Chromosome variation in protoplast-derived potato plants

Area of Science:

• Plant genetics
• Cytology
• Plant biotechnology

Background:

• Protoplast culture is a key technique for potato (Solanum tuberosum) genetic improvement.
• Understanding chromosome stability during regeneration is crucial for developing true-to-type plantlets.
• Tetraploid potato cultivars exhibit varying responses to tissue culture-induced genomic changes.

Purpose of the Study:

• To investigate and compare chromosome variation in protoplast-derived potato plants of two tetraploid cultivars.
• To characterize the nature and extent of aneuploidy in regenerants.
• To identify differences in chromosome stability between Maris Bard and Fortyfold cultivars.

Main Methods:

• Protoplast isolation from tetraploid potato cultivars Maris Bard and Fortyfold.
• Regeneration of plants from protoplast-derived calluses.
• Cytological analysis of chromosome numbers in regenerated plantlets.
• Comparison of aneuploidy levels and patterns between cultivars.

Main Results:

• High levels of aneuploidy were observed in regenerants from both Maris Bard and Fortyfold.
• Maris Bard regenerants exhibited a wider range of aneuploidy (46-92 chromosomes) and fewer plants with the normal 48 chromosomes.
• Fortyfold regenerants showed a higher proportion of plants with 48 chromosomes and a more limited aneuploid range.
• Chromosome variation was detected at callus, within-callus, and shoot culture levels for both cultivars.

Conclusions:

• Protoplast culture in tetraploid potatoes can induce significant chromosome instability.
• The two cultivars, Maris Bard and Fortyfold, differ in their susceptibility to and patterns of aneuploidy during regeneration.
• Further research is needed to elucidate the specific mechanisms driving these observed chromosome variations.