Selection studies on fig ( Ficus carica L . ) in Antalya Province of Turkey

Turkey is one of the gene centers of fig in the world and there are great variations and distributions in wild fig forms as well as fig cultivars. The primary objective of this study is to select valuable fig genetic resources in Ibradi and Kumluca (Antalya) province and to conserve the promising figs genetic resources. Populations consisting of native fig genotypes were selected and chracterized in terms of pomological and morphological traits. The data revealed that some of the fruit and leaf characteristics of the investigated fig types were significantly different in terms of location and fig types. Consequently, it is suggested that these promising fig genetic resources could be used for further breeding programs and therefore they need to be preserved.


Fig (Ficus carica L.
) is among the oldest fruits and is known to man from ancient times (Aksoy, 1998).Today, the fig is an important fruit crop in many parts of the world.Figs are cultivated around the world in subtropical and tropical regions and to some extent in moderate climatic regions of the temperate zones (Storey, 1975).
Fig is considered as one of the oldest fruit trees in the Mediterranean region.Its wild genetic resource (relatives) still exists in many countries.Turkey is also considered as an important gene center of figs and some temperate fruit species in the world.It is known that Anatolia is the native land of fig and wild figs spread from here to the Mediterranean, Syria, Iran, Iraq, Saudi Arabia, South Caucasia and Crimera (Condit, 1947;Kuden and Tanriver, 1998).
Turkey is one of the main fig producing countries of the world and is considered the first in the trade of fresh or dried figs worldwide (Aksoy et al., 2003).The fig production in Turkey is about one fourth of the world production (1 108 398 Mt) (FAO, 2008).In the world market, there is an increasing demand for fresh figs, therefore production with standard varieties accompanied by advanced handling, attractive packaging and trans-*Corresponding author.E-mail: sgozlekci@gmail.com.portation facilities will enable the establishment of a strong and lasting chain between the producer and the consumer.Because of increasing demand for fresh consumption cultivars, any attempt to increase fig production is of value (Aksoy et al., 1992).
Fig is commonly consumed as fresh and dried fruits.Westwood (1978) reported that calories, carbohydrate and protein content of figs are high.Fig contains 1.3 to 3.6% protein, 9.5 to 52.9% total sugar, 45 to 300 kcal energy, 5.2 to 28.6% glucose, and 4.1 to 22.7% fructose per 100 g of fresh and dried fruits, respectively (Aksoy et al., 2001).Mature and young fig fruit extracts are used for medicinal purposes.Its high fibre content helps in the digestive system (Wang et al., 2003) (Kuden and Tanriver, 1998).Figs are native trees of Anatolia and originated from Caucasian and the Mediterranean regions, including Turkey (Condit, 1947;Aksoy, 1995;Aksoy, 1996).East Mediterranean and Southeast Anatolia (Kuden and Tanriver, 1998) regions are known for the genetic resources of figs, especially for fresh fig cultivars (Ozbek, 1978).Although there are some selection studies conducted in different ecological regions on fig in Turkey (Cetiner, 1981;Eroglu, 1982;Aksoy et al., 1992;Sen et al., 1993;Kuden et al., 1995;Ilgin and Kuden, 1996;Ozkaya, 1997;Koyuncu, 2004), there are none in the Mediterranean region.In the coastal regions of Turkey, the fig orchards or plantations are been abandoned due to high income from tourism.Therefore, fig trees grown in all of the coastal regions are under high risk because they are continually subjected to genetic erosion.Due to these reasons and continuous genetic erosion, it is necessary to collect, describe and also maintain them in situ and ex situ.
The objectives of this study are to: 1) Determine fig ecotypes of good quality for fresh consumption in Ibradi and Kumluca, in Antalya province of Turkey and the surrounding area of west Mediterranean region and 2) study their pomological and morphological characteristics.In order to preserve their genetic diversity, cuttings from 24 selected fig ecotypes were used.

Experimental materials
The experimental materials of the present study were fruits of 8 and 16 native landraces of fig (F.carica L.) collected in Ibradi and Kumluca (Antalya provinces) located in the west Mediterranean region of Turkey.

Fruit and leaf characteristics
Twenty fruits for each fig landrace were randomly sampled for measurements and analyses.The characteristics were fruit weight (g), fruit length (mm), fruit diameter (mm), neck length (mm), ostiol width (mm), fruit shape index, fruit skin (external) and flesh color, leaf width (mm), leaf length (mm), petiole length (mm), the number of the fruits and leaves per shoot, number of leaf lobes, total soluble solid content (%) and titratable acidity (%).The results were comparatively investigated in Ibradi and Kumluca (Antalya province).
Fruit width and fruit length were measured by using a digital caliper with a sensitivity of 0.01 mm.Fruit weight was measured using a digital balance with a sensitivity of 0.001 g.Fruit shape index was explained as the ratio of fruit width to fruit length.Fruits samples were homogenized and filtered, then the total soluble solid content (TSS) was measured using an ATAGO (ATC-I, Japan) handheld refractometer.Titratable acidity was measured by titration method and was calculated as percent citric acid (AOAC, 1995).Fruit and leaf characteristics of the samples were determined according to Fig Descriptors (IPGRI and CHIEAM, 2003).

Statistical analyses
Analysis of variance and descriptive statistics were separately performed for Ibradi and Kumluca samples using the PC-SAS software package (SAS-Institute, 1987).

Fruit and leaf characteristics in Ibradi and Kumluca
Analyses of variance showed that there were statistically significant differences among samples for all traits (P < 0.05) (Table 1).As seen in Table 1, mean values of parameters showed large differences in both fig types collected in Ibradi and Kumluca.Ibradi is located in the high plateau of Antalya, while Kumluca is in the coast.Therefore, these provinces had altitude differences of about 900 m.The results of this study clearly demonstrate the strong effect of the climate on fig production and fruit quality.
The fruit weight of Ibradi types ranged from 13.40 to 51.94 g, while the fruit weight of Kumluca types ranged from 19.98 to 62.55 g (Tables 1 and 2).Although results obtained on fruit weight in the present study are in agreement with some previous studies (Chessa and Nieddu, 1990;Aksoy et al., 1992;Kuden et al., 1995;Ilgin, 1995;Koyuncu, 1998;Koyuncu et al., 1998;Bostan et al., 1998;Aksoy et al., 2003;Koyuncu 2004), there are some other studies that are not in agreement (Yang et al., 1994;Karadeniz, 2003;Ferrara and Papa, 2003).These differences could be attributed to genotypes variations and environmental conditions.
The fruit width was between 30.58 and 47.54 mm in Ibradi, while it was between 32.63 and 50.21 mm in Kumluca.Fruit shortest length was recorded at 31.71 and 35.84 mm and the tallest at 43.79 and 56.65 mm in Ibradi and Kumluca, respectively.Results obtained on fruit length and fruit width are in agreement with previously published data (Aksoy et al., 1992;Kuden et al., 1995;Ilgin and Küden, 1996;Bostan et al., 1998;Koyuncu, 1998;Koyuncu et al., 1998;Ozkaya, 1997;Kuden and Tanriver, 1998;Ferrara and Papa, 2003;Koyuncu, 2004).In terms of fruit size obtained in this study, results demonstrated mostly a medium size.Aksoy et al. (1992) reported that the fruit size (width and length) and fruit weight were considered as an important trait in the fresh consumption group.Usually, small fruits are used for making jam, whereas big ones are consumed as fresh fruit in Antalya region.The fruit shape index of Ibradi genotypes was 0.92 to 1.10 mm.The fruit shape was oblate, spherical and oblong.In Kumluca, the fruit shape index was 0.67 to 1.08 mm (Table 1) and varied from oblate to oblong.Ferrara and Papa (2003) reported that the fruit shape ranged from turbinate to spherical in all the cultivars.Condit (1941) indicated that the fruit shape index is of great importance in packaging and transportation.According to fruit shape,  (Ozeker and Isfendiyaroglu, 1997).With respect to neck length, K13 type (13.74 mm) and K46 type (12.90 mm) had the highest values.Also, it was found that the neck length was changed between 0.7 and 21.2 mm which are in accordance with the results of Aksoy et al. (2003).
The ostiolum width of the fruits in Ibradi was 2.20 to 5.35 mm, while in Kumluca, the ostiolum width of the fruits varied from 1.73 to 5.48 mm (Table 1).
The results obtained are in accordance with the previous studies (Chessa and Nieddu, 1990;Aksoy et al., 1992;Ilgin, 1995;Ozkaya, 1997 andBostan et al., 1998).On the other hand, findings in the study are not in agreement with Ozeker and Isfendiyaroglu (1998), perhaps due to genotypic and environmental differences.Both in Ibradi and Kumluca figs, leaf dimensions showed large variability.The leaf length was between 16.89 and 32.87 mm in Ibradi, while it was between 19.57 and 31.16mm in Kumluca.
The lowest values recorded for leaf width, were 10.86 and 10.80 mm and the highest ones were 22.36 and 23.56 mm in Ibradi and Kumluca, respectively.In Ibradi and Kumluca figs, the petiole lengths were between 3.61 and 9.37 mm and 5.60 and 10.71 mm, respectively (Tables 1  and 2).In similar studies, leaf length, leaf width and petiole length were reported to be between 22.7 and 28.9 mm, 20.7 and 25.6 mm, 8.0 and 14.3 mm (Bostan et al., 1998), 20.2 and 25.7 mm, 18.5 and 25.5 mm, 7.2 and 17.1mm (Koyuncu et al., 1998), 20.37 and 23.19 mm, 19.45 and 22.28 mm and 7.35 and 10.38 mm (Sanchnez et al., 2003), respectively.
In Ibradi fig types, the mean number of the leaves and fruits per shoot ranged between 6.77 and 8.73 and 3.63 and 4.17, respectively (Table 1).The mean number of the leaves and fruits per shoot of the Kumluca province types varied between 5.18 and 11.18 mm and 2.81 and 8.65 mm, respectively.Typically, the lobe of the leaves of the selected types ranged between 3 and 5(Data not shown).These results are in agreement with previous reports (Ilgin, 1995;Ozkaya, 1997;Koyuncu et al., 1998;Koyuncu, 2004).In Ibradi and Kumluca province fig types, the fruit skin (external) color ranged from green-yellow to dark blue.In Kumluca, the most frequent color of the skin was dark blue for 12 cultivars; and the remaining were light green.The fruit flesh color changed between amber, pink and red to dark red (data not shown).Aksoy et al., (1992) reported that there were great variabilities for skin color in fig types and cultivars.Likewise, great variations for skin color were observed in this study.
The fruits of nine promising types (I15, I16, I17, I27, K13, K22, K37, K53 and K70) could be use in chocolate and confectionary industry due to their small sizes.Furthermore, the I24 (30.10%),I15 (28%) and K51 (30.02%) fig types demonstrated the highest total soluble solid contents, whereas the I16 (16.06%) and K59 (16.17%) fig types showed the lowest total soluble solid content.In addition, the types with high sugar content may be used for jam making and as dried fruit.Because of the large and medium fruits demonstrated by these fig types (K14 "large", K18, K51, I11 and I12 "medium"), they are recommended for table figs for both domestic and foreign markets.

Conclusions
Results in this study indicated that some quality parameters such as fruit weight, fruit size and total soluble solid content were highly correlated with ostiol width.Moreover, it was observed that the ostiol width was positively correlated with total soluble solid content.Figs having large ostiol widths are not preferred by costumers because of quick fruit decay.Almost all of the parameters evaluated showed significant differences between Ibradi and Kumluca provinces.The fruit length, fruit width and fruit weight of Kumluca were generally higher than those of Ibradi province fruits.It was demonstrated that fig types K14 "large", K18, K51, K70, I11 and I12 "medium" size performed well in the production of high quality fruit for fresh consumption.On the other hand, fig types I15, I24, K29, K46 and K51 which demonstrated high sweet flavor could be considered for making jam and marmalade.These differences could be the result of genotypic variations and environmental conditions.These results revealed that the selected fig types could contribute to further breeding studies and preservation of germplasm.
. Fig fruits are also of importance in the food industry since they are transformed into several processing products such as preserved fruits, canned foods, jam, juice, wine, powder, tea, paste confection, covered with chocolate and baked in pastries.The fig genetic resources comprise great numbers of cultivars in various Mediterranean countries.Figs are an important traditional crop in Turkey, due to the wide adaptability to the soil and climatic conditions, many different local cultivars are grown in different regions.Worldwide, the best quality of dried figs is produced in the Aydin and Izmir provinces of the Aegean region in Turkey (Aksoy et al., 2001).In Turkey, table fig trees are common in all of the coastal areas.The Mediterranean and the South East Anatolian regions are the most important gene centers of table fig cultivars

Table 1 .
Descriptive statistics (means and standard errors) in fig types collected from Ibradi, Antalya.

Table 2 .
Descriptive statistics (means and standard errors) in fig types collected from Kumluca, Antalya.