In Poland the Plant Breeding and Acclimatization Institute is responsible for officially assessing the resistance to Synchytrium endobioticum of domestic potato breeding lines and cultivars from other countries. Cultivation of potato cultivars in Poland requires confirmation of resistance to potato wart disease. The official assessment uses the modified Glynne-Lemmerzahl method (laboratory tests) and pot tests. The full cycle of assessment of resistance to wart disease requires 52 seed potatoes per variety/breeding line. Forty two tubers are used in laboratory tests. To complete the laboratory tests the next 10 tubers are grown in pot tests (in soil with winter sporangia) during the vegetation season. The final results for domestic breeding lines of potato are available after 3 years of investigation. For cultivars from other countries the authorization of resistance to S. endobioticum takes approximately one year. The Polish breeders (breeding lines) or the breeder's representative (cultivars from other countries) receive the certificate only for lines/cultivars with laboratory and field resistance to S. endobioticum.

The study in Belarus the most dangerous and quarantine fungus Synchytrium endobioticum (Schilb.) Perc. – potato wart disease agent has shown that the resistance feature is obligatory and ecologically safe method of losses decrease from the disease. The necessity of immunological evaluation of potato breeding material for wart disease resistance is substantiated. Among the potato hybrid material studied for resistance to the (D1) pathotype of wart disease agent from the breeding institutions of Belarus and Russia for the period of 2003-2007 in preliminary first year testing there were 83,9% of resistant samples, the second year -92,4%, in State testing -91.9%. By immunological evaluation for wart disease resistance it is very important to observe conditions favourable for the interaction of a fungus parasite and a host plant. It is determined that the parasitic fungus activity and the susceptible plants reaction on infection becomes weaker by potato planting at later than recommended time

Verticillium wilt (VW) is a widespread and serious potato (Solanum tuberosum) disease caused by the soilborne fungi Verticillium dahliae and V. albo-atrum. Breeding for VW resistance in potato is challenging due to ambiguous symptom expression, a lack of high throughput screening techniques, and variability in colonization by the fungus among and within plants. Genetic studies have identified major genes that confer resistance in diploid Solanum chacoense (V c ) and interspecific hybrids (V w and V t ). However, to date, these genes have not been used to develop molecular markers for the identification of resistant clones. Tomato Ve1 and Ve2 gene sequence information was used to amplify candidate Ve gene orthologs from both resistant and susceptible diploid potato hybrids. A CAPS marker was generated to track VW resistance in a backcross population segregating for resistance. The marker was also tested for its usefulness in other breeding lines. Our results indicate that this marker is effective for selection of the V w gene in segregating breeding populations.

The plasmodiophorid pathogen Spongospora subterranea f. sp. subterranea causes powdery scab disease of potatoes (Solanum tuberosum L.), which severely affects tuber quality. Adequate chemical control of the disease is lacking, so breeding resistant potato cultivars is important. Little is known about the mechanisms or genetics of host resistance, as the epidemiology of the pathogen makes research on the disease difficult. An environmentally controlled disease screen that allows the accurate and repeatable assessment of diseased tubers (rather than a ranking system) is required to study host resistance in more detail. A high-throughput greenhouse disease assay is described that has been used to assess varying levels of tuber disease resistance of potato genotypes for three consecutive Southern Hemisphere growing seasons (2001-2002, 2002-2003, 2003-2004). This assay allows the evaluation of symptoms on tubers to verify resistance, rather than inferring the tuber infection on the basis of root galling or zoosporangial root infection. The assay was used to determine the level of resistance of genotypes of both known and unknown resistance status. The assay clearly distinguished the susceptible and resistant standards, and the results were highly correlated over the three seasons. The most efficient ways of assessing tuber disease susceptibility of genotypes are discussed. The consistency of the results and the ability to screen many genotypes confirms the value of the assay as a tool for early-generation selection in a plant breeding programme.

The article deals with the analysis of the most dangerous and quarantine-important fungus Synchytrium endobioticum (Schilb.) Perc. - potato wart agent research in Belarus. The necessity of the immunological evaluation of the potato seed material for wart resistance is fortified. The conditions of preliminary and state testing of selection samples in the quarantine stationary plot of the RUC Institute of plant protection in accordance with the methods of potato testing for wart resistance are examined in this paper. It is shown that in preliminary and state testing for resistance to the (D1) potato wart agent pathotype among the studied hybrid potato material from the leading breeding institutions of Belarus and Russia for the period of 2003-2007, 89.8% resistant samples was isolated. While determining the wart disease resistance of the breeding material on susceptible sample tubers beside the usual incrustation form of potato wart affection the infestation of three non-typical forms: leaf, scab and corrugated are observed. Considering the variations of wart-resistant potato samples injury, the necessity of carrying out not less than two years selection material state testing to wart resistance under different field conditions was undertaken in Belarus. | Rakstā atspoguļota Baltkrievijā bīstamākā patogēna - Synchytrium endobioticum (Schilb.) Perc. – kartupeļu vēža izraisītāja - pētījumu analīze, pamatojot nepieciešamību pēc kartupeļu sēklas materiāla izturības izvērtēšanas. Rakstā aprakstīti sagatavošanas un valsts pārbaužu apstākļi paraugu atlasei karantīnas stacionāra laukā Augu aizsardzības institūtā saskaņā ar kartupeļu izturības pret vēzi metodēm. Sagatavošanas un valsts pārbaudēs, kurās nosaka izturību pret kartupeļu vēža izplatītāko patotipu (D1), izvērtējot no vadošajiem Baltkrievijas un Krievijas selekcijas institūtiem saņemto hibrīdo kartupeļu materiālu, laika posmā no 2003. līdz 2007. Gadam tika atlasīti 89.8 % izturīgu paraugu. Selekcijas materiāla izturības izvērtēšanas laikā uz paraugu bumbuļiem, kuri uzrādīja jutību pret kartupeļu vēzi, bez zināmiem infekcijas bojājumiem tika novēroti vēl trīs netipiski bojājumu veidi: plēksnes, kārpveida izaugumi un rievojumi. Pamatojoties uz kartupeļu paraugu izturības pret vēzi mainību, kartupeļu selekcijas materiāla izturības pret vēzi pārbaudes Baltkrievijā jāveic ne mazāk kā divus gadus lauka apstākļos, vēlams dažādos audzēšanas apstākļos pēc mitruma nodrošinājuma un temperatūras režīma.

Potato breeding and seed production in Lithuania is carried out at the Voke Branch of the Lithuanian Institute of Agriculture. Potato breeding work involved Lithuanian potato varieties, varieties from various collection and hybrids. Potato crosses were done at the autotetraploid level in the glasshouse and potato variety collection field. Up to two million hybrids were tested in the trial fields. The key objective was to select the varieties immune to wart disease, cyst nematodes, with high resistance to other diseases, with excellent agronomic and cooking qualities, suitable for the processing industry. As the result of breeding work five new varieties were produced: Venta, VB Rasa, VB Liepa, Goda and VB Aista. They all are immune to the worst potato disease – wart (Synchtrium endobioticum Schilb.). Most of them are resistant to a local patotype of nematodes (Globodera rostochiensis Woll.). Other advantages such as good yield, excellent cooking qualities, good taste or attractive shape were the main items in producing Lithuanian potato varieties as well. Potato seed production from meristem tissue at biotechnological laboratory is carried out in the Voke branch of Lithuanian Institute of Agriculture. It is the centre for potato seed production in Lithuania. | Kartupeļu selekcija un sēklaudzēšana Lietuvā tiek veikta Lietuvas zemkopības institūta Vokes nodaļā. Kartupeļu selekcijas darbs aptver Lietuvas kartupeļu šķirnes, kolekcijas šķirnes un klonus. Kartupeļu krustošana tetraploīdā līmenī tiek veikta siltumnīcās un lauka kolekcijā. Vairāk kā divi miljoni hibrīdu (klonu) tiek izvērtēti izmēģinājumu laukā. Galvenais mērķis ir veidot jaunas kartupeļu šķirnes, kas ir izturīgas pret vēzi un nematodēm, kurām ir augsts izturības līmenis pret citām slimībām, izcilas agronomiskās un garšas īpašības, kā arī piemērotība pārstrādei. Selekcijas darba rezultātā izveidotas piecas jaunas kartupeļu šķirnes: Venta, VB Rasa, VB Liepa, Goda un VB Aista. Tās visas ir izturīgas pret bīstamāko kartupeļu slimību – kartupeļu vēzi (Synchtrium endobioticum Schilb), vairākas no tām ir izturīgas pret vietējo nematodes patotipu (Globodera rostochiensis Woll.). Citas pazīmes kā augsta raža, izcilas garšas īpašības, kā arī pievilcīga forma bija galvenie iemesli šo šķirņu atlasē.

Host plant resistance offers an attractive method of control for early blight (caused by the foliar fungus Alternaria solani), a widespread disease that appears annually in potato crops worldwide. We tested the assumed ability of taxonomy to predict the presence of early blight resistance genes in wild Solanum species for which resistance was observed in related species. We also tested associations to ploidy, crossing group, breeding system, and geography. As in a prior study of Sclerotinia sclerotiorum (white mold) resistance, tremendous variation for resistance to early blight was found to occur within and among species. There was no discernable relationship between the distribution of resistant phenotypes and taxonomic series (based on an intuitive interpretation of morphological data), clade (based on a cladistic analysis of plastid DNA data), ploidy, breeding system, geographic distance, or climate parameters. Species and individual accessions with high proportions of early blight resistant plants were identified, but high levels of inter- and intra-accession variability were observed. Consequently, the designation of species or accessions as resistant or susceptible must take this variation into account. This study calls into question the assumption that taxonomic or geographic data can be used to predict sources of early blight resistance in wild Solanum species.

Taro leaf blight disease, caused by Phytophthora colocasiae, is a major limiting factor in taro production worldwide. P. colocasiae is an aerial pathogen similar to P. infestans, causal agent of potato late blight disease, but occurs in warmer climates. In the year-round subsistence cropping systems of the Pacific Islands, resistant cultivars are essential. Breeding lines from Southeast Asia and Oceania were tested in American Samoa for resistance to taro leaf blight using a detached-leaf bioassay and field trials. Mean lesion diameters from bioassays were highly correlated with field estimates of the number of healthy leaves per plant and yield (corm weight). However, the bioassay did not adequately assess infection efficiency. Additional experiments revealed that attached leaves had smaller lesion diameters than detached leaves incubated in closed containers, but both were very highly correlated. Taro resistance increased with plant age and the second-oldest leaf was more resistant than the third-oldest leaf. The bioassay was a fast, space-saving, effective method of screening taro lines for post-penetration resistance to P. colocasiae. It also provided an easily standardized method of evaluating host-pathogen interactions under controlled conditions.

The challenges facing potato breeding have actually changed very little over the years with resistance to pests and pathogens remaining high on the agenda together with improvements in storability, reduction in blemishes, and novelty and consistency in cooking/processing qualities. The need to expand the range of targets for potato improvement is being driven by requirements for reduced agrochemical usage and by predictions of the effects of changing climates. Thus fertiliser and water use efficiency are moving up the political agenda. Genetic variation present in germplasm collections needs to be harnessed to provide the genes and alleles required. This paper provides examples of the functional genomics tools and approaches being developed and deployed to provide new options for advancing the breeding of next generation crops. Whilst genetic modification (GM) approaches remain contentious in Europe, this paper will also provide some recent examples of the range of potential impacts that GM approaches could make. It will also consider the value of so-called intragenic or cisgenic approaches to potato genetic engineering.

Scientists and farmers in Uganda identified preferred sweet potato: (1) varieties through participatory varietal selection (PVS); and (2) new clones from seedling populations through a participatory plant breeding (PPB) approach. During these two processes, farmers identified 51 attributes of their landraces and of released varieties and used 21 criteria to select clones from amongst the seedling populations. Scientists had, in publications, listed attributes (11 main attributes identified), morphological descriptors (11) of released varieties and varietal needs (23) of sweet potato farmers. One released variety (NASPOT 1) was selected by farmers during PVS, mostly for its high and early yield of large, sweet and mealy roots, and several clones were selected through PPB amongst the seedling populations for a wider range of attributes. Some varietal attributes needed by farmers were not included by scientists either because they were very laborious, for example, selecting on-station for clones suitable for sequential piece-meal harvesting, or because occurrence of important abiotic or biotic stresses such as drought or pest damage were difficult to predict. Farmers seldom mentioned disease resistance but did mention pest resistance, consistent with easy visibility of both the causes of and the damage due to pests. Unlike scientists, farmers made no mention of a need for cultivars to have perceptually distinct features, despite this being a common attribute of landraces of most crops.