By Andy Schmitz, Director of Horticulture and General Manager

This article was originally published in The Brenton Arboretum Autumn 2014 newsletter.

Why is wild seed collecting important?

Back in October of 2011, Pecan (Carya illinoinensis) nuts were collected from Port Louisa National Wildlife Refuge in Louisa County, Iowa by Jeff Carstens from the Plant Introduction Station in Ames, Iowa and myself. Some of these nuts were grown into seedlings and planted in the pecan grouping here at the arboretum. Since hickory nuts are recalcitrant, they will not survive long-term under optimum seed storage conditions, and must be grown into a tree for preservation. So, collected nuts were also shipped to the National Collection of Genetic Resources for Pecans and Hickories in Somerville, Texas to be planted and grown to preserve the genetics of this population.

In the past month, L.J. Grauke from the National Collection of Genetic Resources for Pecans and Hickories informed Jeff Carstens and me that they had a severe outbreak of black pecan aphid in their greenhouses where they were growing out 2500 seedlings of pecans from wild collections ranging from Mexico to Missouri. The black aphid feeding causes bright yellow-orange chlorotic spots on the leaflets and can cause defoliation. All 2500 seedlings of pecans were affected by the black aphids, except for the 50 seedlings grown from the Louisa County, Iowa site. The genetics obtained from the Louisa County population appear to be completely resistant to the aphid. This is the invaluable information we learn from growing out wild collected specimens of known origin.

One of our missions here at the arboretum is to improve our collections through wild collecting and through acquiring plants from known sources, which includes other arboretums. This work continues today.

In 2014, we have 21 different wild sourced seed accessions growing and another 40 plants which were grown from wild sourced seed we received from the Morton Arboretum in Lisle, Illinois and from the Plant Introduction Station in Ames, Iowa. Currently, these trees are in seedling containers or in the nursery and will eventually be added to the permanent collections. In early October, I was in southern Iowa collecting nuts from native shellbark hickory, (Carya laciniosa). Seedlings of this collection will be planted at the arboretum and, again, nuts will be sent by the Plant Introduction Station to the National Collection of Genetic Resources for Pecans and Hickories in Texas. And, who knows, three years from now we might find out some interesting information about this wild collected seed.