Yamaguchi Naoya, Hagihara Seiji, Hirai Dai
Hokkaido Research Organization Tokachi Agricultural Experiment Station, 2, Minami 9 sen, Shinsei, Memuro-cho, Kasai-gun, Hokkaido 082-0081, Japan.
Hokkaido Research Organization Kitami Agricultural Experiment Station, Yayoi 52, Kunneppu-cho, Tokoro-gun, Hokkaido 099-1496, Japan.
Breed Sci. 2019 Sep;69(3):521-528. doi: 10.1270/jsbbs.19024. Epub 2019 Jul 19.
In Hokkaido, the northernmost region of Japan, soybean [ (L.) Merr.] crops are damaged by cold weather. Chilling temperatures negatively affect seed appearance by causing seed coat discoloration around the hilum region, which is called cold-induced discoloration (CD). An assay for CD tolerance using a phytotron was developed, and two quantitative trait loci (QTLs) associated with CD tolerance were identified. The major QTL was located in the proximal region of the locus, and structural variation of this locus can serve as a useful DNA marker, called the Ic marker. To use this marker in breeding programs, the effects need to be assessed under field conditions because the Ic marker has been developed solely under phytotron conditions. The aim of this study was thus to assess the effect of the Ic marker under a cool field environment. We confirmed that the allele was highly effective using 27 cultivars and breeding lines including a near-isogenic line grown in the field where severe cold-weather damage occurred. This allele had no negative influence on the agronomic traits in the near-isogenic line. Our results suggest that marker-assisted selection for the allele is effective for improving CD tolerance in breeding programs.
在日本最北部的北海道地区，大豆[（L.）Merr.]作物受到寒冷天气的损害。低温会导致种脐区域周围种皮变色，从而对种子外观产生负面影响，这种现象被称为冷诱导变色（CD）。我们开发了一种利用人工气候箱测定CD耐受性的方法，并鉴定出了两个与CD耐受性相关的数量性状位点（QTL）。主要的QTL位于 位点的近端区域，该位点的结构变异可作为一种有用的DNA标记，称为Ic标记。为了在育种计划中使用该标记，需要在田间条件下评估其效果，因为Ic标记仅在人工气候箱条件下开发。因此，本研究的目的是在凉爽的田间环境下评估Ic标记的效果。我们使用包括一个近等基因系在内的27个品种和育种系，在发生严重寒冷天气损害的田间进行种植，证实了 等位基因具有高效性。该等位基因对近等基因系的农艺性状没有负面影响。我们的结果表明，在育种计划中，针对 等位基因进行标记辅助选择对于提高CD耐受性是有效的。
