Rare instances of haploid inducer DNA in potato dihaploids and ploidy-dependent genome instability (original) (raw)
Related papers
Genomic Outcomes of Haploid Induction Crosses in Potato (Solanum tuberosum L.)
The challenges of breeding autotetraploid potato (Solanum tuberosum) have motivated the development of alternative breeding strategies. A common approach is to obtain uniparental dihaploids from a tetraploid of interest through pollination with S. tuberosum Andigenum Group (formerly S. phureja) cultivars. The mechanism underlying haploid formation of these crosses is unclear, and questions regarding the frequency of paternal DNA transmission remain. Previous reports described aneuploid and euploid progeny, which, in some cases, displayed genetic markers from the haploid inducer. Here, we surveyed a population of 167 presumed dihaploids for large-scale structural variation that would underlie chromosomal addition from the haploid inducer, and for small-scale introgression of genetic markers. In 19 progeny, we detected ten of the twelve possible trisomies and, in all cases, demonstrated the non-inducer parent origin of the additional chromosome. Deep sequencing indicated that occasion...
Ploidy level manipulations in potato through sexual hybridisation
Annals of Applied Biology, 2005
There is no better use of sexual reproduction in regard to breeding and genetic research than the ploidy level manipulations possible in the potato and its relatives. Unique reproductive characteristics of tuber-bearing Solanum species make possible: the production of gametes with unreduced chromosome number; the presence of an endosperm dosage system that regulates success of interploidy/interspecific crosses; the possibility to easily extract maternal haploids following crosses with S. phureja. This paper reviews results obtained in scaling genomic multiples up and down in potato, and relates these manipulations to breeding strategies for the genetic improvement of the cultivated potato. Several ploidy series have been developed, ranging from the monoploid to the hexaploid level. Cultivated tetraploids were scaled down to the diploid and monoploid level by haploidy. Scaling upward was achieved by sexual polyploidisation via 2n gametes that resulted in triploid, tetraploid, pentaploid, and hexaploid genotypes with a broad genetic base. Altogether, the success of ploidy level manipulations constitutes further proof that sexual polyploidisation played an important role in the polyploid evolution of Solanum species, and supports the idea that gene flow can be relatively easily accomplished through interploid and bridge crosses.
Euphytica, 2010
Two (di)haploids (2n = 2x = 24) and nine tetraploids (2n = 4x = 48) obtained from Solanum tuberosum through anther culture were characterized for nDNA variation, phenotypic variation and nuclear microsatellite polymorphism. Androgenic (di)haploids were also characterized for late blight resistance. The (di)haploid C-13 was derived from Indian tetraploid potato cv. Kufri Chipsona-2, while D4 from TPS (true potato seed) parental line JTH/C-107, which is an interspecific hybrid between Indian tetraploid cv. Kufri Jyoti and diploid (2n = 2x = 24) cultivated species S. phureja Juz. & Buk. IVP-35. C-13 and D4 (both male-fertile) could be distinguished from their corresponding tetraploid anther donors based on plant height, shoot number, terminal leaflet length and width, leaf ratio, anther length, pollen diameter and corolla width and radius. A complete reversal of flower color occurred in D4, and C-13 was highly resistant to late blight. Most interestingly, about 3–7% increase in nDNA content occurred in most of the anther-derived tetraploids. Both the androgenic (di)haploids and their anther donors had unique genotypes at the microsatellite loci POTM1-2, STM0015 and STM0019b. However, the nine anther-derived tetraploids shared the same allelic profiles with their anther donor JTH/C-107 at all the microsatellite loci, except at STM0019a where they were characterized by the absence of a standard donor allele (186-bp). A typical (di)haploid-specific allele was detected for the locus STWAX-2 where the standard donor alleles were replaced by a 230-bp allele in both C-13 and D4. The over-expression of microsatellite variation in D4 that also shows triallelic profiles at the microsatellite loci POTM1-2 and STM0015 can perhaps be attributed to its chimeric structure, which might have been formed through incomplete fusion of two different pro-embryos during the first steps of microspore division.
Genetics and Cytogenetics of the Potato
The Potato Crop, 2020
Tetraploid potato (Solanum tuberosum L.) is a genetically complex, polysomic tetraploid (2n = 4x = 48), highly heterozygous crop, which makes genetic research and utilization of potato wild relatives in breeding difficult. Notwithstanding, the potato reference genome, transcriptome, resequencing, and single nucleotide polymorphism (SNP) genotyping analysis provide new means for increasing the understanding of potato genetics and cytogenetics. An alternative approach based on the use of haploids (2n = 2x = 24) produced from tetraploid S. tuberosum along with available genomic tools have also provided means to get insights into natural mechanisms that take place within the genetic load and chromosomal architecture of tetraploid potatoes. This chapter gives an overview of potato genetic and cytogenetic research relevant to germplasm enhancement and breeding. The reader will encounter findings that open new doors to explore inbred line breeding in potato and strategic roads to access the diversity across the polyploid series of this crop's genetic resources. The text includes classical concepts and explains the foundations of potato genetics and mechanisms underlying natural cytogenetics phenomena as well as their breeding applications. Hopefully, this chapter will encourage further research that will lead to successfully develop broad-based potato breeding populations and derive highly heterozygous cultivars that meet the demands of having a resilient crop addressing the threats brought by climate change.
Evidence for somatic translocation during potato dihaploid induction
Heredity, 1995
Potato dihaploid PDH55 (Solanum tuberosum) is exclusively euploid (2n 24) but apparently contains and expresses DNA from dihaploid inducer WP48 (S. phureja). Genomic in situ hybridization (GISH) suggested 1VP48 DNA incorporated stably into PDH55 by somatic translocation. This finding has two important implications. Firstly, the long-held implicit assumption that euploid dihaploids produced by dihaploid inducers are pure S. tuberosum seems incorrect. This may complicate meiotic, genetical and molecular studies involving potato diliaploids. Secondly, if such translocations are not rare, the phenomenon may offer a novel way to introduce useful traits directly from wild dihaploid-inducing species into S. tuberosum.
Genomic Origins of Potato Polyploids: GBSSI Gene Sequencing Data
Crop Science, 2008
Chromosome pairing relationships within cultivated potato (Solanum tuberosum) and its wild tuber-bearing relatives (Solanum sect. Petota) have been interpreted by genome formulas, developed in the early 1900s, through techniques of classic meiotic analysis of interspecifi c hybrids. Here we reexamine potato genome hypotheses with the fi rst phylogenetic analysis of all major genomes of sect. Petota using cloned DNA sequences of the single-copy nuclear gene GBSSI (waxy). Our results provide the fi rst molecular confi rmation of allopolyploidy in wild potato. They both support prior hypotheses and identify novel genome origins never before proposed. The data will be useful to help design crossing strategies to incorporate wild species germplasm into cultivated potato.
Plant Cell, Tissue and Organ Culture, 1984
Plants were regenerated from cultured excised leaf segments of monohaploid (2n = x = 12) and diphaloid (2n = 2x = 24) potato (Solanum tuberosum L.) and a sample has been studied cytologically. In the case of monohaploids, a single leaf regeneration cycle resulted in almost total recovery of doubled monohaploid plants (2n = 2x = 24), whilst 50% of the plants regenerated from doubled monohaploid leaves had doubled again to the doubled double monohaploid (or homozygous tetraploid, 2n = 4x --48) level. Regeneration from dihaploid leaf pieces also gave a good proportion (60%) of doubled genotypes. Very few mixoploids and very few aneuploids were found. These results, together with the general applicability of the method to a large number of potato eultivars, suggest that it can be used as a simple and reliable method of obtaining homozygous tetraploid potatoes.
Interspecific Hybridization in Potato by Unilateral Sexual Polyploidization
XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on New Developments in Plant Genetics and Breeding, 2012
This work was carried out in the Laboratory of Plant Biotechnology at University of Passo Fundo, in South Brazil. The objective of these experiments was to test, for local condition, the hybridization technique strategy by sexual unilateral polyploidization in potato in order to transfer genes from wild diploid into the tetraploid cultivated species. Initially, the temperature effect on the occurrence of unreduced (2n) pollen grains in two diploid clones at temperature of 10, 15, 20, 25, 30 and 35°C was evaluated. The highest frequency of unreduced pollen grains was observed in temperatures of 15°C with an average of 30.7% for one clone and 7.6% for the other. Both clones were used as male parents in crosses with tetraploid cultivars. A total of 109 crosses were performed, and in 14 of them, 2,4-D was applied after pollinations. After pollination, three fruits were obtained from 14 flowers that were treated with 2,4D. However, only one of them was fertile, producing five plants, which presented morphological traits from both parents, eliminating the self-pollination hypothesis. The number of mitotic chromosomes of F 1 plants was 48. This tetraploid ploidy level shows that the tetraploid cultivar oosfere was fertilized by the unreduced pollen of diploid species. This indicated the overcoming of a critical restriction for the genes transference between plants with different ploidy levels had occurred. Although this strategy needs to be optimized, this work shows the possibility of using non reduced pollen grain as a bridge to transfer desirable traits from wild gene pool to the cultivated one under our conditions. This enlarges the genetic variability of the crop, increasing the potential of developing new potato cultivars having disease resistance, good eating quality and superior agronomic traits.
Genome, 1992
The ratio of the first division restitution (FDR) to second division restitution (SDR) 2n eggs was estimated in 4182t, a haploid (2n = 2x = 24) of Solanum tuberosum L. that produces 2n eggs by the two modes. The segregation of three genes previously mapped relative to their centromeres, Pgm-2 (2.0 cM), Mdh-1 (33.5 cM), and 6-Pgdh-3 (30.1 cM) was analyzed in the tetraploid offspring of a 2x × 4x cross. Based on the segregation of the Pgm-2 locus, 39.7% of the progeny originated from FDR 2n eggs and 60.3% from SDR. Segregation patterns of the two distal loci within the FDR-derived 4x subpopulation indicated that the gene–centromere recombination rate during megasporogenesis was significantly reduced for Mdh-1 when compared with a previous estimate during microsporogenesis. In the SDR-derived 4x subpopulation, the gene–centromere recombination rates for Mdh-1 and 6-Pgdh-3 were not significantly different from previous estimates. Tetraploid progeny generated from one 2x × 4x cross where...