genetic conservation of indigenous corn varieties

Tonette Laude

NDSU Corn Breeding Program

RationaleIndigenous corn varieties consist of heterogeneous

population.Preservation of indigenous varieties is necessary to

keep varietal existence and identity. This will also help preserve the culture.

There have been problems in keeping these corn varieties.

Goal: to restore these varieties by increasing the seeds and

maintaining them viable without loss in variability.

Red Lake Flint

Northern Iroquois Yellow Flint

ConsiderationsSample size

large enoughhow many plants?need to get more ears

Variabilitymaintain the diversity no selection done http://www.homestead-farm.net/photos/2006-Oct7/21-Indian-Corn.jpg

MethodsIsolation

By distance general recommendation is 250m apart for ND, 1 to 2 miles apart

By time flowering time should not meet with other varieties can plant at the same time, if other varieties have later

relative maturity

Controlled pollination

1. Find ear shoots at this stage. Note: no silk has emerged yet.

2. Bag it to protect from contamination.

3. Find a tassel with 50% pollen shedding. Bag the tassel to allow us to collect pollen.

4. Look for a bagged ear shoot. Check if tiny silks have emerged. Make a cut not more than 1 inch from the tip then put back the bag.

Tassel bagging done day before pollination.

Steps in pollination5. Collect pollen by tapping the tassel bag. Detassel

this plant by removing its tassel.

6. Find a plant with bagged ear shoot. Remove the shoot bag and pour the pollen from the tassel bag. This time, place the tassel bag to cover the ear. Be sure to detassel also this plant.

Seed processingAt physiological maturity, hand harvest all of the

pollinated ears and dry.Count the number of ears and create 3 balanced

bulks of 500 kernels each. Excess kernels will go to big bulk.For balanced bulk, i.e. harvested 250 ears, get 2

kernels/ear to create a bulk of 500 kernels. This is used for seed maintenance from next generations. Check seed germination after storage.

Big bulk is used for production.

The methods presented will be useful to restore and maintain indigenous corn varieties.

As long as these varieties are maintained with good sample size and variability, the identity of the varieties will still be the same.

Thank youThank you