Agriculture (Biology)

Supporting wild pollinators in a temperate agricultural landscape: maintaining mosaics of natural features and production.

by Pia Lentini

Lentini, PE, Martin, TG, Gibbons, P, Fischer, J and Cunningham, SA (2012) Supporting wild pollinators in a temperate agricultural landscape: maintaining mosaics of natural features and production. Biological Conservation 149, 84-92.

Pollination has received attention recently due to reported sharp declines of Apis mellifera in several locations, and... more Pollination has received attention recently due to reported sharp declines of Apis mellifera in several locations, and it has been proposed that diverse native bee communities may be key for continued pollination of economically important crops. However, there is some inconsistency in the literature as to how these communities should best be managed. To address this issue, we collected bees from an intensively managed agricultural region in eastern Australia using blue vane traps. Both linear remnants of vegetation, which form part of a larger corridor network, and adjacent fields of native and exotic pastures, wheat, canola, and lucerne were sampled. A total of 3 249 individual bees, representing four families and 36 species were collected. Highly modified environments of nectar-bearing crop supported the most species-rich bee assemblages, and the highest abundance of individual bee species. Distance from the remnants did not limit the body size of species occupying fields (up to 400m). However, richness of bee assemblages also responded positively to the presence of conservation land in nearby areas, or the number of remnant native trees surrounding traps. Linear remnants of native vegetation contributed to assemblage heterogeneity by adding unique species to the regional pool. Our findings indicate that agricultural industries that currently rely on pollination by A. mellifera should ensure that intensive land use is complemented by untilled areas in the form of conservation land, or farm dams and scattered trees in fields, to support wild pollinators that may act as insurance against further future losses of managed hives.

Time-series piecewise evolutionary segmentation based on wavelet transformation and Support Vector Machines

by Theodore Tsiligiridis

In: Proceedings of the 5th International Symposium on Wavelets Applications to World Problems (IWW2010), June 7-10, Konstantinoupolis (Instanbul), Turkey,
co-authored with T. Glezakos, S. Kintzios, C.P. Yialouris

Teosinte Inflorescence Phytolith Assemblages Mirror Zea Taxonomy

by John P. Hart

Co-authored with RG Matson, RG Thompson, and M. Blake. PLoS ONE. 2011.

Molecular DNA analyses of the New World grass (Poaceae) genus Zea, comprising five species, has resolved taxonomic... more Molecular DNA analyses of the New World grass (Poaceae) genus Zea, comprising five species, has resolved taxonomic issues including the most likely teosinte progenitor (Zea mays ssp. parviglumis) of maize (Zea mays ssp. mays). However, archaeologically, little is known about the use of teosinte by humans both prior to and after the domestication of maize. One potential line of evidence to explore these relationships is opaline phytoliths produced in teosinte fruit cases. Here we use multidimensional scaling and multiple discriminant analyses to determine if rondel phytolith assemblages from teosinte fruitcases reflect teosinte taxonomy. Our results indicate that rondel phytolith assemblages from the various taxa, including subspecies, can be statistically discriminated. This indicates that it will be possible to investigate the archaeological histories of teosinte use pending the recovery of appropriate samples.

Phytochemical variation in Fritillaria cirrhosa D. Don (Chuan Bei Mu) in relation to plant reproductive stage and timing of harvest

by Eve Emshwiller

Konchar, Katie M., Xiaoli Li, Yongping Yang, and Eve Emshwiller. (OnlineFirst) Economic Botany.

Economic development in southwest China and the increasing use of traditional Chinese medicine (TCM) worldwide have... more Economic development in southwest China and the increasing use of traditional Chinese medicine (TCM) worldwide have led to intensified collection of native medicinal plants. Fritillaria cirrhosa D. Don (Chuan Bei Mu), commonly used for the treatment of cough in TCM, is endemic to the Hengduan Mountain region of southwest China and is under increasing pressure from over-collection and decreasing suitable alpine habitat. The bioactive compounds in F. cirrhosa bulbs, isosteroidal alkaloids, are greatly influenced by environmental conditions and fluctuate in content and concentration with plant age and reproductive stage. Aiming at obtaining useful information for the sustainable management of wild F. cirrhosa populations, we evaluated how the phytochemical composition of F. cirrhosa bulbs varies at various stages of plant reproductive development. Using chemical methods and high performance liquid chromatography, two major bioactive alkaloids were extracted and analyzed from F. cirrhosa bulb samples collected throughout the Hengduan Mountain region. Plant reproductive stage was found to affect the concentration of bioactive alkaloids in F. cirrhosa bulbs. Bulb alkaloid concentration was highest during the early stages of fruit development and decreased significantly with fruit maturation. These results lend biochemical support to the practice of harvesting F. cirrhosa during the early stages of plant senescence (i.e., early fruit development).

The Role of Organic Acids in the Domestication of Oxalis tuberosa: A New Model for Studying Domestication Resulting in Opposing Crop Phenotypes

by Eve Emshwiller

E. Jane Bradbury and Eve Emshwiller (2011) Economic Botany 65 (1): 76-84
DOI: 10.1007/s12231-010-9141-0

The Role of Organic Acids in the Domestication of Oxalis tuberosa: A New Model for Studying Domestication Resulting in... more The Role of Organic Acids in the Domestication of Oxalis tuberosa: A New Model for Studying Domestication Resulting in Opposing Crop Phenotypes. Though few crops display directly opposing domesticated phenotypes, these crops may be the key to understanding domestication processes that address conflicting selective pressures in the agricultural ecosystem. Two relatively well-known examples are cassava (Manihot esculenta Crantz), which has high-cyanide and low-cyanide varieties, and potato (Solanum section Petota). Among the potatoes are several species, including the common potato (Solanum tuberosum L.), that have low levels of glycoalkaloids and there are other species of “bitter potato” with elevated levels of glycoalkaloids. We propose that Oxalis tuberosa Molina, “oca,” may represent a third example of such a crop system, with opposing high organic acid and low organic acid cultivars. Each cultivar set has different cultural food preparation practices (“use-categories”), similar to the “use-categories” that have been described for potatoes in the Andes (Brush et al. Economic Botany 35;70–88, 1981; Zimmerer Journal of Biogeography 18;165–178, 1991). Our initial analyses suggest that organic acids in tubers may be an important biochemical difference between use-categories, based on both oxalic acid and pH data. Here, we review our understanding of organic acids in oca tubers, while highlighting areas that merit further investigation.

Los ácidos orgánicos y la domesticación de Oxalis tuberosa: un nuevo modelo para el estudio de la domesticación que resulta en los fenotipos domésticos opuestos. Aunque pocos cultivos presentan fenotipos domésticos directamente opuestos , estos cultivos pueden ser la clave para entender los procesos de domesticación que muestran conflicto en la presión selectiva en el ecosistema agrícola. Dos ejemplos relativamente bien conocidos son la yuca (Manihot esculenta Crantz), que tiene variedades de alto y bajo contenido de cianuro, y la papa (Solanum sección Petota). Entre las papas hay varias especies, incluyendo la papa común (Solanum tuberosum L.), que tienen bajos niveles de glicoalcaloides mientras otras especies como las "papas amargas", tienen elevados niveles de glicoalcaloides. Nosotros proponemos que Oxalis tuberosa Molina, oca, puede representar un tercer ejemplo de este sistema de cultivo, con niveles altos y bajos de ácidos orgánicos. Cada grupo de variedades de oca tiene diferentes practicas culturales respecto a su preparación como alimentos (categorías de uso), similar a las categorías de uso que se han descrito para las papas en los Andes (Brush et al. Economic Botany 35;70–88, 1981; Zimmerer Journal of Biogeography 18;165–178, 1991). Los análisis iniciales sugieren que los ácidos orgánicos en los tubérculos pueden deberse a una diferencia bioquímica importante entre el uso de categorías basadas en el ácido oxálico y los datos de pH. En este artículo examinamos nuestra interpretación de los ácidos orgánicos en los tubérculos de oca, además de destacar las áreas que merecen mayor investigación.

QUIRÓS CASTILLO J. A., 2009, Arqueología de los espacios agrarios medievales en el País Vasco, Hispania 233, pp. 619-652

by Juan Antonio Quirós Castillo

The objective of this paper is to analyze the changes undergone by medieval rural societies in the Basque Country on... more The objective of this paper is to analyze the changes undergone by medieval rural societies in the Basque Country on the basis of archaeological digs undertaken in the last few years. Three types of archaeological evidence are presented and discussed: the cultivation spaces (manuring processes, terraced spaces), the storage structures and the species cultivated. These findings allow a diachronic characterization of Basque rural landscapes, with emphasis on the region of Alava during the 5th-12th centuries. The agrarian techniques documented allow us to propose the existence of a well-structured landscape in the Early Middle Ages, which changed in the 8th century due to the creation of dense village networks. Income silos which resulted in a reorientation of production activities in the framework of a feudal-type social system, are found towards the end of the millennium

Evolution and conservation of clonally-propagated crops: insights from AFLP data and folk taxonomy of the Andean tuber “oca,” Oxalis tuberosa.

by Eve Emshwiller

Emshwiller, Eve.  2006.  pp. 308-332 in: T. Motley, N. Zerega, and H. Cross (eds.), Darwin’s Harvest: New Approaches to the Origins, Evolution, and Conservation of Crops, Columbia University Press. [scanned book chapter]

Documenting Domestication

by Eve Emshwiller

Zeder, Melinda A., Dan Bradley, Eve Emshwiller, Bruce Smith.  2006.  Chapter 1 in: M. A. Zeder, D. Bradley, E. Emshwiller, B. Smith (eds.). Documenting Domestication: New Genetic and Archaeological Paradigms.  University of California Press.

Origins of Domestication and Polyploidy In the Andean Tuber Crop Oxalis Tuberosa Molina(Oxalidaceae)

by Eve Emshwiller

PhD Dissertation under the direction of Jeff Doyle, Cornell University, 1999.  PDF is ~14 MB.

Origins of domestication and polyploidy in oca (Oxalis tuberosa: Oxalidaceae). 2. Chloroplast-expressed glutamine synthetase data.

by Eve Emshwiller

Emshwiller, Eve and Jeff J. Doyle.  2002.  American Journal of Botany. 89(7):1042-1056.

In continuing study of the origins of the octoploid tuber crop oca, Oxalis tuberosa Molina, we used phylogenetic... more In continuing study of the origins of the octoploid tuber crop oca, Oxalis tuberosa Molina, we used phylogenetic analysis of DNA sequences of the chloroplast-active (nuclear encoded) isozyme of glutamine synthetase (ncpGS) from cultivated oca, its allies in the "Oxalis tuberosa alliance," and other Andean Oxalis. Multiple ncpGS sequences found within individuals of both the cultigen and a yet unnamed wild tuber-bearing taxon of Bolivia were separated by molecular cloning, but some cloned sequences appeared to be artifacts of polymerase chain reaction (PCR) recombination and/or Taq error. Nonetheless, three classes of nonrecombinant sequences each joined a different part of the O. tuberosa alliance clade on the ncpGS gene tree. Octoploid oca shares two sequence classes with the Bolivian tuber-bearing taxon (of unknown ploidy level). Fixed heterozygosity of these two sequence classes in all ocas sampled suggests that they represent homeologous loci and that oca is allopolyploid. A third sequence class, found in eight of nine oca plants sampled, might represent a third homeologous locus, suggesting that oca may be autoallopolyploid, and is shared with another wild tuber-bearing species, tetraploid O. picchensis of southern Peru. Thus, ncpGS data identify these two taxa as the best candidates as progenitors of cultivated oca.

Origins of Polyploid Crops

by Eve Emshwiller

Emshwiller, Eve.  2006.  In: M. A. Zeder et al. (eds.). Documenting Domestication: New Genetic and Archaeological Paradigms. University of California Press.

Genetic data and plant domestication

by Eve Emshwiller

Emshwiller, Eve.  2006.  In: M. A. Zeder et al. (eds.). Documenting Domestication: New Genetic and Archaeological Paradigms. University of California Press. [scanned book chapter]

Origins of domestication and polyploidy in oca (Oxalis tuberosa: Oxalidaceae) 3: AFLP data of oca and four wild, tuber-bearing taxa.

by Eve Emshwiller

Eve Emshwiller, Terra Theim, Alfredo Grau, Victor Nina and Franz Terrazas 2009. American Journal of Botany.  96(10):1839-1848.

Many crops are polyploids, and it can be challenging to untangle the often complicated history of their origins of... more Many crops are polyploids, and it can be challenging to untangle the often complicated history of their origins of domestication and origins of polyploidy. To complement other studies of the origins of polyploidy of the octoploid tuber crop oca (Oxalis tuberosa) that used DNA sequence data and phylogenetic methods, we here compared AFLP data for oca with four wild, tuber-bearing Oxalis taxa found in different regions of the central Andes. Results confirmed the divergence of two use-categories of cultivated oca that indigenous farmers use for different purposes, suggesting the possibility that they might have had separate origins of domestication. Despite previous results with nuclear-encoded, chloroplast-expressed glutamine synthetase suggesting that O. picchensis might be a progenitor of oca, AFLP data of this species, as well as different populations of wild, tuber-bearing Oxalis found in Lima Department, Peru, were relatively divergent from O. tuberosa. Results from all analytical methods suggested that the unnamed wild, tuber-bearing Oxalis found in Bolivia and O. chicligastensis in NW Argentina are the best candidates as the genome donors for polyploid O. tuberosa, but the results were somewhat equivocal about which of these two taxa is the more strongly supported as oca’s progenitor.

Documenting domestication: The intersection of genetics and archaeology.

by Eve Emshwiller

Zeder, Melinda A., Eve Emshwiller, Daniel G. Bradley, Bruce D. Smith. 2006. Trends in Genetics 22(3):139-155.

Domestication, a process of increasing mutual dependence between human societies and the plant and animal populations... more Domestication, a process of increasing mutual dependence between human societies and the plant and animal populations they target, has long been an area of interest in genetics and archaeology. Geneticists seek out markers of domestication in the genomes of domesticated species, both past and present day. Archaeologists examine the archaeological record for complementary markers – evidence of the human behavior patterns that cause the genetic changes associated with domestication, and the morphological changes in target species that result from them. In this article, we summarize the recent advances in genetics and archaeology in documenting plant and animal domestication, and highlight several promising areas where the complementary perspectives of both disciplines provide reciprocal illumination.