辣椒新型质核互作雄性不育材料H9A不育机理研究

A study of male sterile mechanism of new cytoplasmic-nuclear male sterile material H9A in pepper

为研究辣椒雄性不育的机理,在花期,采用常规的石蜡切片法,对新型辣椒雄性不育材料H9A及其保持系H9B小孢子不同发育时期进行细胞形态学观察;采用DDRT-PCR技术对H9A与H9B小孢子发育过程进行mRNA差异显示,筛选差异表达的基因。切片观察发现:供试雄性不育材料的小孢子败育发生在单核前期,此时花蕾纵径0.526～0.572 cm,横径0.318～0.372 cm,花冠和花萼之比约为1∶4;通过DDRT-PCR,共获得27条差异表达的cDNA片段,其中在H9A中获得12条,在H9B中获得15条。结果说明新型辣椒雄性不育材料H9A的小孢子败育发生在单核前期,败育原因可能是绒毡层细胞程序性死亡异常并极度液泡化膨胀,四分体受挤压后破裂降解,不能形成正常的单核花粉粒。败育时期与花蕾外部形态相关。在败育期表达的27条差异cDNA片段为研究辣椒雄性不育机理的候选基因奠定了基础。

To observe the abortion process during the development of microspore and to isolate the genes related to male sterility in the new cytoplasmic-nuclear male sterile material HgA, to further reveal the male sterile mechanism in pepper. The cell morphological observation between the new male sterile material H9A and its maintainer H9B was conducted by means of normal paraffin section method. The DDRT-PCR was used to isolate the differentially expressed genes during the development of microspore between H9A and H9B. The results showed that the microspore abortion of H9A occurred in the early uninucleate stage, during this period, the buds were 0. 526 - 0. 572 cm in height and 0.318-0.372 cm in diameter, the length was approximately in the ratio of 1 ： 4 between corolla and calyx; Twenty seven differentially expressed cDNA fragments were isolated by DDRT-PCR, including 12 cDNA fragments in HgA and 15 in H9B. The reason for the abortion was possibly that the tapetum cells were subjected to hypertrophy via vacuolation so that the tetrads were extruded and broken into pieces,so the normal uninucleate pollen grains could not form. The microspore abortion stage was related to the external shape of the flower bud. The 27 cDNA fragments acquired in this study could be candidate genes related to male sterility and their function needs further study.