Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany.
Theor Appl Genet. 2013 Apr;126(4):1039-52. doi: 10.1007/s00122-012-2035-z. Epub 2013 Jan 9.
Tuber yield, starch content, starch yield and chip color are complex traits that are important for industrial uses and food processing of potato. Chip color depends on the quantity of reducing sugars glucose and fructose in the tubers, which are generated by starch degradation. Reducing sugars accumulate when tubers are stored at low temperatures. Early and efficient selection of cultivars with superior yield, starch yield and chip color is hampered by the fact that reliable phenotypic selection requires multiple year and location trials. Application of DNA-based markers early in the breeding cycle, which are diagnostic for superior alleles of genes that control natural variation of tuber quality, will reduce the number of clones to be evaluated in field trials. Association mapping using genes functional in carbohydrate metabolism as markers has discovered alleles of invertases and starch phosphorylases that are associated with tuber quality traits. Here, we report on new DNA variants at loci encoding ADP-glucose pyrophosphorylase and the invertase Pain-1, which are associated with positive or negative effect with chip color, tuber starch content and starch yield. Marker-assisted selection (MAS) and marker validation were performed in tetraploid breeding populations, using various combinations of 11 allele-specific markers associated with tuber quality traits. To facilitate MAS, user-friendly PCR assays were developed for specific candidate gene alleles. In a multi-parental population of advanced breeding clones, genotypes were selected for having different combinations of five positive and the corresponding negative marker alleles. Genotypes combining five positive marker alleles performed on average better than genotypes with four negative alleles and one positive allele. When tested individually, seven of eight markers showed an effect on at least one quality trait. The direction of effect was as expected. Combinations of two to three marker alleles were identified that significantly improved average chip quality after cold storage and tuber starch content. In F1 progeny of a single-cross combination, MAS with six markers did not give the expected result. Reasons and implications for MAS in potato are discussed.
块茎产量、淀粉含量、淀粉产量和薯片颜色是复杂的性状，对马铃薯的工业用途和食品加工很重要。薯片颜色取决于块茎中还原糖葡萄糖和果糖的含量，这些糖是由淀粉降解产生的。当块茎在低温下储存时，还原糖会积累。由于可靠的表型选择需要多年和多个地点的试验，因此早期和有效地选择具有高产、高淀粉产量和良好薯片颜色的品种受到阻碍。在育种早期应用基于 DNA 的标记物，这些标记物可用于控制块茎品质自然变异的基因的优异等位基因的诊断，将减少需要在田间试验中评估的克隆数量。利用碳水化合物代谢相关基因作为标记物的关联作图已经发现了与块茎品质性状相关的转化酶和淀粉磷酸化酶等位基因。在这里，我们报告了在编码 ADP-葡萄糖焦磷酸化酶和转化酶 Pain-1 的基因座上的新 DNA 变体，这些变体与薯片颜色、块茎淀粉含量和淀粉产量呈正相关或负相关。使用与块茎品质性状相关的 11 个等位基因特异性标记物的各种组合，在四倍体育种群体中进行了标记辅助选择 (MAS) 和标记验证。为了促进 MAS，针对特定候选基因等位基因开发了用户友好的 PCR 检测。在一个多亲本的高级育种群体中，根据不同的组合选择基因型，这些组合具有与块茎品质性状相关的五个阳性和相应的阴性标记等位基因。具有五个阳性标记等位基因的基因型的平均表现优于具有四个阴性等位基因和一个阳性等位基因的基因型。在单独测试时，八个标记中的七个标记至少对一个品质性状有影响。效应的方向与预期一致。鉴定出了两个到三个标记等位基因的组合，可以显著提高冷藏后平均薯片品质和块茎淀粉含量。在单交组合的 F1 后代中，MAS 用六个标记并没有得到预期的结果。讨论了马铃薯 MAS 的原因和意义。
