HERBACIOUS PLANT GRAFTING MANUAL

Germinate pea seeds

• Scarify seeds in concentrated sulfuric acid for 5 minutes.
  This is done to soften the seed coat. If omitted, seeds may take longer to germinate and germination may be less regular

• Imbibe seeds in aerated water for 24 hrs.
  Same as above

• Plant seeds in wet vermiculite 1-2 cm deep.
  If seeds are only pushed into the surface, roots may not grow well, especially if air is dry (in this respect the picture on the right is wrong)

• Leave to germinate in vermiculite dark until shoots are 2-3 cm long. Too short seedlings are hard to graft, extensive etiolation is not desirable because we want the plants to be as close to "normal" as possible. Using other medium than vermiculite is probably OK, it is convenient to use something that does not stick to the roots too much

Graft seedlings

• Prepare pieces of tubing that will fit tightly the epicotyl, (PE is best, possibly other materials) make them 1 cm long and slit-cut them along their axis.
  Tight fit is important, because this is the part that will hold the grafted parts together. If they are not held tight, air gets in, dries the area of contact and the scion dies. Use several diameters, if necessary

• Isolate two seedlings that are to be grafted and cut them with a sharp razor in the middle of the epicotyl at an angle of 20-30 degrees.
  Blunt blade may cause problems in healing, angle increases the area of contact and makes attachment easier

• Attach a piece of tubing to the stock, so that half of it is empty, ready to accept the scion
  This is a moment to check how well the tubing fits. Choose a size that will have to open slightly to accomodate the stock

• Slide the scion into the tubing
  Make the contact with the stock as tight as possible. Don't push too hard, so as to damage the tissues

• Place grafted plants back into vermiculte
  

Wait for the grafts to take

• Leave the grafted plants in a moist environment with moderate light
  This can be done by covering them and keeping the vermiculite wet. You may increase light to normal levels after a few days.

• Buds in the axils of the cotyledons will start breaking, cut them off as needed
  If these lateral buds are left to grow, they overtake the whole plant and the scion may die. Their growth can also be prevented by cutting off the cotyledons, but we want to keep them there for a few days to keep the plant happy

• After 7-10 days it should be clear which grafts have taken. Cut off the cotyledons and use those grafted plants as desired
  In our experiments we transferred them to hydroponics

About this manual

In case you need a reference for a publication, use:

Matej Lexa, John M. Cheeseman
Growth and nitrogen relations in reciprocal grafts of wild-type and nitrate reductase deficient mutants of pea (Pisum sativum L. var. Juneau)
Journal of Experimental Botany 48, 1241-1250 (1997)

This document was created on April 29, 1996.