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1.
Alberto Sánchez-Estrada Martín Ernesto Tiznado-Hernández Angel Javier Ojeda-Contreras Ana Isabel Valenzuela-Quintanar Rosalba Troncoso-Rojas 《Journal of Phytopathology》2009,157(1):24-32
Fungal disease in netted melon fruit is an important factor affecting their postharvest quality and therefore an important cause of large economic losses around the world. Among the alternatives to control fungal diseases, the induction of the natural defence response (NDR) in fruits is promising. The objective of this study was to induce the NDR in netted melon treated with a bio-elicitor formulated from Fusarium oxysporum growth in a potato dextrose agar enriched with netted melon skin. Netted melon fruits (cv 'Primo') were not treated (C), untreated and inoculated with F. oxysporum (IN), treated with a bio-elicitor (FES), or treated with the bio-elicitor and inoculated (FES + IN). After treatments, fruits were stored for 8 days at 20°C with 90–92% relative humidity. Melon was sampled every 2 days at 20°C to evaluate the development of Fusarium rot symptoms as disease index percentage (DI), changes in phenolic compounds, changes in phenylalanine ammonia-lyase (PAL) activity, chitinase activity (ChA) and β-1,3-glucanase activity (GA). It was found that DI in netted melon fruit was significantly reduced in the FES + IN as compared with the IN treatment. FES + IN and FES treatments showed the highest increase of phenolic acids. Higher levels of PAL activity were observed in the treatments IN, FES, and FES + IN with respect to C, after 4 days of storage. A large increase in ChA activity was observed in the treatments IN, FES and FES + IN after 6 days of storage. No differences in GA activity were found among FES, FES + IN and C treatments throughout storage. IN treatment showed the highest increase in GA activity after 4 days of storage. It is concluded that the bio-elicitor activates the NDR as measured by the increase in phenolic acids synthesis, PAL and ChA enzymes activity, in a similar way as the infection by the living pathogen. 相似文献
2.
The plant resistance activator acibenzolar‐S‐methyl (BTH), the signalling molecules salicylic acid (SA) and methyl jasmonate (MeJA) were tested by seed treatment for their ability to protect melon seedlings from gummy stem blight and white mould disease caused by the soil‐borne fungal pathogens Didymella bryoniae and Sclerotinia sclerotiorum, respectively. Didymella bryoniae infection on melon seedlings was completely suppressed by MeJA treatment. Necrotic lesions akin hypersensitive response occurred on all inoculated seedlings and prevented pathogen diffusion into healthy tissues. Didymella bryoniae infection was restricted following BTH seed treatment as well, although the percentage of necrotic lesions in comparison with the water soaked lesions was significantly lower than that from MeJA‐induced seedlings. BTH protected melon seedlings against S. sclerotiorum by the occurrence of a high percentage of necrotic lesions. A lower level of resistance was also achieved by MeJA seed treatment. The augmented level of resistance of tissues from BTH and MeJA‐treated seeds was associated with rapid increases in the activity of the pathogenesis‐related proteins chitinase and peroxidase. MeJA also determined a rapid and transient accumulation of lipoxygenase. Moreover, BTH and MeJA treatments determined the differential induction of particular de novo synthesized isoenzymes of these proteins. Results indicate that BTH and MeJA applied to melon seeds may activate on seedlings diverse metabolic pathways leading to the enhancement of resistance against distinct pathogens. 相似文献
3.
A Rapid Assay for Monitoring Peroxidase Activity in Melon as a Marker for Resistance to Pseudoperonospora cubensis 总被引:1,自引:0,他引:1
Abstract A rapid assay for monitoring peroxidase activity in melon as a marker for resistance to Pseudoperonospora cubensis was developed. A high correlation was demonstrated between peroxidase activity and resistance in test wells containing leaf disks of melon plants with known levels of susceptibility or resistance to P. cubensis. The possibility of using such an assay for a preliminary selection of melons resistant to P. cubensis is suggested. 相似文献
4.
Hector G. Nuñez-Palenius Miguel Gomez-Lim Neftali Ochoa-Alejo Rebecca Grumet Gene Lester Daniel J. Cantliffe 《Critical reviews in biotechnology》2013,33(1):13-55
Among Cucurbitaceae, Cucumis melo is one of the most important cultivated cucurbits. They are grown primarily for their fruit, which generally have a sweet aromatic flavor, with great diversity and size (50 g to 15 kg), flesh color (orange, green, white, and pink), rind color (green, yellow, white, orange, red, and gray), form (round, flat, and elongated), and dimension (4 to 200 cm). C. melo can be broken down into seven distinct types based on the previously discussed variations in the species. The melon fruits can be either climacteric or nonclimacteric, and as such, fruit can adhere to the stem or have an abscission layer where they will fall from the plant naturally at maturity. Traditional plant breeding of melons has been done for 100 years wherein plants were primarily developed as open-pollinated cultivars. More recently, in the past 30 years, melon improvement has been done by more traditional hybridization techniques. An improvement in germplasm is relatively slow and is limited by a restricted gene pool. Strong sexual incompatibility at the interspecific and intergeneric levels has restricted rapid development of new cultivars with high levels of disease resistance, insect resistance, flavor, and sweetness. In order to increase the rate and diversity of new traits in melon it would be advantageous to introduce new genes needed to enhance both melon productivity and melon fruit quality. This requires plant tissue and plant transformation techniques to introduce new or foreign genes into C. melo germplasm. In order to achieve a successful commercial application from biotechnology, a competent plant regeneration system of in vitro cultures for melon is required. More than 40 in vitro melon regeneration programs have been reported; however, regeneration of the various melon types has been highly variable and in some cases impossible. The reasons for this are still unknown, but this plays a heavy negative role on trying to use plant transformation technology to improve melon germplasm. In vitro manipulation of melon is difficult; genotypic responses to the culture method (i.e., organogenesis, somatic embryogenesis, etc.) as well as conditions for environmental and hormonal requirements for plant growth and regeneration continue to be poorly understood for developing simple in vitro procedures to culture and transform all C. melo genotypes. In many cases, this has to be done on an individual line basis. The present paper describes the various research findings related to successful approaches to plant regeneration and transgenic transformation of C. melo. It also describes potential improvement of melon to improve fruit quality characteristics and postharvest handling. Despite more than 140 transgenic melon field trials in the United States in 1996, there are still no commercial transgenic melon cultivars on the market. This may be a combination of technical or performance factors, intellectual property rights concerns, and, most likely, a lack of public acceptance. Regardless, the future for improvement of melon germplasm is bright when considering the knowledge base for both techniques and gene pools potentially useable for melon improvement. 相似文献
5.
Nuñez-Palenius HG Gomez-Lim M Ochoa-Alejo N Grumet R Lester G Cantliffe DJ 《Critical reviews in biotechnology》2008,28(1):13-55
Among Cucurbitaceae, Cucumis melo is one of the most important cultivated cucurbits. They are grown primarily for their fruit, which generally have a sweet aromatic flavor, with great diversity and size (50 g to 15 kg), flesh color (orange, green, white, and pink), rind color (green, yellow, white, orange, red, and gray), form (round, flat, and elongated), and dimension (4 to 200 cm). C. melo can be broken down into seven distinct types based on the previously discussed variations in the species. The melon fruits can be either climacteric or nonclimacteric, and as such, fruit can adhere to the stem or have an abscission layer where they will fall from the plant naturally at maturity. Traditional plant breeding of melons has been done for 100 years wherein plants were primarily developed as open-pollinated cultivars. More recently, in the past 30 years, melon improvement has been done by more traditional hybridization techniques. An improvement in germplasm is relatively slow and is limited by a restricted gene pool. Strong sexual incompatibility at the interspecific and intergeneric levels has restricted rapid development of new cultivars with high levels of disease resistance, insect resistance, flavor, and sweetness. In order to increase the rate and diversity of new traits in melon it would be advantageous to introduce new genes needed to enhance both melon productivity and melon fruit quality. This requires plant tissue and plant transformation techniques to introduce new or foreign genes into C. melo germplasm. In order to achieve a successful commercial application from biotechnology, a competent plant regeneration system of in vitro cultures for melon is required. More than 40 in vitro melon regeneration programs have been reported; however, regeneration of the various melon types has been highly variable and in some cases impossible. The reasons for this are still unknown, but this plays a heavy negative role on trying to use plant transformation technology to improve melon germplasm. In vitro manipulation of melon is difficult; genotypic responses to the culture method (i.e., organogenesis, somatic embryogenesis, etc.) as well as conditions for environmental and hormonal requirements for plant growth and regeneration continue to be poorly understood for developing simple in vitro procedures to culture and transform all C. melo genotypes. In many cases, this has to be done on an individual line basis. The present paper describes the various research findings related to successful approaches to plant regeneration and transgenic transformation of C. melo. It also describes potential improvement of melon to improve fruit quality characteristics and postharvest handling. Despite more than 140 transgenic melon field trials in the United States in 1996, there are still no commercial transgenic melon cultivars on the market. This may be a combination of technical or performance factors, intellectual property rights concerns, and, most likely, a lack of public acceptance. Regardless, the future for improvement of melon germplasm is bright when considering the knowledge base for both techniques and gene pools potentially useable for melon improvement. 相似文献
6.
甜瓜以营养丰富口味独特而深受世人青睐。同时,其采后病害高效、"绿色"防治药剂的缺乏也成为多年来困扰甜瓜生产的难题。本文采用直接生物测定的方法,从健康的甜瓜表面分离到1株有生防潜能的菌株X4。该菌株对引起甜瓜主要采后病害的粉红单端胞菌(Trichothecium roseum)、镰刀菌(Fusarium spp.)和链格孢菌(Alternaria alternata)的防治效果分别达到了90.6%、84.4%和67.4%;定殖实验显示,接菌4 d后该菌在瓜内数量可上升并稳定至1.1×10~6CFU/ml;通过16S rDNA测定、形态特征观察及生理生化测定结果表明该菌为Pseudomonas fluorescens biovarⅢ。 相似文献
7.
热处理和壳聚糖涂膜对采后接菌哈密瓜生理生化特性的影响 总被引:2,自引:0,他引:2
以‘西州蜜25号’哈密瓜果实为试材,分别进行55℃热水浸渍3min、2%壳聚糖涂膜及两者结合处理(55℃热水浸渍3min+2%壳聚糖涂膜),以不进行任何预处理为对照,再对各处理的哈密瓜接种交链孢菌(Alternariaalternata),研究接菌哈密瓜在常温贮藏过程中抗病性和相关生理生化指标的变化情况。结果表明,与对照相比较,3种预处理均能明显抑制哈密瓜细胞膜渗透率、呼吸强度、乙烯释放量上升,显著提高贮藏后期果实几丁质酶、β-1,3-葡聚糖酶、苯丙氨酸解氨酶和过氧化物酶的活性,从而增强了哈密瓜的抗病性,有效降低贮藏过程中接菌哈密瓜病斑直径和病斑深度、防止哈密瓜的腐烂变质,并以55℃热水浸渍3min+2%壳聚糖涂膜结合处理的效果最佳。 相似文献
8.
The conversions of incorporated 14C-glucose in fruit flesh and in seeds were investigated at different stages of fruit development. In addition, the biochemical mechanism of sucrose synthesis in fruits of Bai-Lan melon were also studied. The results were summarized as follows: In fruit flesh and in seeds at young fruit stage, more than half of the incorporated 14C was found in the dilute acid hydrolyzable and non-hydrolyzable fractions, both of which represent the structural elements. While in the fruits approaching maturity (42 days old), a relatively small amount of 14C associated with the structural elements was found. The contributions of 14C of fractions hydrolyzed and non-hydrolyzed by dilute acid to the total radioactivity were reduced to 18% and 32%, respectively, in fruit flesh and in seeds. The results of identification of soluable sugar by using paper chromatography indicated that, the 14C was only associated with fructose after infiltrating the young fruit slices with 14C-glucose, but the 14C was predominately incorporated into sucrose at later stage of fruit development. The above results of 14C labeling experiments suggest that the pattern of metabolism is changed with fruit development. The greater part of metabolites is used in synthesis of structural elements which is necessary for growth and related processes at early stage of fruit developrnent. However, as the fruit reaches full size. the demand for carbon used in structural tissue is reduced. At this time, the direction of the enzymatic reactions changed in favor of sucrose synthesis. The activity of sucrose synthesis in young fruits was rather low when various substrates were supplied. It was possible that the enzymes related to sucrose synthesis were absent in young fruits of Bai-Lan melon. The activity of sucrose synthesis in fruits at later stage of development increased by about 5-fold of that at early stage. The higher activity of sucrose synthesis was observed when UDPG+F-6-P were supplied as substrates. It is shown that the sucrose in Bai- Lan melon fruits may be mainly synthesized by sucrose phosphate synthetase catalyzing the reaction between UDPG and F-6-P to yield sucrose-P. The biochemical mechanism of sucrose synthesis in Bai-Lan melon fruits is briefly discussed. 相似文献
9.
Effects of a biocontrol agent and methyl jasmonate on postharvest diseases of peach fruit and the possible mechanisms involved 总被引:5,自引:0,他引:5
AIMS: To investigate effects of application of 200 micromol l(-1) methyl jasmonate [MeJA (200)] and Cryptococcus laurentii alone or in combination against postharvest diseases (Monilinia fructicola and Penicillium expansum) in peach fruit stored at 25 and 0 degrees C, and to evaluate the possible mechanisms involved. METHODS AND RESULTS: The efficacy of controlling postharvest diseases by resistance induced in peach fruit treated with MeJA (200) and C. laurentii alone or in combination and the relationship between activities of defence-related enzymes in peach fruit and lesions caused by M. fructicola and P. expansum were examined. At the same time, the effects of MeJA (200) on the population of C. laurentii in the peach wounds and on the mycelial growth of M. fructicola and P. expansumin vitro were investigated. The results indicated that treatment of peach fruit with C. laurentii at 1 x 10(8) CFU ml(-1) alone, or combining C. laurentii at 5 x 10(7) CFU ml(-1) with MeJA (200) all resulted in a lower lesion diameter of brown rot and blue mould caused by M. fructicola and P. expansum compared with the controls in peach fruit. MeJA (200) enhanced the population of C. laurentii, and inhibited mycelial growth of P. expansum. However, it had a little effect on M. fructicolain vitro. MeJA and C. laurentii alone or in combination induced higher activities of Chitinase, beta-1,3-glucanase, phenylalanine ammonia-lyase and peroxidase (POD) than applying the yeast alone at both 25 and 0 degrees C. CONCLUSIONS: MeJA (200) not only directly inhibited mycelial spread of postharvest pathogens, but also increased population of C. laurentii, which induced stronger disease resistance in fruit than MeJA or yeast alone, and resulted in a lower lesion diameter of brown rot and blue mould caused by M. fructicola and P. expansum. SIGNIFICANCE AND IMPACT OF THE STUDY: MeJA (200) in combination with C. laurentii was beneficial for controlling brown rot and blue mould caused by M. fructicola and P. expansum in peach fruit. The inhibitory mechanism was mainly because of resistance induced in peach fruit by MeJA and C. laurentii. In addition, direct inhibition of MeJA on P. expansum also played a role in controlling blue mould. 相似文献
10.
Mango fruits (Mangifera indica L.) were treated by vacuum infiltration of 1.0 mm benzo‐(1,2,3)‐thiadiazole‐7‐carbothioic acid s ‐methyl ester (BTH) after harvest. Seventy‐two hours after the treatment with BTH, the fruit were inoculated with 15 μl of conidial suspension of Colletotrichum gloeosporioides (1 × 105 conidia/ml) and incubated at 13°C, 85–90% RH for disease development. Disease incidence and lesion diameter in mango fruit after the inoculation were significantly (P < 0.05) reduced by the BTH treatment during the incubation. Peroxidase, polyphenoloxidase, phenylalanine ammonia‐lyase, chitinase and β‐1,3‐glucanase activities and total phenolic compounds content in the fruits were all enhanced by the BTH treatment during the incubation. The catalase activity in the fruit was inhibited, whereas the level of hydrogen peroxide was increased by the BTH treatment during the infection. These responses may be involved in the induced resistance against the pathogen infection in mango fruit by BTH treatment. Application of BTH in fruit possesses promising results in the control of postharvest diseases as an alternative to traditional methods. 相似文献
11.
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13.
Gamma irradiation‐induced disease resistance of pear (Pyrus pyrifolia “Niitaka”) against Penicillium expansum 下载免费PDF全文
In this study, the effects of gamma irradiation on the resistance of pear fruit against Penicillium expansum, the causal agent of blue mould disease, were investigated. A low dose of gamma irradiation for 14 days increased the disease resistance and firmness of pear fruits. Remarkably, exposure to 200 Gy of gamma irradiation significantly maintained fruit firmness, markedly reduced disease incidence and enhanced the activity of defence‐related enzymes (e.g., β‐1,3‐glucanase, phenylalanine ammonia lyase, peroxidase and polyphenol oxidase) and expression of pathogenesis‐related (PR) genes (e.g., PR‐1, PR‐3 and PR‐4). Therefore, the gamma irradiation‐induced resistance against P. expansum involves both metabolic changes and the induction of expression of defence‐related genes. In addition, scanning electron microscopic analysis revealed that gamma irradiation significantly inhibits the growth of P. expansum. These results suggest that exposure of mature harvested pear fruits to artificial gamma irradiation confers fungal disease resistance; therefore, gamma irradiation represents an important strategy for controlling postharvest diseases in pear fruit. 相似文献
14.
Manjukarunambika Kolandasamy Ponmurugan Ponnusamy 《Archives Of Phytopathology And Plant Protection》2013,46(4):451-462
Red root rot caused by Poria hypolateritia is a dreadful disease in tea plant due to sudden death of bushes. In response to fungal pathogen, variation in the defence-related enzymes was investigated. The infected tea root was undertaken to study about various defence-related and pathogen-related enzymes. The infected root, as a prime response to disease attack, was subjected to the analysis of phenolics, phenylalanine ammonia lyase, tyrosine ammonia lyase, peroxidase, polyphenol oxidase, catalase, chitinase, β-1,3-glucanase and protease were assayed. The results on assay of defence-related enzymes revealed that the activity was significantly higher in infected roots when compared with healthy roots. Phenolics were accumulated more in infected roots. The sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis further confirmed the presence of induced pathogenesis-related proteins in the infected root tissues. The activity of all enzymes was increased up to threefold amount when compared with normal ones. The accumulation of defence enzymes in plants revealed the virulence of root pathogen in stimulating induced systemic resistance of tea plants and phytopathogenicity causing pathogenesis. This study exemplify to recognise underlying processes in causing infection and to identify the existence of host–pathogen relationship. 相似文献
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16.
在树上正生长发育的香蕉果实,随着果实长大,果皮中过氧化物酶(POD)和多酚氧化酶(PPO)活性不断升高。采后的香蕉和芒果果实的果皮中,POD和PPO活性变化与呼吸代谢相关。苯丙氨酸解氨酶(PAL)主要分布在果皮中,并随着果实成熟度的提高,其活性呈极显著下降趋势。感病果实的果皮中三种酶活性均比健康果皮高。说明果皮中三种酶活性的变化与炭疽菌的潜伏侵染有关。 相似文献
17.
Kristen A. Hadfield Jocelyn K.C. Rose Debbie S. Yaver Randy M. Berka Alan B. Bennett 《Plant physiology》1998,117(2):363-373
Ripening-associated pectin
disassembly in melon is characterized by a decrease in molecular mass
and an increase in the solubilization of polyuronide, modifications
that in other fruit have been attributed to the activity of
polygalacturonase (PG). Although it has been reported that PG activity
is absent during melon fruit ripening, a mechanism for PG-independent
pectin disassembly has not been positively identified. Here we provide
evidence that pectin disassembly in melon (Cucumis melo)
may be PG mediated. Three melon cDNA clones with significant homology
to other cloned PGs were isolated from the rapidly ripening cultivar
Charentais (C. melo cv Reticulatus F1 Alpha) and were
expressed at high levels during fruit ripening. The expression pattern
correlated temporally with an increase in pectin-degrading activity and
a decrease in the molecular mass of cell wall pectins, suggesting that
these genes encode functional PGs. MPG1 and MPG2 were closely related
to peach fruit and tomato abscission zone PGs, and MPG3 was closely
related to tomato fruit PG. MPG1, the most abundant melon PG mRNA, was
expressed in Aspergillus oryzae. The culture filtrate
exponentially decreased the viscosity of a pectin solution and
catalyzed the linear release of reducing groups, suggesting that MPG1
encodes an endo-PG with the potential to depolymerize melon fruit cell
wall pectin. Because MPG1 belongs to a group of PGs divergent from the
well-characterized tomato fruit PG, this supports the involvement
of a second class of PGs in fruit ripening-associated pectin
disassembly.Fruit ripening is a genetically programmed event that is
characterized by a number of biochemical and physiological processes
that alter fruit color, flavor, aroma, and texture (Brady, 1987).
Extensive cell wall modifications occur during ripening and are thought
to underlie processes such as fruit softening, tissue deterioration,
and pathogen susceptibility. These modifications are regulated at least
in part by the expression of genes that encode cell wall-modifying
enzymes (Fischer and Bennett, 1991). Pectins are a major class of cell
wall polysaccharides that are degraded during ripening, undergoing both
solubilization and depolymerization. In tomato the majority of
ripening-associated pectin degradation is attributable to the cell wall
hydrolase PG. Transgenic tomato plants with altered PG gene expression
indicated that PG-dependent pectin degradation is neither required nor
sufficient for tomato fruit softening to occur (Sheehy et al., 1988;
Smith et al., 1988; Giovannoni et al., 1989). However, data from
experiments using fruit of the same transgenic lines strongly suggested
that PG-mediated pectin degradation is important in the later,
deteriorative stages of ripening and in pathogen susceptibility of
tomato fruit (Schuch et al., 1991; Kramer et al., 1992).In melon (Cucumis melo) substantial amounts of pectin
depolymerization and solubilization take place during ripening
(McCollum et al., 1989; Ranwala et al., 1992; Rose et al., 1998),
implicating a role for PG in ripening-associated cell wall disassembly
in melons. However, melons have been reported to lack PG enzyme
activity (Hobson, 1962; Lester and Dunlap, 1985; McCollum et al., 1989;
Ranwala et al., 1992). The possibility exists that PG is present in
melon but that it does not conform to the expected enzymic properties
in terms of abundance and/or lability, a point illustrated by recent
reports in apple and strawberry, which were previously reported to lack
PG activity but that do in fact accumulate low amounts of protein
and/or measurable activity (Nogata et al., 1993; Wu et al., 1993). In
light of the unexplained discrepancy between ripening-associated pectin
depolymerization and undetectable PG activity in melons, we have
undertaken a study to reexamine the status of PG in melon using the
rapidly ripening cv Charentais (C. melo cv Reticulatus F1
Alpha).As reported for other cultivars, Charentais melons exhibit substantial
solubilization and a downshift in the molecular-mass profile of
water-soluble pectins, but this is associated with the later stages of
ripening, after softening is initiated (Rose et al., 1998). By
utilizing a molecular approach to analyze PG in melon, we have
attempted to overcome some of the potential limitations of biochemical
methods, such as low abundance of protein, reliance on other cell wall
components, and unknown cofactors for activity and/or lability during
extraction. In doing so, we have identified and characterized a
multigene family encoding putative PGs from Charentais melon, including
three PG homologs that are expressed abundantly during fruit ripening.
The pattern of PG gene expression correlates temporally with the
depolymerization of water-soluble pectins and an increase in
pectin-degrading enzyme activity. Three additional PG homologs were
also identified and shown to be expressed in mature anthers and
fruit-abscission zones, tissues that, similar to ripening fruit, are
undergoing cell separation. The most abundant ripening-associated
putative PG mRNA, MPG1, was expressed in the filamentous fungus
Aspergillus oryzae. The culture filtrate from the
transformed A. oryzae strain XMPG1 exhibited
endo-PG activity, further supporting a role for
endo-PG in ripening-associated pectin disassembly in
Charentais melon fruit. 相似文献
18.
The biological control activity of Cryptococcus laurentii alone or in combination with Benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) against postharvest black rot caused by Alternaria alternata in strawberries was investigated. As a stand-alone treatment, C. laurentii significantly reduced the incidence and lesion diameter of black rot in strawberries at 20 °C. The incidence and lesion diameter in strawberries treated with BTH alone was not significantly different from that in the control. C. laurentii in combination with BTH (0.1 g L−1) was more effective than C. laurentii alone or BTH alone. BTH only slightly increased the population of C. laurentii in strawberry wounds and nutrient yeast dextrose broth (NYDB) and had little inhibition effect on the growth of A. alternate in potato dextrose agar (PDA). The enzyme analysis results showed that BTH significantly increased the activity of defense enzymes, including polyphenol oxidase (PPO), peroxidase (POD), and catalase (CAT) in strawberries treated with C. laurentii in combination with BTH. All these results indicated that the action mode of BTH enhancing the biocontrol efficacy of C. laurentii against A. alternata may involve in its ability to induce defense enzymes including PPO, POD and CAT in strawberries rather than its direct effect on C. laurentii or A. alternata. 相似文献
19.
O2和CO2配比对低温贮藏李品质及生理变化的影响 总被引:1,自引:0,他引:1
为了探索适宜‘黑宝石’李贮藏的气体参数,研究了不同气体成分(6.0%O2+5.0%CO2、6.0%O2+1.0%CO2、10.0%O2+5.0%CO2和10.0%O2+1.0%CO2)处理对贮藏及货架期‘黑宝石’李采后品质(硬度、总糖、可滴定酸和腐烂指数)、抗氧化酶(SOD、POD和CAT)活性及MDA含量的影响。结果显示:(1)在贮藏0~45 d期间,冷藏对照果实的腐烂指数在8%以下,其货架果实的硬度仍可下降;贮藏至75 d时,冷藏对照果实的腐烂指数达38%,而且其果实失去了软化能力。(2)气调处理可减缓低温贮藏李果实硬度的下降,降低果实的腐烂指数,维持货架果实的后熟能力,但6.0%O2+1.0%CO2处理对果实腐烂指数的影响不显著。(3)气调处理可提高低温贮藏李果实的SOD、POD和CAT活性,抑制这3种酶在货架模拟过程中的升高,且可降低低温贮藏及货架期果实的MDA含量。(4)气调贮藏中以6.0%O2+5.0%CO2处理的效果最佳,果实的贮藏期可达75 d。研究说明,常规冷藏(0~1.5℃)可满足‘黑宝石’李果实采后短期贮藏(<45 d)的需要,而适宜的气调贮藏可使其贮藏期限延长30 d左右。 相似文献
20.
Effectiveness of preharvest application of submicron chitosan dispersions for controlling Alternaria rot in postharvest jujube fruit 下载免费PDF全文
Honglian Guo Zijuan Xing Qiaoyin Yu Yue Zhao Enlong Zhu 《Journal of Phytopathology》2017,165(7-8):425-431
The efficacy of submicron chitosan dispersions (SCD) on Alternaria alternata rot of the ‘Lingwu changzao’ jujube (Zizyphus jujuba Mill. cv. Lingwu changzao) fruit and possible mechanisms involved were investigated in this study. When jujube fruit at the preharvest stage were sprayed twice with SCD (10 mg/ml) water solution and then natural infections were allowed to develop, there was a significant reduction in disease incidence and lesion index compared to control fruit during storage period, and similar results were obtained from postharvest fruit inoculated with the Alternaria rot pathogen. Scanning electron microscopy of the pathogen revealed that hyphae and spores were damaged and deformed when growing on the surface of fruit pretreated with SCD or CHO. The slowed softening of jujube fruit resulted from the protopectin content increasing compared with the control. Furthermore, SCD sprays inhibited cell wall hydrolysing enzymes, pectinase activity was decreased, and the increase in cellulase activity was postponed (from 30 days to 45 days).It was concluded that preharvest application of SCD was a more effective alternative to conventional chitosan for preventing postharvest from Alternaria rot of ‘Lingwu changzao’ jujube fruit. 相似文献