Introduction

Persimmon (Diospyros kaki) belongs to the family Ebenaceae is widely grown in the climatic zones range in the world. This species is native to Japan and has wide leaves and delicious fruit. Planting this tree, because its fruits, first developed in Western countries and in the first decade of the 19^th century was introduced to California and Southern Europe [1], and later entered Iran. And has also in many parts of the country expanded. In color, the ripe fruit of the cultivated strains range from light yellow-orange to dark red-orange depending on the species and variety. The fruit has a high tannin content which makes the immature fruit astringent and bitter. It is edible in its crisp firm state, but has its best flavor when allowed to rest and soften slightly after harvest [2].

Fruit harvested at different times have a significant impact on fruit quality characteristics [3-5]. Harvest index, based on experience and ecological conditions of climate zones evaluated at the end of December is completed. Harvest index, based on experience and ecological conditions of climate zones is complete at the end of December. Fruit picked before ripening to increase during storage and maintaining quality characteristics it is very important. Fruits that are harvested too early, smaller and color, aroma and taste them down [6,7].

The plant growth is influenced by genetic and environmental characteristics, so it could be more due to the differences in a variety of environmental factors to genetic changes. Thus, the lack of environmental factors, plant growth will be disorder and will stop [8]. Temperature is one of the factors affecting photosynthesis and plant metabolism at the cellular level. Seasonal and diurnal temperature changes has a significant effect on plant growth [9].

The difference in the temperature range can be attributed to variations in latitude, topography, proximity to large bodies of water represented. This constructive climate, due to the high heat capacity of water, this constructive climate, due to the high heat capacity of water, as evident in annual and the diurnal temperature range (DTR). Generally, higher temperatures lead to an increase in the rates of sugar accumulation in the fruit ripening and organic acids degardation, while low temperatures can lead to a reduction in the organic acids degradation and rates of sugar accumulation [10]. According to the daily temperature range, grape quality varies during the ripening period, because this parameter affects the sugar, anthocyanin compounds and as well as the aroma. During the day, photosynthesis occurs and at night photosynthesis product move from the source leaves to the fruit. Cool night temperature in during grape ripening favor the sugar accumulation and restrict the vegetative growth [11], Mori et al. [12], reported that at higher temperatures from 10˚C respiratory activity increases exponentially.

Persimmon fruit is rich in the carbohydrates, organic acids, vitamins (especially A and C), minerals, phenolic compounds and carotenoids [13,14]. Phenolic compounds with ascorbic acid protects the body against oxidative stress [15,16]. The amount of ascorbic acid (vitamin C) is a basic indicator to define the marketability of fruit and vegetables [17]. It is believed that vitamin C acts as an intermediate in the biosynthesis and metabolism of substances that are involved in the immune system [18]. Ebrahimzadeh et al. [19], reported a significant difference among citrus species for vitamin C contents. Therefore, the aim of this study was to investigate the effects of different climate zones, as a manifestation of changes in temperature and humidity, is the persimmon fruit quality.

Material and Methods

Climate regions features

In order to evaluate the effect of different climatic conditions on biochemical properties of persimmon fruit, from five areas (cities) with different climatic conditions, including: Sari (36.56° N, 53.06° E), Yazd (31.89° N, 54.36° E), Kiasar (36.23° N, 53.54° E), Kashan (33.98° N, 51.47° E ) and Shahrud (36.41° N, 54.97°E) were sampled. Characteristics and geographical areas listed in Table 1.

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   Table 1:

   Geographical location and climatic characteristics of the regions studied.
   
   

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   Table 1:Geographical location and climatic characteristics of the regions studied.
   Regional climate	Longitude (˚E)	Latitude (˚N)	*AMSL (m)	**temperature (˚C)	**precipitation (mm)	The number of frost day
   Sari	53.06°	36.56°	132	15	789.2	11
   Shahrud	54.97°	36.41°	1130	12	375	98
   Kashan	51.47°	33.98°	1570	18	116	65
   Kiasar	53.54°	36.23°	1378	13	656	51
   Yazd	54.36°	31.89°	1230	20.2	62	55
   *The term above mean sea level (AMSL) is the elevation or altitude of any object, relative to the average sea level. ** Average of annual temperature and precipitation.

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Meteorological data

Daily data of maximum temperature, minimum temperature, average temperature and average relative humidity (During the growing season in 2014) of Iran Meteorological Organization (IMO) were received. Annual average calculated in Table 2 were reported. The difference between the dailymaximum and minimum temperature, the diurnal temperature range (DTR) was calculated.

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   Table 2:

   Vitamin C, chlorophyll a, b and ab activity and carotenoid content of fruit harvested in different regional climate, during growth of persimmon fruit in 2012.
   
   

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   Table 2: Vitamin C, chlorophyll a, b and ab activity and carotenoid content of fruit harvested in different regional climate, during growth of persimmon fruit in 2012.
   Regional climate	Vitamin **(mg/100ml)	Chlorophyll a ***(mg/g.f.w)	Chlorophyll b (mg/g.f.w)	Chlorophyll ab (mg/g.f.w)	Carotenoid (mg/g.f.w)
   Sari	0.75c*	0.05a	0.03a	0.04a	0.22b
   Shahrud	1.43b	0.01b	0.02a	0.03a	0.19b
   Kashan	1.63a	0.01b	0.02a	0.03a	0.24b
   Kiasar	1.40b	0.01b	0.02a	0.03a	0.19b
   Yazd	1.74a	0.06a	0.03a	0.04a	0.42a
   **Mg of fruit weight per the 100 ml fruit juice. ***Mg of fruit weight per the gram fruit fresh weight. *means along different treatment on last column that carry the same letter have no significance difference (5%).

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${\text{DTR}}_{\left(˚\text{C}\right)}=T_{max}-T_{min}\text{ (1)}$

Fruits

In this study, based on a randomized complete block design with three replications, from trees that have the same morphological characteristics, such as height, age and canopy, were sampled. To harvest fruit, the color index similar to citrus fruit (orange light-orange) was used.

Measuring of biochemical characteristics of fruit

To measure vitamin C from 2,6-Dichloroindophenoltitration method was used and the amount of vitamin C was calculated from the following equation [20].

${\text{Vit}}_{\left(\text{c}\right)}(\frac{\text{mg}}{100})=\frac{\text{e*d*b}}{\text{c*a}}\times 100$

Total soluble solid (TSS) in the juice was determined with a hand- refract meter (PR-32 palette, Atago Co., Japan) at room temperature and expressed as a Percentage [21]. Titratable acidity (TA) was determined in the presence of phenolphthalein (pH=8.2) and expressed as citric acid percent (Rabiei, 2006). pH of the juice was measured using a pH meter (Jenway,3020).To determine the amount of chlorophyll and carotenoid, first 0.5 g of sample was pulverized in the presence of 10 ml acetone 80%. The solution was centrifuged for 5 min at 5000rpm. Using a spectrophotometer (UV-1800 PC), the absorption rate in wavelength of 480, 510, 645 and 663 nm was recorded. Acetone 80% was used as a blank spectrophotometry [22]. The following formula for the amount of chlorophyll a, b, a * b and carotenoid were calculated:

Fruit biochemical data were analyzed using ANOVA of SAS software (SAS 9.1), and the SNK post hoc test was employed to compare treatment means.

$Chloa\left(mg/g.\text{f}.\text{w}\right)=12.7\left(A663\right)-2.69\left(\text{A}645\right)\text{*}\frac{V}{1000}\text{*}W$

$Chlob\left(mg/g.\text{f}.\text{w}\right)=12.9\left(A645\right)-2.69\left(\text{A}663\right)\text{*}\frac{V}{1000}\text{*}W$

$Chloa\times b\left(mg/g.\text{f}.\text{w}\right)=20.2\left(A645\right)-8.02\left(\text{A}6663\right)\text{*}\frac{V}{1000}\text{*}W$

$Car\left(mg/g.\text{f}.\text{w}\right)=7.6\left(A480\right)-1.49\left(\text{A}510\right)\text{*}\frac{V}{1000}\text{*}W$

Result and Discussion

Vitamin C (ascorbic acid) content

Different climatic conditions in the regions studied, very significant effect on the amount of ascorbic acid (P ≤0.01). Based on research findings, fruits that were harvested from the areas of climate Yazd and Kashan, total vitamin C contentmore than the fruits that were harvested from other parts of the climate (Table 2).

According to Table 2, the highest vitamin C content of the fruit harvested from Yazd and Kashan climate regions, respectively, with values of 74.1 and 63.1 (mg/100 ml of fruit juice) and the lowest level was in sari climate region (76.0 mg/100ml of fruit juice). Many actions and reactions that occur in plants, each to be affected by temperature fall. The role of temperature on photosynthesis and respiration reactions can be noted among. The net value of the daily work of photosynthesis by plants and accumulated difference between the amount of carbohydrate that is made during the day and the amount of carbohydrate per day (24 hours) consumed by respiration. Plant for biological activity and construction, only products that is added daily during the photosynthesis process, it can consume or store it in an organ or other plant organs accumulated. However, it was found that when the total daily respiration is more than the daily photosynthesis, the plant products that already had accumulated storage consumes, if the trend continues, with a lack of food plants will be lost. With increasing temperature, respiratory rate becomes faster than the rate of photosynthesis, and the pure substance that is made daily by the plant reduced. The process of photosynthesis is limited to circumstances where there is enough light during the day, while the respiration process continues over a day (every hour of the day) the night temperature?? Has an important influence ІІe on the pure substance that is made daily as a result of photosynthesis in plants. By breathing at 25°C, more food is consumed than 15°C [23].

Thus, areas with relatively cool nights and warm days are the pure substance stored in the plant and the yield will increase. On the contrary, in areas that are relatively warm nights of the pure substance stored and the yield is generally low. Based on the findings of the report could be said that in areas where the temperature difference between day and night was higher than other regions, have increased the amount of material stored and also had a higher qualitative characteristics. Therefore, it is believed that the reason for the higher rate of vitamin C fruits harvested from climatic regions of Kashan, Yazd, and shahrud than the Kiasar and Sari climate is the temperature Hamedani et al. [24]. Temperature difference between day and night for them. Hamedani et al. [24], Showed that the amount of vitamin C content in the orange fruit is affected by the temperature and the amount varied at different temperatures.

Chlorophyll and carotenoid contents of fruit

Determining the chlorophyll a and b and ab activity fruits harvested from different climatic regions showed that the climatic conditions of the region had a significant effect on the chlorophyll a activity (P ≤ 0.01). While climatic conditions of the regions studied the activity of chlorophyll b and ab fruit had no significant effect (Figure 1). Results showed that the chlorophyll a activity affected by regional climate. As fruits that were harvested from the region of Yazd, highest of the chlorophyll­ a activity, compared with other parts of the climate. While, the amount of activity chlorophylls b and ab in different climatic conditions studied did not change. Also, different climatic conditions have a significant effect on fruit carotenoids content (P ≤ 0.01). Based on the results, the carotenoid content of fruits that harvested from the region of Yazd, a higher rate than other parts of the climate (Figure 1).

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   Figure 1:

   Diurnal Temperature Rate (DTR) (a) and Relative Humidity (b) changes, during growth of persimmon fruit in 2014.
   
   
   

In the early season vegetative growth to reproductive parts (fruits) more. Therefore, many materials are synthesized by the leaves of the vegetative organs stores; but with the growth of fruit photosynthetic products in the fruit stored [25]. Therefore, the amount of chlorophyll in fruit during ripening is reduced (Fattahi moghaddam 2010). As the fruits exposed to higher and lower temperatures than optimal, the fruit quality decreases. Perveen et al. [26], showed at temperatures close to zero and less than zero, the amount of chlorophyll a, b and carotenoid content in wheat was zero temperature. Sharma et al. [27], reported that, at a temperature close to 30°C, chlorophyll and carotenoid content is highest than 45°C.

Acidity (pH), Titratable Acidity (TA) and Total Soluble Solid (TSS)

The results showed that the different climatic conditions had a significant effect on pH, TA and TSS of fruit (P ≤ 0.01). Thus, the fruits harvested in the Kashan region with value 6.6 had the highest pH while the highest TA and TSS (0.04 and 22.13 mg/100ml) was for the shahrud area, (Table 3). The physiological activity of fruit in many species with exposure to high and low temperatures reduced [28]. Fruit soluble solids content more dependent on the synthesis and transport of assimilates from the leaves to fruits [29]. Role of the high temperatures in transfer of the fruit, during fruit ripening is known [30]. As low night temperatures reduce the soluble solids content [31]. Therefore, it is believed that high levels of soluble solids content in Kashan and Yazd climates than the Kiasar and Sari climates, related to the higher the day and night temperature in these areas. Based on the results of Javanmardi and Kubota [32], by studying changes in quality of tomatoes grown in greenhouse conditions showed that, Approaching the peak temperature and solar radiation Fruit titratable acid content decreased with the increase in sugar. The results of this study, the results Khanal et al. [33], to increase the soluble solids content and titratable acid reduced the fruit under different temperature conditions confirmed.

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   Table 3:

   Acidity (pH), Titrable Acidity (TA) and Total Soluble Solid (TSS) of fruit harvested in different regional climate, during growth of persimmon fruit in 1392.
   
   

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   Table 3: Acidity (pH), Titrable Acidity (TA) and Total Soluble Solid (TSS) of fruit harvested in different regional climate, during growth of persimmon fruit in 1392.
   Regional  climate	Acidity (pH)	Titratable acidity (TA%)	Total soluble solidity  (TSS)
   Sari	6.3b	0.01d	17.2c
   Shahrud	6.3b	0.04a	20.1b
   Kashan	6.6a	0.02c	22.3a
   Kiasar	6.4b	0.02c	17.1c
   Yazd	6.3b	0.03b	22.1a
   Means along different treatment on last column that carry the same letter have no significance difference (5%).

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Conclusion

Based on the finding, the effect of different regional climate on persimmon fruit quality were significant (P ≤0.01).It is believed that, the day and night temperature changes on the amount of vitamin C, chlorophyll a, b and a, b activity and carotenoid content of harvested fruits was effective. Based on these findings, and considering the use of the properties of persimmon fruit in different sectors of agriculture, industry, medicine and nutrition, the importance of fruit quality should be taken into consideration more than ever.