• Peas
• University of Saskatchewan

Objective

To use synchrotron techniques as an aid in selecting heat stress resistant crops via pollen coat lipids and leaf wax.

Outcome

In this grower-funded project, the University of Saskatchewan looked at lipids in the waxy surface or cuticle layer of pea leaves and pea pollen grains. The research team aims to develop a method to find more heat resistant pollen using the lipids in leaves. To do this, they used a spectral technique at the Canadian Light Source, which scanned samples in the mid infrared (Mid-IR) wavelength range. They looked at leaf wax and pollen grains from 11 pea varieties exposed to five days of high temperature (35/18 °C day/night) and compared them to samples from plants grown at normal temperatures (24/18 °C day/night). Varieties were grouped into three groups based on their pollen lipids. Pea varieties also differ in leaf cuticle lipids. CDC Vienna exhibited the most lipids and CDC Sage had the least. Heat stress caused chemical modifications of leaf cuticles in 03H107P04HO2026, CDC Golden, CDC Sage, Naparnyk and TMP15213. The varietal difference in lipid performance in heat means that there is potential for heat tolerance in pea. The varietal range in pollen coat lipids is less than in leaf lipids. The research team then measured tiny pods, their interior ovules (developing seeds), and the size of the funiculi (placenta) to ovules, processes soon after pollination that are difficult to measure by conventional techniques.  Heat stress damage reduced ovule sizes and slowed pod growth.

Download PDF Summary