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首页> 外文学位 >Farmer varietal identifications and environmental adaptation of Phaseolus bean species in Oaxaca, Mexico.
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Farmer varietal identifications and environmental adaptation of Phaseolus bean species in Oaxaca, Mexico.

机译：墨西哥瓦哈卡州菜豆种类的农民品种鉴定和环境适应。

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摘要

In situ conservation of crop genetic resources complements ex situ conservation, yet little is known about how small-scale farmers perceive and manage diversity in their own fields. The smallholder farmers of highland Oaxaca manage fields in different agroecological zones along an altitudinal gradient and regularly interplant a great diversity of bean landraces of three species: common bean (P. vulgaris), runner bean (P. coccineus), and year bean [P. dumosus (= P. polyanthus)]. We investigated the role of farmers from a community in the Sierra Juarez, Oaxaca in managing Phaseolus diversity in their fields by conducting two experiments: (1) making a germplasm collection from fields in the community and assessing the spatial allocation of diversity using molecular methods, and (2) evaluating the empirical basis and consistency of farmers' bean variety identifications through a seed sorting experiment.;In our first experiment, we collected seeds from 287 plants in ten sampled fields in the community of Santa Maria Jaltianguis and evaluated the diversity present in the collection at ten nuclear microsatellite markers and three polymorphic cpDNA microsatellite markers. The DeltaK statistic identified three core population clusters within the collection following a STRUCTURE analysis, a finding corroborated by morphological observations and principal coordinate analysis and NJ tree construction of molecular data. The first two populations were identified as P. vulgaris ecogeographic races Mesoamerica and Jalisco and the third population as the related species P. coccineus and P. dumosus. Each of the fields sampled in this collection consisted predominantly of a single Phaseolus species or ecogeographic race, but cpDNA microsatellite markers provided evidence for low levels of gene flow between races Jalisco and Mesoamerica. Three farmers, who each managed two bean fields at different altitudes, had distinct approaches to distributing genetic diversity among their respective fields to presumably optimize bean adaptation.;In our second experiment we investigated the empirical basis and consistency of farmers' bean variety identifications in Santa Maria Jaltianguis by asking farmers to sort a sample of 300 local seeds that included three Phaseolus species into varieties. Nuclear and chloroplast SSR genotypes and seed morphology data were used to (a) establish species identities, including the presence of one interspecific hybrid; (b) test the hypothesis that farmer varieties reflect morphological and biological structures; (c) test the hypothesis that there is agreement among farmers in classification of varieties. Together with other indicators of socioeconomic and climatic change, our results indicate that named varieties underestimate diversity present at the community level due to the intravarietal variation tolerated in farmer classifications.;Our results show that farmers in Santa Maria Jaltianguis recognize real genetic differences within and among their seedlots and plant available Phaseolus species and races in the environments to which they are adapted. The predominant genetic differentiation across fields suggests that individual fields should be the main sampling unit in explorations for ex situ conservation. We also observed idiosyncrasies among farmers in the ways that they allocate genetic diversity across multiple landholdings and classify seeds into local varieties. This suggests that the impact of socioeconomic and climatic changes on crop diversity conserved in situ will not be uniform across households. The diversity of growing environments and strategies by which farmers manage their seed lots in Santa Maria Jaltianguis may serve to buffer this community against social and climatic changes in the future.
机译：作物遗传资源的原地保护与非原地保护相辅相成，但关于小农如何看待和管理其各自领域的多样性知之甚少。瓦哈卡州高地的小农户沿着海拔梯度管理着不同农业生态区的田地，并定期种植多种多样的三种豆类地方品种：普通豆（菜豆），红花菜豆（球果）和一年生豆[P]。 。 dumosus（= P. polyanthus）]。我们通过进行两个实验研究了瓦哈卡州塞拉华雷斯山脉一个社区的农民在管理其菜豆多样性方面的作用：（1）从该社区的田地中收集种质，并使用分子方法评估多样性的空间分配， （2）通过种子分选实验评估农户豆类品种鉴定的经验基础和一致性。在我们的第一个实验中，我们从圣玛丽亚贾尔吉吉斯社区的十个采样田中的287种植物中收集了种子，并评估了其多样性在收集中有十个核微卫星标记和三个多态cpDNA微卫星标记。在进行结构分析后，DeltaK统计数据确定了集合中的三个核心种群群，这一发现得到了形态学观察和主坐标分析以及分子数据的NJ树构建的证实。前两个种群被确定为中美洲和哈利斯科州的寻常型生态地理小种，第三类被定为相关物种P. coccineus和P. dumosus。此集合中采样的每个字段主要由单个菜豆物种或生态地理种族组成，但是cpDNA微卫星标记为哈利斯科州和中美洲种族之间的基因流水平低提供了证据。三个分别管理两个不同海拔豆田的农民采用不同的方法在各自的田间分配遗传多样性，以优化豆类适应性。在我们的第二个实验中，我们调查了圣诞老人对农民豆类品种鉴定的经验基础和一致性Maria Jaltianguis要求农民对300种当地种子进行采样，其中包括3种菜豆。核和叶绿体SSR基因型和种子形态数据用于（a）建立物种身份，包括一个种间杂种的存在； （b）检验农民品种反映形态和生物结构的假设； （c）检验以下假设：农民在品种分类上达成一致。与社会经济和气候变化的其他指标一起，我们的结果表明，由于农民分类中容许的种内变异，命名品种低估了社区一级的多样性。；我们的结果表明，圣玛丽亚贾尔吉吉斯的农民认识到内部和内部的真实遗传差异它们的种子田和可种植的菜豆种类和种族在它们适应的环境中。跨田间的主要遗传分化表明，单个田间应作为非原生境保护勘探的主要采样单位。我们还观察到农民之间的特殊性，即他们在多个土地上分配遗传多样性并将种子分类为当地品种。这表明社会经济和气候变化对就地保存的作物多样性的影响在各家庭之间将是不一致的。农民在Santa Maria Jaltianguis管理种子地的生长环境和策略的多样性可能有助于缓冲该社区，使其免受将来的社会和气候变化的影响。

著录项

  • 作者

    Worthington, Margaret Leigh.;

  • 作者单位

    University of California, Davis.;

  • 授予单位 University of California, Davis.;
  • 学科 Agriculture Agronomy.;Agriculture Plant Culture.
  • 学位 M.S.
  • 年度 2011
  • 页码 142 p.
  • 总页数 142
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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