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Jun 19 2025
2In a major scientific breakthrough, researchers have uncovered how dogroses (Rosa canina) overcome complex genetic barriers to reproduce successfully. Published in Nature, the study highlights how differences in centromere size—a key region of chromosomes—enable the plant’s unusual mode of inheritance. The findings shed new light on plant genetics and could pave the way for developing more resilient agricultural crops.
Led by Dr. André Marques of the Max Planck Institute for Plant Breeding Research, Prof. Dr. Christiane Ritz of the Senckenberg Museum of Natural History in Görlitz, and Dr. Aleš Kovařík from the Czech Academy of Sciences, the international team focused on the dogrose’s rare reproductive strategy, which has puzzled botanists for over a century.
Dogroses are the most widespread wild roses in Central Europe, known for their ornamental value and versatile fruits—rose hips—used in teas and even itching powder. Beyond their utility, dogroses stand out genetically. Unlike most organisms that have two sets of chromosomes, dogroses carry five (a condition known as pentaploidy). Typically, an odd number of chromosome sets hinders regular cell division, often leading to infertility in plants.
Yet dogroses have evolved an exceptional workaround. Through a process known as Canina meiosis, only two of the five chromosome sets participate in the standard sexual reproduction cycle, contributing equally to egg and pollen cells. The remaining three sets, called univalents, do not pair or recombine but are passed down clonally—unchanged and only through the egg cell. This results in a remarkable combination of sexual and clonal inheritance.
"Dogroses are essentially blending two modes of reproduction within the same genome," explained Dr. Marques. "It’s a sophisticated system that has fascinated researchers, but until now, the underlying mechanisms remained a mystery."
The key, as the researchers found, lies in the centromeres—central regions on chromosomes where spindle fibers attach during cell division. These fibers guide chromosome movement to ensure accurate separation during both mitosis and meiosis.
By examining the genomes of three different dogrose species at high resolution, the team discovered that the univalent chromosomes have significantly larger centromeres. These expanded centromeres contain multiple repetitions of a rose-specific DNA sequence and bind more strongly to the spindle-associated protein CENH3, increasing their likelihood of being retained in egg cells.
"This centromere enlargement appears to tip the scales in favor of certain chromosomes being preserved," noted Dr. Kovařík. "It’s an elegant solution to an otherwise detrimental genetic imbalance."
According to Prof. Ritz, this discovery does more than explain a long-standing botanical puzzle. It also holds tangible value for plant breeding. Many cultivated crops are polyploid like the dogrose, and while polyploidy can offer benefits such as disease resistance, it often complicates reproduction.
"Understanding how dogroses manage polyploidy could help us stabilize fertility in other plants with multiple chromosome sets," said Ritz. "This could be a game-changer for crop resilience."
Dr. Marques agrees: “Our research may lead to new strategies for breeding hardier, more productive crops—using nature’s own tricks.”
Source:https://phys.org/news/2025-06-seemingly-impossible-reproduction-dogroses-hinges.html
This is non-financial/medical advice and made using AI so could be wrong.
