The Rhododendron Collection at the University of British Columbia
Roy L. Taylor, Director
The Botanical Garden of The University of British Columbia, Vancouver, B. C.
This paper was presented at the 1974 Annual Meeting of the Society
held in Portland, Oregon
I would like to take the opportunity this morning to talk to you about one of our major developments at the University of British Columbia Botanical Garden; namely, the establishment of the Rhododendron Species Collection. Mr. Jock Brydon has already talked to you about the recent developments of the Rhododendron Species Foundation and the future movement of this collection to its permanent home at the Weyerhauser Corporation headquarters near Tacoma. This is an important development for it is necessary to have more than one site for establishment of permanent collections of rhododendrons in this region. This, I am sure, was made most evident during the last five years when various regions of the Pacific Coast have been subject to extreme temperatures and varying periods of drought. The variation in our weather patterns was most explicitly illustrated in 1972-73 when our lowest temperatures in Vancouver, British Columbia, were higher than those at Berkeley, California.
I would like to discuss some of the rationale that underlies the development of a species collection. Such collections form part of a long-range objective to provide for the development of new rhododendron horticultural entities through plant breeding programs. Plant breeding is really the evolution of plants at the will of man and like all evolution is dependent upon the variation that one finds in the material you are using.
Many decades have passed now since some of the early plant collectors made their extensive forays into areas such as southeast Asia and collected many of the genotypes of rhododendrons that have been so important to the development of our ornamental material today. These early plant collectors recognized the importance of collecting variation but they also realized that not all variation could be transmitted to the gardens in Europe. Fortunately, rhododendrons, as out-breeders, do provide a substantial amount of variation when collected in the form of seeds from material growing in natural sites. Seeds resulting from out crossing possess considerable variation which is displayed in their progeny; therefore, collections of seeds from native habitats of rhododendrons are a relatively easy way of ensuring the capture of considerable variation.
The early plant explorations correspond to a stage in general plant taxonomy and systematics that could be called exploratory or is sometimes termed alphataxonomy. This stage in the scientific study of flowering plants was concerned with the exploration, collection and description of new materials. With increased sophistication of our transportation and communications systems, the exploration phase was soon replaced by a more contemplative stage; namely, the development of major catalogues and floras of regions, the age of floristics. This in turn has been largely replaced by an attempt by the systematists to study in detail specific groups of plants and their interrelations. This change in intensity of research by the taxonomist and systematist has resulted in the development of extensive monographs of groups of plants based on new methodologies and disciplines such as genetics (see Phillipson and Phillipson, 1972). Today we can add other fields such as modern biochemistry or chemosytematics (see Reynolds et al., 1969), electron microscopy (see Taylor, 1972), tissue culture and even cell hybridization. I have diverged briefly into this discussion of the development of the scientific program that parallels our ornamental plant breeding programs because it does provide an insight into the overall decrease in the general collection and establishment of variation in our plant materials during the past two or three decades. One could say it is no longer the "in thing". This is particularly true for the genus rhododendron as I believe there has been less emphasis placed on the accumulation of new native variation in the genus in the past 30 years as there was in the preceding 30 years.
This then brings us to the discussion of the establishment of specific collections of rhododendrons, particularly those of species which provide the baselines and foundations for our breeding programs. Indeed, if we are going to continue to pursue the development of new and interesting forms of rhododendrons for the use and pleasure of not only ourselves but the general public, then we must be prepared to devote both energy and financial commitments to the establishment of special collections of the genus to provide basic gene pools. Such gene pools will provide the genetic material for the establishment of new breeding programs and will bring together much material which can be used for comparative purposes in breeding programs.
Much interest has been expressed during the past 10 years in the establishment of gene pools as important genetic resources for plant breeding programs. The International Biological Program focused attention on problems related to the genetic resources in plants and a handbook has been produced by the IBP that is entitled "Genetic Resources in Plants: Their Exploration and Conservation," edited by Frankel and Bennett (Frankel and Bennett 1970). This handbook, first published in 1970, is well worth reviewing for it does specifically attempt to circumscribe the many problems that relate to our plant resources, particularly those that have been important to our economic development in agriculture. In the introductory remarks by Professor Frankel, he has given a number of recommendations which resulted from the United Nations Food and Agriculture Organization IBP Conference of 1967. In summarizing these recommendations, one could say that a principal goal of establishing gene pools would be the need to determine the location and nature of our genetic resources and the establishment of the priorities and plans for future explorations to obtain new materials. In addition to surveying and discovering new materials there is a similar urgency in surveying material in existing collections. Professor Frankel points out that there is little purpose in assembling material unless it is effectively used and preserved. The efficient utilization of genetic resources requires that they should be adequately evaluated and classified. Such programs would indeed involve the need for documentation at all stages so that the collections can be used both now and in the future. Programs, such as the development of gene pools, concern plants distributed throughout the world, and can only be achieved through international cooperation and coordination. Specific conservation of native materials must be achieved through cooperation of local jurisdictions but can be encouraged through international participation.
There is no question in my mind that rhododendrons from an ornamental and horticultural point of view clearly need to be part of the world genetic resources program. It is for this reason, as well as others, that when the new program for the Botanical Garden at The University of British Columbia was initiated five years ago based on the theme 'Plants and Man', the establishment of a Rhododendron Species Collection ranked as a high priority. Rhododendrons exemplify in a most spectacular way the interrelationship between plants and man, for man has certainly been most important in the manipulation and development of new forms and at the same time the plants have given man great pleasure.
In considering the establishment of the Rhododendron Species Collection at the University, several aspects were considered (see Taylor 1973 a and b). First, the site in a general sense represents a climatically acceptable region for the development of temperate rhododendrons. We have suitable weather conditions for the growing of most of the temperate species and some of the less hardy forms can be grown providing some protection is given. The initial stimulus for the garden had already been made at the University through the generosity of Mr. and Mrs. Ted Grieg of Royston Nurseries on Vancouver Island. This initial collection formed the basis for the development of the species collection and it was augmented through the generosity of Dr. Leon Koerner, a benefactor of the University and rhododendron lover. The program really began its active development after this initial start through the cooperative arrangement with the Rhododendron Species Foundation This new foundation had been recently established through the efforts of many rhododendron growers in the Pacific Northwest, but principally through the activities and dogged determination of Dr. and Mrs. Milton Walker of Portland. As an aside it is interesting to note that the stimulus far this Rhododendron Species Foundation was the result of the purchase of a Rhododendron strigillosum by Dr. Walker, the price tag indicating a plant of some note and renown. The plant had a very good "pedigree" and Dr. Walker was quite sure that he had purchased a real find. When this extraordinary plant produced its first trusses in the following spring, to and behold it appeared that it was not what had been expected. The unfortunate event confirmed a nagging doubt that had troubled Dr. Walker for some time. This incident strengthened his decision that there was a need for the development of a species foundation which would promote and indeed eventually demand that material being sold was not only authentic but well documented. The University of British Columbia was asked to participate with this new program by providing the propagation facilities for the material which was gathered from the principal rhododendron collections in Great Britain. This program has been a most useful one for the continued expansion of both the species collections.
In the last few years we have been actively pursuing new acquisitions through other contacts with gardens throughout the world. We have been assisted in this program by a grant from the Vancouver Chapter of the American Rhododendron Society, and through the interest of the members in our program.
I have recently been involved in the development of a program for a National Botanical Garden System for Canada (see Taylor 1973 c). Included in this program is the provision for the establishment and maintenance of principal plant collections that are of economic value or of horticultural interest. This program has recently been reviewed by the federal government and it is my understanding that the draft of this proposal to the Cabinet will soon be made asking for support for the establishment of this program. This is an important development for it does provide both financial assistance and assurance of continuity of collections that judged by a National Botanical Garden Council as being important to the horticultural interest of Canada.
Another aspect of the development of the species collection has been the establishment of a documentation system which will enable information associated with the collection to be stored and utilized by plant breeders. Our accession system at The University of British Columbia (see Taylor et al., 1973) is modeled in part on the Plant Records System of the American Horticultural Society (see Brown 1973), and is completely computerized. The information contained in our system can be easily transmitted to the Plant Records Center and incorporated in the international data bank now functioning at the new AHS Headquarters at Mount Vernon. Each of our plant collections is provided with a three-part number (see Taylor, 1973 d). The first five digits correspond to a unique plant number given to that particular collection. The next three digits relate to the source of the material and the final two digits correspond to the year in which the accessioned material was established in the garden program. In addition to this basic information many other specific pieces of information are recorded about each collection. We like to know the specific geographical location of the collection site of the material or its natural range and we maintain propagation records when material is propagated noting specifically any special treatments that have been used in the program. This initial assessment provides the standard documentation that accompanies the plant throughout its life history in the Botanical Garden. In addition to the basic records we have an inventory and assessment program based on the ARS program. I was particularly pleased to see the write-up in a recent bulletin on the inventory and assessment of rhododendrons (see Ford and Hoitink 1974). Such information provides important resource material for response to public inquiries. In addition, it is through documentation, inventory and assessment that material is garnered thus facilitating the development of special reports and publications on the suitability of rhododendrons for specific areas and inclusion in breeding programs.
These several aspects, which I have discussed in general terms, have served as the basis for the development of our species collections at the University. We have had some special problems related to the propagation of our collection. The collection is not without Phytophthora and we have tried to reduce the effects of this soil born pathogen by careful management of the collection. This management program has been facilitated by the establishment of soil moisture recording devices placed throughout our collection to enable more careful monitoring of the soil moisture levels. We have also been attempting to assess the relative need for shade and sun for each of our species as well as media requirements. The species do react differently to environmental stresses from one region to another and a species collection can provide important documentation and information for local or regional growers. Of interest is the relationship of rhododendrons to other woody species. To determine compatibility of rhododendrons to other woody plants, when they are grown together in a collection, considerable time and many trials must be conducted. Many of the problems associated with the development of a species collection require not only careful planning but patience.
The species collection at U. B. C. is being used in a number of ways. We are in the process of developing a major propagation program of the mother plants to provide material for a 26-acre site which is to be devoted to the display of rhododendrons and Asian woody materials. In addition we participate in collection of seeds and make pollen freely available from many of our species to plant breeders. The propagation of material of the species is being distributed to the Vancouver Chapter of the American Rhododendron Society. The Chapter has established a committee which works with our garden program to select new material for the collection and assist in the distribution of the propagated material made available by the Botanical Garden. We hope to develop a very active distribution program by this means and I hope that it will indeed strengthen not only the Botanical Garden's program but also the Chapter's activities as it relates to species. We have also had the Vancouver Chapter of the American Rhododendron Society develop a species study group which utilizes the collection. In addition to our local programs, we continue to maintain an active international seed exchange program with over 500 institutions. Living material is provided for specific research programs and to augment collections at other botanical gardens. We anticipate that these programs will continue to form an important utilization of our species collection.
I would like to say a few words about the future of the Rhododendron Species Collection at the University. A recent inventory indicated that the present holdings consist of 314 species and 797 different accessions representing more than 3000 documented plants. This collection will be increased through acquisition of new materials. We hope to become more active in the future in the introduction to our collection of new variation from natural wild populations. This will entail onsite collections both through specific survey parties or through increased cooperative international programs, particularly with governments such as those of China. In the next few years we anticipate an increased utilization of rhododendron species as display materials in our own garden program, and particularly in the gardens of the Vancouver Chapter of the American Rhododendron Society. We intend to continue our close cooperation with the members of the ARS through our Vancouver Chapter and also through our active participation and exchange materials with the Rhododendron Species Foundation at Tacoma. I think the future for rhododendrons in the Pacific Northwest region looks bright and I am certainly optimistic that within the next decade we will achieve an outstanding collection of rhododendron species in this region.
Brown, Richard A. 1973. Plants in the Computer - American Horticultural Society Plants Record Center. American Horticulturist 52(4): 36-42.
Ford, John E. and J. A. J. Hoitink. 1974. Standards for Evaluation of Rhododendron Hybrids in Test Gardens. Quarterly Bulletin American Rhododendron Society 28(1): 25-29.
Frankel, O. H. and E. Bennett, eds. 1970. IBP Handbook No. 11 Genetic Resources in Plants - Their Exploration and Conservation. Blackwell Scientific Publications, Oxford and Edinburgh.
Philipson, W. R. and M. N. Philipson. 1972. A History of Rhododendron Classification. Notes from the Royal Botanic Garden of Edinburgh. 32(2): 223-238.
Reynolds, T., S. M. Smith and P. A. Thompson. 1969. A chromatographic survey of the anthocyanin types in the genus Rhododendron, Kew Bulletin 23(3): 413-437.
Taylor, Roy L. 1972. Rhododendron Pollen. Davidsoma 3(1): 1-3.
Taylor, Roy L. 1973a. Introduction to the Rhododendron on Campus. Davidsonia 4(2): 11-13.
Taylor, Roy L. 1973b. Rhododendron Species-A Developing Collection at UBC. Davidsonia 4(2): 14-15.
Taylor, Roy L., Chairman Writing Committee. 1973c. A National Botanical Garden System for Canada. Special Study prepared by the Organizing Committee for N.B.G.S.C. for the Ministry of State for Science and Technology.
Taylor, Roy L., 1973d. What does that label mean? Davidsonia 4(2): 22 23.
Taylor, Roy L., Stephen Sziklai and Annie Y. M. Cheng. 1973e. UBC Botanical Garden Accession System (BGAS). Technical Bulletin No. 2, The Botanical Garden, The University of British Columbia, Vancouver.