out to know the influence of earthworm humus (HL) and naphthaleneacetic acid (ANA) on the growth and yield of two zucchini cultivars in shade houses. A randomized block experimental design with eight treatments and 10 repetitions was used. The treatments influenced plant height, leaf area index, stem dry weight, leaf dry weight, plant dry weight and fruit set; however, there were no differences because of the treatments in stem diameter, leaf greenness and number of leaves. With the HMX58 cultivar, the highest plant height was obtained: while because of the Prestige cultivar, the highest index of leaf area, dry weight of leaves and dry weight of the whole plant. The highest yield was obtained with the HMX58+LC treatment, while fruit set and number of fruits increased because of earthworm humus. The diameter and weight of the fruit increased because of ANA in both cultivars, and the length of the fruit in the Prestige cultivar.

Evaluation of Zucchini (Cucurbita pepo L.) Genotypes for Spring Season Production in the Mid–Hills of Nepal

Zucchini (Cucurbita pepo L.) is one of the most popular and demanded vegetable in Nepal. Seedlings of seven genotypes of squash gourd; Super Squash Ball, Squash Long, Squash Light, Squash Green Ball, Squash Green House Sondo V (check) and Grey Zucchini (check) were transplanted on second week of March in two consecutive years; 2016 and 2017 in field condition at Khumaltar with a spacing of 90 x 90 cm in four replications. The standard recommended dose of fertilizers (240:180:60 NPK kg/ha + 15 ton FYM/ha) and minimum pesticide and fungicide was applied. The main objective of this experiment was to find out suitable high yielding and insect pest and disease tolerant hybrid Zucchini cultivars for commercial production in mid-hills of Nepal. Crops were evaluated for their vegetative, insect pest and disease, and yield attributing parameters. Among the tested genotypes; Squash Long was found highly uniform, vigorous, least virus and insect damage, significantly higher number of fruits(8.6), and yield (3894 g) per plant and yield (46.89 t/ha) followed by Super Squash Ball having highly uniform, less insect and powdery mildew damage, significantly higher number of fruits (8.5) and yield (2565 g) per plant and yield (29.28 t/ha) as compared to check Sondo V and Grey Zucchini where Sondo V had yield (22.50 t/ha and 1703 g/plant), number of fruits (5.6), per plant respectively. Squash Long and Super Squash Ball have been selected and recommended for cultivation during spring season in mid-hills of Nepal.

Yellow Squash and Zucchini Cultivar Selection for Resistance to Cucurbit Leaf Crumple Virus in the Southeastern United States

Large populations of sweetpotato whiteflies (Bemisia tabaci) have become more regular occurrences during the fall months in parts of the southeastern United States. Large populations of sweetpotato whiteflies have resulted in a significant increase in the incidence of sweetpotato whitefly-transmitted viruses, particularly the cucurbit leaf crumple virus (CuLCrV), which has the potential to cause complete yield loss of fall-planted yellow squash and zucchini (Cucurbita pepo). This study evaluated commercial cultivars of yellow squash and zucchini for resistance against CuLCrV and estimated the yield and fruit quality under environmental conditions during the fall growing season in the southeastern United States. A factorial experimental design was conducted with nine yellow squash and 11 zucchini cultivars during Fall 2017, Fall 2018, and Fall 2019 in Tifton, GA. In situ weather stations monitored the weather conditions during growing seasons, and yellow pest monitor cards monitored the sweetpotato whitefly populations in 2018 and 2019. During all growing seasons, yellow squash and zucchini plants were rated weekly for the severity of CuLCrV. Harvests were conducted 12 times during each season, and fruit were graded as fancy, medium, and culls. Rainfall distribution directly affected the sweetpotato whitefly populations during the production year. In 2018, frequent rainfall events created field conditions that reduced the sweetpotato whitefly populations compared with those during 2017 and 2019. The severity of CuLCrV negatively impacted both the yield and quality of fruit of yellow squash and zucchini, and no resistant commercial cultivars of yellow squash or zucchini were identified. Nonetheless, the yellow squash cultivars Lioness, Gold Prize, and Grand Prize, and the zucchini cultivars SV6009YG and SV0914YG had the highest yields when subjected to the highest sweetpotato whitefly populations during the study.

A combined BSA-Seq and linkage mapping approach identifies genomic regions associated with Phytophthora root and crown rot resistance in squash

Two QTL mapping approaches were used to identify a total of six QTL associated with Phytophthora root and crown rot resistance in a biparental squash population. Phytophthora root and crown rot, caused by the soilborne oomycete pathogen Phytophthora capsici, leads to severe yield losses in squash (Cucurbita pepo). To identify quantitative trait loci (QTL) involved in resistance to this disease, we crossed a partially resistant squash breeding line with a susceptible zucchini cultivar and evaluated over 13,000 F2 seedlings in a greenhouse screen. Bulked segregant analysis with whole genome resequencing (BSA-Seq) resulted in the identification of five genomic regions-on chromosomes 4, 5, 8, 12, and 16-featuring significant allele frequency differentiation between susceptible and resistant bulks in each of two independent replicates. In addition, we conducted linkage mapping using a population of 176 F3 families derived from individually genotyped F2 individuals. Variation in disease severity among these families was best explained by a four-QTL model, comprising the same loci identified via BSA-Seq on chromosomes 4, 5, and 8 as well as an additional locus on chromosome 19, for a combined total of six QTL identified between both methods. Loci, whether those identified by BSA-Seq or linkage mapping, were of small-to-moderate effect, collectively accounting for 28-35% and individually for 2-10% of the phenotypic variance explained. However, a multiple linear regression model using one marker in each BSA-Seq QTL could predict F2:3 disease severity with only a slight drop in cross-validation accuracy compared to genomic prediction models using genome-wide markers. These results suggest that marker-assisted selection could be a suitable approach for improving Phytophthora crown and root rot resistance in squash.

Spacing between plants and cultivar affect the production componentes of Italian zucchini

ABSTRACT The italian zucchini is a vegetable of national importance, much appreciated, which requires techniques that aim to increase production in less space. Plant spacing can influence the development of plants and the fruit production. The objective of this study was to evaluate the performance of Italian zucchini cultivars as a function of plant spacing. The experimental design was a randomized blocks in a 2 x 4 factorial scheme with four repetitions. The treatments consisted of a combination of two cultivars of zucchini (Alícia and Caserta) and four spacings between plants (0.4, 0.5, 0.6 and 0.7 m). The evaluated characteristics were: total number of fruits plant-1, number of commercial fruits plant-1, total productivity, commercial and non commercial, fresh mass of commercial fruits and dry mass of the plant. The cultivars responded differently to spacings between plants. The Alicia hybrid showed higher commercial yield, 28,490.5 kg ha-1 at spacing of 0.64 m between plants and Caserta cultivar, 26,398.8 kg ha-1 at spacing of 0.4 m.

Molecular response to cold storage in fruit of two zucchini cultivars differing in their chilling sensitivity

Molecular response to cold storage in fruit of two zucchini cultivars differing in their chilling sensitivity

Effects of Hydroponics Systems on Growth, Yield and Quality of Zucchini (Cucurbita pepo L.)

There is dearth of information pertaining to hydroponics production of zucchini in the Kingdom of Eswatini. The objective of this study was to determine the effects of hydroponics systems on growth, yield and nutritional content of zucchini. The research was conducted in three greenhouses of the Horticulture Department, Faculty of Agriculture, Luyengo Campus at the University of Eswatini between July and October 2018. The experiment was laid out in a split-plot design replicated four times. Three hydroponics systems were used as the main plots, i.e. elevated tray, ground lay bed and Nutrient Film Technique (NFT) systems. The sub-plots were allocated to the three varieties, i.e., Amanda, Hygreen and Terminator. The zucchini grown in elevated tray hydroponics system had the highest yield in all the varieties compared to the other hydroponics systems. The results showed that there were significant differences in the growth, yield and nutritional content of zucchini cultivars grown in the different hydroponics systems. The tallest plants (26.1cm) were obtained in cultivar Terminator grown in the elevated tray system and the highest number of leaves (15) was obtained in cultivar Terminator grown in the elevated tray system. Cultivar Terminator grown in the elevated tray system had the highest total yield (15.8 tons/ha) while Hygreen plants produced in the NFT system recorded the lowest total yield (1.04 tons/ha). There were no significant differences in the iron content of zucchini among the cultivars grown in the different hydroponics systems. The results of this study revealed that different zucchini cultivars responded differently when grown in the different hydroponics systems. Therefore based on the results of this study it is recommended that Terminator zucchini cultivar can be produced in the elevated tray hydroponics system.

Growth, yield, nutrient accumulation and export and thermal sum of Italian zucchini

ABSTRACT Studies on plant nutrition are essential for a correct fertilizer management, improving yield and quality of the product, and it also may contribute for an updating recommendation. The aim of this study was to evaluate growth, nutrient accumulation and export, thermal sum and yield of zucchini cultivar Corona F1. The experiment was carried out from August 8 to October 25, 2013, in Santo Antônio de Posse, São Paulo State. At the end of the research, 84 days after transplanting (DAT), we observed 95 cm average height with 36 leaves and 45.8 t ha-1 maximum yield. The nutrient accumulation, in g plant-1, was: N (14.2) > K (9.3) > Ca (8.0) > Mg (2.5) > S (1.2) > P (0.9) and in mg plant-1, Mn (49.3) > Fe (34.9) > Zn (19.6) > B (16.4) > Cu (2.1) and export, in kg ha-1, was N (94.9) > K (44.1) > Ca (43.0) > Mg (12.6) > S (6.3 ) > P (5.3), in g ha-1, Mn (271.0) > Fe (159.2) > Zn (105.6) > B (82.8) > Cu (11.9). The highest nutrient demand occurred between 40 and 50 DAT. Cultivar Corona F1 cycle was completed within 1.538 degree-days.

First RNA-seq approach to study fruit set and parthenocarpy in zucchini (Cucurbita pepo L.)

BackgroundZucchini fruit set can be limited due to unfavourable environmental conditions in off-seasons crops that caused ineffective pollination/fertilization. Parthenocarpy, the natural or artificial fruit development without fertilization, has been recognized as an important trait to avoid this problem, and is related to auxin signalling. Nevertheless, differences found in transcriptome analysis during early fruit development of zucchini suggest that other complementary pathways could regulate fruit formation in parthenocarpic cultivars of this species. The development of next-generation sequencing technologies (NGS) as RNA-sequencing (RNA-seq) opens a new horizon for mapping and quantifying transcriptome to understand the molecular basis of pathways that could regulate parthenocarpy in this species. The aim of the current study was to analyze fruit transcriptome of two cultivars of zucchini, a non-parthenocarpic cultivar and a parthenocarpic cultivar, in an attempt to identify key genes involved in parthenocarpy.ResultsRNA-seq analysis of six libraries (unpollinated, pollinated and auxin treated fruit in a non-parthenocarpic and parthenocarpic cultivar) was performed mapping to a new version of C. pepo transcriptome, with a mean of 92% success rate of mapping. In the non-parthenocarpic cultivar, 6479 and 2186 genes were differentially expressed (DEGs) in pollinated fruit and auxin treated fruit, respectively. In the parthenocarpic cultivar, 10,497 in pollinated fruit and 5718 in auxin treated fruit. A comparison between transcriptome of the unpollinated fruit for each cultivar has been performed determining that 6120 genes were differentially expressed. Annotation analysis of these DEGs revealed that cell cycle, regulation of transcription, carbohydrate metabolism and coordination between auxin, ethylene and gibberellin were enriched biological processes during pollinated and parthenocarpic fruit set.ConclusionThis analysis revealed the important role of hormones during fruit set, establishing the activating role of auxins and gibberellins against the inhibitory role of ethylene and different candidate genes that could be useful as markers for parthenocarpic selection in the current breeding programs of zucchini.

Effect of cold storage time on chilling injury in two zucchini cultivars

Chilling injury (CI) is one of the most serious problems that reduce the quality of zucchini. Usually the damage increases during exposure to room temperature after cold storage, therefore the aim of this experiment was to evaluate the fruit postharvest quality of two zucchini cultivars when they are transferred to room temperature after different cold storage times. All fruits used were harvested from plants of two commercial hybrids ('Sinatra' and 'Victoria'), grown in the same field trial under standard greenhouse conditions in Almeria, Spain. Fruits of uniform length (18-20 cm) were harvested on the same day in the middle of the productive period with a view to minimizing the effects of environmental conditions. Fruits were stored for two weeks, but under the following conditions: they were randomly divided in 6 different lots of 36 fruits each in order to apply 6 different cold storage times: 2, 3, 5, 7, 10 and 14 days at 4°C. After cold treatments, the fruits were kept at 20°C during 12, 11, 9, 7, 4 and 0 days, respectively, for completing the two weeks of conservation. CI was evaluated after each cold storage (2, 3, 5, 7, 10 and 14 days) and ethylene production and respiration rate were assessed at 0, 7 and 14 days of storage in a lot of fruits of each cultivar and cold storage time. Respiration rate increases gradually during the 14-day experience, regardless of length of cold storage, however, ethylene production reached a maximum peak at 7 days, then ethylene production decreased irrespective of the cold storage time. A different sensitivity to CI was found between the two cultivars, 'Sinatra' being the most sensitive.

Biomarkers for selection of parthenocarpic zucchini cultivars

Biomarkers for selection of parthenocarpic zucchini cultivars

Survival of Fusarium solani f. sp. cucurbitae and Fungicide Application, Soil Solarization, and Biosolarization for Control of Crown and Foot Rot of Zucchini Squash.

Fusarium crown and foot rot of zucchini squash (Cucurbita pepo L.) caused by Fusarium solani f. sp. cucurbitae is one of the major diseases affecting zucchini squash production in Almería, Spain. Experiments were conducted to determine the pathogen's ability to survive in infested bags of perlite and to test several control methods under greenhouse conditions. The pathogen survived in the bags for at least 20 months with enough inoculum at that time to produce disease symptoms in zucchini plants, although disease severity was significantly reduced after 14 months. A total of 14 zucchini cultivars were inoculated with F. solani f. sp. cucurbitae, and all were highly susceptible to the disease. Eight fungicides and two microbial products, Trichoderma harzianum and Rhizophagus irregularis, were tested to determine their efficacy for the control of this disease. Prochloraz, carbendazim, and thiophanate-methyl, which are not labeled for use in zucchini in Spain, were highly effective for the control of the disease, while the other products were ineffective. Two soil solarization and biosolarization experiments were conducted in a greenhouse for 45-day periods during the summer. Inocula in the soil samples decreased by more than 99%, indicating the efficacy of completely closing the greenhouse windows, solarization, and biosolarization in reducing inoculum. Fungicide applications, crop rotation for at least two years, and soil solarization or biosolarization are promising control methods for this disease.

Auxin signalling regulation during induced and parthenocarpic fruit set in zucchini

Fruit set and fruit development can be limited due to ineffective pollination in off-season crops of Cucurbita pepo. To avoid this problem, parthenocarpy, the natural or artificial fruit development without fertilization, is required. The application of synthetic growth regulators is a common practice for inducing stimulative parthenocarpy in zucchini cultivars, but this method increases production costs and may cause other fruit defects. The disadvantages associated with this can be overcome through the use of vegetative parthenocarpic cultivars, which allow fruit set without any external stimuli. Three zucchini cultivars have been studied and differences have been found in parthenocarpic fruit development. Ethylene release of unpollinated fruit has corroborated the parthenocarpic fruit development. Vegetative parthenocarpy was observed in the Whitaker cultivar. Furthermore, the involvement of the auxin signalling pathway in controlling fruit set and parthenocarpy have been studied. Transcriptome analysis of auxin signalling genes, CpARF8, CpIAA9 and CpTIR1, have shown tissue-specific expression and have revealed a decrease in the expression levels of these genes in pollinated fruits after the fertilization signal, indicating their role in the transition from ovary to fruit. Nevertheless, it has also been shown that expression of these genes can be different between parthenocarpic cultivars.

Yellow Squash and Zucchini Cultivar Evaluation in Georgia

Ten yellow squash (Cucurbita pepo) and nine zucchini (C. pepo) cultivars were evaluated in southwest Georgia during spring and fall growing seasons in 2014 and 2015. Plants were grown using plastic mulch and drip irrigation following standard production practices for squash in Georgia. Plants were harvested 10 to 13 times during each study season. Fruit were graded into fancy, medium, and culls. Virus pressure was low during the trials. For yellow squash yields, there were significant cultivar by season interactions; however, Solstice, a straightneck yellow squash, and Gentry, a crookneck cultivar, were consistently among the highest yielding yellow types. Despite having no documented virus resistance, ‘Gentry’ performed well during the fall season. However, ‘Precious II’, a yellow straightneck cultivar with the presence of the precocious yellow gene, experienced high cull rates in the fall due to virus effects on the fruit. There was a year by season by cultivar interaction for zucchini yield. Despite this interaction, ‘Respect’ was ranked among the highest yielding cultivars in all four seasons of the trial. Differences were also observed between seasons for yellow and zucchini squash, with fall yields generally being lower than those in the spring. The results of this study suggest significant differences in the adaptability of squash cultivars for spring and fall production in Georgia. In addition, virus resistance, while important, should not be the exclusive factor for determining cultivars for fall-planted squash in Georgia.

Quality of Fresh Cut Zucchini as Affected by Cultivar, Maturity at Processing and Packaging

Appropriate plant material at processing and film packaging selection has a strong influence on product quality preservation. This is the first report studying the feasibility for minimal processing of four zucchini cultivars at two maturity stages, immature (MS1) and mature, stored at 6 °C during 10 days under different packaging conditions. The treatments consisted a 4 × 2 × 2 × 3 factorial combination of variety, maturity at processing, film packaging and storage time, including correlation studies between quality parameters. Negative effect on final quality after processing at MS1 was observed as a result of a higher respiration rate (between 15.91 and 20.12% than at mature), CO2 production and soluble solid consumption contributing to loss of firmness, slice discolouration and less overall quality. After 10 days under 25 µm film, cv. ‘Cronos’ showed the highest values in total chlorophylls (9.03 mg/100 g FW), while slices at MS1 suffered a noticeable oxidative stress increasing the total phenolic content (cv. ‘Parador’ > ‘Amalthée’ > ‘Cronos’ > ‘Cassiope’). At the end of storage, the highest vitamin C content was observed in trays sealed with 25 µm film (more evident in cv. ‘Cronos’ at MS1). In conclusion, processing more mature zucchini and 25 µm film packaging were the most effective combination for preserving quality. Copyright © 2016 John Wiley & Sons, Ltd.

Ethylene biosynthesis and signaling elements involved in chilling injury and other postharvest quality traits in the non-climacteric fruit of zucchini (Cucurbita pepo)

The immature non-climacteric fruit of zucchini is very sensitive to postharvest chilling injury (PCI). Although the fruit produces very low ethylene at harvest, cold storage induces an increase in ethylene production in the refrigerated fruit, and upon rewarming up to room temperature. The production of ethylene after rewarming was proportional to cold damage and found to be higher in the fruit of the cultivars most susceptible to chilling. The effects of the ethylene inhibitor 1-methycyclopropene (1-MCP) has been analyzed using the postharvest quality parameters of nine zucchini cultivars stored at 20°C and 4°C for 14 days. We have also determined the evolution of ethylene production in the fruit of these cultivars, and assessed the expression profiles of twelve ethylene biosynthesis and signaling genes in both control fruit and in 1-MCP treated fruit, of two cultivars that responded to 1-MCP. The 1-MCP treatment reduced the rate and delayed the onset of PCI symptoms and reduced fruit weight loss, although only in the fruit of the most chilling-susceptible cultivars, and concomitantly we found a reduction in the respiration rate and in the level of cold-induced ethylene. This data suggests that ethylene is not only a response of the fruit to cold damage, as occurs upon rewarming, but could also play a regulation role in the onset of PCI in this non-climacteric fruit. The genes CpACO1 and CpACS1 were found to be involved in the biosynthesis of the cold-induced ethylene, but the role played by CpACO1 was found to be the key function, since it was induced higher than CpACS1 in response to cold storage. More over CpACO1 was the only ethylene biosynthesis gene that was downregulated by the 1-MCP treatment. Some of the ethylene perception and signaling genes, including CpETR1, CpCTR1 and CpEIN3.1 were also induced in response to cold storage, and were downregulated in response to 1-MCP, indicating that the positive effect of 1-MCP in the fruit of certain zucchini cultivars is also associated with a downregulation of genes involved in ethylene perception and signal transduction pathways.