Priya Davidar1, Allison A Snow2, Muthu Rajkumar1, Remy Pasquet3, Marie-Christine Daunay4, Evans Mutegi2. 1. Department of Ecology and Environmental Sciences, Pondicherry University, Kalapet, Pondicherry 605014, India. 2. Department of Evolution, Ecology, and Organismal Biology, Ohio State University, 318 W. 12th Avenue, Columbus, Ohio 43210 USA. 3. IRD, UR 072, LEGS 91198 Gif-sur-yvette, France; Université Paris-Sud 11 91400 Orsay, France. 4. INRA, Unité de Génétique & Amélioration des Fruits et Légumes, UR1052, Domaine St Maurice, CS 60094 F-84143 Montfavet cedex, France.
Abstract
UNLABELLED: • PREMISE OF THE STUDY: In India and elsewhere, transgenic Bt eggplant (Solanum melongena) has been developed to reduce insect herbivore damage, but published studies of the potential for pollen-mediated, crop- to- wild gene flow are scant. This information is useful for risk assessments as well as in situ conservation strategies for wild germplasm.• METHODS: In 2010-2014, we surveyed 23 populations of wild/weedy eggplant (Solanum insanum; known as wild brinjal), carried out hand-pollination experiments, and observed pollinators to assess the potential for crop- to- wild gene flow in southern India.• KEY RESULTS: Wild brinjal is a spiny, low-growing perennial commonly found in disturbed sites such as roadsides, wastelands, and sparsely vegetated areas near villages and agricultural fields. Fourteen of the 23 wild populations in our study occurred within 0.5 km of cultivated brinjal and at least nine flowered in synchrony with the crop. Hand crosses between wild and cultivated brinjal resulted in seed set and viable F1 progeny. Wild brinjal flowers that were bagged to exclude pollinators did not set fruit, and fruit set from manual self-pollination was low. The exserted stigmas of wild brinjal are likely to promote outcrossing. The most effective pollinators appeared to be bees (Amegilla, Xylocopa, Nomia, and Heterotrigona spp.), which also were observed foraging for pollen on crop brinjal.• CONCLUSION: Our findings suggest that hybridization is possible between cultivated and wild brinjal in southern India. Thus, as part of the risk assessment process, we assume that transgenes from the crop could spread to wild brinjal populations that occur nearby.
UNLABELLED: • PREMISE OF THE STUDY: In India and elsewhere, transgenic Bt eggplant (Solanum melongena) has been developed to reduce insect herbivore damage, but published studies of the potential for pollen-mediated, crop- to- wild gene flow are scant. This information is useful for risk assessments as well as in situ conservation strategies for wild germplasm.• METHODS: In 2010-2014, we surveyed 23 populations of wild/weedy eggplant (Solanum insanum; known as wild brinjal), carried out hand-pollination experiments, and observed pollinators to assess the potential for crop- to- wild gene flow in southern India.• KEY RESULTS: Wild brinjal is a spiny, low-growing perennial commonly found in disturbed sites such as roadsides, wastelands, and sparsely vegetated areas near villages and agricultural fields. Fourteen of the 23 wild populations in our study occurred within 0.5 km of cultivated brinjal and at least nine flowered in synchrony with the crop. Hand crosses between wild and cultivated brinjal resulted in seed set and viable F1 progeny. Wild brinjal flowers that were bagged to exclude pollinators did not set fruit, and fruit set from manual self-pollination was low. The exserted stigmas of wild brinjal are likely to promote outcrossing. The most effective pollinators appeared to be bees (Amegilla, Xylocopa, Nomia, and Heterotrigona spp.), which also were observed foraging for pollen on crop brinjal.• CONCLUSION: Our findings suggest that hybridization is possible between cultivated and wild brinjal in southern India. Thus, as part of the risk assessment process, we assume that transgenes from the crop could spread to wild brinjal populations that occur nearby.