SvSv-lines is an effective tool for involvement of the valuable genepool of 1 EBN diploid potato species into breeding

Abstract

There is a set of wild potato species valuable for breeding, in particular 1 EBN diploid species from Mexico, which is practically not crossable to cultivated potatoes, including Solanum tuberosum dihaploids (2х, 2 EBN), because of strict pre- and postzygotic interspecific reproductive barriers. It is proposed to involve that species germplasm into breeding by using the original SvSv-lines (F2 S. tuberosum dihaploids×S. verrucosum), in which St -alleles have been substituted for Sv from the self-compatible diploid species S. verrucosum not producing stylar S-RNase. It was anticipated that SvSv-lines have the same ability for elimination of prezygotic incompatibility in interspecific hybridization as S. verrucosum due to S-genes of that species in homozygous state. However, their use would help avoid undesirable effects associated with S. verrucosum application (male sterility and reduced tuber formation in hybrids). The aim of the research was estimation of the efficiency of using SvSv-lines, in comparison with S. verrucosum, as a bridge for involvement of the 1 EBN potato species S. bulbocastanum, S. pinnatisectum and S. polyadenium into breeding. It was revealed that SvSv-lines excels S. verrucosum in hybridization efficacy due to abundant and prolonged flowering in later term than S. verrucosum, when flowering of pollinator species occurs. There were significantly less sterile or low fertility genotypes among the hybrids between SvSv-lines and 1 EBN wild species. They had higher ability for tuber formation, and so they were suitable for long term field trials, contrast to hybrids with S. verrucosum. The interspecific hybrids produced were crossed as female parents to S. tuberosum dihaploids.

Keywords

• potato
• hybridization between distantly related species
• prezygotic incompatibility
• endosperm balance number – ebn
• s. verrucosum
• svsv-lines