Epigenetic consequences of interploidal hybridisation in synthetic and natural interspecific potato hybrids

Abstract

Summary Interploidal hybridisation can generate changes in plant chromosome numbers, which might exert effects additional to the expected due to genome merger per se (that is genetic, epigenetic and phenotypic novelties). Wild potatoes are suitable to address this question in an evolutionary context. To this end, we performed genetic (AFLP and single sequence repeart (SSR)), epigenetic (MSAP), and cytological comparisons in: (1) natural populations of the diploid cytotype of the hybrid taxonomic species Solanum × rechei (2n = 2×, 3×) and its parental species, the triploid cytotype of Solanum microdontum (2n = 2×, 3×) and Solanum kurtzianum (2n = 2×); and (2) newly synthesised intraploidal (2× × 2×) and interploidal (3× × 2×) S. microdontum × S. kurtzianum hybrids. Aneuploidy was detected in S. × rechei and the synthetic interploidal progeny; this phenomenon might have originated the significantly higher number of methylation changes observed in the interploidal vs the intraploidal hybrids. The wide epigenetic variability induced by interploidal hybridisation is consistent with the novel epigenetic pattern established in S. × rechei compared to its parental species in nature. These results suggest that aneuploid potato lineages can persist throughout the short term, and possibly medium term, and that differences in parental ploidy resulting in aneuploidy are an additional source of epigenetic variation.

Epigenomic patterns reflect irrigation and grafting in the grapevine clone ‘Chambourcin’

“…The effect of the initial graft is traumatic to the plant (Melnyk, 2017) and elicits a multitude of genome-regulatory responses, but it also requires long-term management of molecular communication between different genomes, similar to what occurs in interspecifichybrids. This result is concordant with previous research in different systems that has shown that genome-genome interactions result in an epigenomic signature, for example, in interspecific hybrids (Gaut et al, 2007;Landry et al, 2007;Ishikawa and Kinoshita, 2009;Wu et al, 2013;Cara et al, 2019) and in allopolyploids (Springer et al, 2015). One implication of the graftassociated epigenomic variation reported here is that specific scion genotypes could be epigenomically predictable based on the rootstock to which they are grafted.…”

Current research frontiers in plant epigenetics: an introduction to a Virtual Issue

“…However, they observed in the allopolyploids considerable but regional re‐patterning in the DNA methylation landscape that was missing in the diploid hybrid genomes, indicating that in this system hybridity can exacerbate, only in combination with polyploidy, a rewiring of epigenetic and gene expression landscape. The instability in the DNA methylation landscape is even greater in the case of interploidal hybrids as shown in a study of several natural and artificial cytotypes of Solanum (Cara et al , 2019).…”

Methylation-sensitive Amplified Polymorphism as a Tool to Analyze Wild Potato Hybrids

“…This work was supported by Agencia Nacional de Promoción Científica y Tecnológica and Universidad Nacional de Cuyo, Argentina PICT 1243. This protocol was adapted from our previous work (Cara et al, 2019).…”

“…Wild potatoes (Solanum, section Petota) are a group of species related to the cultivated potato Solanum tuberosum L. Internal breeding barriers can be incomplete, thus, interspecific hybridization occurs in areas of sympatry (Camadro et al, 2012). Epigenetic changes in response to interspecific hybridization have been documented in synthetic and natural hybrids of wild potato species (Cara et al, 2019). Solanum x rechei H. & H. is a hybrid species that grows in sympatry with its wild progenitors, Solanum kurtzianum B.…”