Author: A. K. Trivedi
ICAR - National Bureau of Plant Genetic Resources
Regional Station Bhowali â€" 263 132, District â€" Nainital (Uttarakhand)
Introduction
Agro- biodiversity is a component of biodiversity which is the combination of life forms and their interactions with one another and with the physical environment which has made the earth habitable for humans. Plant genetic resources for food and agriculture (PGRFA) are the back bone of global food security. They comprise diversity of genetic material available in traditional varieties, modern cultivars, crop wild relatives and other wild species. Available genetic diversity provides the options to develop, new and more productive crops, through selection and breeding, which are tolerant/ resistant to various abiotic and biotic stresses and adapted to changing environments. Whether they are used in traditional farming systems, conventional breeding, or new biotechnologies, plant genetic resources are the foundation for sustainable agriculture and global food security now and in the future. The ability of certain varieties to withstand drought, grow in poor soil, resist an insect or disease, give higher protein yields or produce a better tasting food are traits passed on naturally by the genes present in that particular plant genetic resource. This genetic material constitutes the raw material that plant breeders use to breed new crop varieties. Without genetic diversity, options for long-term sustainability and agricultural self-reliance are lost. Further wild species of crop plants and their relatives are the source of many genes imparting resistance against many disease pests and abiotic stresses. They are also source of genes that determine quality and other attributes.
To fulfil the ever increasing demand of food, better understanding and management of plant genetic resources is essential. Genetically uniform modern varieties are replacing the highly diverse local cultivars and landraces in traditional agro-ecosystems. Changes in land-use pattern are significantly affecting diversity of the wild species. Globalization, industrialization, urbanization, changing life styles and market economies are contributing indirectly to the loss of diversity, particularly of minor and neglected crops. Therefore, available germplasm ought to be conserved. Germplasm conservation requires proper collection to capture maximum variation. Afterwards, conservation and regeneration of collected germplasm is required to minimize losses through time.
Figure 1. Components of Plant Genetic Resources
Germplasm collection
Germplasm collection involves gathering samples of a species from populations in the field or natural habitats for conservation and subsequent use. The unit of collection may be seeds or vegetative propagules, depending on the breeding system of the species. Collection is easy in species producing small seeds in abundance. However, it becomes problematic when seeds are unavailable or non-viable due to damage of plants by grazing or diseases; large and fleshy seeds that are difficult to transport; or where samples are not likely to remain viable during transportation due to remoteness of the collection site from the genebank.
Germplasm conservation
Collected Plant Genetic Resources can be conserved by two methods, namely in situ and ex situ. In situ conservation involves maintaining genetic resources in the natural habitats where they occur. In this method wild and uncultivated plant communities are conserved in their natural habitat and crop cultivars in farmers’ fields as in the traditional agricultural systems. Ex situ conservation involves conservation outside the native habitat. It is usually used to safeguard populations in danger of destruction, replacement or deterioration. Approaches to ex situ conservation include methods like seed storage, field genebanks and botanical gardens. DNA and pollen storage also contribute indirectly to ex situ conservation of plant genetic resources. Among the various ex situ conservation methods, seed storage is the most convenient for long-term conservation of plant genetic resources. This involves desiccation of seeds to low moisture contents and storage at low temperatures.
On-farm conservation
On-farm conservation is in situ conservation of plant genetic resources at farmer’s field. It ensures involvement and active participation of farmers and local people in conservation of plant genetic resources. Hence land races useful for local community and suitable for local climate are conserved for long time. On-farm conservation of plant genetic resources requires a recognition that farmers control the decision making process; and that conservation is concerned with the maintenance of the capacity of crop plants to change and adapt. Good participatory practices strengthen local capacity to manage on-farm conservation. Good practice is a system or process, which, over time maintains, enhances and creates crop genetic diversity, and ensures their availability to and from farmers and other citizens for improved livelihoods on a sustainable basis. For community-based on-farm conservation some practices are considered as good such as; participatory extent, distribution analysis, social seed networks, participatory community sensitization, diversity fairs, diversity blocks, diversity kits, community biodiversity register as well as participatory plant breeding etc.
Farming communities are maintaining considerable amounts of genetic diversity for food and agriculture in some cases reason may be economic inability to purchase modern varieties but in turn it enhances agro-biodiversity conservation. Local knowledge and culture can be considered as an important part of agro-biodiversity conservation. It is, therefore, crucial to understand local circumstances (i.e., local crop diversity, local knowledge, local customs, local food culture, local seed system and local institutions) before promoting on farm conservation in a particular area. Within a community some farmers are maintaining and conserving relatively more diversity, they play important role in informal social seed networks. Such farmers should be promoted through government assistance in developmental activities. On-farm conservation is community-based hence community participation is essential in this process. Sensitization of farming community can be used to enhance community participation. A community may be sensitized through village level workshop, traditional food fair, lok geet (local songs), road side drama etc.
Farmer's choice for conservation
Farmers choose to maintain the landraces they value by planting the seed, selecting the seed from the harvest or exchanging it with other farmers, and replanting. Their choices determine whether or not genetic resources of social value for crop improvement continue to be grown in situ. Farmers may cease growing landraces if changes in the production or marketing environment cause them to lose their relative value. Maintaining diversity of any land race by farmers indicates that the land race is valuable for that particular agro-climatic condition because farmers continue to grow land races beneficial to them in resource crunch condition. Moreover, it is also important to understand options for cultivation of modern varieties because in some crops released varieties are not available for a particular production environment. Farmers adopt two choices either to shift less divers land race or to modern variety, both cause genetic erosion.
The status of crop diversity in the farmer's field is mostly measured by counting farmer-named varieties. It has been observed that there is consistency between farmers’ naming of varieties and that of on the basis of agro-morphological and biochemical characterization. For farmers, genetic diversity in the field means varietal diversity, which they can clearly distinguish on the basis of agro-morphological traits, phenological attributes, postharvest characteristics and differential adaptive performance under abiotic and biotic stresses.
Value of conserved landraces
The value of landraces lies in their evolutionary potentials and future use in plant breeding. Because the social benefits of conserving genetic resources are often obscure, widely spread and not fully fetched by farmers. Assessing values and costs of conserving evolutionary potential of genetic resources provides a basis for determining the total value of any genetic resource in traditional farming systems. When varieties such as landraces are not traded on markets, farmers’ perceptions of their importance can be used as indicators of their perceived private value to them. Although the potential public value of these landraces as rare, diverse and adaptable genetic resources cannot be accurately predicted. Breeders’ and conservationists’ perceptions of the relative distinctness of varieties can be used as perceived public value. The varieties with both the highest current use value (private value to farmers) and the greatest potential value (public value to society in general) are those that cost least to conserve on farms. But need is to promote and support the land races with rare public value but farmers are investing in diversity conservation of such land races. Therefore, in the current scenario on-farm conservation need to be promoted to ensure food security.
Identifying locations and households for conservation
For long term on-farm conservation of crop genetic diversity suitable locations should be identified where farm households have a high probability of cultivating landraces. In such sites incentives for diversity conservation can be created to the households. The proportions of households growing diverse, rare and adaptive landraces are comparatively higher in the remote villages as compared to villages located near towns and road side.
Impact of farmers networks in on-farm conservation
In on-farm agro-biodiversity conservation as well as utilization farmers' informal seed systems play a significant role. In this informal seed system farmers' networks are important component through which seed and other genetic materials flow among the farming community members. Along with the material flow, knowledge-based information is also disseminated from farmer to farmer through similar networks. So with the help of associated indigenous technical knowledge recipients utilize material properly. A network is usually dynamic in nature, which may change over time due to various factors that influence the social structure of a community. For any intervention to be effective, it will be important to determine stability of the networks over time. Stable network will be useful in informal seed systems for conservation and utilization of plant genetic resources.
Participatory plant breeding (PPB) as a new crop improvement approach
Participatory Plant Breeding (PPB) is a process of involving scientists and farming communities in breeding activities in order to increase the value of crops by improvement of their genetic material. In order to encourage on-farm conservation farmers should be involved in plant breeding and varietal selection programme. Presence of plant breeders in this process will make it worthy. It is a selection of segregating lines by farmers in collaboration with breeders in their target environments using their own selection criteria. It may be used as a method to create new varietal diversity for the targeted environment. It is expected that it will be successful in producing a farmer acceptable variety than produced through conventional breeding programme. This is because selection is done in the target environment and under actual management conditions of farmers. PPB basically helps to develop farmers’ varietal choice and to disseminate technology faster. Successful implementation of PPB may have social, economic or genetic benefits, in both long and short term aspects.
Peoples' Biodiversity Charter (PBC) as a tool to monitor local crop diversity
There are different methods to document the knowledge base on genetic resources held by local communities such as Peoples’ Biodiversity Charter, Community Seed Register and Village Community Register. The purpose of PBC is to build capacity of local institutions to manage information at community level for on-farm management of agro-biodiversity for social, economic and environmental benefits. PBC refers to "a record, kept in a paper or electronic format by community members, of the genetic resources in a community, including information on their passport data, agroecology, cultural and use values. It helps to access the information and crop seeds, market and seed networks, document status of crop resources with reasons for maintenance, in describing ecology and diversity with area-specific needs.
Strengthening on-farm conservation through a community seed bank
Small scale farming households need different types of seeds to allow for varied physical environments, to benefit from the many end uses of each crop and as a coping strategy for complex, diverse and risky environments. Certain landraces are maintained because of their religious and cultural significance in specific communities. But due to unavailability of seeds of these land races farmers choose the modern varieties. The community seed bank will lead to sustainable local seed security. It will fulfil the community’s requirement for quality landrace seed and will help to increase farmers’ access to quality seed as a means of conserving local crop diversity to maintain on-farm. This approach is based on indigenous knowledge and is low cost, managed by the local community.
Importance of home gardens in on-farm conservation
Home garden refers to the traditional use of land around a homestead where several species of plants are grown and maintained by the household members and their products are primarily intended for family consumption and utilization. Home gardens are used as traditional sources of food and nutrition. These are important contributors to food security and livelihoods of farming communities. Home gardens are typically cultivated with a mixture of annual and perennial plants that can be harvested on a daily or seasonal basis. Home gardens, with their intensive and multiple uses, provide a good safety net for these households during food deficit periods. These gardens have been important sources of food, fodder, fuel, medicines, spices, herbs, flowers, construction materials, income and are important means of on-farm conservation of a wide range of plant genetic resources.
Awareness Programs
Community participation is vital to on-farm conservation and in the use of local agro-biodiversity. A community will conserve agro-biodiversity if they know the importance and value of material conserved. Farmers and farming communities may not be aware of the benefit of the local agro-biodiversity they have. Therefore, it is important to create awareness and sensitization of farming communities on the value of agro-biodiversity as well as need for its conservation. Awareness adds value to the local crops and makes farming communities, consumers, development workers, and policy-makers conscious of conservation and utilization of local agro-biodiversity. There are different methods to make aware and sensitize community for conservation of agro-biodiversity such as personal contact, group approach and mass media approach. Mass media approach is most cost effective and reaching to large population. Among the different means of mass media, radio broadcasting is the fastest and most powerful means of reaching large areas and masses of rural people at a time. Therefore, farming communities may be easily sensitized about on-farm conservation through radio broadcasting in local language.
Conclusion
Conservation of agro-biodiversity is essential for the future generation. It is crucial to food production; but these resources have been eroding at an unprecedented rate as a result of introduction and promotion of modern varieties and cash crops. Along with these important resources of mankind, the traditional knowledge of cultivation, management and use associated with them are also in serious threat of extinction. In view of the farmers’ knowledge and their contribution in management of agro-biodiversity, on-farm conservation may be a boon to conserve plant genetic resources for food and agriculture for future generations. Therefore, there is an urgent need to promote on-farm conservation of agro-biodiversity in the farmer’s field.
About Author / Additional Info:
Senior Scientist, ICAR-National Bureau of Plant Genetic Resources, Regional Station Bhowali