Monosomics in common bean, Phaseolus vulgaris

Area of Science:

• Plant genetics
• Cytology
• Common bean (Phaseolus vulgaris) research

Background:

• Colchicine treatment can induce polyploidy and aneuploidy in plants.
• Monosomics, organisms with one missing chromosome, are valuable for genetic studies.
• Phaseolus vulgaris has a diploid chromosome number of 2n = 22.

Purpose of the Study:

• To identify and characterize monosomic individuals in Phaseolus vulgaris.
• To investigate the effects of monosomy on plant growth and morphology.
• To determine the transmission rates of specific monosomic chromosomes.

Main Methods:

• Induction of aneuploidy using colchicine treatment in Phaseolus vulgaris.
• Analysis of selfed progeny to identify monosomic individuals.
• Karyotype analysis using Giemsa staining to identify specific chromosomes (H and J).
• Phenotypic evaluation of monosomic plants compared to euploid sibs.

Main Results:

• Two monosomic plants, involving chromosomes H and J, were identified in the progeny.
• Monosomic plants displayed reduced growth rate and smaller size compared to euploids.
• No distinct morphological differences were observed between the two monosomic types.
• Transmission frequencies for monosomic H and J were 9% and 10%, respectively.

Conclusions:

• Colchicine treatment effectively induced monosomy in Phaseolus vulgaris.
• Monosomy for chromosomes H and J negatively impacts plant growth.
• Specific monosomic chromosomes can be identified and their transmission rates quantified.