Siberian gene pool of steppe cherry polyploids (Prunus fruticosa Pall.): cytomorphological estimation and prospects for breeding

Abstract

The first spontaneous cherry polyploids were detected in the Altai gene pool of Russia and inside of the interspecific hybrids of Prunus fruticosa Pall. only. To date, polyploid genotypes with a complex of economically valuable traits and of various origins has preserved in the collection of FASCA. Collection includes: 1) F1 of spontaneous origin; 2) F2 obtained from hybridization of the first spontaneous hexaploid genotypes; 3) hybrids induced in vitro. These hybrids have a genetic origin from steppe cherry crossings with P. cerasus L., P. maackii Rupr., P. serrulata Lindl., P. canescens Bois., P. incisa Thumb., etc. Hexaploid amitotic clone lines were obtained by of 0.1% trifluralin treatment. The cellular mechanism of polyploids occurrence is the male and female unreduced gametes functioning. The study of microsporogenesis in 38 hybrids has revealed the 17 genetic producers of unreduced male gametes. According to the ploidy level of seedlings, the 8 sources of unreduced female gametes were selected. The morphophysiological characteristics of mature pollen were studied and the patterns for the preliminary selection of polyploids were revealed. The main strategy for the cherry breeding in the 21th century is the creation of polygenome hybrids with increased adaptation and high fruit quality.