An Hongzhou, Hu Mei, Li Pengfei, Geng Guangdong, Zhang Qingqin, Zhang Suqin
College of Agriculture, Guizhou University, Guiyang, Guizhou, China; Guizhou Subcenter of National Wheat Improvement Center, Guiyang, Guizhou, China.
College of Agriculture, Guizhou University, Guiyang, Guizhou, China.
PLoS One. 2015 May 7;10(5):e0126398. doi: 10.1371/journal.pone.0126398. eCollection 2015.
The meiotic behavior of pollen mother cells (PMCs) of the F2 and F3 progeny from Triticum timopheevii × hexaploid wild oat was investigated by cytological analysis and sequential C-banding-genomic in situ hybridization (GISH) in the present study. A cytological analysis showed that the chromosome numbers of the F2 and F3 progeny ranged from 28 to 41. A large number of univalents, lagging chromosomes, chromosome bridges and micronuclei were found at the metaphase I, anaphase I, anaphase II and tetrad stages in the F2 and F3 progeny. The averages of univalents were 3.50 and 2.73 per cell, and those of lagging chromosomes were 3.37 and 1.87 in the F2 and F3 progeny, respectively. The PMC meiotic indices of the F2 and F3 progeny were 12.22 and 20.34, respectively, indicating considerable genetic instability. A sequential C-banding-GISH analysis revealed that some chromosomes and fragments from the hexaploid wild oat were detected at metaphase I and anaphase I in the progeny, showing that the progeny were of true intergeneric hybrid origin. The alien chromosomes 6A, 7A, 3C and 2D were lost during transmission from F2 to F3. In addition, partial T. timopheevii chromosomes appeared in the form of univalents or lagging chromosomes, which might result from large genome differences between the parents, and the wild oat chromosome introgression interfered with the wheat homologues' normally pairing.
本研究通过细胞学分析以及连续C带-基因组原位杂交（GISH）技术，对提莫菲维小麦×六倍体野生燕麦F2和F3后代花粉母细胞（PMC）的减数分裂行为进行了研究。细胞学分析表明，F2和F3后代的染色体数目在28至41之间。在F2和F3后代的减数第一次分裂中期、后期I、后期II和四分体时期发现了大量单价体、落后染色体、染色体桥和微核。F2和F3后代中单价体的平均数目分别为每个细胞3.50条和2.73条，落后染色体的平均数目分别为3.37条和1.87条。F2和F3后代的PMC减数分裂指数分别为12.22和20.34，表明存在相当程度的遗传不稳定性。连续C带-GISH分析显示，在后代的减数第一次分裂中期和后期I检测到了一些来自六倍体野生燕麦的染色体和片段，表明这些后代是真正的属间杂种起源。在从F2向F3传递的过程中，外源染色体6A、7A、3C和2D丢失。此外，部分提莫菲维小麦染色体以单价体或落后染色体的形式出现，这可能是由于亲本之间基因组差异较大，且野生燕麦染色体的渗入干扰了小麦同源染色体的正常配对。
