NARO Institute of Crop Science , 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518, Japan ; Okayama Universitiy , 3-1-1 Tsushima-naka, Kita, Okayama 700-8530, Japan.
Breed Sci. 2011 Dec;61(4):405-12. doi: 10.1270/jsbbs.61.405. Epub 2011 Dec 15.
The genotypes of photoperiod response genes Ppd-B1 and Ppd-D1 in Japanese wheat cultivars were determined by a PCR-based method, and heading times were compared among genotypes. Most of the Japanese wheat cultivars, except those from the Hokkaido region, carried the photoperiod-insensitive allele Ppd-D1a, and heading was accelerated 10.3 days compared with the Ppd-D1b genotype. Early cultivars with Ppd-D1a may have been selected to avoid damage from preharvest rain. In the Hokkaido region, Ppd-D1a frequency was lower and heading date was late regardless of Ppd-D1 genotype, suggesting another genetic mechanism for late heading in Hokkaido cultivars. In this study, only 11 cultivars proved to carry Ppd-B1a, and all of them carried another photoperiod-insensitive allele, Ppd-D1a. The Ppd-B1a/Ppd-D1a genotype headed 6.7 days earlier than the Ppd-B1b/Ppd-D1a genotype, indicating a significant effect of Ppd-B1a in the genetic background with Ppd-D1a. Early-maturity breeding in Japan is believed to be accelerated by the introduction of the Ppd-B1a allele into medium-heading cultivars carrying Ppd-D1a. Pedigree analysis showed that Ppd-B1a in three extra-early commercial cultivars was inherited from 'Shiroboro 21' by early-heading Chugoku lines bred at the Chugoku Agriculture Experimental Station.
通过基于 PCR 的方法确定了日本小麦品种的光周期反应基因 Ppd-B1 和 Ppd-D1 的基因型，并比较了基因型之间的抽穗时间。除北海道地区外，大多数日本小麦品种都携带光周期不敏感等位基因 Ppd-D1a，与 Ppd-D1b 基因型相比，抽穗提前了 10.3 天。具有 Ppd-D1a 的早熟品种可能是为了避免收获前降雨的损害而被选择的。在北海道地区，无论 Ppd-D1 基因型如何，Ppd-D1a 的频率较低，抽穗期较晚，这表明北海道品种中存在另一种晚抽穗的遗传机制。在本研究中，只有 11 个品种被证明携带 Ppd-B1a，并且它们都携带另一个光周期不敏感等位基因 Ppd-D1a。Ppd-B1a/Ppd-D1a 基因型比 Ppd-B1b/Ppd-D1a 基因型提前 6.7 天抽穗，表明 Ppd-B1a 在具有 Ppd-D1a 的遗传背景中具有显著的作用。日本的早熟育种被认为是通过将 Ppd-B1a 等位基因引入携带 Ppd-D1a 的中熟品种而加速的。系谱分析表明，三个特早熟商业品种中的 Ppd-B1a 是由中国农业实验站育成的早抽穗中国品种从“白穗 21”遗传而来的。
