Climate changes and rising temperatures have become major limiting factors in pea cultivation. A new study conducted at the University of Saskatchewan has indicated that pea plants with longer flowering time and higher pod numbers may be more resistant to heat stress. Rosalind Bueckert, lead author of the study, said that tolerance to heat stress in peas seems to be dependent on a few traits. However, two traits are most important: higher pod numbers and longer flowering duration.

Bueckert and her colleagues Tom Warkentin and Shaoming Huang are the first to discover the location of genes that affect heat stress in peas. "Heat stress means fewer flowers, fewer pods, and ultimately, lower yields," says Bueckert. Pea plants that have more pods to begin with have higher yields after a heat-stress event. Bueckert added that if a pea variety flowers for a longer time, it has more opportunities to have a higher yield, even under heat stress because the plant has more time to recover from extreme weather events during flowering.

The researchers evaluated more than a hundred varieties of pea to determine the traits important to combat heat resistance. While flowering duration and pod number are the two most important traits for heat resistance in peas, the team is also looking at other traits. For example, "semi-leafless varieties of pea are better at dealing with heat stress than leafy varieties," says Bueckert.

For more information, read the American Society of Agronomy News.

Figure: Extreme heat has resulted in these pea blossoms not producing a pod. Photo credit Rosalind Bueckert.