Wang Yan, Jia Hui-Min, Shen Yu-Tong, Zhao Hai-Bo, Yang Qin-Song, Zhu Chang-Qing, Sun De-Li, Wang Guo-Yun, Zhou Chao-Chao, Jiao Yun, Chai Chun-Yan, Yan Li-Ju, Li Xiong-Wei, Jia Hui-Juan, Gao Zhong-Shan
1Fruit Science Institute, College of Agriculture and Biotechnology, Zhejiang University, 310058 Hangzhou, China.
2Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 201602 Shanghai, China.
Hortic Res. 2020 Apr 1;7(1):53. doi: 10.1038/s41438-020-0276-6. eCollection 2020.
Red bayberry () is an evergreen fruit tree found in southern China whose whole-genome sequence has recently been published. We updated the linkage map of the species by adding 118 SSR markers and the female-specific marker MrFT2_BD-SEX. The integrated map included eight linkage groups and spanned 491 cM. Eleven sex-associated markers were identified, six of which were located in linkage group 8, in agreement with the previously reported location of the sex-determining region. The MrFT2_BD-SEX marker was genotyped in 203 cultivated accessions. Among the females of the accessions, we found two female-specific alleles, designated W-b (151 bp) and W-d (129 bp). We previously found that Dongkui, a female cultivar, could produce viable pollen (we refer to such plants Dongkui-male) and serve as the paternal parent in crosses. The genotypes of the MrFT2_BD-SEX marker were W-b/Z in Biqi and W-d/Z in Dongkui-male. The progeny of a cross between these parents produced a 3:1 female (W-) to male (ZZ) ratio and the expected 1:1:1:1 ratio of W-b/W-d: W-b/Z: W-d/Z: Z/Z. In addition, the flowering and fruiting phenotypes of all the F1 progeny fit their genotypes. Our results confirm the existence of ZW sex determination and show that the female phenotype is controlled by a single dominant locus (W) in a small genomic region (59 kb and less than 3.3 cM). Furthermore, we have produced a homozygous "super female" (WW) that should produce all-female offspring in the F2 generation, providing a foundation for commercial use and presenting great potential for use in modern breeding programs.
杨梅（）是一种在中国南方发现的常绿果树，其全基因组序列最近已发表。我们通过添加118个SSR标记和雌性特异性标记MrFT2_BD-SEX更新了该物种的连锁图谱。整合后的图谱包括8个连锁群，跨度为491 cM。鉴定出11个与性别相关的标记，其中6个位于连锁群8中，这与先前报道的性别决定区域的位置一致。在203份栽培种质中对MrFT2_BD-SEX标记进行了基因分型。在这些种质的雌性中，我们发现了两个雌性特异性等位基因，命名为W-b（151 bp）和W-d（129 bp）。我们之前发现，雌性品种东魁可以产生可育花粉（我们将这种植物称为东魁雄株），并可作为杂交中的父本。MrFT2_BD-SEX标记在荸荠中的基因型为W-b/Z，在东魁雄株中的基因型为W-d/Z。这些亲本之间杂交的后代产生了3:1的雌性（W-）与雄性（ZZ）比例以及预期的1:1:1:1的W-b/W-d: W-b/Z: W-d/Z: Z/Z比例。此外，所有F1后代的开花和结果表型都与其基因型相符。我们的结果证实了ZW性别决定的存在，并表明雌性表型由一个小基因组区域（59 kb且小于3.3 cM）中的单个显性位点（W）控制。此外，我们培育出了纯合的“超级雌性”（WW），其在F2代中应该产生全雌性后代，为商业应用奠定了基础，并在现代育种计划中具有巨大的应用潜力。
