Cytoplasmic male sterility and prospects for its utilization in potato breeding, genetic studies and hybrid seed production

Abstract

Increasing interest in cytoplasmic male sterility (CMS) and the search for pollen fertility restorer (Rf) genes in potato have arisen due to a new strategy in breeding of this important crop which is based on the development of heterotic hybrids produced by crossing of inbred diploid lines. The paper reviews the main results of the studies on the CMS-Rf genetic systems in different crop species, the modern methods and approaches of investigating the molecular mechanisms of CMS and pollen fertility restoration, and also the available published data on the status of these studies on potato. The nature of the chimeric mitochondrial genes associated with CMS is considered; the peculiarities of the structure and functions of pollen fertility restorer genes are discussed.Examples of CMS-Rf genetic systems in crop species including representatives of the Solanaceae family are presented. The main results of the research on the molecular mechanisms of CMS and fertility restoration obtained in the postgenomic era for various crop species using methods of transcriptomic and proteomic analyses are provided. As in many plant species, CMS in potato is of a hybrid origin. The results are presented of investigating the genetic control of male sterility in potato that have been carried out using conventional approaches (hybridological analysis) and that led to the formation of the concept of ‘genetic-cytoplasmic male sterility’ in some species of the Petota section of the Solanum genus. The characteristics of potato cytoplasmic types carrying male sterility factors are discussed. According to the modern classification of Hosaka and Sanetomo (2012) these types include T/beta, W/gamma, and D, each distinguished by the specific phenotypic appearance of male sterility traits and also by the frequency of their occurrence in the breeding gene pool and in various potato species. The results of the studies on developing DNA markers for identifying different cytoplasmic types in potato are presented.