Genetic Stability of Rice Aneuploid During Its Asexual Propagation

For undertanding the genetic stability of rice (Oryza sativa L.) aneuploid during its asexual propagation, a telotetrasome (2n+·8S+·8S) was selected from the progenies of a rice telotrisome (2n+·8S), and preserved by asexual reproduction. One of the extra short arms (·8S) was easily lost in the asexual propagation offspring of 2n+·8S+·8S, resulting in morphological variation. The behaviors of the 2 extra ·8S were observed using fluorescence in situ hybridization (FISH) technique. One of the 2 extra ·8S was found without detectable centromeric satellite repeat (CentO) and centromere-specific retrotransposon (CRR), and failed to be transmitted stably; whereas the other extra ·8S contained CRR but no detectable CentO, which could be transmitted stably during asexual propagation. However, the extra ·8S contained both CentO and CRR sequences in the initial telotrisomic line (2n+·8S). Therefore, the CentO and CRR sequences of the extra ·8S may be randomly lost during asexual propagation, which results in instable inheritance in aneuploid rice with extra ·8S.