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Featured researches published by Bohdan Lojka.


Genetic Resources and Crop Evolution | 2011

Ethnobotanical knowledge and agrobiodiversity in subsistence farming: case study of home gardens in Phong My commune, central Vietnam

Martina Vlkova; Zbynek Polesny; Vladimir Verner; Jan Banout; Marek Dvorak; Jaroslav Havlik; Bohdan Lojka; Petr Ehl; Jitka Krausova

Ethnobotanical survey was conducted in 101 randomly selected home gardens of Phong My commune, central Vietnam, situated in the buffer-zone of Natural Reserve. Data were collected through semi-structured questionnaires and direct observation. Sixty-seven species belonging to 35 families were identified to be used for various purposes. For each species the botanical and vernacular names, plant parts used and main purposes of use are given. The major use categories reported for plant species were food (86%), medicine (32%) and firewood (32%), however, seventy-seven percent of all inventoried plants have multiple uses. The species Artocarpus heterophyllus Lam., Citrus grandis Osbeck, Citrusreticulata Blanco, Ipomoea batatas (L.) Lam. and Musa spp. were identified as the main sources of plant foods consumed within the households. Statistical analyses indicated by Shannon-Wiener and Margalef indices have shown that local species diversity and richness is affected by home garden size. On the contrary, no relationship between diversity and home garden age was found. On the basis of a cluster analysis of plant species diversity, five home garden types were differentiated. In comparison to previously reported studies on tropical home gardens, the diversity in Phong My is lower, probably due to market-oriented strategy. Nevertheless, based on the results achieved, we can conclude that useful plants cultivated in local home gardens provide valuable foods complementing daily diet and subsequently contributing to socioeconomic status of the households.


Annals of Forest Science | 2016

Genetic diversity and hybridization in the two species Inga ingoides and Inga edulis: potential applications for agroforestry in the Peruvian Amazon

Alexandr Rollo; Bohdan Lojka; David Honys; Bohumil Mandák; Julio A. Chia Wong; Carmen Santos; Rita Costa; Celestino Quintela-Sabarís; Maria Margarida Ribeiro

Key messageSlash and burn practices affect tropical forests. Our results showed strong introgression between Inga ingoides and Inga edulis in the species contact area. Interspecific hybridization could be sought to improve yield and tolerance to flooding and further increase the economic potential of the poorly drained Amazonian soils and minimize deforestation.ContextInga species are important components of tropical American forests, as well as a local food source. Little is known about the genetic structure of these species; in particular the amount of introgression among species remains unknown.AimsWe assessed the degree of genetic divergence and introgression among populations of I. ingoides (Rich.) Willd. and I. edulis Mart. (Fabaceae) from three Peruvian Amazon tributary rivers.MethodsUsing microsatellite markers we determined the genetic structure of populations using an analysis of molecular variance and a Bayesian analysis of population structure in areas affected by seasonal river fluctuations and in ‘terra firme’ forests.ResultsOverall genetic differentiation was weak. The degree of genetic variation was similar in the two species. A putatively strong introgression was detected between the two species and an intense gene flow was identified among populations. This indicates that an intense gene flow had happened in the past, leading also to a small differentiation among populations within species.ConclusionSelection of natural hybrids or artificial hybridization between I. edulis and I. ingoides could be applied to improve legume size and yield in the later species, while maintaining tolerance to flooding. Improved I. ingoides could be used in multipurpose agroforestry on open areas along the rivers, instead of using the usual slash and burn practice to create inland open areas.


Scientia Agriculturae Bohemica | 2015

Genetic Diversity Of Plukenetia Volubilis L. Assessed By ISSR Markers

Martin Ocelak; P. Hlásná Čepková; Iva Viehmannová; Zdislava Dvořáková; Danter Cachique Huansi; Bohdan Lojka

Abstract The diversity and genetic relationships in 173 sacha inchi samples were analyzed using ISSR markers. Thirty ISSR primers were used, only 8 showed variability in tested samples. ISSR fragments ranged from 200 to 2500 bp. The mean number of bands per primer was 12 and the average number of polymorphic bands per primer was 11. The lowest percentages of polymorphic bands (27%), gene diversity (0.103), and Shannon’s information index (0.15) were exhibited by the Santa Lucia population, which was also geographically most distant. This fact may be attributed to a very small size of this group. In contrast, the Dos de Mayo population exhibited the highest percentage of polymorphic bands (78%), and the Santa Cruz population the highest Nei’s gene diversity index (0.238) and Shannon’s information index (0.357). The obtained level of genetic variability was 36% among tested populations and 64% within populations. Although the diversity indices were low, a cluster analysis revealed 8 clusters containing mainly samples belonging to individual populations. Principal coordinate analysis clearly distinguished Chumbaquihui, Pucallpa, Dos de Mayo, and Aguas de Oro populations, the others were intermixed. The obtained results indicated the level of genetic diversity present in this location of Peru, although it is influenced by anthropological aspects and independent on the geographical distances.


PLOS ONE | 2017

Morphological and genetic diversity of camu-camu [Myrciaria dubia (Kunth) McVaugh] in the Peruvian Amazon

Jan Šmíd; Marie Kalousová; Bohumil Mandák; Jakub Houška; Anna Chládová; Mario Pinedo; Bohdan Lojka

Camu-camu [Myrciaria dubia (Kunth) McVaugh] is currently an important and promising fruit species grown in the Peruvian Amazon, as well as in Brazil, Colombia, and Bolivia. The species is valued for its high content of fruit-based vitamin C. Large plantations have been established only in the last two decades, and a substantial part of the production is still obtained by collecting fruits from the wild. Domestication of the species is at an early stage; most farmers cultivate the plants without any breeding, or only through a simple mass selection process. The main objective of the study was to characterize morphological and genetic variation within and among cultivated and natural populations of camu-camu in the Peruvian Amazon. In total, we sampled 13 populations: ten wild in the Iquitos region, and three cultivated in the Pucallpa region in the Peruvian Amazon. To assess the genetic diversity using seven microsatellite loci, we analyzed samples from ten individual trees per each population (n = 126). Morphological data was collected from five trees from each population (n = 65). The analysis did not reveal statistically significant differences for most of the morphological descriptors. For wild and cultivated populations, the observed heterozygosity was 0.347 and 0.404 (expected 0.516 and 0.506), and the fixation index was 0.328 and 0.200, respectively. Wild populations could be divided into two groups according to the UPGMA and STRUCTURE analysis. In cultivated populations, their approximate origin was determined. Our findings indicate a high genetic diversity among the populations, but also a high degree of inbreeding within the populations. This can be explained by either the isolation of these populations from each other or the low number of individuals in some populations. This high level of genetic diversity can be explored for the selection of superior individuals for further breeding.


Bosque (valdivia) | 2016

Genetic diversity in Guazuma crinita from eleven provenances in the Peruvian Amazon revealed by ISSR markers

Lady Laura Tuisima Coral; Petra Hlásná Čepková; Bohdan Lojka; John C. Weber; Serafín Filomeno Alves-Milho

Guazuma crinita es una importante especie maderable de rapido crecimiento ampliamente usada en sistemas agroforestales en la Amazonia Peruana. Los objetivos de nuestra investigacion fueron; (i) evaluar la diversidad genetica de G. crinita revelada por marcadores de intersecuencias simples repetidas (ISSR) ademas de (ii) estimar la correlacion entre las distancias geneticas y geograficas entre procedencias. La muestra incluyo 44 genotipos de 11 procedencias en las cuencas de Aguaytia y Pachitea en la Amazonia Peruana. Diez cebadores ISSR amplificaron un total de 65 bandas de las cuales 61 fueron polimorficas (93,8 %). El rango de amplificaciones de ADN vario desde 260 hasta 2.200 bp. Entre las procedencias, Macuya exhibio el mayor porcentaje de bandas polimorficas (PPB) con 67,7 %, 0,21 diversidad genetica de Nei (He) y 0,33 de indice de Shannon (I). La diferenciacion genetica general (Gst) fue 0,03, indicando 97 % de la variacion genetica dentro de las procedencias. El flujo genetico (Nm) fue 12,9 alelos por generacion. El analisis de agrupamiento no estuvo relacionado con el origen geografico sugiriendo una fuente genetica en comun. Sin embargo, se encontro una correlacion positiva debil (r = 0,27, P < 0,05) entre las distancias geneticas y geograficas. Este es el primer estudio sobre la diversidad y estructura genetica de G. crinita. Se recomiendan estrategias de conservacion in situ para las poblaciones con altos niveles de diversidad genetica


Archive | 2017

Multistrata Systems: Potentials and Challenges of Cocoa-based Agroforests in the Humid Tropics

Bohdan Lojka; L. Pawera; M. Kalousová; Ludvik Bortl; Vladimir Verner; Jakub Houška; Wouter Vanhove; P. Van Damme

Multistrata agroforests comprise a wide range of agroforestry practices that includes assemblage of woody and nonwoody plant components, with the wide range of practices on the continuum from using shade trees in perennial plantation to very diversified agroforests that mimic the original forest-like structure. In the humid tropical lowlands, such systems often consist of cocoa (Theobroma cacao) grown under the shade of trees. In this review, we explore the reliability of research on and the feasibility of achieving the environmental and economic benefits of cocoa agroforests, highlighting future opportunities and challenges of cocoa growing. Unsustainable intensification in a form of monocultures with high agricultural inputs reduces ecological resilience of a land-use system, whereas paradoxically, environmental and climate changes require more than ever a higher capacity of land-use systems to cope with increasing global environmental pressure. Over the past decade, a number of new studies focusing on cocoa agroforests have been published. We review current cultivation of cocoa in the world and outline the establishment and management of cocoa agroforests. Further on, we explored the idea that cocoa agroforests could be a solution to prevent phenomenon of boom-and-bust cycle of cocoa cultivation and highlighted the possibilities for improvement of cocoa cultivation using its vast genetic base. Then the benefits of cocoa agroforests for (agro)biodiversity and soil conservation are summarized and economic perspectives of multistrata systems assessed. In final discussion, we performed a SWOT analysis, highlighting future opportunities and challenges and proposing recommendation to improve the extension, adoption and sustainability of cocoa agroforests.


Agricultura Tropica et Subtropica | 2012

Preliminary Study of Diversity of Plukenetia volubilis Based on the Morphological and Genetic Characteristics

Blanka Krivankova; Petra Hlásná Čepková; Martin Ocelak; Gaelle Juton; Miroslav Bechyne; Bohdan Lojka

Abstract The aim of this study was to make an initial step in clarification of morphological diversity of sacha inchi (Plukenetia volubilis L.), a traditional oilseed crop, together with use of ISSR primers for a preliminary assessment of genetic variability in the species. Quantitave and qualitative morphological data together with leaf samples for twenty plant individuals of sacha inchi from five distinct populations were gathered in three different communities neighbouring the city of Pucallpa in Peru. Morphological data were processed into PCA analysis graph while for DNA analysis the method of fingerprinting processed into PCO graph and dendrogram was used. Visible morphological dissimilarities in the plant appearance were confirmed and observable differences in phenotypical characteristics among different types of associated cultivations were recorded. For genetic variability twelve from eighteen ISSR primers used and tested in the study could be used directly for further molecular pursuit on this species. Dendrogram with six main clusters was created and thus confirmed polymorphism as allogamy plants shows. Obtained results contributed to the identification of suitable method for further assessment of genetic variability within this species. New horizons for the focus of further research and improvements in onward development and genetic conservation of sacha inchi cultivation were identified, thus linking the observation of morphological features with DNA analysis proved as effective.


Solar Energy | 2011

Design and performance evaluation of a Double-pass solar drier for drying of red chilli (Capsicum annum L.)

Jan Banout; Petr Ehl; Jaroslav Havlik; Bohdan Lojka; Zbynek Polesny; Vladimir Verner


Agroforestry Systems | 2007

Performance of an improved fallow system in the Peruvian Amazon—modelling approach

Bohdan Lojka; Jana Lojkova; Jan Banout; Zbynek Polesny; Daniel Preininger


Journal of Food Process Engineering | 2010

Effect of solar drying on the composition of essential oil of Sacha culantro (Eryngium foetidum L.) grown in the Peruvian Amazon.

Jan Banout; Jaroslav Havlik; Michal Kulik; Pavel Kloucek; Bohdan Lojka; Irena Valterová

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Jan Banout

Czech University of Life Sciences Prague

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Zbynek Polesny

Czech University of Life Sciences Prague

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Vladimir Verner

Czech University of Life Sciences Prague

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Daniel Preininger

Czech University of Life Sciences Prague

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Jakub Houška

Czech University of Life Sciences Prague

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Jaroslav Havlik

Czech University of Life Sciences Prague

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Petra Hlásná Čepková

Czech University of Life Sciences Prague

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Jana Lojkova

Czech University of Life Sciences Prague

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Petr Ehl

Czech University of Life Sciences Prague

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