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UKAID Department for International Development (R4D) 1999

Modelling gene flow to assess the risk to biodiversity in traditional cropping systems : a case study with pigeonpea

Biodiversity Pigeonpea

UKAID Department for International Development (R4D)

Titre : Modelling gene flow to assess the risk to biodiversity in traditional cropping systems : a case study with pigeonpea

Pays : India

Projet de recherche pour le Développement : R7261(C)

DFID Programme : CGIAR Competitive Research Facility and Holdback Funds

Organismes de mise en œuvre  : Lead Institutes : International Crops Research Institute for Semi-Arid Tropics (ICRISAT) ; School of Biological Studies, University of Birmingham ; University of Birmingham

Durée : Start Date : 01-04-1999 — End Date : 30-03-2002

Objectifs  : Model the distribution and maintenance of genetic diversity and gene flow in pigeonpea production systems that include traditional varieties, improved varieties for hybrids, and wild species

Descriptif
Pigeonpea (Cajanus cajan (L) Millsp) is a very important subsistence food crop in traditional cropping systems in peninsular India. This region is both the centre of origin for the domesticated species and the region with the maximum diversity. The genetic diversity of this crop in the field is slowly being eroded with the introduction of improved varieties, and a change in its status to that of a cash crop. The same phenomenon is occurring in other pigeonpea-growing regions of the world, where this crop, which was traditionally grown by women in gardens or on field margins, is being converted to a high value cash crop that is mainly grown in monoculture systems, using a shorter-duration plant type. This shift is not yet complete, so the two types of varieties, traditional landraces and improved varieties or hybrids, are grown side-by-side in many areas. Pigeonpeas are a partially self-pollinated and insect-pollinated species. The degree of cross-pollination can be influenced by the flower type, abundance of insect pollinators, and weather conditions during flowering. The distribution of diversity among and within landraces is unknown, and the degree of gene flow within the cultivated species or between the cultivated and wild species has not been documented. Thus, the impact of the introduction of improved varieties on the traditional landraces in relation to genetic erosion is unknown. Pigeonpeas are plagued by a number of pests, including insects, nematodes, and fungal/bacterial diseases. These pests cause major economic losses to Indian producers every year, and their control involves substantial use of pesticides in the cropping system. The increasing status of pigeonpea as a cash crop, its value as a legume alternative in the cotton-growing regions, and the complementarity of some of its pests with those of cotton and chili make it a prime target for the use of transformation, especially to introduce Bt genes. The introduction and adoption of products of biotechnology in pigeonpeas needs to be assessed for possible risks to traditional cropping systems.

Total Cost to DFID : £199,276

Présentation : Recherche for Developàment (R4D)

Page publiée le 10 juillet 2021