Cytoplasmic Male Sterility Incidence in Potato Breeding Populations with Late Blight Resistance and Identification of Breeding Lines with a Potential Fertility Restorer Mechanism

Potato Berries as a Valuable Source of Compounds Potentially Applicable in Crop Protection and Pharmaceutical Sectors: A Review

Potato (Solanum tuberosum) is a major agricultural crop cultivated worldwide. To meet market demand, breeding programs focus on enhancing important agricultural traits such as disease resistance and improvement of tuber palatability. However, while potato tubers get a lot of attention from research, potato berries are mostly overlooked due to their level of toxicity and lack of usefulness for the food production sector. Generally, they remain unused in the production fields after harvesting the tuber. These berries are toxic due to high levels of glycoalkaloids, which might confer some interesting bioactivities. Berries of various solanaceous species contain bioactive secondary metabolites, suggesting that potato berries might contain similarly valuable metabolites. Therefore, possible applications of potato berries, e.g., in the protection of plants against pests and pathogens, as well as the medical exploitation of their anti-inflammatory, anticarcinogenic, and antifungal properties, are plausible. The presence of valuable compounds in potato berries could also contribute to the bioeconomy by providing a novel use for otherwise discarded agricultural side streams. Here we review the potential use of these berries for the extraction of compounds that can be exploited to produce pharmaceuticals and plant protection products.

Identification, Elucidation and Deployment of a Cytoplasmic Male Sterility System for Hybrid Potato

Recent advances in diploid F1 hybrid potato breeding rely on the production of inbred lines using the S-locus inhibitor (Sli) gene. As a result of this method, female parent lines are self-fertile and require emasculation before hybrid seed production. The resulting F1 hybrids are self-fertile as well and produce many undesirable berries in the field. Utilization of cytoplasmic male sterility would eliminate the need for emasculation, resulting in more efficient hybrid seed production and male sterile F1 hybrids. We observed plants that completely lacked anthers in an F2 population derived from an interspecific cross between diploid S. tuberosum and S. microdontum. We studied the antherless trait to determine its suitability for use in hybrid potato breeding. We mapped the causal locus to the short arm of Chromosome 6, developed KASP markers for the antherless (al) locus and introduced it into lines with T and A cytoplasm. We found that antherless type male sterility is not expressed in T and A cytoplasm, proving that it is a form of CMS. We hybridized male sterile al/al plants with P cytoplasm with pollen from al/al plants with T and A cytoplasm and we show that the resulting hybrids set significantly fewer berries in the field. Here, we show that the antherless CMS system can be readily deployed in diploid F1 hybrid potato breeding to improve hybridization efficiency and reduce berry set in the field.

Analysis of Thermal Characteristics of Potato and Hop Pollen for Their Cryopreservation and Cross-Breeding

This study investigated the thermal properties of potato and hop pollen for cryopreservation and subsequent cross-breeding. Phase transitions and frozen water content in selected pollen samples were measured using a differential scanning calorimeter (DSC). Unlike hop pollen, potato pollen showed high variability in thermal properties and water content. Three specific types of pollen samples based on their thermal characteristics and water content were distinguished by DSC in potato: (1) 'glassy', with a water content lower than 0.21 g water per g dry matter; (2) 'transient', with a water content between 0.27 and 0.34 g of water per g of dry matter; (3) 'frozen', with a water content higher than 0.34 g of water per g of dry matter. Only the 'glassy' pollen samples with a low water content showed suitable properties for its long-term storage using cryopreservation in potato and hops. Cryopreservation of pollen did not significantly reduce its viability, and cryopreserved pollen was successfully used to produce both potato and hop hybrids. The results indicate that cryopreservation is a feasible technique for the preservation and utilization of pollen of these crops in the breeding process.

Potato and sweetpotato breeding at the international potato center: approaches, outcomes and the way forward

Root and tuber crop breeding is at the front and center of CIP's science program, which seeks to develop and disseminate sustainable agri-food technologies, information and practices to serve objectives including poverty alleviation, income generation, food security and the sustainable use of natural resources. CIP was established in 1971 in Peru, which is part of potato's center of origin and diversity, with an initial mandate on potato and expanding to include sweetpotato in 1986. Potato and sweetpotato are among the top 10 most consumed food staples globally and provide some of the most affordable sources of energy and vital nutrients. Sweetpotato plays a key role in securing food for many households in Africa and South Asia, while potato is important worldwide. Both crops grow in a range of conditions with relatively few inputs and simple agronomic techniques. Potato is adapted to the cooler environments, while sweetpotato grows well in hot climates, and hence, the two crops complement each other. Germplasm enhancement (pre-breeding), the development of new varieties and building capacity for breeding and variety testing in changing climates with emphasis on adaptation, resistance, nutritional quality and resource-use efficiency are CIP's central activities with significant benefits to the poor. Investments in potato and sweetpotato breeding and allied disciplines at CIP have resulted in the release of many varieties some of which have had documented impact in the release countries. Partnership with diverse types of organizations has been key to the centers way of working toward improving livelihoods through crop production in the global South.

Converting Hybrid Potato Breeding Science into Practice

Research on diploid hybrid potato has made fast advances in recent years. In this review we give an overview of the most recent and relevant research outcomes. We define different components needed for a complete hybrid program: inbred line development, hybrid evaluation, cropping systems and variety registration. For each of these components the important research results are discussed and the outcomes and issues that merit further study are identified. We connect fundamental and applied research to application in a breeding program, based on the experiences at the breeding company Solynta. In the concluding remarks, we set hybrid breeding in a societal perspective, and we identify bottlenecks that need to be overcome to allow successful adoption of hybrid potato.

Comparative Analysis of the Genetic Diversity of Chilean Cultivated Potato Based on a Molecular Study of Authentic Herbarium Specimens and Present-Day Gene Bank Accessions

At the end of the 1920s, Vavilov organized several potato-collecting missions in South and Central America. Vavilov and his colleagues, Juzepczuk and Bukasov, participated in these expeditions and worked on gathered material, designated two centers of potato varietal riches and diversity-the Peru-Bolivia high-mountain center and the southern coast of Chile. The WIR Herbarium holds authentic specimens of many taxa described by Russian taxonomists. Here, a set of 20 plastid DNA-specific markers was applied for 49 authentic herbarium specimens of Solanum tuberosum L. from the WIR Herbarium to analyze the genetic diversity of the landrace population collected by Juzepczuk in 1928 in southern-central Chile. Two plastid DNA types, T and A, and two chlorotypes were identified in herbarium specimens, with a clear predominance (96%) of chlorotype cpT_III. In addition, we analyzed 46 living Chilean accessions from the VIR field potato gene bank that were collected after the appearance of Phytophthora infestans in Chile. These living accessions were differentiated into four chlorotypes. Finding a D-type cytoplasm in living Chilean accessions that possess two new chlorotypes indicates a replacement of native cultivars and introgression from the wild Mexican species S. demissum that was actively used in breeding as a source of race-specific resistance to late blight.