Variability of morphological parameters and determination of volatile organic compounds of sweet chestnut (Castanea sativa Mill.) genotypes fruits

Abstract

Objective – to select the best genotypes of sweet chestnut (Castanea sativa Mill.) by morphological properties and to investigate of the qualitative and quantitative content of volatile organic compounds in fruits of the collection of M.M. Gryshko National Botanical Garden of the NAS of Ukraine. Material and methods. There was investigated the 28 genotypes of 30-yea-rold plants that were introduced by seeds from Czech Republic, Carpathians, Kyrgyzstan. Morphometric measurments were conducted: fruit weight, fruit length, fruit width, fruit thickness, hilum length, hilum width. The investigation of the volatiles was conducted by the method of Chernohorod and Vinohradov (2006) using cromatographymass spectrometry. Basic statistical analyses were performed using PAST 2.17. Hierarchical cluster analyses of similarity between genotypes were computed on the basis of the Bray-Curtis similarity index. Variability of all these parameters was evaluated using descriptive statistics. Level of variability determined by Stehikova (1998). Correlation between traits was determined using the Pearson correlation coefficient. Results. Morphometric parameters were following: weight of fruits from 1.70 to 18.60 g, length – from 8.07 to 33.39 mm, width – from 16.34 to 40.95 mm, thickness – from 9.02 to 28.70 mm and hilum length – from 6.62 to 31.30 mm, hilum width – from 6.50 to 19.99 mm. Index of fruit shape and hilum was determined in range from 0.81 to 0.98 and from 1.48 to 2.03 respectively. During the analysis of qualitative composition and quantitative content of volatiles of fruits from the 2 selected genotypes 74 compounds were detected, and 27 compounds among them were identified. Identified compounds belong to hydrocarbons, aldehydes, carboxylic acids and their ethers, monoterpenes, sesquiterpenes, triterpenes. Conclusions. Genotypes of seed origin were quite variable. They differ by weight, shape, size and color of fruits. The high level of variation was refered to important selection feature such as mass of fruits, which says about promising of process of selection on this direction. The most genotypes have a small mass of fruits, but certain genotypes characterized by higher sign of fruit mass. The hilum has a various shape and size that can be a diagnostic feature of cultivar characteristic. The outcome of the research points to the fact that the collection of Castanea sativa is a rich source of genetic diversity and might be used in selection for creation of new genotypes and cultivars. Investigated plants are promising raw for future pharmacognostic researches.