Blockage of mitosis in maize root tips using colchicine-alternatives

Area of Science:

• Plant genetics and breeding
• Cytogenetics
• Agricultural chemistry

Background:

• Colchicine is a widely used chemical agent for inducing polyploidy in plants, particularly in maize (Zea mays L.) breeding for producing homozygous doubled haploids.
• The high toxicity of colchicine to mammals and its negative environmental impact necessitate the search for safer alternatives.

Purpose of the Study:

• To screen for effective and less toxic chemical substitutes for colchicine in maize chromosome doubling.
• To evaluate the potential of herbicides as alternatives for inducing polyploidy in maize.

Main Methods:

• A screening system was established using maize root tips to test various chemical compounds.
• Herbicides including amiprophos methyl, oryzalin, and pronamide were evaluated for their efficacy in chromosome set doubling.

Main Results:

• Amiprophos methyl, oryzalin, and pronamide were identified as effective agents for doubling chromosome sets in maize.
• These herbicides exhibited lower toxicity compared to colchicine, with treated maize seedlings showing recovery and continued growth.

Conclusions:

• Herbicides such as amiprophos methyl, oryzalin, and pronamide represent viable and safer alternatives to colchicine for maize polyploidization.
• Reduced concentrations of these herbicides can achieve chromosome doubling results comparable to colchicine, offering a more environmentally friendly approach to maize breeding.