Meng Liying, Liu Zihan, Zhang Lingli, Hu Gan, Song Xiyue
College of Agronomy, Northwest A&F University , Yangling, Shaanxi , China , 712100.
Breed Sci. 2016 Dec;66(5):752-761. doi: 10.1270/jsbbs.16039. Epub 2016 Nov 26.
Male sterility is an important tool for obtaining crop heterosis. A thermo-sensitive cytoplasmic male-sterile (TCMS) line was developed recently using a new method based on tiller regeneration. In the present study, we explored the critical growth stages required to maintain thermo-sensitive male sterility in TCMS lines and found that fertility is associated with abnormal tapetal and microspore development. We investigated the fertility and cytology of temperature-treated plant anthers at various developmental stages. TCMS line KTM3315A exhibited thermo-sensitive male sterility in Zadoks growth stages 41-49 and 58-59. Morphologically, the line exhibited thermo-sensitive male sterility at 3-9 days before heading and at 3-6 days before flowering, and it was partially restored in three locations during spring and summer. TCMS line KTM3315A plants exhibited premature tapetal programmed cell death (PCD) from the early uninucleate stage of microspore development until the tapetal cells degraded completely. Microspore development was then blocked and the pollen abortion type was stainable abortion. Thus, male fertility in the line KTM3315A is sensitive to temperature and premature tapetal PCD is the main cause of pollen abortion, where it determines the starting period and affects male fertility conversion in K-type TCMS lines at certain temperatures.
雄性不育是获得作物杂种优势的重要工具。最近利用基于分蘖再生的新方法培育出了一个温敏细胞质雄性不育（TCMS）系。在本研究中，我们探究了维持TCMS系温敏雄性不育所需的关键生长阶段，发现育性与绒毡层和小孢子发育异常有关。我们研究了不同发育阶段经温度处理的植株花药的育性和细胞学特征。TCMS系KTM3315A在泽多克生长阶段41 - 49和58 - 59表现出温敏雄性不育。从形态学上看，该系在抽穗前3 - 9天和开花前3 - 6天表现出温敏雄性不育，在春季和夏季的三个地点部分恢复育性。TCMS系KTM3315A植株从微孢子发育的早期单核阶段到绒毡层细胞完全降解，都表现出绒毡层过早的程序性细胞死亡（PCD）。随后小孢子发育受阻，花粉败育类型为可染败育。因此，KTM3315A系的雄性育性对温度敏感，绒毡层过早的PCD是花粉败育的主要原因，它决定了起始时期并在一定温度下影响K型TCMS系的雄性育性转换。
