Spring 2003  Volume 12, Number 1

THE HARDWOOD TREE IMPROVEMENT AND REGENERATION CENTER

by Keith E. Woeste and Charles H. Michler, USDA Forest Service

Whatt is the Hardwood Tree Improvement and Regeneration Center (HTIRC) and where is it located? The HTIRC is a collaborative regional research, development and technology transfer center for hardwood tree improvement through tree breeding, genomics and biotechnology.

Formal partners include the USDA Forest Service North Central Research Station and Northeastern Area State and Private Forestry, Purdue University Department of Forestry and Natural Resources, Indiana Department of Natural Resources Division of Forestry, Indiana Hardwood Lumbermen's Association, and the Walnut Council. The HTIRC seeks interactions with everyone who has an interest in hardwood trees, whether as a scientist, a business operator, a grower or an enthusiast. In particular, we consider the members of the Northern Nut Growers to be an exceptional source of knowledge and informatiion concerning the propagation, management and diversity of fruit and nut bearing trees. We have come lately to a field that the NNGA has been working for about a century.

HTIRC is located at Purdue University, a place internationally  recognized as a center of research in agricultural and forestry genetics. The field of agricultural genomics has recently emerged as one fore-front of genetic research. Genomics may be defined as the study of the structure and function of the entire genetic complement of an organism. The HTIRC is housed in the Whistler Hall of Agricultural Research along with biotechnology and genomics faculty from six departments in the School of Agriculture. This co-location of genetics faculty is intended to stimulate cross fertilization of research ideas and multidisciplinary research that will help keep research in tree genetics on the cutting edge of this rapidly growing discipline. In addition, because of the high standards of achievement and international recognition of its faculty, high quality undergraduate and graduate students should be drawn to the various programs represented in Whistler Hall.

WHY WAS THE HTIRC CREATED?

The HTIRC was conceived in 1998 because of a perceived void in hardwood improvement research in the central hardwood region of the Midwest and Northeast. In the aftermath of the closure of the USDA Forest Service, North Central Research Station Laboratory in Carbondale, Illinois, there was no longer a federal presence in hard-wood tree improvement research and university research activities did not close to fill the void. At the same time, around the late 90's, a number of specific, pressing questions were emerging that required scientific investigation:

1. The central hardwoods region was expe6encing a severe production shortage of hardwood seedlings estimated anywhere from 25 to 50 million trees annually. In addition, the majority of seedlings being produced in state nurseries are of unknown genetic source because nurseries rely upon seed collectors to collect and transport seed to the point of purchase at the nursery. Thus, the majority of seedlings being produced are unirnproved, of unknown fitness for sustainable forestry, and of unknown genetic diversity.

2. The hardwood industry was concerned about the future quatity and quality of the resource for its lumber and manufacturing sectors. Due to political and social pressures, federal forests have significantly reduced the volume of hardwood timber that is being harvested annually. Small private woodlots that supply a significant amount of hardwood timber are not being man-aged in a sustainable manner, ownership is not continuous over numerous rotations to insure sound forest management, and many woodlots are being converted to residential and recreational uses. In addition, the diameter of timber harvested today continues to be smaller than what it has been due to shorter rotations. Last, the hardwood industry was concerned that it was not taking advantage of new biotechnologies that could increase wood production through tree improvement activities that improve wood quality, growth, and pest resistance.

3. Professional foresters are concerned about loss of genetic quality in remaining hardwood woodlots and natural forests. They believe that trees currently being managed for future timber harvest do not have the desirable straightness and vigor and that post forest harvest practices of continually taking the "trees' may have resulted in loss of genetic quality of the remaining germplasm.

WHAT IS THE MISSION OF THE HTIRC?

The mission of the Hardwood Tree Improvement and Regeneration Center is to advance the science of hardwood tree improvement and genomics in the central hardwood region of the United States. The HTIRC will:

-- Develop and disseminate knowledge on improving the genetic quality of hardwood tree species. The HTIRC will be vertically integrated with molecular and classical geneticists, tree physiologists, silviculturalists, and nursery and regeneration specialists. 'Improvement' means different things to different people. The HTIRC will work to ensure that its research benefits the public broadly, from the practical, such as evaluating next generation selections for seed orchards or developing information on best management practices, to the technical, such as the creation of genetic markets and genetic maps for advanced genetic research. The HTIRC welcomes and encourages public input concerning their research methods and objectives.

-- Conserve and find hardwood germplasm. The HTIRC seeks to  understand how much genetic diversity exists for fine hardwoods, the geographic and temporal patterns that underlie the genetic resource, and the impacts of management and conservation of the germplasm. A very small sample of the germplasm for walnut and several other species is conserved at the Martell Forest, near West Lafayette, Indiana. The need for larger collections and more formal conservation programs with the HTIRC will be assessed.

--Restore and regenerate sustainable hardwood forests and riparian zones for production of forest products and maintenance of genetically diverse ecosystems. Much of the United States and European demand for hardwood lumber is currently met within the United States northern and central hardwood zones, and hardwood production has not shifted to developing countries in any significant manner. The time may come when this pattern of production for world markets can no longer be maintained because of decreased supply and the environmental consequences of heavy timber extraction on natural environments.

In the central hardwood region, water quality has been degraded by agricultural intrusion along waterways. Flooding has further degraded these riparian zones that include major rivers and their tributaries. A significant effort is being made to restore hardwood trees and other native vegetation in riparian zones. For the most part, unimproved trees are being used, and knowledge of how to restore these degraded areas is lacking, which has resulted in the failure of many a planting.

Funding for many conservation plantings comes from the Conservation Reserve Program (CRP), Conservation Reserve Enhancement Program (CREP), and Wetland Reserve Program (WRP). These programs currently account for the majority of hardwood tree planting and they are increasingly focused on improvement of water quality and wildlife habitat. The genetic characteristics of the trees being planted are unknown, and the potential exists for genetic failures as these plantings reach maturity.
Many consumers have not differentiated between the role of plantation forests and natural forests. They readily accept that agronomic crops are grown for the purpose of food production and consumption rather than for regeneration of annual vegetation. Trees, however, are often held in a unique esteem, and they are not valued differently if they are in an urban plantation or natural forest environment. If this does not change, plantations may not be accepted as the alternative method for growing highly productive crop trees that would allow the country to maintain natural forests and preserves for bio-diversity and recreation. These attitudes exist despite the fact that it would take only a marginal set aside of land currently in forestland cover to produce all of the wood necessary to meet human demands for wood consumption.

Develop recognized and respected science leaders in forest genetics. Several factors that contribute to the unusual opportunity that exists at the HTIRC to develop leaders in forest genetics. There are no other hardwood tree improvement research centers in the world and few individual hardwood research programs that have a mandate to satisfy a regional clientele and are financially supported to undertake a long-term program in tree improvement. In addition to its affiliation with Purdue University, the HTIRC is formally associated with The Donald Danforth Plant Sciences center in Saint Louis, Missouri, a partnership of the Missouri Botanical Garden, Monsanto, Purdue University, the University of Illinois, the University of Missouri-Columbia, and Washington University in St. Louis. Graduate students and other researchers at the HTIRC should benefit from access to the resources at these institutions. By becoming an internationally recognized center of excellence in hardwood forest genetics, the HTIRC expects to attract outstanding scientists and students from around the world who will extend the impact of HTIRC research.

The HTIRC will not be the single or sole institution performing hardwood research desired by the hardwood industry, nursery operators, government agencies, forest landowners, and general public. The region has many outstanding scientists who perform valuable basic and applied research on various species, and it will be essential that the whole hardwood scientific community remains viable to meet these research needs. In addition, the HTIRC will not employ pathologists, entomologists, biochemists, enzymologists, economists, and all of the other scientific disciplines that will be necessary for research collaborations to provide scientific data for evaluation of the ecological and environment fitness of HTIRC products. Productive working relationships with scientists from other institutions are necessary for the success of the Center.

WHAT ARE THE SPECIFIC STRATEGIC PLANS FOR THE HTIRC?

HTIRC has six (6) strategic directions:

1 .Improve the genetic quality and regeneration of fine hardwoods, including black walnut, block cherry, and northern red oak, through application of classical breeding, genomics, molecular markers, genetic modification, advanced propagation, seed production technologies, and silviculture.

2. Establish a highly credible hardwood genetics research center that will be recognized as a leader in forest genetics and there-by become a leading graduate education and training facility for future scientific leaders in forest genetics.

3. Hire and nurture preeminent scientists who will build the credibility of the research program and be highly competitive for federal research grants.

4. Establish the Martell Experimental Forest and Conference Center as a significant site for education and training of consulting foresters, nursery practitioners, and landowners in nursery management and hardwood culture.

5. Communicate, convey and market the work of HTIRC in order to be perceived as the preeminent international center for hard-wood genomics and biotechnology.

6. Secure funding for an endowment to insure long-term organizational stability, provide for operating support of the research pro-gram, and establish funded research positions with the Center.

WHAT OTHER PLANS ARE THERE FOR BLACK WALNUT RESEARCH?

Black walnut is an important focus on research at the HTIRC. The classical breeding is focusing on acquiring new germplasm of several kinds:

1.Outstanding trees selected from plantations.

2. Trees with possible resistance to anthracnose.

3. Trees with unusual growth or branching habits or unusual phenotypes such as cut leaves, etc.

4. Hybrid trees.

5. Trees with unusual grain patterns.

 
Controlled crosses to improve the growth and anthracnose resistance of the best breeding lines were made this year, and more will be made in the future. Half-sib progeny tests will also be an important part of the breeding program.

Scientists at the HTIRC are currently developing a saturated microsatellite (SSR) genetic map for black walnut. In collaboration with Dr. Jeanne Romero-Severson (Asst. Prof., Agronomy, Purdue University) and Dr. Chuck Simon (USDA/ARS/NCGR Davis, Curator and Research Leader) the scientist will use the map for tagging and ultimately cloning genes of interest, locating areas of cinergy between black walnut and other important species, and identifying quantitative trait loci (QTL) for marker-based selection and fingerprinting of block walnut selection. We have established a second-generation seed orchard isolated from wild black walnut pollen. The parentage and relatedness of selections from this orchard will be determined using SSRS, population parameters will be estimated, and pollen flow will be monitored. Progeny will be genotyped and the data used to identify QTL and to estimate the combining abilities of parents. SSRs will permit the HTIRC to perform genetic analysis with the power of full-sib families using inexpensive, plentiful, easy-to-obtain open-pollinated seed. The scientist will develop and transfer SSR protocols and practices for resolving ownership of timber and certification of the genetic identity of nursery and seed stocks.

It is not known if current nursery, silvicultural, and logging practices,

conservation strategies and land use decisions endanger or enhance the long-term genetic health of the black walnut resource. Scienfists at the HTIRC will evaluate the genetic impact of current logging, silvicultural, and nursery practices. These studies could potentially stimulate support for hardwood silviculture if it can be shown that the decline in quality of available walnut timber is more directly related to sub optimal management than genetic erosion from 'high-grading'. lnformation about genetic diversity within and among the States of the central hardwoods region will permit State nursery managers to understand the genetic consequences of current seed collection methods and facilitate regional collaboration. Microsatellite markets will also be used to sample the genetic diversity in the entire range of black walnut and to identify the location and status of unusual or unique genetic types. These studies will bring considerable refinement to existing seed zone recommendations and permit greater regional cooperation among state nurseries. Collaboration with public and private conservation groups will promote the identification of endangered populations and lead to more informed land use and conservation strategies. Characterizing the genomic diversity within black walnut will permit the breeding program to understand and capture hybrid vigor in this species.

The HTIRC is evaluating technologies (hedges, trellises, containerized rootstock) that reduce juvenility and the size of black walnut breeding stock and increase the precocity and productivity of crossing blocks and seed orchards. Progress in these areas should increase the yield and precocity of black walnut orchards.

The HTIRC has initiated research with the objective of increasing the quality of walnut with wavy or interlocked grain. Despite the potential value of hardwoods with wavy and interlocked grain, little is known about the genetics of this trait, although it is not believed to have a significant negative effect on growth. The scientist will incorporate spiral grain into a portion of the advanced breeding stock. The scientist will collaborate with Dr. Charles Michler (Director, HTIRC) in the collection of germplasm with wavy or interlocked grain. Jack Seifert (Director, Southeast Purdue Agricultural Center (SEPAC) has primary responsibility for the propagation and establishment of replicated trials to evaluate the effect of rootstock and environment on expression of spiral grain.Cyril  Bish (Prof Emeritus, University of Nebraska) and Boynton Merrill, walnut tree farmer, will collect pollen and seeds from trees known to have spiral grain. We will perform controlled crosses, propagate seedlings, and perform genetic analysis. We will also use SSR markers to verify parentage of seedlings from open pollinations and to locate the gene or genes revealed to have the greatest effect on spiral grain development. Dr. Daniel Cassens (Prof., Department of Forestry and Natural Resources, Purdue University), will analyze the wood from trees known to have spiral grain and their progeny to identify methods for detecting the earliest manifestations of spiral grain. Dr. Michler and Dr. Ron Overton of the HTIRC will be responsible for coordinating distribution of selected materials from nurseries, whether as seed, seedlings, or scion wood.

Keith Woeste and Charles Michler can be reached at USDA Forest Service, North Central Research Station, Hardwood Tree Improvement and Regeneration Center, 1159 Forestry Building, Purdue University, West Lafayette, IN,47907.

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