2018
Orozco-Martínez, R.; de la Barrera, E.
Can germination requirements predict tolerance to extreme weather? — An assessment for heirloom maize from the P'urhépecha Plateau Journal Article
In: International Journal of Agriculture and Biology, vol. 20, no. 9, pp. 2039-2044, 2018.
Abstract | Links | BibTeX | Tags: agriculture, cereal, climate change, domestication, drought, ecophysiology, food security, germination, maize
@article{Orozco-Martínez2018,
title = {Can germination requirements predict tolerance to extreme weather? — An assessment for heirloom maize from the P'urhépecha Plateau},
author = {R. Orozco-Martínez and E. de la Barrera },
url = {http://www.fspublishers.org/Issue.php?categoryID=158
http://agro.mx/wp-content/uploads/2018/07/045-OrozcoMtz-delaBarrera-maize-germination.pdf},
doi = {10.17957/IJAB/15.0727},
year = {2018},
date = {2018-07-27},
journal = {International Journal of Agriculture and Biology},
volume = {20},
number = {9},
pages = {2039-2044},
abstract = {The temperature and water potential requirements for seed germination were determined for five heirloom maizes from three different agroclimatological regions from the P'urhépecha community of San Francisco Pichátaro, Michoacán, Mexico. Germination experiments were conducted in environmental controlled chambers exposing seeds to day/night air temperatures (12 h photoperiod) of 15/5, 20/10, or 35/25ºC, and to water potentials of 0, –0.01, –0.05, –0.1, or –0.5 MPa, which were created with aqueous solutions of polyethylene glycol (molecular weight 20,000). Germination was maximal and occurred at a faster rate for seeds incubated at 35/25ºC. In turn, a high water potential of 0.0 or –0.01 MPa was necessary to achieve maximum germination, which decreased under more negative water potentials until germination was completely inhibited for seeds incubated under –0.5 MPa failed. Although an environmental specialization for germination was not observed among the heirloom maize evaluated, their ability to germinate maximally under high temperatures is indicative of their cultivation potential under the increasing air temperatures expected to occur during the present century. In contrast, germination sensitivity to relatively mild water potentials may be a conservative ecophysiological trait of drought-escape for this tropical annual plant.},
keywords = {agriculture, cereal, climate change, domestication, drought, ecophysiology, food security, germination, maize},
pubstate = {published},
tppubtype = {article}
}
The temperature and water potential requirements for seed germination were determined for five heirloom maizes from three different agroclimatological regions from the P'urhépecha community of San Francisco Pichátaro, Michoacán, Mexico. Germination experiments were conducted in environmental controlled chambers exposing seeds to day/night air temperatures (12 h photoperiod) of 15/5, 20/10, or 35/25ºC, and to water potentials of 0, –0.01, –0.05, –0.1, or –0.5 MPa, which were created with aqueous solutions of polyethylene glycol (molecular weight 20,000). Germination was maximal and occurred at a faster rate for seeds incubated at 35/25ºC. In turn, a high water potential of 0.0 or –0.01 MPa was necessary to achieve maximum germination, which decreased under more negative water potentials until germination was completely inhibited for seeds incubated under –0.5 MPa failed. Although an environmental specialization for germination was not observed among the heirloom maize evaluated, their ability to germinate maximally under high temperatures is indicative of their cultivation potential under the increasing air temperatures expected to occur during the present century. In contrast, germination sensitivity to relatively mild water potentials may be a conservative ecophysiological trait of drought-escape for this tropical annual plant.
2016
de la Barrera, E.; Orozco-Martínez, R.
Socio-ecological considerations on the persistence of Mexican heirloom maize Journal Article
In: Maydica, vol. 61, no. 4, pp. M36, 2016.
Abstract | Links | BibTeX | Tags: climate change, food security, maize, orphan crops, risk assessment
@article{delaBarrera2016,
title = {Socio-ecological considerations on the persistence of Mexican heirloom maize},
author = {E. de la Barrera and R. Orozco-Martínez},
url = {http://agro.mx/wp-content/uploads/2017/01/61_4_36.pdf
http://www.maydica.org/articles/61_4_36.pdf
http://agro.mx/wp-content/uploads/2017/01/Maydica-61-4-M36-Apendix-1.pdf},
year = {2016},
date = {2016-12-02},
journal = {Maydica},
volume = {61},
number = {4},
pages = {M36},
abstract = {The vulnerability of 59 Mexican landraces of maize was assessed in relation to five socio-ecological factors, namely, social and economic marginalization, association with indigenous peoples, high biodiversity regions, environmental suitability for cultivation, and climate change effects. The most marginalized states had the highest number of landraces, 80% of which were found in predominantly or substantially indigenous municipalities. While only one third of 152 regions of high biodiversity had collection records, 47 landraces had at least one collection record in these regions. Eleven races can be cultivated in at least 10% of the Mexican territory, while 13 can occupy less than 1% under current environmental conditions. Given a projected temperature increase of 0.5 oC and a 5% reduction in annual precipitation, 66% of the landraces could disappear during the current decade. A normalized Vulnerability Index was constructed (can have values from 0.00 for non-threatened landraces to 1.00 for the most vulnerable) that averaged 0.76 ± 0.02 for the 59 landraces. The most vulnerable third of the landraces were threatened by being from a region of low marginalization combined with a limited potential distribution both under current conditions and under the climate change scenario considered.},
keywords = {climate change, food security, maize, orphan crops, risk assessment},
pubstate = {published},
tppubtype = {article}
}
The vulnerability of 59 Mexican landraces of maize was assessed in relation to five socio-ecological factors, namely, social and economic marginalization, association with indigenous peoples, high biodiversity regions, environmental suitability for cultivation, and climate change effects. The most marginalized states had the highest number of landraces, 80% of which were found in predominantly or substantially indigenous municipalities. While only one third of 152 regions of high biodiversity had collection records, 47 landraces had at least one collection record in these regions. Eleven races can be cultivated in at least 10% of the Mexican territory, while 13 can occupy less than 1% under current environmental conditions. Given a projected temperature increase of 0.5 oC and a 5% reduction in annual precipitation, 66% of the landraces could disappear during the current decade. A normalized Vulnerability Index was constructed (can have values from 0.00 for non-threatened landraces to 1.00 for the most vulnerable) that averaged 0.76 ± 0.02 for the 59 landraces. The most vulnerable third of the landraces were threatened by being from a region of low marginalization combined with a limited potential distribution both under current conditions and under the climate change scenario considered.
2015
Guerrero-Jiménez, Z. D.; de la Barrera, E.
Short-term drought responses by seedlings of three maizes along an environmental gradient in Michoacán, Mexico Journal Article
In: Maydica, vol. 60, no. 2, pp. M017, 2015.
Links | BibTeX | Tags: climate change, drought, ecophysiology, food security, maize
@article{delaBarrera2015,
title = {Short-term drought responses by seedlings of three maizes along an environmental gradient in Michoacán, Mexico},
author = {Z. D. Guerrero-Jiménez and E. de la Barrera},
url = {http://agro.mx/wp-content/uploads/2016/07/036-Guerrero-dlB-Maydica-html.pdf
},
year = {2015},
date = {2015-12-17},
journal = {Maydica},
volume = {60},
number = {2},
pages = {M017},
keywords = {climate change, drought, ecophysiology, food security, maize},
pubstate = {published},
tppubtype = {article}
}