Colchicine-mediated in vitro polyploidization in gerbera hybrid.

Area of Science:

• Plant Biotechnology
• Horticultural Science
• Genetics

Background:

• Gerbera hybrids are important ornamental plants, but limited polyploidization methods hinder genetic improvement.
• Polyploidy can enhance desirable traits like flower size, color intensity, and stress tolerance in ornamental species.

Purpose of the Study:

• To establish an efficient in vitro protocol for high-frequency polyploidization in a gerbera hybrid (BGC-2019-01).
• To characterize the morphological, physiological, and genetic changes in induced tetraploid gerbera plants.

Main Methods:

• In vitro shoots were treated with varying concentrations of colchicine (0.1%, 0.25%, 0.5%) for different durations (4, 6, 8, 12 h).
• Regenerated plantlets were cultured on Murashige and Skoog (MS) medium supplemented with meta-Topolin and indole-3-acetic acid.
• Ploidy levels were confirmed using flow cytometry and chromosome counts. Morphological, stomatal, pigment, and genetic analyses (CDDP, DAMD, ISSR, SCoT) were performed.

Main Results:

• The optimal condition for tetraploid induction was 0.1% colchicine for 4 h, yielding 50% tetraploid plantlets.
• Tetraploid gerbera exhibited delayed shoot initiation, fewer but longer shoots, broader leaves, larger stomata, and higher pigment content.
• Genetic uniformity was confirmed between diploid and tetraploid plants using multiple DNA polymorphism markers.

Conclusions:

• An efficient in vitro polyploidization protocol for gerbera hybrid BGC-2019-01 was successfully developed.
• Induced tetraploids show enhanced ornamental characteristics, including improved vigor and pigment content, making them valuable for breeding programs.
• The developed tetraploids hold significant potential for the genetic improvement of gerbera, particularly for enhancing ornamental value.