Evaluation of Fruit Physical and Color Characterizations of some Oleaster (Elaeagnus angustifolia L.) Genotypes in Northwest of Iran

Oleaster (Elaeagnus angustifolia L.), belonging to the Elaeagnaceae family, is usually a shrub or small spiny tree with a height of 2– 5 m. Branches of oleaster are silvery green and the leaves are egg-shaped or bayonet and the flowers are bell -shaped, very fragrant, cream color, and single or clustered. The fruits are oval-shaped with a length of 1.5 –2 cm and their colors are reddish-brown. Oleaster (Elaeagnus angustifolia L.) is one of the most valuable fruit tree is grown wildly in northwestern of Iran. The oleaster was distributed in East Asia, Southeast Asia, and Queensland in northeastern Australia. This tree was extended along the rivers in many arid and semi-arid regions. It also plays a very important role in maintaining the ecosystem of dry areas, due to high drought tolerance and high salinity and alkalinity tolerance in soil. The evaluation of fruit and seed properties can be useful in selection of superior genotypes for commercially culture. Therefore, the aim of this study was to investigate the physical properties of seed and fruit of some Elaeagnus angustifolia genotypes in east and west Azerbaijan provinces.

In this study, thirty-eight genotypes of Elaeagnus angustifolia L., according to free of pest and disease characteristics were selected and labeled from east and west Azerbaijan provinces, Iran. The fully matured fruits were collected from studied genotypes and then transferred to the lab and different parameters such as physicochemical characterizations of fruit and seed such as weight, length and width of fruit and seed and fruit color parameter were measured. Fruit color was determined by Chroma meter CR-400 (Konica Minolta, Japan). After collected data, to calculate descriptive statistics, correlation and cluster analysis based on Ward’s method was used SPSS Software (Version 22). The factor analysis was also performed using varimax rotation method.

The results showed that there was high diversity in some of the attributes such as leaf width, leaf length/leaf width ratio and flesh weight. The highest diversity was observed in leaf width (37.56 %) and the fruit surface area had lowest diversity (2.09 %). The mean of fruit length, fruit width and fruit width, fruit geometric mean diameter and sphericity were 22.99, 16.09 cm, 1.69 g, 18.09 mm and 79.22 %, respectively. Ersoy et al. (2013) revealed that length, width, thickness and weight of fruit were 2.86 cm, 1.88 cm, 1.87 cm and 2.90 g respectively. The mean of seed length, width, thickness and weight were 2.42 cm, 0.508 cm, 0.503 cm and 0.38 g, respectively. Leaf length was positively correlated with leaf width, fruit length/fruit width ratio, and seed length and seed length/seed width ratio and negatively with fruit sphericity. In the present study, the mean of traits related to fruit color including L*, a*, b*, hue and chroma were 48.09, 13.99, 18.51, 52.18, and 28.23, respectively. In the study of Zare et al. (2012), the mean of L*, a*, b* were 12.42, 2.73 and 2.39, respectively. In the present study, the mean of traits related to fruit color was higher than the mean mentioned in Zare et al. (2012) study, and this discrepancy can be due to different environmental conditions and studied genotypes. In this study, based on factor analysis, the eight main factors were explained a total of 85.92 % of the variance, which 20.59% were related to the first factor and 18.69% to the second factor. The two-dimensional scatter plot was constructed for graphical overview of the relationships among genotypes. According to scatter plot created by two first factors, all studied genotypes were located in two groups. The scatter plot revealed geometrical distances among genotypes reflecting phenotypic and in this regard presumably genetic dissimilarity among them. According to the cluster analysis, genotypes were divided into two main groups. Genotypes in group first had the highest average fruit and seed length, width and weight. The traits related to color such as L* , a* , b* , hue, chroma had a significant role in separation of second group. Therefore, the presence of genotypes in different clusters represented high diversity in terms of evaluated traits among the all genotypes.

This research is a preliminary study that can be based to select the desired genotypes. The study also provides important information on the physical characteristics and fruit color of some Elaeagnus angustifolia genotypes in the east and west Azerbaijan provinces. In general, the results of this study showed that there is high diversity among the studied genotypes.The results obtained might be helpful for breeding programs and introducing of cultivar in Elaeagnus angustifolia.