The fruit samples of two apple cultivars, Iranian native "Dirras-e Mashhad" and imported "Wealthy", were collected from the 20-year-old vase form trees on seed rootstocks grown in Karaj-Iran climatic conditions. The National collection of commercial apple cultivars is established in Horticultural Research Station of KamalShahr under Temperate Fruit Research Center. In late September of 2010, sampling was performed based on precise harvest time by assessment of the starch index (2 - 2.5). At picking, the fruits were gently twisted without exerting any pressure by finger tips and slowly placed in appropriate boxes under the trees shadow. The harvested fruits passed 24 hours of pre-cooling and then were stored at 0.5˚C and 90% of relative humidity.

Origin: Mashahd, Iran, late ripening, days from bloom to pick: 161, the mean of 10 fruits: globose-oblong globose, diameter 66.1 mm, length/diameter ratio 0.83, russet susceptibility class 2, background: green, over-color: red, stalk length: 10 mm, peel thickness: medium-thick, seed size: medium, total seed/fruit and carpel: 7.5 and 5.

Origin: Minnesota, USA, late ripening, days from bloom to pick: 156, the mean of 10 fruits: globose, diameter 62.5 mm, length/diameter ratio 0.79, russet susceptibility class 3, background: green, over-color: red, stalk length: 9 mm, peel medium-thick, seed size: big, mean total seed/fruit and carpel: 4.5 and 4.5.

Fruit weight was recorded by a digital scale with a precision of 0.1 gram, model B502 College. To measure the weight loss, the treated and control fruits of each cultivar weighed in separated boxes and compared to the initial weight. The measurements were computed in monthly temporal intervals for weight loss unto fifth month of cold storage.

Flesh firmness was assessed by the Texture Analyzer, Hounsfield-H5KS model made in England. Thin layer of fruit peel sole per 1 cm² was removed in 3 points by a sharp blade where a cylindrical plunger, 6.4 mm diameter, was pushed into apple flesh tissue, measured in Newton, over a constant distance with a speed of 20 mm per min (Finny & Massie, 1975) [11] .

Once removed ovary tissues, the juice was prepared by squeezing longitudinal slices of 1.5 fruit diameter of 10 fruits from each replication in juicer. The apple juice was passed through the filter paper and collected then into a flask Pre- (Aymard et al. 2005) [12] , TSS, pH and TA values of the two cultivars juice were determined for the defined treatments based on experimental design. TA was measured using caustic soda, 0.1 through the normal formula calculated on the basis of predominant malic acid in apple flesh, equivalent to 67 grams (Watkins, 2003 [13] ; Hosseini, 1990 [14] ). After calibrating pH meter with buffer solutions, pH of 20 mg/l of pure fruit juice was measured by digital pH meter. Few drops of filtered fruit juice put on the ESR prism surface was read in sort of manual ATAGO refractometer model 20181MC ranges (Brix 0 ~ 32%). The measurements were computed in monthly temporal intervals for biochemical traits unto fifth month of cold storage and the data were registered.

Taste-panel assessments founded on purely biological means could not be replaced by instrumental tests. In order to appraise sensorial traits, sound clean fruit samples of each cultivar were distributed to the 10 well-trained panelists as fixed members of the group, before lunch. Appraisements carried out by scoring flavor, aroma, juiciness, taste (sweetness, sourness, acidulous) and general acceptability. Acceptability index represents overall sensorial perception of the panelists, in predefined assessment sheets rated between 0 to 100 where index value 0 indicates dissatisfaction and 100 high satisfactions included all intermediate scales.

To evaluate the eventual increase of storage life and maintaining the quality characteristics of two apple fruit cultivars by use of 1-MCP, a factorial experiment with a treatment of 1-MCP and ENA on two apple cultivars wealthy and Dirras-e Mashhad was applied within completely randomized design. Analysis of variance (ANOVA) was performed using SAS statistical software. Mean comparisons were performed using Duncan’s Multiple Range test, all triplicates.

The biosynthesized ethylene amount per volume was achieved by ethylene- sensitive sensor (Bioconservation, UK). Measured the weight (g) and volume (cm³) of the fruits, three samples were placed into a 1 liter glass vase and 16 h later the values of the gaseous ethylene were registered in ppm.

The CO₂ produced was quantified using equipment Testo Model 435 made in Germany. The analysis was performed using 3 apples weighed by digital balance College B502 then placed in sealing chamber. The emitted CO₂ was estimated in ppm during 30 min. scattered per 1 min. intervals. The data were collected for computations.

The mean comparisons of weight loss percent between cultivars by use of 1- MCP, ENA and also combined treatment (1-MCPe + ENA) showed the highest

*, **, ns: significant at 1, 5 percent and none-significant respectively. DF: Degree of freedom.

decline, significant at p < 0.05 level, in "Wealthy" at 5th month of storage related to "Dirras-e Mashhad" due to non treated samples by 1-MCP and or ENA, while no significant difference was noted during the first 3 months (Tables 2-4). The 1-MCP efficacy was evaluated on quality of "Cortland" and "Empire" apples after storage. The treated samples for 3 hours at any of the temperatures reduced significantly the incidence of superficial scald sole in "Cortland". The final results indicated very high potential of 1-MCP for keep flesh quality during storage; nevertheless its efficacy could be influenced by temperature and duration as well as by apple cultivar (De Ella et al. 2002) [15] . Weight loss comparisons caused by single treatments of 1-MCP and ENA in both of the cultivars during storage time affirmed highest loss in "Wealthy" during the fifth month by ENA presence and lack of 1-MCP, while in the first four months the two cultivars had no significant difference (Table 2, Table 3). The combined treatments of the compounds showed no significant differences during storage (Table 5).

Genetic variability had imminent role in flesh firmness trait so that though the mean comparisons showed decreasing trend for both of the cultivars during storage but "Dirras-e Mashhad" presented lower values related to "Wealthy" at the end of all five stepwise storage months. Also the difference levels varied clearly

The same letters in each column indicate no significant difference in the Duncan test at the 5% possibility level. a:maximum, b:medium, c:minimum. +with -without.

in successive monthly intervals (Figure 1). The effects of storage time and the ENA on flesh firmness showed that use of this chemical in entire months caused more flesh consistency related to control treatment. The highest and lowest mean firmness values, 20/8 and 5/8 Kg/cm², were registered at the end of first and fifth month of storage, relatively in presence and lack of ENA (Table 5).

The mean comparisons of storage period and cultivar interactions effects on the levels of pH, TA and TSS confirmed that pH levels increased over time between the two cultivars which their TA values were inversely changed, decreasing during storage time, either significantly different (p < 0.05). The total amount of dissolved solids over time, demonstrated increasing trend both in "Wealthy" and "Dirras-e Mashhad" (Figures 2-4). Interaction between storage time and 1-MCP

The same letters in each column indicate no significant difference in the Duncan test at the 5% probability level. a:maximum, b:medium, c:minimum. +with ?without.

The same letters in each column indicate no significant difference in the Duncan test at the 5% possibility level. a:maximum, b:medium, c:minimum. +with ?without.

The same letters in each column indicates no significant difference in the Duncan test at the 5% possibility level. a:maximum, b:medium, c:minimum. +with ?without.

on TA, pH and TSS showed that use of 1-MCP affected significantly pH of juice (p < 0.05), inhibiting it to increase. Vice verse, 1-MCP influenced TA significantly (p < 0.05) preventing its decrement. Use of 1-MCP affected equally TSS by increasing values (Figures 5-7). Mean comparisons of interaction effects of

ENA, cultivar and TSS sustained that the highest TSS value was obtained by ENA treatment in "Dirras-e Mashhad" and the lowest in "wealthy" (Table 6). ENA, 1-MCP and TSS mean comparisons of interaction effects endorsed that the

The same letters in each column indicate no significant difference in the Duncan test at the 5% possibility level. a:maximum, b:medium, c:minimum.

highest and the lowest of ethylene absorption is respectively related to use of ENA and non that of 1-MCP. Ethylene absorption was improved by ENA, and ENA+1-MCP treatments affecting mean values of 15.3 and 14.91 of TSS, correspondingly (Table 7).

Application of sole ENA improved general acceptability of "Dirras-e Mashhad"’s at maximum level and the lowest percentage of acceptance through combined treatment of ENA+1-MCP. Contradictory responses were registered in terms of aroma, the maximum level of ENA treated samples was found in "Dirras-e Mashhad", while the minimum rates of aroma was noted in 1-MCP treated samples of "wealthy", combined use of ENA+1-MCP and non-treated (control) treatments of "Dirras-e Mashhad". Furthermore, single treatments showed high acceptance rates in "Dirras-e Mashhad", the cultivar that gained higher scores for each single panel characteristics when treated by ENA. Instead, the non treated samples, as control, led to least scores for fruit taste (Table 8). Others also noticed the that 1-MCP treatment increased fruit firmness in "Cripps Pink" while on "Fuji" and "Gala" firmness got only slightly increased Zanella & Rossi. 2015 [8] . "Bartlett" pear fruit ripening was assessed by exposure to concentrations of 1-MCP as 42 μmol∙m⁻³ or 0.42 μmol∙m⁻³ at harvest and then +4.2˚. Treated fruits contained similar peel yellow color, TA and soluble solid concentration, but higher firmness after 180 days storage compared to control fruit after 60 days storage. Reapplication of the compound based on fruit ethylene production capacity showed to be efficient. A low dose of 1-MCP application at harvest, reapplied by higher doses assessing the rate of ethylene production, re-

The same letters in each column indicate no significant difference in the Duncan test at the 5% possibility level. a:maximum, b:medium, c:minimum.

The same letters in each column indicate no significant difference in Duncan test at the 5% level. a:maximum, b:medium, c:minimum. +with ?without.

moved from cold storage, Bartlett’ pear storage life was extended (Argenta et al. 2016) [16] .

Dehydration could deteriorate fruit weight and quality; the latter decayed organoleptic characteristics and also the appearance causing peel shrinkage. So during post harvest, all factors affecting the increase of the rate of fruit respiration should be controlled to preserve fruit moisture. The cultivars genetically capable of conserving longer the fruit weight are preferred (Bahari et al. 2010) [17] , as it was assessed through a cold storage trial of 49 mid, late and very late ripening commercial apples, ranked in different groups. Morgan & Richards 2002 [18] described different traits of 2000 apple cultivars including fruit storability potential. Weight loss occurs per via respiration and combustion of organic substances like sugars (Wills et al. 1998 [19] , Hajnajari et al. 2010) [20] . Use of 1-MCP and ENA could reduce respiration rate and also decelerate production of ethylene biosynthesis all leading to slowing down conversion of starch into the carbohydrates all with the aim of extending storage life. Due to genetic variability, fruit peel anatomy in different cultivars recites positive role in storability by means of more protective layers of wax or thick epidermis (Veraverbeke et al. 2001) [21] , the traits for which "Dirras-e Mashhad" showed less weight loss than "Wealthy". Cold storage of 7 Iranian early apple cultivars showed that, those with thin fruit peel, soft texture, juicy flesh and smaller size showed more limited storage life of 8 weeks equal to half of the dominant group (Hajnajari & Eshghi, 2013) [22] .

Degradation of pectin compounds is reported as the main factor responsible for loose of flesh firmness in apple during ripening where genetic effect of cultivar showed to be significant on flesh softening. But the texture is defined also by mechanical and geometrical components including hardness, chewiness, viscosity and particle size and shape (Tromp et al. 2005) [5] . Proceeding with maturation, ripening and fruit aging and enzymes activities, cell wall polysaccharides undergo hydrolysis loosing texture integrity and hence softened flesh (Chen et al. 2006) [23] . The use of 1-MCP and NEA decelerated ethylene production, delayed the apple fruit maturity and ripening during storage. According to the reported results (Jeziorek et al. 2010 [24] ; and Sardabi et al. 2014 [25] ), 1-MCP treatment enhanced flesh tissue firmness of "Golden Delicious" fruits; the same response was observed on the treated samples of the apple cultivars in the present study. Newly released early apple "GolBahar" demonstrated 4 months of storability keeping eating quality because of high grade of flesh firmness, 5 kg/cm², as well (Hajnajari, 2016) [26] . These results are equally confirmed by the present study. It was deduced that besides delayed ripening, due to reduced ethylene production, it prevented rapid fruit flesh softening plus preventing any change of over color. Other flesh traits influence the cultivar role including cell density as number of cells per volume unit, cell wall thickness and different metabolism pathway (Johnston & Hewett, 2002) [27] , so "Dirras-e Mashhad" was marked by higher firmness than "Wealthy". The same variability for different flesh traits was registered among 29 apple cultivars stored in +2˚C and 95%RH at 4^th month continued with a decreasing trend of flesh firmness, highest values of storability were found in "Topaz", "Fiesta" and "Fuji" relatively 50.5, 57.3 and 64.1 N (Soska & Tomala, 2006) [28] . In agreement with our results others observed similar cultivar-dependent response regarding flesh firmness trend in the harvested fruits at three different growth stages during storage, even in the samples exposed to 1-MCP related to controlled atmosphere (CA) or low oxygen treatments. 1-MCP treated and untreated fruit samples of "Red Delicious" in both storage conditions, CA and low oxygen in comparison with normal cold storage conditions it was confirmed that the innovative techniques provide considerable storability and particularly flesh firmness (Zanella & Rossi, 2015) [8] .

TSS value is a prevailed index of palatability indicating the amount of converted starch principally in sugars, albeit as a maturity index Tromp et al. 2005 [5] . Surveys performed on the average level of TSS during storage indicated that storing the fruit over longer times, sugar level will increase. Harvested fruits of "Shampion", 5 times at weekly intervals at more stages of fruit growth, during and after predictable optimum harvest date, till physiological maturity or ripening, using starch index approved that quality parameters will change according to harvest date. So, late harvested samples overtook by increased TSS values could shorten the storability (Kvikliene & Valiuškaitė, 2009) [29] , nevertheless, others reported the reduction of TSS during storage (Naseri et al., 2001) [30] . Even some results regarding 1-MCP treatment indicate no significant effect (p < 0.05) on TSS (De Filippi et al. 2004 [31] ; Moran & McManus, 2005 [32] [33] ) but use of NAE and control treatments (normal pathway) both increased the TSS levels during storage. Negative correlation was found between TSS and fruit weight studying pomologies in 8 promising apple genotypes. IRI6 and IRI1 showed relatively 13 and 18.5 of grade (Brix Zand & Hajnajari, 2011) [34] . Timing and 1-MCP reapplication concentration ought to be controlled for desired quality, TA, SSC, flesh firmness as well as physiological disorders Argenta et al. 2016 [16] .

Mean comparisons of pH and TA revealed that in the long run pH increased but TA decreased, alterations caused by malic acid production due to respiratory activities. As a rule, "to lower descends the TA, the higher level will ascend the pH", and since organic acids as the raw materials are used during respiration, reduced acidity and increased pH occurs during storage, so more organic acids will convert to glucose (Shaykh-al-Eslami, 2004) [35] . Others noted TA level comes down during fruit development stages till ripening; the process continued either during storage period. Such trend of TA decline acceleration is predominantly influenced by genetic specification of the cultivar (Soska & Tomala, 2006) [28] . Also Sardabi et al. 2014 [25] reported 1-MCP and ethylene absorber maintained lower pH values comparing to untreated apples. In treated apples by 1-MCP and stored under controlled atmosphere, the main event in fruits was the TA reduction level, stored under different conditions. In accordance with the mentioned reports, the TA diminished in both cultivars in exam even with differences during storage, but disaccording with them, the use of 1-MCP and NEA impeded the pH to increase (Akbudak et al. 2009) [36] .

Generally, fruits at ripening stage would find the desired aroma and flavor. Moreover, cultivars differ from each other in ripening time to achieve the desired sensory properties 9Pelayo-zaldivar, 2005) [4] . The panel group concluded that native "Dirras-e Mashhad" contained better inherent aroma composed of innumerable volatile compounds such as derivates of alcohol, aldehydes, carboxylic esters, ketones and ether, properties decisively depending to the genetics compared with "Wealthy", both grown under identical orchard management and climatic conditions. The observed differences between treatments related to control, affirm the relative efficiencies of the proposed chemicals on qualities and weights of apples. It was shown that use of 1-MCP and ENA could increase the period of qualified cold storage, depending also on the cultivar. The highest flesh stiffness was held at 5th month by ENA, and the least weight loss was achieved by 1-MCP. Other noticeable traits may be defined as flesh firmness, TSS, TA and improved over-color. Genetic factor played prominent role in de/accelerating the alterations. Since those cultivars like Dirras-e Mashhad that suffer less alteration in unit of time, it reflects a higher storage potential. Furthermore sole 1-MCP had significant effect on marketability and key commercial traits of fruits e.g. weight, flesh firmness and over-color intensity indicating it as an acceptable chemical to increase the apple storage time. ENA could also maintain relatively the firmness compared with control. Aroma was not affected by 1-MCP treatment neither in "Wealthy" nor in "Dirras-e Mashhad", in agreement with the other results on "Red Delicious" and "Golden Delicious" (Kondo et al. 2005) [37] . The observations regarding aroma was either reported by Mattheis et al. 2005 [38] , so that 1-MCP treated "Gala" apples, stored in different conditions including CA, produced less volatile compounds than control. Others by treatment of "Granny Smith" apples with 1-MCP could extend the storage time in normal storage conditions for at least 3 months without losing freshness. Descriptive sensory analysis affirmed that 1-MCP treated samples suffered low rates loss of juiciness, cohesiveness, hardness, crunchiness, greenness and sourness during storage as compared to control. All of the samples appeared on the positive side of ‘Freshness’ axis in principal component space. The highest level of freshness loss during the storage period was observed in control samples, which suffered changes in quality after the 9 months of storage, so that the fruit were totally decayed (Tomic et al. 2016) [9] .

The analysis of variance for fruit ethylene emission showed significant difference only in storage time. The mean comparisons of ethylene production at initial time of experiment and 5^th month of storage measured relatively at 3.26 and 53.64 ppm/Kg∙hr. The assessments emphasize the increasing trend of ethylene production correlated directly with respiration of the fruit senescence reflected in cell wall softening due to enzymatic action. Occurrence of known apple disorders such as scald, bitter pit and internal browning during storage all go through the similar metabolic pathway for which the final reaction lead to stimulation and production of ethylene (Tromp et al. 2005) [5] .

The analysis of variance for fruit CO₂ production afforded the significant differences regarding storage period, cultivar, interactions of time × cultivar, time × cultivar × 1MCP and time × KMnO₄ × 1MCP, as well. No significant difference was noted for other traits. The mean comparisons of emitted CO₂ during storage confirmed that the least value 2301.6 was recorded for initial stage of storage, but it in an increasing trend it grows to 2610.1, 3085.2 and 3154.6 ppm/kg∙h in monthly intervals, first to 3rd month of storage, with a slight reduction (3115.3) at the end of 4th month and a noticeable decline (2592.5) at final stage of storage. There was observed significant difference of generated CO₂ at 5 percent of probability between the first 30 days of storage and other consecutive 90 days. The mean comparisons of produced CO₂ by the two apple cultivars showed significant difference during entire period of storage. "Wealthy" with the mean

value of 36.5 ppm/kg∙h produced more CO₂ than "Dirras-e Mashhad" that emitted 34.16 ppm/kg∙h. Interactions between time × cultivar on generated CO₂ demonstrated that over time CO₂ production was gradually increased so that the highest rates were observed in "Wealthy" and "Dirras-e Mashhad", 2839.2 and 3623 ppm/kg.h during the third and second month, while the least values 2317.3 and 2285.8 were registered at initial stage of storage, correspondingly, confirming the "Wealthy" with highest respiration rate. At the end of fifth month both of cultivars decreased the emission of CO₂ (Figure 8).