African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6849

Article in Press

Genetic erosion of cultivated common bean (Pharsalus vulgaris L.) landraces in South Western Kenya

Henry N. Anunda, Evans N. Nyaboga, Nelson O. Amugune1

  •  Received: 18 June 2018
  •  Accepted: 17 October 2019
Common bean (Phaseolus vulgaris, L.) landraces derived from local tropical germplasm and represent an important source of genetic and phenotypic diversity. This germplasm is at present poorly understood and under-exploited by Kenyan crop breeding programs besides of being threatened by diseases, pests, genetic erosion and effects of climate change. The loss of landraces results in decreased genetic base of the remaining cultivars that could be a threat to local, national and regional food security. The main objective of the present study was to assess the status of common bean landraces in south west Kenya (SW). Specifically, the survey was carried out to: find out the common bean landraces currently grown in SW Kenya, determine common bean landraces that have been lost in SW Kenya and to find out the factors that have caused loss of these varieties. Data was collected using a structured pretested questionnaire, which was administered to individual farmers, 10 from each the 5 agro-ecological zones in the region, using purposeful and snowball sampling. Collected data was recorded and analyzed using a SPSS program Version 10.0 for Windows for descriptive statistics. The findings indicate that53% of genetic erosion had occurred to many common bean landraces. The three most underlying causes of genetic erosion, as mentioned by many farmers, were diseases, introduction of new varieties and pests(100%, 94% and 86% respectively). Other factors leading to the loss of landraces include lack of market (66%), unreliable weather (52%), scarcity of land (42%), poor soil conditions (34%), scarcity of quality seed for planting (36%) and inadequate labour (12%). Adaptation strategies have been proposed from the findings that can greatly mitigate the adverse impacts of genetic erosion of common bean landraces in south western Kenya.

Keywords: landrace, genetic erosion, genetic integrity, snowball, agro-ecological zone.