Australia's genetic resources have been neglected. As in the case of our minerals, there is a need for a concerted program of exploration and research to identify and develop the resource. Conservation is also vital to protect our genetic heritage and maximise our contribution to the diversity of world agriculture.
In Western countries the "health food" industry is now a force driving the search for variety in foods. The vegetarian sector has been especially important in establishing a viable market for diverse plant foods in a trend that reflects the diversity of foods used by hunter-gatherer societies such as the Australian aborigine (Table 2, 3).
The need for diversity is readily apparent from a study of the countries of origin of the staple foods. Most are Mediterranean or tropical in origin (Table 1, 2, 4). Thus the majority of our domesticated world crops are plants that are poorly adapted to the arid zones of Australia and other developed and developing nations with large tracts of arid, irrigable land (Cherry 1985).
The present emphasis on marginal lands for agriculture is being exacerbated by the loss of fertile lands to urban, non farming use. In the United States of America 3 million ha of prime land have been lost to agriculture (Nabhan and Felgar 1985). To address these problems substantial international effort is now being devoted to developing new cropping systems for arid regions of the world (Gonzalez 1978; Hall et al. 1979; Manassah and Briskey 1981).
Other points concern the water use efficiency of temperate and tropical plants grown in arid environments, the so called "transplanted" crops (Evans 1980). Certainly there can frequently be a substantial gain in quality due to minimal infestation with pests and disease in arid environments but there is a cost. This cost is the mining of water, the disruption of hydrogeologic cycles and salinization of soils and aquifers; a problem with which Australia is already severely affected (Peck et al. 1983). It has been demonstrated that "transplanted" crops grown under these circumstances use 20% to 40% more water to produce yields equivalent to those produced in more humid climates (Pimental et al. 1982). To complete the argument we have the viewpoint that "transplanted" crops have reached their physiological limit of yield (Austin et al. 1980; Evans 1980). There is the prospect also of global warming and a vastly altered climate that may need to be dealt with in the foreseeable future (WMO 1986).
Arguments in favour of a concerted effort to develop new crops are: (1) a depauperate range of foods in a diverse and populous world; (2) changing markets and demand for new products to meet special interest groups; (3) loss of prime farming land and drift to marginal lands unsuited to existing crops; (4) depletion and degradation of water resources; (5) poor water use and nutrient use efficiency of present day crops; and (6) diminishing returns to breeding with existing crops.
The debate is developing now in order to define appropriate strategies to meet items 3 to 6 listed above; marginal lands, water resources and plant improvement. Alternative plant breeding strategies include introgression from wild relatives (Borlaug 1983) and the application of biotechnology to the insertion of foreign genetic material from whatever source seems appropriate (Qualset 1982; Barton and Brill 1983; Austin, 1988). However attractive these strategies are, another option deserving of equal attention is the domestication of minor crops, their wild relatives, and traditional wild foods (National Academy of Sciences 1975; Nabhan and Felgar 1985).
Some of the key figures in early plant exploration and distribution of genetic resources were Sir Joseph Banks, Ludwig Leichhardt, and Baron Sir Ferdinand von Mueller (Table 5). Baron von Mueller's investigations and writings on the economic flora (Mueller 1879-84) were largely responsible for the establishment of eucalypt oil producing forests and factories in France, Portugal, Brazil, South Africa, and USSR (Elliot and Jones 1983).
The very intensity of the early harvest indicates the level of financial reward available to the avid collector and nurseryman. Elliot and Jones (1983) recorded 286 species exported to England both to botanic gardens and to private nurserymen (Fig. 1). Much of the botanic garden material was extended to private nurseries for subsequent sale to the public. These figures clearly understate the level of collecting because Leichhardt (1847) alone collected some 200 species. Nevertheless the figure indicates those species which met the combined criteria of desirability and suitable agronomic characteristics.
In recent times Elliot and Jones noted that one Midland nursery advertised some 300 species of Australian plants for sale while a second nursery had 125 species for sale. One Irish gardener, presently cultivates more than 50 species of eucalypt in a cool temperate environment indicating the adaptability of the flora (D. Robinson, pers. commun.), diversity rivaling that available in any retail or wholesale nursery or garden in Australia.
The history of export to America is even more dramatic (Fig. 2) with nearly 800 Australian species now in cultivation (Elliot and Jones 1983). Many of these came via England as exchange material from Botanic Gardens although Baron von Mueller was very active in responding to a request for aid in providing advice for plants to rehabilitate the gold fields and provide on-site fuel and building materials. This he did, apparently in return for the U.S. Senate undertaking to publish his writing on the subject and to provide him with 50 copies (Elliot and Jones 1983).
The trade in "bush-picked" wildflowers and plant products is further evidence of the value of Australian genetic resources (Burgman and Hopper 1982). Data collected by the Department of Conservation and Land Management shows that about 21 million stems and about 4 tonnes of seed was harvested in 1980-81. At an average of 20 seeds per gram (guesstimate), this represents about 80 million seeds per annum at a cost of less than 1 cent each, a vastly greater scale of export than that undertaken by Botanic Gardens in their exchange programs. The range of species harvested is another important indicator of resource value and this has been as high as 1,119 (Rye et al. 1980).
Thus the number of species which are exploited presently is in the order of one to two thousand, about 8% of the total resource of 25,000 species. Probably no other continent has such a high proportion of its floral genetic resources being exploited commercially. It is important to note that no food plants are specifically included in the list of presently exploited plants.
The diversity of foods used regularly by Australian aborigines is apparently far greater than that of Western societies (Table 2). Many fall into minor use categories (Peterson 1978). An estimated 207 species have been inventoried as aboriginal food plants (Table 3). This compares to 94 world food crops, many of which are also of minor use (Simmonds 1976).
The list of aboriginal food plants in Table 2 still understates the variety of foods in use. For example, Pate and Dixon (1982) list 36 species of Western Australian geophytes as being used for food (out of a total of 204 species) and Crawford (1982), in his investigation of the Kalumburu area of Western Australia, lists 39 species of food plant not included in Issac's (1987) account. The complete list is undoubtedly very extensive (Latz and Griffin 1978; Henshall et al. 1982).
The variety of edible foods contrasts markedly with the opinion of early explorers such as Burke and Wills (Anon. 1961) and early settlers, who considered the bush as a desert land lacking food resources. Leichhardt (1847) and Grey (1841) showed much more interest in "bush foods" but the early attitudes persist unto the present day. Maiden (1889), supported Hooker's quote that "the products of many plants although `eatable' are not 'fit to eat' and would never be employed as food except in the direst necessity," a view supported also by Pate and Dixon (1982).
This view is now changing and available evidence suggests strong selection in many existing crops for palatability and wholesomeness against an unpalatable and toxic background (Heiser 1981). We should take up the challenge of evaluating those judged most worthy by the aboriginal people themselves in collaboration with agronomists. Participation of aboriginal peoples is important from pragmatic, practical, and social viewpoints.
Figure 3 outlines the interaction between research programs that should be carried out to successfully domesticate any unimproved wild species. The industry is presently founded on the "Eureka" syndrome which represents the search for immediately useful plants from the "wild." This is appropriate at the outset but as Fig. 3 shows, we are likely to ignore a substantial proportion of the useful genetic resource by such a superficial approach. Views on appropriate species and technologies have been presented by authors such as Latz and Griffin (1978), MacConochie (1985), and Maggs (1978).
In floriculture, the job is easier and hence the rapid and broadly based industry development (in terms of number of species). This is because the criteria for floricultural uses at the "novelty" level are not rigorous. If we are to produce a product of real world significance then it must be competitive in all agronomic, floricultural, and postharvest traits. Of these, development of technologies to control flowering is perhaps the most urgent item for the existing cultivars. This has been the key to the success of the rose, the carnation, and the chrysanthemum. For the desirable but as yet uncultivated species, developing selections that possess good agronomic characteristics may be the high priority issue. For any, development of a clear market strategy is vital.
The present industry is based on novelty and diversity. A concerted effort will be needed to develop a flagship product, one that will broaden the market base for floriculture as a whole and establish itself as a market leader along with roses, carnations and chrysanthemums. This is unlikely to be a banksia or a waratah but it may be a bush rose.
|Seeds & pods||4||4||0||3||1||12|
Seeds & pods
Acacia coriacea, A. maritima, A. sophorae, A. stenophylla, A. tunida, Araucaria bidwilli, Avicennia marina, Beilschmiedia bancroftii, Canarium australianum, Elaeocarpus bancroftii, Endiandra palmerstonii, Etada phaseoloides, Eucalyptus gamophylla, E. leptopoda, Hicksbeachia pinnatifolia, Hovea spp., Linum marginale, Lotus australis, L. corniculatus, Macadamia integrifolia, M. tetraphylla, Mallotus nesophyllus, Nelumbo nucifera, Nymphaea spp., Pandanus spiralis, Santalum acuminatum, Stercularia quadrifida, Terminalia grandiflora.
Leaves & buds
Allocasuarina verticillata, Alpina spp., Calamus caryotoides, Calandrinia balonensis, Disphyma clavellatum, Erythrina vespertilio, Hibiscus heterophyllus, Lepidium muellerii, Lepidium spp., Livistona australis, L. eastonii, Lomandra longifolia, Portulaca oleracea, Typha spp.
Eremophila latrobei, Grevillea eriostachya.
Cymbidium caniculatum, Hornstedtia scottiana, Leichardtia australis, Leichardtia spp., Marsdenia viridiflora, Tamarindus indica.
Stems & pith
Cymbidium canaliculatum, Hydriastele wendlandiana, Livistona humilis, Nymphaea spp., Ptychosperma macarthurii
Cyperus bulbosus, Hypoxis marginata, Microstema tuberosum, Nymphaea spp.
Blechnum indicum, Nelumbo nucifera, Typha spp.
Anguillaria dioica, Aponogeton elongatus, Arthropodium milleflorum, Bulbine bulbosa, Cartonema parviflorum, Dioscorea bulbifera, D. hastifolia, D. transversa, Eleocharis dulcis, E. sphacelata, Gastrodia sesamoides, Geodorum neoncaledonicum, Hypoxis hydrometrica, Operculina brownii, Orchidaceae, Portulaca pilosa, Pterostylis barbata, Triglochin procera
Alpina spp., Ampelocissus acetosa, Arthropodium strictus, Boerhavia diffusa, Brachychiton populneum, Buchanania spp., Curcuma australasica, Dianella spp., Eriosema chinense, Erythrina vespertilio, Flemingia involucrata, Geranium solanderi, Ipomoea costata, Ipomoea spp., Lotus australis, L. corniculatus, Microseris scapigera, Murdannia graminea, Thysanotus tuberosus, Vigna lanceolata,
Meals (paste or gruel)
Acacia aneura, A. coriacea, A. cowleana, A. estrophiolata, A. kempeana, A. ligulata, A. murrayana, A. notabilis, A. pyrifolia, A. tetragonophylla, A. victoriae, Chenopodium rhadinostachum, Dactylotenium radulans, Eragrostis dielsii, E. leptocarpa, E. eriopoda, Oryza spp., Panicum australiense, P. decompositum, P. effusum
Alocasia macrorrhiza, Convolvulus erubescens, Curculigo ensifolia, Cyathea spp., Dicksonia antarctica, Eucalyptus microtheca, Marsilea drummondii
|Number of plant species|
|Food type||Australian |
|Leaves & leafy buds||14||10|
|Seeds & seed pods||28||12|
|Family||Crop||Center of diversity|
|Poaceae||Barley||Middle East/Asia Minor|
|Sugar cane||New Guinea|
|Pome fruit||Asia Minor/China|
|Stone fruit||Central Asia/China|
|Solanaceae||Pepper||Central & South America|
|Sir Josephs Banks and Daniel Solander||1770||Official||England|
|Leschenault de la Tour||1801||Official||France|
|Anon.||ca. 1850||Private||United States|
|U.S. Consulate General||1860||Official||United States|
|Fig. 1. Number of species of plant recorded in England from 1770 to 1880 (Elliot and Jones 1983). This data does not include the major exports for timber and essential oils which occurrred in the second half of the 19th century.|
Fig. 2. Number of Australian plant species in cultivation in the U.S. (Elliott and Jones 1983).
Fig. 3. Diagram illustrating the steps in adaptating a new species of plant. The shaded boxes indicate the steps that are often overlooked by collectors (adapted from Simmonds 1979, with permission).