Gene bank of fruit plants: a natural collection of different sugars and acids in apples

Abstract

The fruit plantation was made in monastry Karthusia Pleterje financed by the “National program of the gene bank of cultivated plants”. Different apple and pear cultivars were brought together in this plantation. The plantation was started in 1994, 119 different apple cultivars and 44 different pear cultivars are growing there at the moment. Trees were grafted on the proper rootstocks and five trees were planted together for each cultivar. The sensitivity of different cultivars against diseases and pests can be observed due the biological protection against pests and diseases, which is carried out in the plantation. The data, which are demonstrated in this manuscript were collected for 100 different apple cultivars. The sugar concentrations in apples tightly corresponded with the ripening time. The concentration of fructose was with 64 g/kg fruit the highest in early ripening cultivars, the content of other sugars was lower. The middle-early ripening cultivars showed an increase of the succrose content from 24.6 g/kg, which was the succrose content in early ripening cultivars to 38.5 g/kg, the concentration in middle-late ripening cultivars was 37.6 g/kg. The fructose was with 70.3 g/kg the most present sugar again in late ripening cultivars. The most present organic acid in apple fruits was regardless the ripening time the malic acid. The highest concentration, 4 g/kg of malic acid, was analysed in early ripening cultivars, followed with late ripening cultivars with 3 g/kg malic acid. In both groups of middle-time ripening cultivars less than 3 g/kg malic acid was detected.