Bradshaw J E, Dale M F B, Mackay G R
Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland.
Theor Appl Genet. 2003 Jun;107(1):36-42. doi: 10.1007/s00122-003-1219-y. Epub 2003 Mar 21.
A potato breeding strategy is presented which avoids the common but ineffective practice of intense early-generation visual selection between seedlings in a glasshouse and spaced plants at a seed site. Once pair crosses have been made, progeny tests are used to discard whole progenies before starting conventional within-progeny selection at the unreplicated small-plot stage. Clones are also visually selected from the best progenies for use as parents in the next cycle of crosses whilst they are multiplied to provide enough tubers for assessment of their yield and quality. Mid-parent values, as well as progeny tests, are then used to select between the resultant crosses. Material from other breeding programmes can be included in the parental assessments and used in the next cycle of crosses if superior. Finally, in seeking new cultivars, the number of clones on which to practise selection is increased by sowing more true seed of the best progenies, but without selection until the small-plot stage. Traits considered are resistance to late blight [ Phytophthora infestans (Mont.) de Bary] and to the white potato cyst nematode [ Globodera pallida (Stone)], fry colour and tuber yield and appearance, as visually assessed by breeders. The theoretical superiority of the strategy for seeking new cultivars lies in being able to practise between-cross selection for a number of economically important traits within 1 or 2 years of making crosses, something that is not possible on individuals as seedlings in the glasshouse or spaced plants at the seed site. This also means that full-sib family selection can be operated on a 3-year cycle, an improvement on current practice of clonal selection on what is often at least a nine-year cycle. New cultivars can be sought with more confidence from the best progenies in each cycle, and modern methods of rapid multiplication used to reduce the number of clonal generations required to find the best clones.
本文介绍了一种马铃薯育种策略，该策略避免了在温室中对幼苗和种子田中的间隔种植株进行早期高强度视觉选择这种常见但无效的做法。一旦完成成对杂交，在未重复的小地块阶段开始常规的子代内选择之前，先通过子代测试淘汰整个子代。还从最佳子代中进行视觉选择克隆，以便在繁殖时用作下一轮杂交的亲本，同时繁殖足够数量的块茎以评估其产量和品质。然后使用中亲值以及子代测试在所得杂交组合之间进行选择。如果其他育种计划的材料更优良，可以将其纳入亲本评估并用于下一轮杂交。最后，在寻找新品种时，通过播种更多最佳子代的真种子来增加用于选择的克隆数量，但直到小地块阶段才进行选择。所考虑的性状包括对晚疫病[致病疫霉（Mont.）de Bary]和白土豆胞囊线虫[金色球胞囊线虫（Stone）]的抗性、薯条颜色、块茎产量和外观（育种者通过视觉评估）。该新品种寻找策略的理论优势在于，能够在杂交后的1至2年内对多个经济上重要的性状进行杂交间选择，这对于温室中的幼苗或种子田中的间隔种植株个体来说是不可能的。这也意味着全同胞家系选择可以按3年周期进行，相较于目前通常至少9年周期的克隆选择做法有了改进。可以更有信心地从每个周期的最佳子代中寻找新品种，并使用现代快速繁殖方法来减少找到最佳克隆所需的克隆世代数量。
