The apple tree is one of the most popular and widespread fruit crops in the temperate zone of the Northern Hemisphere due to its great variety diversity and high biological and ecological plasticity. Ecological variety testing plays a significant role in the selection of the most promising range of varieties of fruit crops. It helps to ensure consistently high productivity of plantations based on the maximum degree of correspondence of the variety genotype to the specific soil and climatic conditions of the place of cultivation. The research was aimed at the selection of annual apple tree half-sibs by the indicators of growth dynamics and phytomass formation in the V.M. Krutovsky Botanical Garden located in the suburban area of Krasnoyarsk. Plants propagated by seeds are characterized by wide adaptive capabilities under various environmental conditions. Selection of seedlings before fruiting provides an opportunity to shorten the breeding process. The study of morphological features of the apple tree leaf allows the selection for accelerated breeding of seedlings of this species. The features of seed progeny growth of 37 large-fruited apple tree varieties of different geographical origin were studied. Among those are the following: 6 varieties of V.M. Krutovsky’s selection (Aurora, Krutovsky’s Green, Krasnoyarsk beauty, Krasnoyarskiy Sibiryak, Krasnoyarskoye, No. 22), 10 varieties of I.V. Michurin (Saffron Antonovka, Befler Chinese, Wax, Pepin Kitayka, Saffron Pepin, Renet Bergamot, Slavyanka, Antonovka Yellow, Winter Arkade, Kulon Kitaika), 1 variety of selection by R.I. Schroeder (Nobilis) and foreign (New Zealand) selection (Bismarck). Most varieties (57 %) of folk selection bred in the European part of Russia. Dynamics of preservation of cotyledon leaves, number and size of formed leaves, height and diameter of the root neck of seedlings were determined based on the results of the study during the growing season of 2020. The safety of half-sibs was found to be high under these conditions. Seedlings of varieties Antipaskhalnoye, Anisik obyknovennyi, Babushkino, Malinovka and Saffron Peppin showed the maximum height; seedlings of varieties Antipaskhalnoye, Anisik obyknovennyi, Voronezh Vorgul, Kulon Kitayka and Titovka showed larger trunk diameter; seedlings of varieties Titovka, Papirovka, Krasnoyarskiy Sibiryak and Antipaskhalnoye had large leaves. Reliable differences in leaf weight and LMA (weight of 1 cm2 of leaf in absolutely dry state) were revealed depending on belonging to summer or winter categories of apple varieties. The obtained results allowed identifying promising varieties in terms of rapid growth of seedlings, which is important for further breeding research.
Read full abstract