Integrating Gene Flow, Crop Biology, and Farm Management in On-Farm Conservation of Avocado (Persea americana, Lauraceae)

Kenneth Birnbaum, Rob DeSalle, Charles M. Peters, Philip N. Benfey

Research output: Contribution to journalArticle

Abstract

Maintaining crop diversity on farms where cultivars can evolve is a conservation goal, but few tools are available to assess the long-term maintenance of genetic diversity on farms. One important issue for on-farm conservation is gene flow from crops with a narrow genetic base into related populations that are genetically diverse. In a case study of avocado (Persea americana var. americana) in one of its centers of diversity (San Jerónimo, Costa Rica), we used 10 DNA microsatellite markers in a parentage analysis to estimate gene flow from commercialized varieties into a traditional crop population. Five commercialized genotypes comprised nearly 40% of orchard trees, but they contributed only about 14.5% of the gametes to the youngest cohort of trees. Although commercialized varieties and the diverse population were often planted on the same farm, planting patterns appeared to keep the two types of trees separated on small scales, possibly explaining the limited gene flow. In a simulation that combined gene flow estimates, crop biology, and graft tree management, loss of allelic diversity was less than 10% over 150 yr, and selection was effective in retaining desirable alleles in the diverse subpopulation. Simulations also showed that, in addition to gene flow, managing the genetic makeup and life history traits of the invasive commercialized varieties could have a significant impact on genetic diversity in the target population. The results support the feasibility of on-farm crop conservation, but simulations also showed that higher levels of gene flow could lead to severe losses of genetic diversity even if farmers continue to plant diverse varieties.

Original languageEnglish (US)
Pages (from-to)1619-1627
Number of pages9
JournalAmerican Journal of Botany
Volume90
Issue number11
StatePublished - Nov 2003

Fingerprint

Lauraceae
Persea
Persea americana
Gene Flow
farm management
avocados
gene flow
farm
Biological Sciences
farms
crop
crops
genetic variation
Persea americana var. americana
Population
heirloom varieties
simulation
Costa Rica
center of diversity
parentage

Keywords

  • Avocado
  • Crop conservation
  • Effective population size
  • Ethnobotany
  • Gene flow
  • Genetic diversity
  • Genetic drift
  • Lauraceae
  • Persea americana

ASJC Scopus subject areas

  • Plant Science

Cite this

Integrating Gene Flow, Crop Biology, and Farm Management in On-Farm Conservation of Avocado (Persea americana, Lauraceae). / Birnbaum, Kenneth; DeSalle, Rob; Peters, Charles M.; Benfey, Philip N.

In: American Journal of Botany, Vol. 90, No. 11, 11.2003, p. 1619-1627.

Research output: Contribution to journalArticle

@article{d55ce64135194ef781e6536c2d0c3bcd,
title = "Integrating Gene Flow, Crop Biology, and Farm Management in On-Farm Conservation of Avocado (Persea americana, Lauraceae)",
abstract = "Maintaining crop diversity on farms where cultivars can evolve is a conservation goal, but few tools are available to assess the long-term maintenance of genetic diversity on farms. One important issue for on-farm conservation is gene flow from crops with a narrow genetic base into related populations that are genetically diverse. In a case study of avocado (Persea americana var. americana) in one of its centers of diversity (San Jer{\'o}nimo, Costa Rica), we used 10 DNA microsatellite markers in a parentage analysis to estimate gene flow from commercialized varieties into a traditional crop population. Five commercialized genotypes comprised nearly 40{\%} of orchard trees, but they contributed only about 14.5{\%} of the gametes to the youngest cohort of trees. Although commercialized varieties and the diverse population were often planted on the same farm, planting patterns appeared to keep the two types of trees separated on small scales, possibly explaining the limited gene flow. In a simulation that combined gene flow estimates, crop biology, and graft tree management, loss of allelic diversity was less than 10{\%} over 150 yr, and selection was effective in retaining desirable alleles in the diverse subpopulation. Simulations also showed that, in addition to gene flow, managing the genetic makeup and life history traits of the invasive commercialized varieties could have a significant impact on genetic diversity in the target population. The results support the feasibility of on-farm crop conservation, but simulations also showed that higher levels of gene flow could lead to severe losses of genetic diversity even if farmers continue to plant diverse varieties.",
keywords = "Avocado, Crop conservation, Effective population size, Ethnobotany, Gene flow, Genetic diversity, Genetic drift, Lauraceae, Persea americana",
author = "Kenneth Birnbaum and Rob DeSalle and Peters, {Charles M.} and Benfey, {Philip N.}",
year = "2003",
month = "11",
language = "English (US)",
volume = "90",
pages = "1619--1627",
journal = "American Journal of Botany",
issn = "0002-9122",
publisher = "Botanical Society of America Inc.",
number = "11",

}

TY - JOUR

T1 - Integrating Gene Flow, Crop Biology, and Farm Management in On-Farm Conservation of Avocado (Persea americana, Lauraceae)

AU - Birnbaum, Kenneth

AU - DeSalle, Rob

AU - Peters, Charles M.

AU - Benfey, Philip N.

PY - 2003/11

Y1 - 2003/11

N2 - Maintaining crop diversity on farms where cultivars can evolve is a conservation goal, but few tools are available to assess the long-term maintenance of genetic diversity on farms. One important issue for on-farm conservation is gene flow from crops with a narrow genetic base into related populations that are genetically diverse. In a case study of avocado (Persea americana var. americana) in one of its centers of diversity (San Jerónimo, Costa Rica), we used 10 DNA microsatellite markers in a parentage analysis to estimate gene flow from commercialized varieties into a traditional crop population. Five commercialized genotypes comprised nearly 40% of orchard trees, but they contributed only about 14.5% of the gametes to the youngest cohort of trees. Although commercialized varieties and the diverse population were often planted on the same farm, planting patterns appeared to keep the two types of trees separated on small scales, possibly explaining the limited gene flow. In a simulation that combined gene flow estimates, crop biology, and graft tree management, loss of allelic diversity was less than 10% over 150 yr, and selection was effective in retaining desirable alleles in the diverse subpopulation. Simulations also showed that, in addition to gene flow, managing the genetic makeup and life history traits of the invasive commercialized varieties could have a significant impact on genetic diversity in the target population. The results support the feasibility of on-farm crop conservation, but simulations also showed that higher levels of gene flow could lead to severe losses of genetic diversity even if farmers continue to plant diverse varieties.

AB - Maintaining crop diversity on farms where cultivars can evolve is a conservation goal, but few tools are available to assess the long-term maintenance of genetic diversity on farms. One important issue for on-farm conservation is gene flow from crops with a narrow genetic base into related populations that are genetically diverse. In a case study of avocado (Persea americana var. americana) in one of its centers of diversity (San Jerónimo, Costa Rica), we used 10 DNA microsatellite markers in a parentage analysis to estimate gene flow from commercialized varieties into a traditional crop population. Five commercialized genotypes comprised nearly 40% of orchard trees, but they contributed only about 14.5% of the gametes to the youngest cohort of trees. Although commercialized varieties and the diverse population were often planted on the same farm, planting patterns appeared to keep the two types of trees separated on small scales, possibly explaining the limited gene flow. In a simulation that combined gene flow estimates, crop biology, and graft tree management, loss of allelic diversity was less than 10% over 150 yr, and selection was effective in retaining desirable alleles in the diverse subpopulation. Simulations also showed that, in addition to gene flow, managing the genetic makeup and life history traits of the invasive commercialized varieties could have a significant impact on genetic diversity in the target population. The results support the feasibility of on-farm crop conservation, but simulations also showed that higher levels of gene flow could lead to severe losses of genetic diversity even if farmers continue to plant diverse varieties.

KW - Avocado

KW - Crop conservation

KW - Effective population size

KW - Ethnobotany

KW - Gene flow

KW - Genetic diversity

KW - Genetic drift

KW - Lauraceae

KW - Persea americana

UR - http://www.scopus.com/inward/record.url?scp=0344961932&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0344961932&partnerID=8YFLogxK

M3 - Article

C2 - 21653337

AN - SCOPUS:0344961932

VL - 90

SP - 1619

EP - 1627

JO - American Journal of Botany

JF - American Journal of Botany

SN - 0002-9122

IS - 11

ER -