When pollen is destroyed by heat
How much will our future diet be affected by heat? At around 32 Celsius, the pollen begins to degrade. A problem that could become more and more urgent for the 8 billion human beings…
It should be remembered that, even if for many pollens means allergies, in reality, almost everything that we eat and that grows in the earth depends on pollination. However, farmers have already noticed it: abnormally hot temperatures in spring can actually kill pollen and disrupt crops. The problem has been observed with corn and rice, two of the main foods on the planet. The reproduction of the tomato is also particularly sensitive to heat.
The solution of hatching before the first heat is no longer sufficient, it is necessary to try to develop varieties that are more resistant to heat. Still, it is necessary to understand at what stage of the process the heat does its work.
That's what researchers like Mark Westgate, a professor of agronomy at Iowa State University, who found that it's the growth of the pistil—the female reproductive tract of the plant— which is affected by early heat. Its growth is slowed down, and it cannot accommodate the pollen grain.
In the case of tomatoes, the heat actually burns the pollen grain before it has done its job. In 2018, a team from Wake Forest University in North Carolina observed that antioxidants called flavonols could inhibit molecules that play a destructive role in hot weather.
A researcher from Michigan State University, Jenna Walters, for her part, identified the heat tolerance threshold (35 degrees) in the pollen grain of a fruit that will resonate with Quebecers: the blueberry.< /p>
In all of these examples, it comes down to genetics: creating a strain that, by some detour, would be less affected than others by the inevitable higher temperatures looming on the horizon. But each plant may have its particularities, and the road could be long.
