An experimental study discovered that without bumble bees, a flowering plant that can self-pollinate lost a significant amount of genetic diversity in just nine generations.
When compared to another set of monkeyflower plants that were propagated by bumble bees, a group of plants that were "selfed" lost 13% to 24% of their genetic diversity.
According to the study, this loss could deprive the plants of their capacity to respond to environmental conditions.
The findings indicated major problems for wild plants and agriculture that depend on bees as pollinators since bee numbers are declining in nature.
Rapid loss of genetic variation due to bee population decline
Bianca Ackermann/Unsplash
Experts discovered that when plants had to adopt selfing, there were significant effects on their genomes in a relatively short period, according to the study's lead author, evolutionary scientist Jeremiah Busch of Washington State University, as per ScienceDaily.
Busch noted that while pollinators like bees are crucial to biodiversity in and of themselves, the study showed that their rapid decrease would also have potentially disastrous effects on plants.
According to Busch, losing pollinators won't simply affect the pollinators; plant populations would lose genetic diversity in tens of years, not thousands.
Although scientists were aware that adopting self-pollination may harm a plant species' long-term existence, they were unsure of the genetics of how it operated.
A controlled greenhouse experiment was set up by Busch's colleagues using yellow monkeyflower plants, a widespread wildflower in the Western United States, in which a group of plants was separated from their bumble bee pollinators.
The non-bee plants first produced few seeds, but when they learned to self-pollinate, they began to produce a lot.
The stamens and pistils, which are the flowers' male and female reproductive organs, shifted as well, shifting closer to one another to facilitate pollen transport.
Even while the selfing plants multiplied, they lost genetic diversity in comparison to a control group that received bumble bee visits.
According to Busch, adaptation is the key to explaining these unexpected decreases.
A favored genotype will spread in selfing populations if it has an advantage, but any other mutations it contains will also do so if they are fortunate enough to be present in that plant's genome.
When bees visit plants, the phenomenon of "genetic hitch-hiking" is considerably less evident since the genetic diversity of the parents' progeny is mixed in.
Strong inbreeding substantially changed the effects of adaptation.
According to Busch, future studies should track plants over a longer period to determine whether and when the loss of genetic diversity causes population collapse.
According to preliminary findings of the 15th annual national survey performed by the nonprofit Bee Informed Partnership, or BIP, beekeepers across the United States lost 45.5% of their managed honey bee colonies from April 2020 to April 2021, as per the Auburn University.
Since the survey's inception in 2006, these losses represent the second-highest loss rate (6.1% greater than the average yearly loss rate of 39.4%).
The survey's findings draw attention to the persistently high rates of honey bee colony turnover.
This year's heightened summer and winter losses contributed to the high loss rate, and there was no discernible improvement for beekeepers and their colonies.
The poll findings will be used by BIP to learn more about beekeepers' experiences with colony losses and what may be done to lessen them in the next seasons.
Agricultural organizations, researchers, and the beekeeping industry have been collaborating to investigate why beekeepers are experiencing increased losses in their colonies since the early 2000s and to establish best management practices to lower such losses.
This procedure has been greatly aided by the BIP yearly colony loss study, which has been carried out since 2006.
