The practical use of marker-assisted selection (MAS) is limited in conifers because of the difficulty with developing markers due to a rapid decrease in linkage disequilibrium, the limited genomic information available, and the diverse genetic backgrounds among the breeding material collections. First, in this study, two families were produced by artificial crossing between two male-sterile trees, ‘Shindai11’ and ‘Shindai12’, and a plus tree, ‘Suzu-2’ (Ms1/ms1) (S11-S and S12-S families, respectively). The segregation ratio between the male-sterile and male-fertile trees did not deviate significantly from the expected 1:1 ratio in either family. These results clearly suggested that the male-sterile gene of ‘Shindai11’ and ‘Shindai12’ is MALE STERILITY 1 (MS1). Since it is difficult to understand the relative positions of each marker, due to the lack of a linkage map which all the closely linked markers previously reported are mapped on, we constructed a partial linkage map of the region encompassing MS1 using the S11-S and S12-S families. For the S11-S and S12-S families, 19 and 18 markers were mapped onto the partial linkage maps of the MS1 region, respectively. There was collinearity (conserved gene order) between the two partial linkage maps. Two markers (CJt020762_ms1-1 and reCj19250_2335) were mapped to the same position as the MS1 locus on both maps. Of these markers, we used CJt020762 for the MAS in this study. According to the MAS results for 650 trees from six prefectures of Japan (603 trees from breeding materials and 47 trees from the Ishinomaki natural population), five trees in Niigata Prefecture and one tree in Yamagata Prefecture had heterozygous ms1-1, and three trees in Miyagi Prefecture had heterozygous ms1-2. The results obtained in this study suggested that ms1-1 and ms1-2 have different geographical distributions. Since MAS can be used effectively to reduce the labor and time required for selection of trees with a male-sterile gene, the research should help ensure that the quantity of breeding materials will increase to assist future tree-breeding efforts.

中文翻译：

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日本柳杉D.MALE STERILITY 1的树的标记辅助选择

标记辅助选择（MAS）在针叶树中的实际使用受到限制，因为由于连锁不平衡的迅速降低，可用的有限基因组信息以及育种材料集合之间的不同遗传背景，难以开发标记。首先，在这项研究中，通过两个雄性不育树“ Shindai11”和“ Shindai12”与一个加号树“ Suzu-2”（Ms1 / ms1）（S11-S和S12- S个家庭）。在两个家庭中，雄性不育树和雄性可育树之间的隔离率均未明显偏离预期的1：1比例。这些结果清楚地表明'Shindai11'和'Shindai12'的雄性不育基因为男性不育1（MS1）。由于难以理解每个标记的相对位置，由于缺少链接图，以前报道的所有紧密链接的标记都映射到该图上，因此我们使用S11-S和S11构建了涵盖MS1的区域的部分链接图。S12-S家庭。对于S11-S和S12-S家族，分别将19个标记和18个标记映射到MS1区域的部分连锁图上。两个部分连锁图之间存在共线性（保守的基因顺序）。将两个标记（CJt020762_ ms1-1和reCj19250_2335）映射到与MS1相同的位置在两个地图上的轨迹。在这些标记中，我们在本研究中将CJt020762用于MAS。根据MAS结果，来自日本6个州的650棵树（来自繁殖材料的603棵树和来自石卷自然种群的47棵树），新泻县的5棵树和山形县的1棵树具有ms1-1杂合度，而日本的3棵宫城县有ms1-2的杂合子。这项研究中获得的结果表明ms1-1和ms1-2具有不同的地理分布。由于可以有效地利用MAS来减少选择具有雄性不育基因的树木所需的劳力和时间，因此该研究应有助于确保育种材料的数量增加，以帮助将来的树木育种工作。