Development of somatic hybrids Solanum × michoacanum Bitter. (Rydb.) (+) S. tuberosum L. and autofused 4x S. × michoacanum plants as potential sources of late blight resistance for potato breeding

Abstract

Key messagePhytophthora infestansresistant somatic hybrids ofS. × michoacanum(+)S. tuberosumand autofused 4xS. × michoacanumwere obtained. Our material is promising to introgress resistance fromS. × michoacanuminto cultivated potato background.AbstractSolanum × michoacanum (Bitter.) Rydb. (mch) is a wild diploid (2n = 2x = 24) potato species derived from spontaneous cross of S. bulbocastanum and S. pinnatisectum. This hybrid is a 1 EBN (endosperm balance number) species and can cross effectively only with other 1 EBN species. Plants of mch are resistant to Phytophthora infestans (Mont) de Bary. To introgress late blight resistance genes from mch into S. tuberosum (tbr), genepool somatic hybridization between mch and susceptible diploid potato clones (2n = 2x = 24) or potato cultivar Rywal (2n = 4x = 48) was performed. In total 18,775 calli were obtained from postfusion products from which 1,482 formed shoots. The Simple Sequence Repeat (SSR), Cleaved Amplified Polymorphic Sequences (CAPS) and Random Amplified Polymorphic DNA (RAPD) analyses confirmed hybrid nature of 228 plants and 116 autofused 4xmch. After evaluation of morphological features, flowering, pollen stainability, tuberization and ploidy level, 118 somatic hybrids and 116 autofused 4xmch were tested for late blight resistance using the detached leaf assay. After two seasons of testing three somatic hybrids and 109 4xmch were resistant. Resistant forms have adequate pollen stainability for use in crossing programme and are a promising material useful for introgression resistance from mch into the cultivated potato background.

Genetic composition of interspecific potato somatic hybrids and autofused 4x plants evaluated by DArT and cytoplasmic DNA markers

“…Hybrid plants were derived previously from a protoplast electrofusion between two diploid clones of mch [99–12/8 ( mch /8) and 99–12/39 ( mch /39)], two diploid potato clones [DG 81–68 and dHBard] and cv. Rywal as described previously by Smyda et al (2013). Clones mch /8 and mch /39 were derived from mch [accession VIR5763 from the N. I. Vavilov Research Institute of Plant Industry (VIR) potato collection (Zoteyeva et al 2012)] and both were resistant to P. infestans .…”

“…In specific cases, transfer of desirable resistance genes is possible only through methods different than sexual hybridization due to crossing barriers. Somatic hybrids resistant to P. infestans were previously obtained between Solanum tuberosum ( tbr) and several wild potato species (Orczyk et al 2003; Smyda et al 2013; Chandel et al 2015). Of this group, only few hybrids between tbr and Solanum bulbocastanum (Helgeson et al 1998), Solanum nigrum (Horsman et al 2001), Solanum tarnii (Thieme et al 2008), Solanum commersonii (Carputo et al 2000), and Solanum cardiophyllum (Thieme et al 2010) were subsequently backcrossed sexually to potato cultivars and exploited in potato breeding programs.…”

Protoplast Technology in Genome Manipulation of Potato Through Somatic Cell Fusion

“…After two seasons of testing, the produced somatic hybrids were also resistant. The hybrids were reported to have adequate pollen stainability for use in crossing program and are a novel promising material for introgression resistance into the cultivated potato background (Smyda et al 2013).…”

“…Rydb., which is a wild diploid potato species derived from a spontaneous cross of S. bulbocastanum and S. pinnatisectum with resistance to late blight. To introgress late blight resistance genes from Solanum × michoacanum into S. tuberosum, protoplast fusion was applied (Smyda et al 2013). After two seasons of testing, the produced somatic hybrids were also resistant.…”

Toward breeding new land-sea plant hybrid species irrigable with seawater for dry regions

“…Many interspecific somatic hybrids have been already obtained from related crop species, such as potato. [11][12][13][14] A second investigable approach to breed new land-sea hybrid species is to artificially combine the genomes of 2 plant species to synthetically generate a new allopolyploidy genotype. In bacteria, combining genomes of different strains through stochastic protoplast fusion improved the newborn strain phenotype.…”