Pioneering New Breeding Pathways with 3PaTec: Unlocking the Power of Polyspermy-Induced Triparentage for Sustainable Crop Development

Abstract

Over the last few centuries, advancements in plant breeding have revolutionized agriculture, driving significant increases in global food production. Polyploidy, the increase in chromosome copies, can positively affect plant performance and is assumed to have played a critical role in the domestication of crop plants. Polyploidy is thought to be primarily caused by sperm that, due to meiotic aberrations, deliver unreduced chromosome sets. We have recently identified an alternative pathway to polyploidization by demonstrating that polyspermy, the fertilization of an egg cell by more than one sperm, occurs in planta and results in viable triploid plants. Capitalizing on a novel high-throughput polyspermy detection tool, we have shown that polyspermy involving two pollen donors can generate plants with three parents, one mother and two fathers. This 3PaTec technology not only speeds up breeding processes through an instant combination of beneficial traits from three parents; it also allows selective polyploidization of the egg cell, thereby bypassing the central cell-derived embryo-nourishing endosperm, a major hybridization barrier. Here, we further explore the genetic and developmental factors influencing polyspermy and show that the frequency of polyspermy and triparental plant formation varies among ecotypes and depends on pollen availability, suggesting that polyspermy is an adaptive trait. Additionally, we extend the application of 3PaTec to crops by successfully generating triparental sugar beet in-field using a wind pollination strategy. Our findings highlight the potential of 3PaTec for major crop plants. This innovative breeding technology does not rely on genetic engineering, requiring minimal technical expertise and infrastructure. As a result, it is highly accessible to a wide range of users, contributing to the democratization of plant breeding by empowering individuals from all backgrounds to collaborate and contribute to developing resilient and sustainable crops.