Production and identification of alien chromosome addition lines of nicotiana plumbaginifolia

• Main Authors: Lin, Rong Fang, 林榮芳
• Other Authors: Chen, Qi Chang
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/19375137034097365105

博士 === 國立臺灣大學 === 植物學研究所 === 83 === A triploid hybrid (2n=28) was produced from somatic hybridization between haploid Nicotiana plumbaginifolia (n=10) and diploid N. alata (2n=18). The somatic hybrid was subsequently crossed to di- ploid N. alata. Among a total of 886 plants obtained from the backcross, 41 contained 2n=19 chromosomes. Three of these plants lost one chromosome during maintenance in culture and one was found later to be a trisomic of N. alata. Grouping of monosomic addition plants, each containing a 2n chromosome complement of N. alata and one chromosome of N. plumbaginifolia, based on mor- phological characteristics and identification of the N. plumbagi- nifolia chromosome were difficult. Gross chromosome abberations, such as deletions and rearrangements, and changes in RFLP pat- terns, such as loss ofparental DNA bands and appearance of new bands, occurred in the somatic hybrid as well as chromosome addi- tion plants. Thesewere attributed to incompatibility between the parental genomes and crossing over during meiosis in the hybrid. The latter phe-nomenon was suggested by the frequent occurrence of multivalents in microsporocytes of the somatic hybrid, and was confirmed by the observation of intergenomic chromosome rearran- gementsin monosomic addition plants using genomic in situ hybri- dization.