VARIATION IN MORPHOMETRIC TRAITS OF FRUITS OF MESPILUS GERMANICA L

According to the International Program for the Botanic Gardens Conservation, botanic gardens contribute to the conservation plant species, which are of great socio-economic importance, and develop and implement a policy to use herbal products derived from sustainably developing sources. The aim of this study was to determine morphometric parameters of fruits of seven genotypes of Mespilus germanica L., which are growing in the Forest-Steppe of Ukraine in M. M. Gryshko National Botanical Garden of NAS of Ukraine (Kyiv). Their morphometric parameters were following: fruit weight from 35.29 to 39.12 g, fruit length from 27.69 to 42.29 mm, fruit diameter from 24.98 to 44.75 mm, length of calyx basin from 17.55 to 32.46 mm. The shape index of the fruits was found in the range of 0.79 to 1.23. It was found that fruit diameter positively correlated with traits such as fruit weight and calyx basin length. Fruit weight was also highly correlated with calyx basin length and fruit length. Using the cluster analysis with Euclidian distances allowed to establish the relationships among the fruits Mespilus germanica germplasm and arranged the genotypes into five relatively homogenous clusters. Hence, the introduction population characterized by quite variability and contains plants with almost all types of fruits. Obtained data can be used for breeding programs and introducing of cultivars in Mespilus germanica.


INTRODUCTION
Recently, the increasing importance attached to the consumption of healthy food.Attention is attracted not by traditional fruit crops, but by wild plants with smaller fruits, which, however, contain natural vitamins and antioxidants: cornelian cherry, mountain ash, sea buckthorn, rose hip, service tree, elderberry, bilberry, mulberry, jujube.The Mespilus germanica L. (medlar) is also included in this group of popular fruit trees.This species belonging to the family Rosaceae Juss.was introduced to Greece around 700 BC, and to Rome about 200 BC (Baird and Thieret, 1989).Until the seventeenth century, the medlar was the most important fruit crop.However, interest in it gradually faded away, and later it was replaced by other, more productive and undemanding crops.Currently, medlar is grown quite rarely and, mainly, in botanical gardens or in small farms.Mespilus germanica is indigenous to southwest Asia and possibly also southeastern Europefrom northern Turkey (some occurrence in Greece and on the Crimea) to the Caucasus and Transcaucasus and the north-eastern part of Iran (Lim, 2012).

Scientific hypothesis
In our experiment, we have been supporting that fruit phenotyping variability of evaluated genotypes collection Mespilus germanica not predominate only cultivation conditions but also genetical features.

MATERIAL AND METHODOLOGY Locating trees and data collection
The objects of the research were 10-year-old plants of Mespilus germanica from seed origin, which are growing in Forest-Steppe of Ukraine in M. M. Gryshko National Botanical Garden of NAS of Ukraine (NBG).The study was conducted 2018 year.We have described 7 genotypes of Mespilus germanica.Fruits were harvested at commercial maturity stage (skin brownish, pulp white, fruit hard).

Morphometric characteristics
30 fruits from each genotype were used immediately after harvest for phenotypic measurements such as fruit weight, (FW), in g, fruit length (FL), in mm, fruit diameter (FD), in mm, calyx basin length (CL), in mm.Fruit mass was measured by using a digital balance with a sensitivity of 0.01 g (PS6000/C/1).Linear dimensions of fruits as length and diameter were measured by using a digital calliper gauge with a sensitivity of 0.01 mm than shape index was calculated by using length/width ratio.
The measurements were made in each nut element as shown in Figure 1.

Statistical analyses
Basic statistical analyses were performed using PAST 2.17; hierarchical cluster analyses of similarity between phenotypes were computed on the basis of the Bray-Curtis similarity index; multi-dimensional scaling (MDS) analyses were performed in PRIMER ( Clarke and Gorley, 2006).Variability of all these parameters was evaluated using descriptive statistics.Level of variability determined by Stehlíková (1998).

RESULTS AND DISCUSSION
In this study was selected certain fruit parameters, which can be interesting for commercial use.
The fruit weight, fruit length, fruit diameter, calyx basin length, and shape index of fruits in seven Mespilus germanica genotypes are shown in Tab. 1.
The data in the Table indicate the high variability of fruits, especially their mass.Thus, some genotypes can be used further in the selection process.The images of Mespilus germanica fruits of various genotypes are shown in Figure 2 and 3.
The highest fruit weight was обтаинед in genotype MG-05 as 35.29 g, and followed by MG-04 as 39.12 g (Figure 4).
The fruit weight was determined in the range from    The length of calyx basin increased with the coarsening of fruit.For the length of the calyx, the basin was found between 17.55 (MG-07) and 32.46 (MG-05) mm.Studies in the literature carried showed that the values of length of   Shape index was found between 0.79 (MG-04) and 1.23 (MG-01) (Figure 5).According to shape index results, the genotypes MG-01, MG-06 and MG-07 have pearshaped and the others are apple-shaped fruit form.Ercisli et al. (2012) reported a shape index between 0.81 and 1.09.Miko and Gažo (2014) identified the shape index from 0.73 to 1.12.Akbulut et al. (2016) found a shape index between 0.87 and 1.04.In addition, Nezhadghan and Hassanpou (2018) identified the shape index between 0.78 and 1.51.Our result on shape index could be comparable with those studies.
It was found that fruit diameter positively correlated with traits such as fruit weight (r = 0.98) and calyx basin length (0.85).Fruit weight was also highly correlated with calyx basin length (0.79) and fruit length (0.60).
Multidimensional scaling (MDS) is to detect meaningful underlying dimensions that allow the researcher to explain observed similarities or dissimilarities (distances) between the investigated objects.Results of multidimensional scaling are shown in Figure 6.
In Cluster analysis allowed the assessment of similarity or dissimilarity and clarified some of the relationships among wild cherry accessions.
Based on the cluster analysis of all 7 studied fruit's characteristics, a dendrogram for the genotypes of Mespilus germanica was made (Figure 7).On the dendrogram, you can see that the samples Mg-04 and MG-05 is really separated from the other samples.They differ from other genotypes in all studied parameters.

CONCLUSION
The introduction population of Mespilus germanica at M. M. Gryshko National Botanical Garden of NAS of Ukraine is quite variable and contains plants with almost all types of fruits.Evaluating of 7 genotypes of Mespilus germanica determined the weight of the fruits in the range from 39.12 to 35.29 g, fruit length from 27.69 to 42.29 mm, fruit diameter from 24.98 to 44.75 mm, length of calyx basin from 17.55 to 32.46 mm.The shape index of the fruits was found in the range of 0.79 to 1.23.This study carried revealed that the genotypes MG-04 and MG-05 was promising in terms of the characteristics evaluated in variety development.The presence of a broadly variable population provides the conservation Mespilus germanica, which is of potentially great socio-economic importance, and will help in the future to use herbal products derived from sustainably developing sources.
2.59 g by Nezhadghan and Hassanpou (2018) to 40.80 g by Bostan and Islam (2007).Our fruit weight results are in accordance within the range of the values reported literature (Tab.2).

Figure 1
Figure 1 Variability in the shape of genotypes Mespilus germanica L. fruits.

Figure 4
Figure 4 Mean values for various morphometric parameters of fruits and seeds of Mespilus germanica L. genotypes.

Figure 5
Figure 5 Comparison of the tested Mespilus germanica L. genotypes in the shape index of fruit.

Figure 6
Figure6MDS plot of the similarity illustrating the length (С) and diameter (B) of fruits for studying genotypes of Mespilus germanica L.
Figure, it is possible to see the visual distribution the size of the of the studied genotypes.The genotypes MG-04 (green ellipse) and MG-05 (light green ellipse) with the largest fruit size and the genotypes MG-01 (red ellipse), MG-02 (blue ellipse) and MG-07 (brown ellipse) with the smallest fruit size differ each another with the probability of 95% (the ellipses in the figure do not overlap).We applied cluster analysis to evaluate the differences in the morphological features of the Mespilus germanica fruits.This technique has been carried out earlier for studying the genetic variability of some other plant species (Rakonjac et al., 2014; Blazakis et al., 2017; Grygorieva et al., 2017a; Metougui et al., 2017; Vinogradova et al., 2017).

Figure 7
Figure 7 Dendrogram of 7 genotypes of Mespilus germanica L. based on morphometric characteristics of fruits.

Table 1
The variability of some morphometric parameters of fruits for the collection of Mespilus germanica L. genotypes.

Table 2
Variability of some morphometric characteristics on Mespilus germanica L. fruits according to the authors from different countries.
* Figure 2 Variability in the shape of genotypes Mespilus germanica L. fruits.Figure 3 Variability in the shape of genotypes Mespilus germanica L. fruits.No. 1/2018