Potato (Solanum tuberosum L.) is the most important tuber crop worldwide. Efforts are underway to transform the crop from a clonally propagated tetraploid into a seed-propagated, inbred-line-based hybrid, but this process requires a better understanding of potato genome. Here, we report the 1.67-Gb haplotype-resolved assembly of a diploid potato, RH89-039-16, using a combination of multiple sequencing strategies, including circular consensus sequencing. Comparison of the two haplotypes revealed ~2.1% intragenomic diversity, including 22,134 predicted deleterious mutations in 10,642 annotated genes. In 20,583 pairs of allelic genes, 16.6% and 30.8% exhibited differential expression and methylation between alleles, respectively. Deleterious mutations and differentially expressed alleles were dispersed throughout both haplotypes, complicating strategies to eradicate deleterious alleles or stack beneficial alleles via meiotic recombination. This study offers a holistic view of the genome organization of a clonally propagated diploid species and provides insights into technological evolution in resolving complex genomes.

Potato (Solanum tuberosum L.) is the world’s most important non-cereal food crop, and the vast majority of commercially grown cultivars are highly heterozygous tetraploids. Advances in diploid hybrid breeding based on true seeds have the potential to revolutionize future potato breeding and production1–4. So far, relatively few studies have examined the genome evolution and diversity of wild and cultivated landrace potatoes, which limits the application of their diversity in potato breeding. Here we assemble 44 high-quality diploid potato genomes from 24 wild and 20 cultivated accessions that are representative of Solanum section Petota, the tuber-bearing clade, as well as 2 genomes from the neighbouring section, Etuberosum. Extensive discordance of phylogenomic relationships suggests the complexity of potato evolution. We find that the potato genome substantially expanded its repertoire of disease-resistance genes when compared with closely related seed-propagated solanaceous crops, indicative of the effect of tuber-based propagation strategies on the evolution of the potato genome. We discover a transcription factor that determines tuber identity and interacts with the mobile tuberization inductive signal SP6A. We also identify 561,433 high-confidence structural variants and construct a map of large inversions, which provides insights for improving inbred lines and precluding potential linkage drag, as exemplified by a 5.8-Mb inversion that is associated with carotenoid content in tubers. This study will accelerate hybrid potato breeding and enrich our understanding of the evolution and biology of potato as a global staple food crop.

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Re-domestication of potato into an inbred line-based diploid crop propagated by seed represents a promising alternative to traditional clonal propagation of tetraploid potato, but self-incompatibility has hindered the development of inbred lines. To address this problem, we created self-compatible diploid potatoes by knocking out the self-incompatibility gene S-RNase using the CRISPR-Cas9 system. This strategy opens new avenues for diploid potato breeding and will also be useful for studying other self-incompatible crops.

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Potato is the third most important staple food crop. To address challenges associated with global food security, a hybrid potato breeding system, aimed at converting potato from a tuber-propagated tetraploid crop into a seed-propagated diploid crop through crossing inbred lines, is under development. However, given that most diploid potatoes are self-incompatible, this represents a major obstacle which needs to be addressed in order to develop inbred lines. Here, we report on a self-compatible diploid potato, RH89-039-16 (RH), which can efficiently induce a mating transition from self-incompatibility to self-compatibility, when crossed to self-incompatible lines. We identify the S-locusinhibitor (Sli) gene in RH, capable of interacting with multiple allelic variants of the pistil-specific S-ribonucleases (S-RNases). Further, Sli gene functions like a general S-RNase inhibitor, to impart SC to RH and other self-incompatible potatoes. Discovery of Sli now offers a path forward for the diploid hybrid breeding program.

Soft actuators with apparent uniqueness in exhibiting complex shape morphing are highly desirable for artificial intelligence applications. However, for the majority of soft actuators, in general, it is challenging to achieve versatility, durability, and configurability simultaneously. Enormous works are devoted to meet the multifunctional smart actuators, to little effect. Herein, self-healing and bio-mimetic smart actuators are proposed based on azobenzene chromophores and dynamic disulfide bonds. Benefiting from the dynamic and drivable vitrimer liquid crystal elastomer (V-LCE) materials, a series of actuators with single or compound dynamic three-dimensional structures were fabricated, which were capable of double-stimuli response and complex "bionic" motions, such as the blooming of a flower, grasping and loosening an object, and so forth. Moreover, these flexible actuators showed fascinating properties, such as high robustness, excellent elasticity−plasticity shape-memory properties (R f and R r are close to 100%), easily reconfigurable property, and self-healing. This smart V-LCE provides a guideline to design and fabricate soft versatility actuators, which has prospects for developing smart bionic and artificial intelligence devices.

Summary Potatoes (Solanum tuberosum L.) represent an important tuber crop, worldwide. During its prolonged clonal propagation, numerous deleterious mutations have accumulated in the potato genome, leading to severe inbreeding depression; however, the shaping of this mutation burden during polyploidization and improvement is largely unknown. Here, we sequenced 20 diploid landraces of the Stenotomum group, eight tetraploid landraces, and 20 tetraploid modern cultivars, to analyze variations in their deleterious mutations. We show that deleterious mutations accumulated rapidly during the polyploidization of tetraploid potatoes. This study provides a foundation for future potato improvement.