Effects of 1-methylcyclopropene on skin greasiness and quality of'Yuluxiang'pear during storage at 20℃

During storage at 20℃,specific pear cultivars may exhibit a greasy texture and decline in quality due to fruit senescence.Among these varieties,‘Yuluxiang’is particularly susceptible to peel greasiness,resulting in significant economic losses.Therefore,there is an urgent need for a preservative that can effectively inhibit the development of greasiness.Previous studies have demonstrated the efficacy of 1-methylcyclopropene(1-MCP)in extending the storage period of fruits.We hypothesize that it may also influence the occurrence of postharvest peel greasiness in the‘Yuluxiang’pears.In this study,we treated‘Yuluxiang’pears with 1-MCP.We stored them at 20℃while analyzing the composition and morphology of the surface waxes,recording enzyme activities related to wax synthesis,and measuring indicators associated with fruit storage quality and physiological characteristics.The results demonstrate that prolonged storage at 20℃leads to a rapid increase in skin greasiness,consistent with the observed elevations in L^(*),greasiness score,and the content of total wax and greasy wax components.Moreover,there were indications that cuticular waxes underwent melting,resulting in the formation of an amorphous structure.In comparison to controls,the application of 1-MCP significantly inhibited increments in L^(*) values as well as grease scores while also reducing accumulation rates for oily waxes throughout most stages over its shelf period,additionally delaying transitions from flaky-wax structures towards their amorphous counterparts.During the initial 7 d of storage,several enzymes involved in the biosynthesis and metabolism of greasy wax components,including lipoxygenase(LOX),phospholipase D(PLD),andβ-ketoacyl-CoA synthase(KCS),exhibited an increase followed by a subsequent decline.The activity of LOX during early shelf life(0–7 d)and the KCS activity during middle to late shelf life(14–21 d)were significantly suppressed by 1-MCP.Additionally,1-MCP effectively maintained firmness,total soluble solid(TSS)and titratable acid(TA)contents,peroxidase(POD),and phenylalanine ammonia-lyase(PAL)activities while inhibiting vitamin C degradation and weight loss.Furthermore,it restrained polyphenol oxidase(PPO)activity,ethylene production,and respiration rate increase.These findings demonstrate that 1-MCP not only delays the onset of peel greasiness but also preserves the overall storage quality of‘Yuluxiang’pear at a temperature of 20℃.This study presents a novel approach for developing new preservatives to inhibit pear fruit peel greasiness and provides a theoretical foundation for further research on pear fruit preservation.

1-MCP缓释水凝胶对采后草莓果实品质和抗病性的影响(英文)

近年来,已有大量的研究探究了1-甲基环丙烯(1-methylcyclopropene,1-MCP)在水果保鲜方面的应用,这些研究大多集中于呼吸跃变型果实。然而,对于1-MCP的保鲜应用仍缺乏高效缓释产品,且其在草莓等典型非呼吸跃变果实中的作用仍待进一步探究。本研究基于水凝胶体系开发了一种用于草莓保鲜的1-MCP水凝胶控释保鲜剂。该保鲜剂的水凝胶体系利用丙烯酸羟乙酯(HEA)、丙烯酸(AA)两种单体和交联剂聚乙二醇二丙烯酸酯(PEGDA),在二苯基氧化磷(TPO)的引发下,于水溶性体系中,将1-MCP粉末包裹在多孔水凝胶体系内,制得1-MCP缓释水凝胶,并将其用于常温下草莓保鲜。结果显示,该凝胶具有优异的1-MCP缓释性能,能够均匀且缓慢地释放1-MCP气体,其第12 h的释放率分别是1-MCP粉末组和1-MCP水溶液的7%和3%,达到长期有效释放的效果。果实保鲜实验表明,该凝胶能使草莓果实实现更低的失重率、腐烂率,在第6 d时,实验组比对照组分别低了20%和21%。除此之外,1-MCP缓释水凝胶能使草莓维持更好的果实色泽、更高的硬度、可溶性固形物含量(TSS)和可滴定酸含量(TA),实验组在第2 d时,其a*值、b*值和L*值分别比对照组高了11%、11%和6%,第6 d的硬度、TSS和TA分别比对照组高了21%、15%和18%。综上,1-MCP水凝胶具有缓释1-MCP、提高果实品质等多种功能,且制备方便,可用于草莓等水果的采后保鲜。

1-MCP与MT联合处理对芒果保鲜效果的影响

为探究1-甲基环丙烯(1-MCP)与褪黑素(MT)联合处理对芒果保鲜效果的影响,该研究用0.1 mg/L 1-MCP和0.2 mmol/L MT联合处理芒果后,于25℃贮藏10 d,每2 d取样测定相关指标。结果显示:1-MCP和MT联合处理可以延缓芒果果皮叶绿素降解和类胡萝卜素含量升高,在贮藏第10天,处理组的果皮叶绿素为0.078 mg/g,是对照组的5.27倍;延缓了果肉L*值的下降和a*、b*值的升高,抑制原果胶降解和可溶性果胶含量的升高,贮藏第6天处理组的原果胶含量比对照高2.53倍,而可溶性果胶含量比对照低44.04%,同时在贮藏前期显著抑制了多聚半乳糖醛酸酶(PG)和纤维素酶(Cx)活性,降低了β-半乳糖苷酶(β-Gal)活性,并且维持了果肉更完整的细胞结构,但果肉类黄酮含量在贮藏中期显著低于对照。综上,1-MCP和MT联合处理保持了芒果良好的外观品质,延缓了细胞壁物质的降解,提高了货架期品质。

1-MCP协同活性炭处理抑制鲜切胡萝卜木质化形成研究

鲜切胡萝卜在贮藏过程易发生木质化,导致品质下降。为探究1-MCP协同活性炭处理对鲜切胡萝卜木质化抑制保鲜效果,文章分析了乙烯利、活性炭、1-MCP和1-MCP协同活性炭等4种处理方式对鲜切胡萝卜硬度、总酚、抗氧化性、PPO、POD、PAL和木质素含量的影响。结果表明:1-MCP协同活性炭处理显著延缓了胡萝卜硬度下降;在贮藏第10 d总酚含量达0.20 mg GAE·g^(−1),显著高于其他处理组(P<0.05);抗氧化性也保持最高水平;DPPH自由基清除活性为0.90μmol TE·g^(−1);PPO、POD活性分别为0.23 U·g^(−1)和61.08 U·g^(−1),显著低于对照组(P<0.05);PAL活性和木质素含量分别为81.67 U·g^(−1)和65.88 mg·g^(−1),也显著低于对照组(P<0.05)。可见,1-MCP协同活性炭处理可有效抑制鲜切胡萝卜木质化,提升其贮藏品质。

1-MCP处理对库尔勒香梨酚类及抗氧化活性的影响

以新疆库尔勒香梨为试材,采用1-甲基环丙烯(1-MCP)处理结合低温贮藏的方法,研究了1-MCP处理对香梨贮藏过程中常规指标和多酚及抗氧化活性的影响,以期为库尔勒香梨保鲜提供参考依据。结果表明:库尔勒香梨在4℃和相对湿度90%~95%的条件下,采用1-MCP处理显著抑制了果实硬度、总酸、葡萄糖、蔗糖和山梨醇的下降,延缓了果实的可溶性固形物峰值到达时间,保持总酚、熊果苷、儿茶素、绿原酸和芦丁含量,抑制果实抗氧化能力的下降。综上可知,采用1-MCP处理能够有效保持香梨贮藏品质,延缓香梨酚类化合物含量和抗氧化活性的下降。

Effect of Internal Ethylene and 1-Methylcyclopropene on Ethylene Metabolism and Membrane Lipid Peroxidation in Papaya Fruit

[Objective] This study was conducted to evaluate the effect of 1-methylcy- clopropene （1-MCP） on fruit firmness, and the activity of the enzymes involved in ethylene metabolism and membrane lipid peroxidation. [Method] The nearly ripe fruits of the papaya cultivar Risheng were randomly assigned to one of four groups. Two groups were treated under hypobaric and hypoxic （HH） atmosphere condition for six hours, and immediately soaked in deionized water （HH alone）, or fumigated with 2.0 mg/L 1-MCP （HH＋I-MCP） for 24 h. The other two groups untreated under HH condition were also soaked in deionized water （negative control）, or fumigated with 2.0 mg/L 1-MCP （1-MCP alone） for 24 h. After that, the fruits of all the four treatments were stored at room temperature （23＋1） ℃. Cell membrane permeability, fruit firmness, respiration rate, ethylene release rate, SOD activity, POD activity, CAT activity, MAD content and LOX activity were measured once every three days during storage. [Result] Treatment with 1-MCP delayed the occurrence of the peaks of respiration rate and ethylene release rate, significantly reduced the accumulation of malondialdehyde （MDA）, and inhibited the decrease in papaya fruit firmness. Compared with the control, 1-MCP treatment significantly increased the SOD （su- peroxide dismutase）, POD （peroxidase） and CAT （catalase） activity, reduced the ac- tivity of lipoxygenase （LOX）, a product of lipid peroxidatlon in membranes, and in- hibited ethylene biosynthesis, thus delaying the aging process and prolonging the storage life of papaya fruits. [Conclusion] The results will provide a theoretical basis for analvzina the key factors controllinq postharvest maturity and aging of papaya fruits.

不同1-MCP处理方式对南红梨采后质地与风味品质的影响

目的探究不同1-甲基环丙烯(1-methylcyclopropene,1-MCP)处理方式对南红梨保鲜效果的差异。方法以南红梨为试材,分别进行1-MCP雾化处理和1-MCP便携式小药包熏蒸处理,以不施加1-MCP为CK,处理后用微孔膜包装后快递至目的地,于室温(23℃)条件下进行贮藏,并对货架35 d内的感官指标、生理指标、硬度与软化酶活性进行测定,利用气相色谱-离子迁移谱联用技术(Gas Chromatography-Ion Mobility Spectroscopy,GC-IMS)分析不同处理南红梨挥发性成分的差异。结果CK、1-MCP雾化、1-MCP熏蒸3组分别在14、21、28 d时出现明显后熟特征,挥发性成分浓度剧烈增加,酯类为最多。1-MCP无法改变南红梨挥发性成分,仅能推延成分出现的时间。在不同1-MCP处理组中,熏蒸组能够对果皮转色、呼吸作用、乙烯合成、果实软化、挥发性成分生成起到更好的抑制作用,以延长果实保鲜时间。结论1-MCP对南红梨保鲜具有积极作用,1-MCP雾化组与熏蒸组分别延长采后南红梨的货架期14 d和21 d。本文可为南红梨采后贮运提供新的思路及方法。

1-MCP结合低温贮藏对阳光玫瑰葡萄贮藏品质及生理特性的影响

目的为探究1-MCP结合低温处理对“阳光玫瑰”葡萄贮藏品质的变化。方法以葡萄为试材,分别用0.5、1、1.5、2μL/L 1-MCP进行处理,无1-MCP处理的作为对照(CK)。将试材置于温度为(0±0.5)℃、相对湿度为75%的保鲜库中贮藏,每20 d测定1次葡萄的生理指标。结果较其他浓度处理,1μL/L 1-MCP结合低温处理,抑制了“阳光玫瑰”葡萄的硬度、呼吸强度、MDA含量和PPO活性的升高,减少了落粒率和腐烂率的发生,延缓了SSC、TA含量的下降。结论1μL/L1-MCP结合低温处理,推迟了“阳光玫瑰”葡萄在贮藏期间的后熟衰老进程,最大限度地保持了果实的新鲜品质,延长了果实的贮藏期,可作为“阳光玫瑰”葡萄规模化贮运保鲜的实用技术。

1-MCP处理对甜樱桃果实凹陷、贮藏品质及活性氧代谢的影响

为探究1-甲基环丙烯(1-methylcyclopropene,1-MCP)处理对采后甜樱桃果实凹陷、贮藏品质和活性氧代谢的影响,该研究以“萨米脱”甜樱桃为材料,用1.0μL/L 1-MCP熏蒸处理甜樱桃果实12 h,于(0±0.5)℃下贮藏,定期取样进行相关指标的测定。结果表明,1-MCP处理有效降低甜樱桃果实凹陷率、凹陷指数和腐烂率,并显著抑制果实硬度、可溶性固形物和可滴定酸含量的下降,较好的维持了果实外观和口感。同时1-MCP处理保持较高的超氧化物歧化酶、过氧化氢酶、抗坏血酸过氧化物酶和谷胱甘肽还原酶活性,促进了抗坏血酸含量和谷胱甘肽含量的上升,提高了果实的DPPH自由基和ABTS阳离子自由基清除能力,显著降低超氧阴离子自由基和H_(2)O_(2)含量,抑制丙二醛积累和相对电导率上升。这些结果表明,1-MCP处理可能通过提高抗氧化酶活性,抑制活性氧累积,从而减轻细胞膜氧化损伤,保护细胞膜的完整性,进而抑制甜樱桃果实表面凹陷。该研究为1-MCP在甜樱桃冷链物流保鲜中的应用提供了理论依据。

1-MCP复合杀菌剂对西州蜜甜瓜常温贮藏品质的影响

为了探究不同保鲜剂复合杀菌剂对甜瓜的保鲜效果,以西州蜜甜瓜为试验材料,研究了抑霉唑硫酸盐、ClO2、咪鲜胺、1-MCP、1-MCP复合抑霉唑硫酸盐和无菌水对甜瓜常温贮藏下品质的影响。结果表明,与对照无菌水相比,所有保鲜剂均可显著抑制甜瓜采后腐烂与失重,维持果实硬度和可溶性固形物含量,提升贮藏品质。1-MCP与1-MCP复合杀菌剂处理可显著抑制西州蜜果实的呼吸速率和乙烯释放速率,呼吸峰值较对照无菌水分别降低43.7%和37.5%,乙烯释放峰值较对照无菌水分别降低47.9%和53.7%,呼吸峰值和乙烯释放峰值出现时间均推迟3 d。其中1-MCP复合杀菌剂对果实可滴定酸和Vc含量保持效果显著,与对照无菌水相比,可滴定酸含量提高40.0%,Vc含量提高38.2%,对西州蜜甜瓜的保鲜效果最好。

1-MCP协同高浓度CO_(2)短激对青皮无花果采后软化的影响

以山东威海青皮无花果为实验材料,分别研究了1-甲基环丙烯(1-methylcyclopropene,1-MCP)处理、高浓度CO_(2)短时应激处理(短激)、1-MCP协同高浓度CO_(2)短激对果实采后软化等贮藏品质的调控规律。结果表明:与对照组(CK)相比,1-MCP和高浓度CO_(2)单独与两者协同处理都可抑制青皮无花果采后呼吸强度,降低多聚半乳糖醛酸酶(PG)、果胶甲酯酶(PME)、纤维素酶(Cx)、β-葡萄糖苷酶(β-Glu)的酶活性,维持果实色泽和硬度,延缓果实软化和降低腐烂率。其中,1-MCP协同高浓度CO_(2)短激处理效果最好,贮藏20 d后,1-MCP协同高浓度CO_(2)短激处理组硬度为1.74 N,原果胶含量比对照组高38.4%,果胶甲酯酶和可溶性果胶仅为对照组的79%和80%。本研究为青皮无花果采后抗软化提供了理论依据。

塞外红苹果果实1-MCP熏蒸结合低温贮藏方法的研究

以产于内蒙古开鲁县的塞外红苹果果实为试材,采后用0、1.0μL/L 1-甲基环丙烯(1-MCP)熏蒸处理,随后分别在-1、1、3℃低温条件下贮藏,分析其低温贮藏和20℃货架期品质以及采后生理变化规律,以期明确塞外红果实的最适贮藏温度和贮藏时间。结果表明,与只冷藏相比,采用1-MCP熏蒸处理结合低温贮藏能显著延缓塞外红果实硬度的降低,保持贮藏和货架期间果实相对较高的可溶性固形物含量、可滴定酸含量、维生素C含量,抑制乙醇的生成,能明显抑制多聚半乳糖醛酸酶和纤维素酶活性的上升,有效延缓果实软化衰老,相关性分析结果显示,各生理指标均存在极显著相关性。综合比较认为:1-MCP熏蒸处理结合1℃冷藏至120 d,再在20℃货架上放置5 d,塞外红果实硬度保持在9.0 kg/cm^(2)以上,整体保鲜效果最好;1-MCP熏蒸处理结合-1℃冷藏,果实硬度也较高,但后期果皮颜色发暗,商品价值较低;1-MCP熏蒸处理结合3℃冷藏,建议贮藏时间控制在90 d以内。

纳米银和 1-MCP 处理对月季切花的保鲜作用

研究了纳米银和1-MCP处理对月季切花‘卡罗拉’瓶插寿命和花径、相对鲜重(RFW)和瓶插液吸收(VSU)、相对叶绿素含量和丙二醛(MDA)含量、相对电导率以及抗氧化能力的调节作用。结果表明:与对照相比,纳米银和1-MCP单独处理与组合处理均能显著提高花瓣还原力,提升抗坏血酸过氧化物酶(APX)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性,降低花瓣中丙二醛(MDA)含量和叶片中相对电导率,并抑制叶绿素含量的下降。与纳米银和1-MCP单独处理相比,纳米银和1-MCP组合处理对延长月季切花瓶插寿命、增大切花花径、促进切花吸水、维持切花的质膜稳定性和提升切花的抗氧化能力更为有效。总之,纳米银和1-MCP组合处理可通过维持切花的水分平衡和质膜稳定性、提高切花的抗氧化能力、降低切花的膜脂质过氧化水平来延长月季切花的瓶插寿命。

Mechanism and Kinetics of Thermal Dissociation of Inclusion Complex of β-Cyclodextrin and 1-Methylcyclopropene

The inclusion-complex of CD-MCP （β-cyclodextrin （β-CD） including 1-methylcyclopropene （1-MCP）） was prepared and characterized. Basing on programmed-heating procedure and weight-temperature analysis, as well as the application of Satava-Sestak＇s, Ozawa＇s and Kissinger＇s methods, the mechanism and kinetics of thermal dissociation of this inclusion complex were studied. An additional mass loss is found at 170-180℃. The mechanism of thermal dissociation of CD-MCP is dominated by a one-dimensional random nucleation and subsequent growth process （A2/3）. The activation energy Es and the pre-exponential factor AS for the process are 102.14 kJ/mol and 3.63×10^10s^-1, respectively. This ES value shows that there is no strong chemical intere, ctions between β-CD and 1-MC;P,

Preharvest application of 1-methylcyclopropene and Ethephon altered cuticular wax biosynthesis and fruit quality of apples at harvest and during cold storage

To investigate the roles of Harvista(a sprayable 1-methylcyclopropene,1-MCP,available component is 150 g·hm^(-2))and Ethephon(1 mL·L^(-1))applied at preharvest in apple(Malus domestica Borkh.'Golden Delicious')fruit cuticular wax biosynthesis,the expression of genes related to fruit cuticular wax biosynthesis and ethylene biosynthesis and signaling,ethylene production rate,respiration rate,wax constituents and structure,and fruit quality were determined at harvest and during cold storage.The results showed that 1-MCP inhibited the expression levels of ethylene biosynthesis and signaling-related genes,decreased fruit ethylene production,and inhibited the expression of Md LACS1,Md CER6,Md CER4 and Md WSD1,which resulted in decreases in alcohols,acids,and esters content in fruit cuticular wax.1-MCP also reduced fruit dropping rate from 17.17%to 12%;maintained fruit firmness,soluble solids,titratable acidity during cold storage;showed about as one fifth in the total length and one third in the widest width of wax crack as that in control at harvest.In contrast,Ethephon produced the opposite effects.In conclusion,1-MCP inhibited fruit ethylene biosynthesis and signaling,and influenced fruit cuticular wax biosynthesis.Thus,the fruit cuticular wax constituents and structure was altered,and the fruit quality were maintained at harvest and during cold storage.The results provide a new technology for improving apple fruit harvest and postharvest quality by preharvest application of sprayable 1-MCP.

Current progress in application of 1-Methylcyclopropene to improve postharvest quality of cut flowers

Floral senescence or petal abscission that determine cut flower quality and longevity are primarily caused by the regulation of endogenous ethylene and perception of endogenous and exogenous ethylene in floral organs(such as the petals and gynoecium),in ethylene-sensitive species.Several attempts have been made to prolong flower quality and longevity using silver ions and other chemicals that inhibit ethylene production and perception in floral organs.Among the available compounds,1-methylcyclopropene(1-MCP)has been increasingly used as ethylene-action/perception inhibitor because of its ability to inhibit ethylene action/perception and it is environmentally safe.Although 1-MCP has been used in several cut flower crops for about 25 years,there has been no review yet that critically emphasizes the benefits or difficulties of using this compound for the prolongation of cut flower quality and longevity.Here,we outline the role of 1-MCP in inhibiting ethylene action/perception and petal senescence in cut flowers through the blocking of receptor binding sites,and we discuss how various factors affecting efficacy of 1-MCP(such as concentration,treatment time and temperature,genotype,and flower stage)are involved in the achievement of flower longevity.Moreover,we highlight the advantages of applying nonvolatile and liquid 1-MCP formulation types,as opposed to using the conventional 1-MCP treatment(powder formulation type).We expect that this review will provide useful information for the future utilization of 1-MCP for the maintenance of cut flower longevity.

Effects of 1-Methylcyclopropene on NO Content,NOS Activity,and H_2O_2 Content in Postharvest Suli Pears

Studies were conducted over the effects of 1-methylcycolpropene （1-MCP） treatment on postharvest life of Suli pears （Pyrus bretschneideri Rehd.） stored at room and cold temperatures on nitric oxide （NO）,nitric oxide synthase （NOS） activity,and hydrogen dioxide （H2O2）.Results showed that the 1-MCP treatment had little effect on total soluble solids （TSS） at both room and cold temperatures.1-MCP delayed softening of Suli pear fruits,decreased respiratory rate and H2O2 accumulation,and increased NO and NOS activity at room temperature storage,while the effect of cold temperature storage was relatively inferior.There was a significant positive correlation between NOS activity and NO content.It is concluded that 1-MCP had effects on endogenous NO content and accumulation of H2O2.Similarly,H2O2 acting as a signaling molecule via regulating NO level affects the ripening and senescence of Suli pears.

Regulation of Propylene and 1-Methylcyclopropene on Expressions of ACS and ACO Genes in Persimmon Fruits

The regulation of postharvest treatment with propylene and 1-MCP on ethylene release rate and expressions of 1- aminocyclopropane-l-carboxylic acid synthase （ACS） and 1-aminocyclopropane-1-carboxylic acid oxidase （ACO） genes in Fuping Janshi persimmon （Diospyros kaki L.） fruit were investigated. Fruits were treated with propylene and 1-MCP, then stored at 20℃, ethylene release rate of the treated fruits was measured at regular intervals and RNA was extracted for Northern blotting analysis. The results suggested that treatment with propylene accelerated the expressions of ACS and ACO genes and then enhanced the ethylene biosynthesis, while treatment with 1-MCP inhibited the expressions of two genes and their ethylene biosynthesis. Furthermore, different effects on expressions caused by treatments with propylene and 1-MCP existed in various fruit tissues, the inhibitory effect on ACS and ACO genes by 1-MCP was the strongest in pericarp, followed by pulp and core tissues, in the area near fruit stalk, the inhibitory effect was the weakest. While the enhanced effect on ACS and ACO genes by propylene increased from pulp, core, and pericarp to the area near fruit stalk. Expression of each member of ACS and ACO families in various tissues was also completely different, in control and propylene treatment, DKACS3 gene just expressed in the area near fruit stalk and did not express in other tissues, but DKACS2 gene expressed in four tissues by treatment with propylene.

Effect of Internal Ethylene and 1-methylcyclopropene on Ripening of Papaya Fruit(Carica papaya L.)

With papaya fruit （ Carica papaya ） as an experimental material, variations of its physiological indices were investigated through hypobaric hypoxia （HH, 10 kPa, 1.5 kPa O 2） treatment followed by fumigation with 1-methylcyclopropene （1-MCP）, so as to discuss the effect of interaction between 1-MCP and internal ethylene on ripening of papaya fruit during postharvest storage. The results indicated that HH treatment significantly reduced internal ethylene concentration （IEC） by 57.6%. However, there were no remarkable differences in other physiological indices between various treatments and control （CK）. The 1-MCP and HH＋1-MCP treatments could significant postpone the softening process and color change of papaya fruit. The two treatments achieved the effects of significantly inhibiting the occurrence of fruit disease and the increase of pericarp cell membrane permeability, effectively delaying the variation of soluble solid and Vc contents, and better maintaining soluble solid and Vc contents in fruit, thereby better keeping nutritional substances and flavor quality in fruit in later storage period and prolonging the storage time of fruit.

High Temperature and the Ethylene Antagonist 1-Methylcyclopropene Alter Ethylene Evolution Patterns,Antioxidant Responses,and Boll Growth in Gossypium hirsutum

The cotton (Gossypium hirsutum L.) crop experiences high temperatures during flowering and boll development, but information regarding the impact of ethylene inhibition and high temperature on early boll development is limited. The objective of this study was to determine the effects of high temperature and the anti-ethylene compound 1-methylcy-cloprone (1-MCP) on G. hirsutum boll development. Treatments consisted of temperature regime (38/20?C and 30/ 20?C), 1-MCP treatment, and days past anthesis (DPA). High temperature decreased ethylene synthesis by 61% at 2 DPA, and 1-MCP caused a 40% decrease in ethylene production at 1 DPA. Glutathione reductase activity increased under high temperature, whereas superoxide dismutase activity (SOD) and membrane peroxidation (malondialdehyde content) remained unchanged. 1-MCP treatment did not affect GR activity in developing bolls. High temperature and 1-MCP treatment increased the weight of cotton bolls collected 8 DPA with an increase of 0.7 and 1 g, respectively. We propose that increased GR activity in bolls exposed to high temperature may mitigate oxidative damage. Additionally, we conclude that ethylene inhibition (either high temperature or 1-MCP-induced) immediately after flowering (1 or 2 DPA) could potentially have positive impacts on early boll growth.