Phenotypic and meiotic differences between diploid and polyploid plants

Choudhary, Anushree (2019). Phenotypic and meiotic differences between diploid and polyploid plants. University of Birmingham. Ph.D.

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Abstract

Polyploidy is present in a large number of crop plants and is considered as one of the driving forces in the evolution of angiosperms. Unlocking genetic variation in various autopolyploid crop plants is highly relevant to crop breeders. Homologous recombination, a tightly controlled cell process during the production of gametes in meiosis, is responsible for creation of genetic variation. Owing to the presence of more than two homologous chromosomes, polyploid meiosis faces a variety of challenges, such as multivalent formation and mis-segregation.

Using a plant trial with more than 300 diploid and tetraploid Arabidopsis thaliana F2 individuals, significant differences were found in various traits between the two populations. Cytological analysis using FISH on diploid and tetraploid plants revealed an overall increase in meiotic recombination in tetraploids, although the per bivalent frequency was reduced. The process of meiotic recombination was further explored in potato (Solanum tuberosum), a globally important autotetraploid crop. Chiasma frequency and multivalent frequency for chromosomes 1 and 2 varied according to variety, where the diploid variety showed a reduced chiasma frequency compared with tetraploid varieties. Immunolocalisation of the axis and synaptonemal complex proteins, ASY1 and ZYP1, demonstrated the complexities that may arise during meiosis in an autotetraploid plant.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):