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Phenotypic differentiation between wild and domesticated varieties of Crescentia cujete L. and culturally relevant uses of their fruits as bowls in the Yucatan Peninsula, Mexico.

Aguirre-Dugua X, Pérez-Negrón E, Casas A - J Ethnobiol Ethnomed (2013)

Bottom Line: We sampled 238 bowls at homes of people interviewed and compared their shape, volume and thickness with 139 fruits collected in homegardens and 179 from the wild.Roundness was the most relevant character for these uses, as bowls from households showed a strong selection towards round shapes compared with wild and homegarden fruits.By choosing the best fruits from domesticated varieties propagated in homegardens, the Maya people model the domestication process of this important tree in their culture.

View Article: PubMed Central - HTML - PubMed

Affiliation: Centro de Investigaciones en Ecosistemas, Universidad Nacional Autónoma de México, Campus Morelia, Apartado Postal 27-3 (Santa María de Guido), Morelia, Michoacán 58190, México. acasas@cieco.unam.mx.

ABSTRACT

Background: Selection criteria are important for analyzing domestication of perennial plant species, which experience a selection pressure throughout several human generations. We analyze the preferred morphological characteristics of Crescentia cujete fruits, which are used as bowls by the Maya of Yucatan, according to the uses they are given and the phenotypic consequences of artificial selection between one wild and three domesticated varieties.

Methods: We performed 40 semi-structured interviews in seven communities. We calculated Sutrop's salience index (S) of five classes of ceremonial and daily life uses, and of each item from the two most salient classes. We sampled 238 bowls at homes of people interviewed and compared their shape, volume and thickness with 139 fruits collected in homegardens and 179 from the wild. Morphology of varieties was assessed in fruit (n = 114 trees) and vegetative characters (n = 136 trees). Differences between varieties were evaluated through linear discriminant analysis (LDA).

Results: Use of bowls as containers for the Day of the Dead offerings was the most salient class (S = 0.489) with chocolate as its most salient beverage (S = 0.491), followed by consumption of daily beverages (S = 0.423), especially maize-based pozol (S = 0.412). The sacred saka' and balche' are offered in different sized bowls during agricultural and domestic rituals. Roundness was the most relevant character for these uses, as bowls from households showed a strong selection towards round shapes compared with wild and homegarden fruits. Larger fruits from domesticated varieties were also preferred over small wild fruits, although in the household different sizes of the domesticated varieties are useful. LDA separated wild from domesticated trees (p < 0.001) according to both fruit and vegetative variables, but domesticated varieties were not different among themselves.

Conclusions: The association between C. cujete bowls and traditional beverages in ritual and daily life situations has driven for centuries the selection of preferred fruit morphology in this tree. Selection of fruit roundness and volume has allowed for the differentiation between the wild variety and the three domesticated ones, counteracting gene flow among them. By choosing the best fruits from domesticated varieties propagated in homegardens, the Maya people model the domestication process of this important tree in their culture.

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Linear discriminant analysis between five categories of C. cujete trees growing in putative wild (black symbols) and homegarden (white symbols) sites, based on A) fruit characters (n = 114 trees) and B) vegetative characters (n = 136 trees).
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Figure 8: Linear discriminant analysis between five categories of C. cujete trees growing in putative wild (black symbols) and homegarden (white symbols) sites, based on A) fruit characters (n = 114 trees) and B) vegetative characters (n = 136 trees).

Mentions: The first discriminant function of the LDA based on fruit characters accounted for 97.9% of the total variance and was significant (Wilk’s λ = 0.076, p < 0.001) showing a clear differentiation of wild and domesticated groups; the second discriminant function related to the discrimination among domesticated varieties accounted for an additional 1.4% of the variance and was not significant (Wilk’s λ = 0.818, p = 0.119). When considering vegetative characters, differentiation of groups by the first discriminant function accounted for 88.3% of the total variance and was statistically significant (Wilk’s λ = 0.210, p < 0.001); the second discriminant function was statistically significant but accounted for only 5.8% of the total variance (Wilk’s λ = 0.734, p < 0.05) (Figure 8).


Phenotypic differentiation between wild and domesticated varieties of Crescentia cujete L. and culturally relevant uses of their fruits as bowls in the Yucatan Peninsula, Mexico.

Aguirre-Dugua X, Pérez-Negrón E, Casas A - J Ethnobiol Ethnomed (2013)

Linear discriminant analysis between five categories of C. cujete trees growing in putative wild (black symbols) and homegarden (white symbols) sites, based on A) fruit characters (n = 114 trees) and B) vegetative characters (n = 136 trees).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3842825&req=5

Figure 8: Linear discriminant analysis between five categories of C. cujete trees growing in putative wild (black symbols) and homegarden (white symbols) sites, based on A) fruit characters (n = 114 trees) and B) vegetative characters (n = 136 trees).
Mentions: The first discriminant function of the LDA based on fruit characters accounted for 97.9% of the total variance and was significant (Wilk’s λ = 0.076, p < 0.001) showing a clear differentiation of wild and domesticated groups; the second discriminant function related to the discrimination among domesticated varieties accounted for an additional 1.4% of the variance and was not significant (Wilk’s λ = 0.818, p = 0.119). When considering vegetative characters, differentiation of groups by the first discriminant function accounted for 88.3% of the total variance and was statistically significant (Wilk’s λ = 0.210, p < 0.001); the second discriminant function was statistically significant but accounted for only 5.8% of the total variance (Wilk’s λ = 0.734, p < 0.05) (Figure 8).

Bottom Line: We sampled 238 bowls at homes of people interviewed and compared their shape, volume and thickness with 139 fruits collected in homegardens and 179 from the wild.Roundness was the most relevant character for these uses, as bowls from households showed a strong selection towards round shapes compared with wild and homegarden fruits.By choosing the best fruits from domesticated varieties propagated in homegardens, the Maya people model the domestication process of this important tree in their culture.

View Article: PubMed Central - HTML - PubMed

Affiliation: Centro de Investigaciones en Ecosistemas, Universidad Nacional Autónoma de México, Campus Morelia, Apartado Postal 27-3 (Santa María de Guido), Morelia, Michoacán 58190, México. acasas@cieco.unam.mx.

ABSTRACT

Background: Selection criteria are important for analyzing domestication of perennial plant species, which experience a selection pressure throughout several human generations. We analyze the preferred morphological characteristics of Crescentia cujete fruits, which are used as bowls by the Maya of Yucatan, according to the uses they are given and the phenotypic consequences of artificial selection between one wild and three domesticated varieties.

Methods: We performed 40 semi-structured interviews in seven communities. We calculated Sutrop's salience index (S) of five classes of ceremonial and daily life uses, and of each item from the two most salient classes. We sampled 238 bowls at homes of people interviewed and compared their shape, volume and thickness with 139 fruits collected in homegardens and 179 from the wild. Morphology of varieties was assessed in fruit (n = 114 trees) and vegetative characters (n = 136 trees). Differences between varieties were evaluated through linear discriminant analysis (LDA).

Results: Use of bowls as containers for the Day of the Dead offerings was the most salient class (S = 0.489) with chocolate as its most salient beverage (S = 0.491), followed by consumption of daily beverages (S = 0.423), especially maize-based pozol (S = 0.412). The sacred saka' and balche' are offered in different sized bowls during agricultural and domestic rituals. Roundness was the most relevant character for these uses, as bowls from households showed a strong selection towards round shapes compared with wild and homegarden fruits. Larger fruits from domesticated varieties were also preferred over small wild fruits, although in the household different sizes of the domesticated varieties are useful. LDA separated wild from domesticated trees (p < 0.001) according to both fruit and vegetative variables, but domesticated varieties were not different among themselves.

Conclusions: The association between C. cujete bowls and traditional beverages in ritual and daily life situations has driven for centuries the selection of preferred fruit morphology in this tree. Selection of fruit roundness and volume has allowed for the differentiation between the wild variety and the three domesticated ones, counteracting gene flow among them. By choosing the best fruits from domesticated varieties propagated in homegardens, the Maya people model the domestication process of this important tree in their culture.

Show MeSH
Related in: MedlinePlus