Descriptions of common phenotypes

We take a bunch of phenotypes on plants. Every experiment should have its own SOPs (standard operating procedures) explaining exactly how to measure its target phenotypes. This page just gives a general overview to get familiar with what we tend to look at.

It is VERY IMPORTANT that things be recorded properly. If something gets mislabeled, it's almost impossible to correct, so make sure it's right.

General phenotypes

• Stand Count is just a count of the plants in a plot. Can be done early to check germination efficiency ("germination count"), or late ("stand count") as a covariate for harvest.

Reproductive phenotypes

• Flowering time is when the plant flowers. For a plot with multiple plants, we usually measure when half the plants have flowered.
  • Anthesis is male flowering for maize. A plant has anthesed when at least half the anthers on the main spike have opened up.
  • Silking is female flowering for maize. A plant has silked when you can see any silks at all poking out of the ear (but make sure they're not bits of leaf).

Harvest phenotypes

• Yield means how much we got out at the end of the season (usually of grain, but could be biomass, etc.)
  • Machine-harvested maize plots (e.g., Genomes to Fields) are contracted out to Statewide Variety Testing, and their combine automatically counts total weight, test weight (=weight per standard volume), and % moisture.
  • Hand-harvested plots are usually part of the nursery. We usually take 20-kernel weight and Total weight (both in grams) to get the (approximate) total seed count for the plot.