Rao Zhixiong, Sun Ruotian, Liu Shengjun, Ai Wanqi, Song Lizhi, Wang Xia, Xu Qiang
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070 Hubei Province China.
Mol Breed. 2024 Dec 16;45(1):1. doi: 10.1007/s11032-024-01521-5. eCollection 2025 Jan.
Male sterility is an important trait for breeding and for the seedless fruit production in citrus. We identified one seedling which exhibiting male sterility and seedlessness (named hereafter), from a cross between two fertile parents, with sour orange () as seed parent and Ponkan mandarin () as pollen parent. Analysis using pollen viability staining, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) revealed that the mature pollen of the was aborted, displaying collapse and deformity. Further cytological analysis identified the abnormal formation of monad, dyad, and tetrad instead of the normal tetrad formation, leading to meiotic failure in the seedless hybrid. By comparative transcript profiling of meiotic anther of fertile and sterile hybrids, we observed significant downregulation of () and genes in the hybrid, which known to control the transition from meiosis I to meiosis II in plants. These results indicated abnormal meiosis led to the male sterility of the seedless hybrid and that the decreased activities of kinases and cyclins may associated with the failure of the transition of meiosis I to meiosis II during anthers development.
The online version contains supplementary material available at 10.1007/s11032-024-01521-5.
雄性不育是柑橘育种和无籽果实生产中的一个重要性状。我们从两个可育亲本的杂交后代中鉴定出一株表现出雄性不育和无籽的幼苗（以下简称该幼苗），以酸橙（）为母本，椪柑（）为父本。通过花粉活力染色、扫描电子显微镜（SEM）和透射电子显微镜（TEM）分析发现，该幼苗的成熟花粉败育，表现为塌陷和畸形。进一步的细胞学分析发现，该无籽杂种中形成的是异常的单核、二分体和四分体，而不是正常的四分体，导致减数分裂失败。通过对可育和不育杂种减数分裂期花药的转录组比较分析，我们观察到该杂种中已知控制植物减数分裂I向减数分裂II转变的（）和基因显著下调。这些结果表明，异常减数分裂导致了无籽杂种的雄性不育，激酶和细胞周期蛋白活性的降低可能与花药发育过程中减数分裂I向减数分裂II转变的失败有关。
在线版本包含可在10.1007/s11032-024-01521-5获取的补充材料。
