Effect Of 1-methylcyclopropene Research Articles

COMMODITY EVALUATION OF APPLES TREATED WITH 1–METHYLCYCLOPROPENE AFTER HARVEST

The thesis being presented is study on marketable quality of early winter apple fruits cultivars ‘Calville’ and ‘Spartan’ during refrigerated storage under the condition of their post-harvest treatment with 1-methylcyclopropene (1-MCP). The suppression of apple’s ripening after harvest is necessary to reduce the losses of marketable fruit quality during storage and receive a high economic effect from the sale of product. SmartFresh technology, based on inhibition of ethylene due to the effect of 1-methylcyclopropene (1-MCP), use to improve the quality of the majority of apple’s cultivars. The post–harvest application of 1-MCP effectively restrains the development of physiological disorders such as superficial scald and fruit rot, but sometimes may increase susceptibility to flesh browning, especially stored during 6 or more months. Research objects were early-winter apple cultivars ‘Calville’ and ‘Spartan’, treated after harvest with 1-MCP (‘SmartFreshTM’ 0,068 g·m-3) for 24 h at 5 °C, during storage at 3±1 °C and relative humidity 85–90 % for two, three, four, five and six months (non-treated fruits – control). The value of weight loss, superficial scald, fruit rot and core browning damage carried by weighing of respective factions of fruits. Data are means of three replicates and expressed as a percentage of fruit’s weight before storage. There was a significant increase in more than two times, compared to the control, the yield of standard products and, in particular, higher and first grades of 1-MCP treated fruits after six months of storage in combination with a significant decrease in technical defect, which has a decisive impact on expected proceeds and the level of profitability of storage. The weight losses of both early-winter apple cultivars increased during storage with not-substantial difference between the both treated with 1-MCP and control fruits. During storage standard product fraction of 1-MCP treated fruits both cultivars decreased quadratically with high correlation coefficients. After six months of storage control apples cv. ‘Calville’ had most fruits with superficial scald, core browning and rot, and cv. ‘Spartan’ – with core browning and rot, while the damage product of 1-MCP treated apples consisted mainly of rotting fruits. Consequently, post-harvest treatment of apple fruits with ethylene inhibitor 1-MCP increased the marketable quality and efficiency of the storing of early–winter apple cultivars ‘Calville’ and ‘Spartan’, reducing the intensity of physiological disorder’s and rot’s damage.

The isolated or combined effects of dynamic controlled atmosphere (DCA) and 1-MCP on the chemical composition of cuticular wax and metabolism of ‘Maxi Gala’ apples after long-term storage

Apples have a continuous hydrophobic layer that covers the surface of the fruit, which is called the cuticle. The effects of 1-methylcyclopropene (1-MCP) on the cuticular wax layer of apples were reported after cold storage, although the interaction between 1-MCP and dynamic controlled atmosphere (DCA) is not yet known. Therefore, this study aimed to analyze the effects of 1-MCP on the wax composition and metabolism of ‘Maxi Gala’ apples after storage in a controlled atmosphere (CA) and dynamic controlled atmosphere based on chlorophyll fluorescence (DCA-CF) and respiratory quotient (DCA-RQ; RQ = 1.3 and 1.5). The 1-MCP treatment effectively decreased ethylene production for CA and DCA-CF treatments, while in DCA-RQ treatments produced no effect. The average extracted cuticular wax content of ‘Maxi Gala’ apples was 16.65 g m−2 and no differences in storage conditions or 1-MCP application were observed. Alkanes, alcohols, fatty acids, aldehydes, and terpenoids were identified in the chemical composition of the cuticular waxes, being alkanes and fatty acids the predominant ones. Moreover, 1-MCP decreased fatty acid and 10-nonacosanol concentrations in the fruit. Fruit with the 1-MCP application and stored in DCA had lower α-farnesene concentrations. The wax compositions of the DCA-stored apples with and without 1-MCP were similar. However, 1-MCP treatment resulted in a greater mass loss in fruit stored in DCA.

Effect of 1-Methylcyclopropene (1-MCP) and Storage Atmosphere on the Volatile Aroma Composition of Cloudy and Clear Apple Juices

The effects of 1-methylcyclopropene (1-MCP), storage atmosphere (controlled (CA) or regular (RA)), and juice processing (clear or cloudy) on the volatile aroma compounds from McIntosh and Honeycrisp apples following 4-month storage were studied. All the major esters, aldehydes, and total volatile content from McIntosh juice were significantly affected by the two-way interaction between harvest maturity and 1-MCP treatment (p ≤ 0.01), as well as harvest maturity and storage atmosphere (p ≤ 0.001). In McIntosh juices, a remarkable reduction of all types of esters, aldehydes, most alcohols, and total volatile compounds was found when juices were prepared from 1-MCP-treated apples. In Honeycrisp, significant differences in the level of esters and the total volatile aroma was caused by storage atmosphere and juice processing techniques (p ≤ 0.001), but not by 1-MCP treatment. As compared to clear juices, cloudy juice samples from Honeycrisp had a considerably higher content of total volatiles, esters, and aldehydes.

The Combined Effect of 1-methylcyclopropene (1-MCP) and Ethylene on Green-life and Postharvest Quality of Banana Fruit

ABSTRACT 1-methylcyclopropene (1-MCP) extends shelf-life of banana fruit, however, it induces uneven ripening. The strong effect 1-MCP has on ethylene receptors probably condition the fruit to ripen unevenly. Combined application of 1-MCP and ethephon has been reported to alleviate this negative effect. However, limited work reported the effect of the treatment at cold storage. Hence, the present study determined whether the combined application of 1-MCP and ethylene prolongs banana green-life during cold storage and induces uniform ripening during shelf-life. The study comprised four treatments: control (untreated), gaseous 1-MCP at 400 nL L−1 and combination of 400 nL L−1 1-MCP with liquid ethephon at 50 or 100 µL L−1 concentrations. The treatments were arranged in a completely randomized design (CRD) with 4 replicates. The treated fruit were cold stored at 14°C for 30 d and thereafter 23°C to simulate shelf-life for 9 d. The results showed that 400 nL L−1 1-MCP and combined with 50 and 100 µL L−1 ethephon prolonged green-life and delayed ripening during cold storage compared to the control. In addition, there was more softening, yellow color development, and accumulation of soluble sugars in fruit treated with 1-MCP+ethephon compared to 1-MCP during shelf-life. The combined application of 1-MCP and ethylene is an effective strategy that prolongs banana green-life during cold storage and induces uniform ripening during shelf-life. This strategy has potential to be used when banana fruit are exported to distant markets, since it also prolongs green-life for a long time.

Effect of 1-methylcyclopropene on the aroma volatiles, polyphenols contents, and antioxidant activity of post-harvest ripening peach (Prunus persica L.) fruit

Peach is a perishable fruit that quickly loses its aroma and bioactive components during storage. In this article, we evaluated the effect of treatment with 1-methylcyclopropene (1-MCP) on the quality of stored peaches depending on shelf-life temperature. Ethylene production and aroma content were determined using gas chromatography mass spectrometry (GC-MS). Polyphenol levels were monitored using high-performance liquid chromatography (HPLC), and the antioxidant capacity of peach samples was determined using 2,2-diphenyl-1 picrylhydrazyl (DPPH), 2,2?-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and ferric reducing antioxidant power (FRAP) assays. We found that treatment with 1-MCP could delay the ripening process and reduce the decay of peach fruit depending upon shelf-life temperature. Furthermore, treatment with 1-MCP efficiently delayed climacteric ethylene production, maintained high levels of total soluble solids (TSS), titratable acidity and characteristic lactones, including ?-decalactone, ?-decalactone, ?-octalatone, jasmine lactone and ? dodecalactone. Moreover, treatment with 1-MCP also helped maintain high levels of chlorogenic acid, L epicatechin, catechin, quercetin-3-rutinoside and neochlorogenic acid, as well as high antioxidant activity. Principal component analysis showed that treatment with 1-MCP during the second week of storage coincided with activity of lactones, poly-phenols and antioxidants, which was consistent with changes in phytochemicals. These results revealed that treatment with 1-MCP offers potential as a preservation strategy for maintaining the flavour and nutritional quality of peach fruit under shelf-life conditions.

1-Methylcyclopropene treatment controls ethanol accumulation associated with regulation of mitochondrial energy metabolism in kiwifruit (Actinidia deliciosa) cv. "Bruno" during storage at room temperature.

In this paper, the effects of 1-methylcyclopropene (1-MCP) treatment on the ethanol accumulation and mitochondrial energy metabolism in kiwifruit (Actinidia deliciosa) cv. "Bruno" were investigated during storage at room temperature (24±1°C). The results showed that 1-MCP treatment significantly reduced the ethanol accumulation, maintained higher levels of adenosine triphosphate (ATP) content and energy charge (EC), enhanced enzymes activities involved in mitochondrial energy metabolism, such as succinic dehydrogenase, cytochrome C oxidase, H+ -adenosine triphosphatase (H+ -ATPase), and Ca2+ -adenosine triphosphatase (Ca2+ -ATPase), and regulated the NADH/NAD+ ratio, and pyruvate to tricarboxylic acid cycle (TCA) by suppressing the glutamate-pyruvate transaminase and promoting the pyruvate dehydrogenase activity, and decarboxylation of citric acid in harvested kiwifruit. These shifts in mitochondrial energy metabolism and oxidative phosphorylation correlated the higher ATP yield and an elevated EC with lower ethanol accumulation (13.71% of those in the control fruit) under 1-MCP treatment, and reduced the susceptibility of ethanol related off-flavor disorder in kiwifruit during storage. PRACTICAL APPLICATIONS: A kiwifruit (Actinidia deliciosa) cv. "Bruno," a major cultivatedkiwifruit in China, is prone to accumulate ethanol sharply after respiratory climacteric during storage. Ethanol has been accounted as a vital aroma volatile metabolite in various fruits. However, over accumulation of ethanol often leads to the development of alcohol off-flavor disorder, particularly in typical climacteric fruit such as kiwifruit. This work was aimed to maintain the flavor quality of kiwifruit cv. "Bruno" via improving the mitochondrial energy metabolism and functional TCA cycle, and limiting the ethanol accumulation under 1-MCP treatment. Thus, 1-MCP treatment could be beneficial to prevent the occurrence of alcohol off-flavor disorder along with sustainment of the flavor quality of kiwifruit cv. "Bruno" during storage at room temperature.

Effect of 1-methylcyclopropene (1-MCP) application and periodic cold storage on ripening of “Bartlett” pear during ambient shelf life periods

Bartlett pears harvested at commercial maturity (10.64 kg/cm2 flesh firmness and 3.15 starch iodine rating) were fumigated with 1-methylcyclopropene (3.3%VP SmartFreshTM) in a concentration range of 100–1,000 nl/L inside airtight chambers. The fruit were stored under cold storage conditions (2 ± 1°C with 95 ± 2%) followed by ambient holdings after monthly intervals. Treated fruit had significantly (p < .05) highest flesh firmness, total soluble solid, ascorbic acid, phenols, sensory scores with lowest PLW, spoilage, calcium content, and respiration rate. Further, fruit treated with 1,000 nl/L 1-MCP retained edible quality during the successive ambient holding period of 15, 9, 6, and 3 days after 30, 60, 90, and 120 days of cold storage. The untreated control fruit after 30 and 60 days of cold storage could be stored only up to 9 and 3 days under ambient holding conditions and lost their sensory acceptability after 90 days of cold storage. Practical Applications Response of pear fruit to 1-MCP treatments is highly variable based on storage atmosphere, mode of application, and concentration of the active ingredient. In our findings, we reported that fumigating freshly harvested pears with 800, 900, and 1,000 nl/L 1-MCP for 24 hr in airtight chambers retained highest fruit quality. Further, fumigation facilities can be established near production areas and fruit can be treated with 800 nl/L 1-MCP with a shelf life of 15, 9, 6, and 3 d after 30, 60, 90, and 120 days of cold storage. Threshold acceptability values for the most important quality parameters, namely, TSS, firmness, and PLW were standardized which can be used in the future to predict the shelf-life period of the fruit.

The Effects of 1-Methylcyclopropene in the Regulation of Antioxidative System and Softening of Mango Fruit during Storage

The function of 1-methylcyclopropene (1-MCP) in the regulation of quality and antioxidative system of mango fruit was investigated during storage at ambient temperature. Changes in fruit quality, colour, ethylene production, respiration rate, fruit softening enzyme activities, and antioxidative enzyme activities were studied in this study. The results demonstrated that 1-MCP was beneficial for maintaining quality. 1-MCP treatment retarded the decline of firmness, weight, total soluble solid, and titratable acidity, which served as significant parameters for assessing fruit quality in the process of storage. Compared with the fruit of the control group, the treatment with 1-MCP dramatically delayed the colour change of both the pulp and peel and suppressed climacteric peaks of ethylene generation and respiration speed. The significant inducement of peroxidase, catalase, and superoxide dismutase activities were followed by 1-MCP treatment. The fruit treated with 1-MCP displayed significantly inhibited activation of enzymes on the cell wall, i.e., pectin esterase (PE), endo-1,4-β-d-glucanase (EGase), exopolygalacturonase (exo-PG), and endopolygalacturonase (endo-PG), during storage. The results suggested that 1-MCP imposed underlying impact on the maintenance of the softening and extension of postharvest life of mango fruit.

Effect of 1-methylcyclopropene on antioxidants of cantaloupe (Cucumis melo) fruit during storage

Effect of 1-methylcyclopropene on antioxidants of cantaloupe (Cucumis melo) fruit during storage

The effect of 1-methylcyclopropene on storage and quality properties of kiwifruit for fruit slices

The effect of 1-methylcyclopropene on storage and quality properties of kiwifruit for fruit slices

Effects of 1-Methylcyclopropene and Controlled Atmosphere on Ethylene Synthesis and Quality Attributes of Avocado cvs. Edranol and Fuerte

Avocado production worldwide relies on several varieties, with “Hass” being the most commercialized; however, the available genotypes include a number of green-skin varieties with important roles in several countries. Because many technologies have already been developed in “Hass” avocado, the main objective of this study was to evaluate the effects of controlled atmosphere (CA) storage and 1-methylcyclopropene (1-MCP) application during long-term storage of “Edranol” and “Fuerte” avocados. Fruits of both varieties were harvested at two maturity stages: an early harvest close to 20–23% dry matter (DM) content and another after two months, with 22% and 32% DM content for Edranol and Fuerte, respectively. After harvest, the fruit was stored under the following conditions: (i) regular air storage (RA), (ii) CA with 4% O2and 6% CO2, and (iii) 1-MCP applied at 300 ppm. Avocados were stored at 5°C and 85% relative humidity. Physiological and quality evaluations were performed immediately after 30 and 50 days; afterwards, the avocados were maintained at 20°C (shelf life) until they reached the ready-to-eat stage. Ethylene synthesis was assessed by measuring the transcript accumulation of the ACO and ACS genes. The two varieties showed distinct respiration and ethylene production rates during ripening, and fruit stored under CA or after application of 1-MCP showed lower respiration rates than fruit stored under RA, with the lowest rate in 1-MCP-treated avocados. ACS and ACO transcript levels were also lower under both conditions. CA and 1-MCP were very effective tools for extending storage life mainly by reducing the fruit softening rate and the incidence of pulp disorders in both varieties, and interestingly, these techniques did not severely affect the days to reach the ready-to-eat stage. Therefore, the use of CA and 1-MCP technologies in “Fuerte” and “Edranol” seems to be suitable for maintaining quality through 50 days of storage.

Physiological and transcriptomic analysis reveals the roles of 1-MCP in the ripening and fruit aroma quality of banana fruit (Fenjiao).

Fenjiao (Musa ABB Pisang Awak) is a popular banana cultivar due to its good taste and stress resistance, but it has a short shelf-life and deteriorates rapidly post-harvest. The effects of 1-methylcyclopropene (1-MCP) treatment on fruit physiology and quality and transcriptomic profiles are investigated in this study. The results showed that 1-MCP significantly delayed fruit ripening by repressing fruit softening and inhibiting the respiratory rate and ethylene production. The 1-MCP treatment delayed sugar accumulation and influenced the content of the precursors of the biosynthesis of aroma volatiles. 1-MCP reduced the production of flavor-contributing volatile esters isoamyl isobutyrate, isoamyl acetate and trans-2-hexenal and hexanal, but dramatically increased the hexyl acetate production at the full-ripening stage. The transcriptomic analysis showed that 1-MCP dramatically affected the transcript profiles during fruit ripening, especially the KEGG pathways involved in amino acid metabolism, biosynthesis of other secondary metabolites, carbohydrate metabolism, lipid metabolism, signal transduction, and translation classes. The key genes and the corresponding enzyme activities involved in the volatile and ethylene synthesis were severely repressed due to the 1-MCP treatment. The 1-MCP treatment effectively delayed Fenjiao fruit ripening, but affected volatile production by reducing the precursor production and expression level of genes involved in the metabolism pathways of ethylene, auxin and volatiles.

Effects of 1-methylcyclopropene on ascorbate-glutathione cycle enzyme activities of postharvest Dendrobium ‘Khao Sanan’

Effects of 1-methylcyclopropene on ascorbate-glutathione cycle enzyme activities of postharvest <i>Dendrobium</i> ‘Khao Sanan’

Effects of 1-methylcyclopropene (1-MCP) on the expression of genes involved in the chlorophyll degradation pathway of apple fruit during storage

The ripening of the apple (Malus × domestica Borkh.) fruit is regulated by the phytohormone ethylene, where degreening is an important physiological metabolism caused by chlorophyll (Chl) degradation. However, to date, research on how ethylene affects the Chl degradation pathway of apple peel during ripening remains scarce. In this study, the effects of ethylene on the expression of Chl catabolic genes (CCGs) of apple peel during ripening were studied by treating harvested commercial mature apples with 0.5 μL L−1 1-methylcyclopropene (1-MCP). The results showed that 1-MCP treatment led to a delayed climacteric peak of respiration and ethylene production, exhibiting higher Chl content and hue angle (H˚) compared to untreated fruit during ripening. Lower quantities of pheophorbide a oxygenase (PAO), pheophytinase (PPH) and red Chl catabolite reductase (RCCR) were also observed in peel tissues under 1-MCP treatment during ripening. Further study with quantitative real-time polymerase chain reaction (qPCR) revealed that the expression of CCGs, except for MdNYE1a, increased atdifferentdegrees upon ripening. Meanwhile, the apples treated with 1-MCP presented a downregulated expression of MdRCCR2, MdNYC1, MdNYC3 and MdNOL2 and a fluctuating expression of MdNYE1a, MdPPH1, MdPAO6, MdPAO8 and MdHCAR compared with the controls during ripening. Our results indicated the regulatory role of ethylene in the Chl degradation pathway of apple peel during ripening.

Effect of 1-methylcyclopropene (1-MCP) on quality of button mushrooms (Agaricus bisporus) packaged in different packaging materials

The effects of 1-MCP treatment on the quality of Agaricus bisporus mushrooms packed in three different packaging films, i.e., low permeable packaging (LPP), medium permeable packaging (MPP) and high permeable packaging (HPP), were evaluated. Quality factors included weight loss, color, texture, and sensory. Results show that 1-MCP can slow down the respiration rate of mushrooms. In LPP and MPP, where O2 supply was limited, the respiration rate of mushrooms can be reduced by around 25%, while in HPP where there was constant O2 supply, the respiration rate reduced by around 2%. The best effectiveness was obtained from the combination of 1-MCP and MPP, which created headspace composition of less than 0.1% of O2, and 5–10% CO2, providing more than 15 d of shelf life. This combination provided several benefits for mushroom quality including maintaining sensory quality, weight, and firmness, as well as altering the formation of flavor nucleotides process which has the potential to improve umami taste.

Effect of 1-methylcyclopropene on cactus pear fruit at different maturity stages during storage

1-Methylcyclopropene (1‑MCP) is an ethylene antagonist widely used to retain quality and prolong the postharvest storage period of various climacteric fruits. To date, there is little information about the effects of 1‑MCP on postharvest storage performance of cactus pear fruits. Recently, data revealed that exposure of 1‑MCP at 1000 ppb had several beneficial effects in preserving postharvest quality of cactus pear fruits, as indicated by inhibition of peel color change. In this paper, we investigated the effect of 1‑MCP on quality of cactus pear fruit harvested from the scozzolatura crop at early and late ripeness stages. Fruit was tested at two different ripening stages: “commercial ripe” (CR; fruit commercially ripe with 90% green ground-color and 10% orange color) and “ripe on tree” (ROT; late fruit ripe on tree with 100% orange color and no green ground-color). Fruit was sanitized by immersion in 200 mg kg(‑1) sodium hypochlorite for 5 min, and stored at 8°C for 30 days. Color (L* and ΔE), visual appearance, crunchiness score, carotenoids, phenolic content and respiration rate were measured at harvest and after 7, 14, 21 and 30 days. The results did not show beneficial effects of 1‑MCP in terms of color or visual or crunchiness score; in contrast, significant differences occurred in all samples in terms of carotenoid and polyphenol content.

Cloning and expression analysis of polygalacturonase and pectin methylesterase genes during softening in apricot (Prunus armeniaca L.) fruit

Apricot softening is an important physiological process that influences fruit quality and postharvest life. Polygalacturonase (PG; EC 3.2.1.6.9) and pectin methylesterase (PME; EC 3.1.11) are two important cell wall hydrolases that have been widely studied during fruit softening. However, the roles of PG and PME genes in apricot softening remain unclear. In the present study, PaPG1 and PaPME1 from the apricot fruit were cloned and characterized. Moreover, the effects of 1-methylcyclopropene (1-MCP) treatment on firmness, ethylene production, PaPG1 and PaPME1 expression levels as well as PG and PME activities in apricots during storage at 4 ℃ were investigated, and the quality traits of apricot fruit during shelf life at 25 ℃ after cold storage were analyzed. Results showed that the application of 1-MCP significantly inhibited the decrease in fruit firmness as well as the increase in ethylene production, and markedly suppressed the expression levels of PaPG1 and PaPME1 and the increases in PG and PME activities of the apricots during cold storage. In addition, the 1-MCP treated apricots exhibited higher firmness, titratable acid (TA) content as well as lower ethylene production, respiration rate and weight loss compared to the control during shelf life at 25 ℃. These results suggested that 1-MCP treatment delayed the softening and ripening of the apricots during cold storage, and maintained better quality and consumer acceptability of the apricots during shelf life. PG and PME genes might play crucial roles in the development of apricot softening during cold storage.

Effect of 1‐MCP on postharvest quality of French prune during storage at low temperature

The effect of 1-methylcyclopropene (1-MCP) treatment on postharvest quality of French prune (Prunus domestica L.) during low temperature storage was investigated. French prunes were exposed to 1.2 μl/L 1-MCP and stored at 1 ± 1°C under 90 ± 5% RH. The physiological and biochemical indexes were measured and recorded weekly throughout the experimental period. Our experimental results showed that 1-MCP had a significant effect on maintaining fruit hardness (~20%), titratable acidity (~29%), ascorbic acid (~18%), total soluble solid (~21%), anthocyanin, retarding moisture loss (~44%), and delaying the color changes and harvest ripening (~7 d) as compared to non-1-MCP treated fruit. Furthermore, 1-MCP treatment significantly inhibited malondialdehyde (MDA) production (~33%) and maintained the total phenolic content. Therefore, 1-MCP, an ethylene antagonist, could effectively maintain postharvest quality of prune during storage at low temperature. Practical applications French prune (Prunus domestica L.) is very popular in the world, because it has the very high nutritional value. However, the harvested French prunes tend to soften rapidly at ambient temperature. Low temperature storage is beneficial to prolong the postharvest life of prunes. Besides, 1-methylcyclopropene (1-MCP) is effective in delaying fruit ripening and extending the postharvest life. The aim of this study is to evaluate the influence of 1-MCP on postharvest quality of French prune during low temperature storage. In general, 1-MCP could effectively maintain postharvest quality of prune during storage at low temperature.

Effects of 1-methylcyclopropene on the quality attributes of harvested Chinese mushroom (Volvariella volvacea) fruiting bodies.

The effects of paper containing different concentrations of 1‐methylcyclopropene (1‐MCP) on the quality of Chinese mushrooms were investigated. Mushrooms were first stored with paper containing 0, 0.25, 0.50, 0.75, 1.00, or 1.25 μl L−1 1‐MCP at 15 ± 1°C for 12 hr and then continued for up to 8 days. 1‐MCP reduced the respiratory peak, weight loss, degree of cap browning, relative leakage rate, and soluble solid content, and delayed the change in the surface hue angle. Mushrooms exposed to paper containing 1‐MCP maintained firmness and sensory attributes. The storage time of Chinese mushrooms treated with 1‐MCP at the best concentration (0.75 μl L−1) was 8 days, which was 4 days longer than that of the control. Browning in mushrooms was related to the vitamin C content, total phenol content, and polyphenol oxidase activity. The results would be very useful to the mushroom industry and provide a theoretical basis for the potential researches of the mechanisms maturation and senescence in Chinese mushrooms.

1-Methylcyclopropene Effects on Field-Grown Cotton: Morphological Characteristics and Yield

Upland cotton (Gossypium hirsutum L.) is an important socioeconomic crop throughout most of the southern U.S. In Texas, cotton is the lead cash crop and its productivity is often limited by abiotic stress events such as drought and elevated ambient temperatures. The objective of this study was to assess the effects of 1-methylcyclopropene (1-MCP) applications triggered by canopy temperature and forecasted ambient temperatures on field-grown cotton plants. Yield and crop morphological responses to 1-MCP applications were investigated in field studies conducted during the summers of 2012 to 2014 at the Texas A&amp;M University Field Laboratory in Burleson County, TX. Positive effects of 1-MCP were found for fruit retention in 2013 and 2014 for both irrigated and dryland studies; however, a negative impact was found in the 2012 irrigated study. By harvest, 1-MCP applications had no effect on final cotton yield or fiber quality parameters. Applications of 1-MCP affected some morphological characteristics of cotton plants; however, it did not improve crop yield.