Behavior of meiotic chromosomes in Pinus wallichiana, P. strobus and their hybrid and nrDNA localization in pollen mother cells of the hybrid by using FISH.
The complete process of meiosis was investigated in Pinus wallichiana, P. strobus and their artificial hybrid (F1) using microsporocytes. It is revealed that there were slightly lower chiasma frequency, lower ring bivalent frequency, lower meiotic index and distinctly higher frequency of aberrance (chromosomal bridges, fragments or micronuclei) in pollen mother cells (PMCs) of the hybrid (F1) than those of the parental species, which showed a certain degree of differentiation between homologous chromosomes of the two parents. However, relatively higher frequency of ring bivalents and higher meiotic index in all the three entities indicate the great stability of genomes of parental species, and the differentiation of genomes between the two parents must have been slight. Total nineteen signal loci of 18S rDNA were observed in nine bivalents of the hybrid (F1), among which one bivalent bears two loci, while the others have only one. It is suggested that distinct differentiation at genetic level existed in homologous chromosomes of the two parental species, whereas only slight differentiation at karyotypic and genomic levels take place between the parent species.
Deng
Hui-Sheng
HS
College of Life Science, Zhejiang University, Hangzhou 310029, China.
Zhang
Da-Ming
DM
Fu
Cheng-Xin
CX
Hong
De-Yuan
DY
D000705:Anaphase; D032461:Chromosomes, Plant / Q000378:metabolism*; D003433:Crosses, Genetic; D004275:DNA, Ribosomal / Q000378:metabolism*; D006824:Hybridization, Genetic; D017404:In Situ Hybridization, Fluorescence; D008540:Meiosis; D008677:Metaphase; D028223:Pinus / Q000166:cytology* / Q000378:metabolism; D011058:Pollen / Q000166:cytology* / Q000378:metabolism; D011418:Prophase; D013692:Telophase
D004275:DNA, Ribosomal