On-farm conservation of plant genetic resources for food and agriculture*

Abstract

Plant genetic resources for food and a griculture (PGRFA) are of critical importance to the food security of the present and future generations. They are the most fundamental of all resources on earth. They are threatened due to various fa ctors such as (i) replacement of landraces and farmers’ varieties by widely adapted improved varieties and hybrids 1 , which generally have genetic homogeneity and related pedigree, (ii) habitat destruction, (iii) developmental projects, (iv) infr astructural development, (v) alien -species invasion, (vi) mechanization of agricu lture, etc. Most of these thre ats have emerged as a result of development for overall progress and food security. In fact, erosion of genetic diversity, inclu ding that of ecosystems down to species level, started with evolution of agricu lture and got enhanced with formal plant breeding and the advent of high -yielding varieties. It needs to be unde rstood that once a cultivar is better than others, it is bound to be cultivated on a larger area. Thus, plant breeding itself adversely a ffects on-farm crop diversity, even though it is also a fact that genes from diverse g enetic resources are combined together in improved cultivars. It has now been realized that a balance between overall pr ogress and environmental protection and conservation and sustainable utiliz ation of PGRFA is urgently required to ensure food security of the present ge neration and for the future. There are several features unique to PGRFA, which have to be understood before their conservation issues are di scussed. The most important is that PGRFA are the result of conscious and unco nscious human intervention. The selection and improvement of PGRF A by farmers is going on since the origin of agriculture and the in situ diversity of these is co ncentrated in particular parts of the world. These so called ‘centres of diversity’ are largely located in develo ping countries. The association of crop species with human migration has led to the spread of many crops, varieties and genotypes to different corners of the world and they have continued to evolve both inside and away from their historic centres of dive rsity. Also, countries are interdependent with respect to PGRFA since most of the crops grown by them have originated/ domesticated elsewhere. Further, only a small portion of these resources has been collected and used in crop improvement; and PGRFA, in ge neral, are under-conserved and under-utilized. The activities related to conservation and utiliz ation of PGRFA have been carried out in parallel without adequate linkage and coordination, which has resulted in ove rlaps as well as gaps in resource conservation and utilization 2 . Several conventions and treaties like Convention on Biological Diversity (CBD), International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA) and Global Plan of Action (GPA) for conservation and sustainable utilization of PGRFA at the international level, have recognized the importance of these aspects of PGRFA. The GPA was adopted at Leipzig, Germany in June 1996 during the Technical Conference on Plant Genetic Resources. It focuses attention to the importance of PGRFA for world food security, and commits countries to implement the plan. One of the major activities of GPA is ‘in situ conservation and development’ that includes ‘supporting on-farm conservation and improvement of PGRFA’. Here we present our viewpoint on on-farm and conservation of PGRFA, in a narrow sense, that is conservation of locally adapted cultivars and landraces. Conventional conservation methods