ABSTRACT Astrocaryum aculeatum Mart. Moreover, Astrocaryum acaule Mart. are palm trees with ecological and extractive importance in the Amazon. These are hearty species that have been associated with archaeological sites and thrive in the presence of humans in certain areas. This work aimed to verify the effect of global climate change on the potential geographic distribution of A. acaule and A. aculeatum in the current period and future climate scenarios using ecological niche modeling in Brazilian phytogeographic domains. The modeling was based on 19 bioclimatic variables obtained from the Worldclim website and four algorithms (Climate space model, Envelope Score, Niche Mosaic, and Environmental Distance). Additionally, the Environmental Distance algorithm showed greater similarity regarding species distribution with potential occurrence in the five Brazilian domains (Amazon, Pantanal, Caatinga, Cerrado, and Atlantic Forest). The dispersion patterns were very similar between the two Astrocaryum palms though A. aculeatum was more sensitive to climatic variations. A. acaule may be more resilient to changes, as demonstrated by being able to recolonize in the southern portion of the Amazon in future scenarios in the year 2070. The modeling helped to delimit potential areas for A. aculeatum and A. acaule, indicating the need for the conservation of the species in more sensitive regions.

RESUMO Astrocaryum aculeatum Mart. e Astrocaryum acaule Mart. são palmeiras que apresentam importância ecológica e para o extrativismo na Amazônia. São espécies rústicas e que foram associadas a sítios arqueológicos e à presença de humanos em determinadas áreas. O objetivo deste trabalho foi verificar o efeito das mudanças climáticas globais na distribuição geográfica potencial de A. acaule e A. aculeatum, no período atual e em cenários climáticos futuros, utilizando a modelagem de nicho ecológico nos domínios fitogeográficos brasileiros. As modelagens foram baseadas em 19 variáveis bioclimáticas, obtidas no site do Worldclim, e quatro algoritmos (Climate space model, Envelope Score, Niche Mosaic e Enviromental Distance), dos quais o algoritmo Environmental Distance apresentou maior similaridade quanto à distribuição das espécies com ocorrência potencial nos cinco domínios brasileiros (Amazônia, Pantanal, Caatinga, Cerrado e Mata Atlântica). Os padrões de dispersão foram muito similares entre as duas palmeiras de Astrocaryum, porém A. aculeatum é mais sensível às variações climáticas. A. acaule tem potencial para ser mais resiliente às mudanças, podendo recolonizar a porção sul da Amazônia em cenários futuros, no ano de 2070. A modelagem auxiliou a delimitar as áreas potenciais de A. aculeatum e A. acaule, indicando a necessidade de conservação das espécies em regiões mais sensíveis.

ABSTRACT The importance of non-conventional food plants has been evidenced due to their great potential for phenotypic plasticity, resilience and resistance to permanence in inhospitable places. This study aimed to evaluate the natural distribution of two of these species (Eryngium foetidum and Fridericia chica) in the present period (2009-2019) and the projection for two future climate scenarios (RCP 4.5 - “less pessimistic” and RCP 8.5 - “more pessimistic”) in two-time intervals (2020-2050 and 2051-2070), in the six Brazilian phytogeographic domains. Nineteen bioclimatic variables obtained from the WorldClim database and four algorithm models were tested: Climate Space Model, Envelope Score, Niche Mosaic and Environmental Distance. The Environmental Distance algorithm presented the best discrimination of the models adjusted for the two species. From the projections, it is possible to perceive that the species are severely affected in the phytogeographic domains of the Amazon, Pantanal and Pampa, becoming practically extinct in the RCP 8.5 scenario, for the period of 2051-2070.

RESUMO A importância de plantas alimentícias não convencionais tem sido evidenciada devido ao seu grande potencial de plasticidade fenotípica, resiliência e resistência à permanência em lugares inóspitos. Objetivou-se estudar a distribuição natural de duas espécies dessas plantas (Eryngium foetidum e Fridericia chica) no período presente (2009-2019) e a sua projeção para dois cenários climáticos futuros (RCP 4.5 - “menos pessimista” e RCP 8.5 - “mais pessimista”) em dois intervalos de tempo (2020-2050 e 2051-2070), nos seis domínios fitogeográficos brasileiros. Foram utilizadas 19 variáveis bioclimáticas obtidas da base de dados do WorldClim e quatro modelos de algoritmos foram testados: Climate Space Model, Envelope Score, Niche Mosaic e Environmental Distance. O algoritmo Environmental Distance apresentou a melhor discriminação dos modelos ajustados para as duas espécies. A partir das projeções, é possível perceber que as espécies são severamente afetadas nos domínios fitogeográficos da Amazônia, Pantanal e Pampa, tornando-se praticamente extintas no cenário RCP 8.5 para o período de 2051-2070.

Abstract We evaluated the genetic diversity, coancestry and heritability of an E. benthamii trial. The 115 individuals were genotyped (13 SSR) and had their height and diameter at breast height (dbh) measured. Heritability was estimated using the RR-BLUP and the pairwise kinship coefficient method. An average of nine alleles per locus was observed. The expected heterozygosity (0.655) was similar to the observed heterozygosity, with the estimated inbreeding (0.02) being low. The group coancestry (0.051) demonstrates that the trees are related to some degree. The trees were clustered in five groups using the Evanno’s method. The average kinship within each group ranges from 0.042 to 0.082. The heritability estimated by RR-BLUP was low. The heritability estimated using the kinship coefficients is moderate, reaching estimated genetic gains of 14% for dbh. After knowing how genetic groups are distributed within the population, strategies for collecting, conserving, and using these germplasm resources can be performed.

RESUMO Stryphnodendron pulcherrimum é uma espécie medicinal usada entre as comunidades tradicionais da Amazônia devido à sua atividade bactericida e propriedades anti-infamatórias. Apesar de estar adaptada a ambientes rústicos, não há informações de como as mudanças climáticas poderão afetar a ocorrência da espécie. Objetivou-se avaliar a distribuição natural de S. pulcherrimum no período atual e como sua distribuição geográfica potencial poderá ser afetada diante de cenários de mudanças climáticas futuras nos domínios ftogeográficos brasileiros. Foram utilizadas 19 variáveis bioclimáticas a partir da base de dados do WorldClim. Quatro modelos de algoritmo (Climate Space Model, Envelope Score, Niche Mosaic e Enviromental Distance - presente) e um software (Open Modeller - futuro) foram utilizados para verificar a ocorrência potencial de S. pulcherrimum em cinco domínios (Amazônia, Cerrado, Caatinga, Mata Atlântica e Pantanal) e três períodos (2009-2019 - presente; 2020-2050 e 2051-2070 - futuro). Houve perdas de áreas favoráveis à ocorrência de S. pulcherrimum na Amazônia, Cerrado e Pantanal, e as mudanças climáticas globais poderão afetar sua distribuição natural especialmente na Mata Atlântica e Amazônia, sendo que, na Amazônia, a espécie pode estar totalmente extinta, no cenário mais pessimista, até 2070.

ABSTRACT Stryphnodendron pulcherrimum is a species used medicinally among traditional Amazonian communities for its bactericidal activity and anti-inflammatory properties. Despite being adapted to rustic environments, there is no information regarding how climate change might affect the species occurrence. The present study aimed to evaluate the natural distribution of S. pulcherrimum in the current period and how its potential geographic distribution may be affected in response to future climate change scenarios in Brazilian phytogeographic domains. A total of 19 bioclimatic variables were used from the WorldClim database. Four algorithm models (Climate Space Model, Envelope Score, Niche Mosaic and Environmental Distance - present) and one software (Open Modeller - future) were used to verify the potential occurrence of S. pulcherrimum in five Brazilian domains (Amazon, Cerrado, Caatinga, Atlantic Forest and Pantanal) and three intervals (2009-2019 - present; 2020-2050 and 2051-2070 - future). There were losses of areas favorable to the occurrence of S. pulcherrimum in the Amazon, Cerrado and Pantanal, and global climate change may affect its natural distribution especially in the Atlantic Forest and Amazon. In the Amazon, the species may be totally extinct, in the worst scenario, by 2070.

RESUMO Urena lobata L. é uma espécie comercial, utilizada para a extração de fibras nos estados do Amazonas e Pará, que apresenta relevante importância socioeconômica para a região Amazônica. Apesar de sua importância e vasta distribuição pelo Brasil, não existem dados sobre a resposta da espécie às mudanças climáticas globais. Objetivou-se apresentar a distribuição geográfica potencial de U. lobata no período atual (2009-2019) e prever áreas de adequabilidade climática para sua ocorrência em dois cenários futuros (RCP 4.5 e RCP 8.5), em dois intervalos de tempo (2020-2050 e 2051-2070), diante das mudanças climáticas globais. Foram utilizadas 19 variáveis bioclimáticas obtidas do WorldClim e quatro algoritmos (Climate Space Model, Envelope Score, Niche Mosaic e Environmental Distance), dos quais o Envelope Score foi o modelo mais representativo para a espécie, para verificar sua ocorrência ao longo dos domínios fitogeográficos brasileiros (Amazônia, Caatinga, Cerrado, Pantanal, Mata Atlântica e Pampa). Observou-se vulnerabilidade para a espécie, já que houve perdas de áreas favoráveis na Amazônia, Pantanal, Mata Atlântica, Cerrado e Caatinga, tornando-se praticamente extinta no pior cenário (RCP 8.5), no ano de 2070. Entretanto, para esse mesmo cenário e ano, observou-se aumento significativo de área no Pampa.

ABSTRACT Urena lobata L. is a commercial species used for fiber extraction in the Brazilian states of Amazonas and Pará that presents relevant socioeconomic importance for the Amazon region. Despite its importance and wide distribution throughout Brazil, there are no data on the species response to global climate change. This study aimed to present the potential geographical distribution of U. lobata in the current period (2009-2019) and predict areas of climatic suitability for its occurrence in two future scenarios (RCP 4.5 and RCP 8.5), at two time intervals (2020-2050 and 2051-2070), in the face of global climate change. A total of 19 bioclimatic variables were obtained from the WorldClim database and four algorithms (Climate Space Model, Envelope Score, Niche Mosaic and Environmental Distance), from which the Envelope Score was the most representative model for the species to verify its occurrence along the Brazilian phytogeographic domains (Amazon, Caatinga, Cerrado, Pantanal, Atlantic Forest and Pampa). Vulnerability was observed for the species, since there were losses of favorable areas in the Amazon, Pantanal, Atlantic Forest, Cerrado and Caatinga, becoming practically extinct in the worst scenario (RCP 8.5), in the year 2070. However, for this same scenario and year, there was a significant area increase in the Pampa.

ABSTRACT A strategy for genetic improvement of coffee Coffea canephora plants is to aggregate through artificial crossings the characteristics of the Conilon botanical variety, such as shorter height and drought resistance, with the higher average grain size and resistance to pests and diseases of the Robusta variety. Efficiently separating the clones into these two groups with the aid of appropriate analytical procedures makes field tasks easier for professionals and, thus, allows the systematic production of intervarietal hybrids. This study verifies if the non-parametric discriminant analyzes of the k-nearest neighbors (k-NN) and k-average neighbors (k-AN) would be able to correctly classify 130 coffee clones in their botanical varieties previously designated as Conilon, Robusta and Intervarietal Hybrids populations from ten quantitative agronomic characteristics, including the processed coffee beans yield, considering the existing population genetic divergence. These characteristics were found to be good discriminatory variables and the discriminant analyzes k-NN and k-AN, based on the principle of similarity by neighborhood, classified the clones with high hit rates. The k-AN discriminant analysis was able to better discriminate intervarietal hybrids from the group clones Conilon. The results correctly reflected the genetic diversity between the botanical varieties and intervarietal hybrids of Coffea canephora, allowing us to conclude that these classification methods can assist breeders in the main task of discriminating Conilon from Robusta clones.

RESUMO O estudo sobre a espécie nativa de rápido crescimento e capacidade de nodulação, Ormosia discolor, pretende conservar recursos genéticos e disponibilizar lotes de sementes de alto vigor para pomares de sementes. Este trabalho avalia as características físicas e fisiológicas de sementes de 20 O. discolor, como subsídio para a seleção de árvores matrizes superiores. Vinte matrizes selecionadas de uma população do estado do Amazonas foram inventariadas. Foram realizados testes físicos nas sementes coletadas, incluindo teor de água, biometria, peso de mil sementes e teste de permeabilidade do tegumento. Para estimativa do vigor e classificação quanto ao armazenamento, as sementes foram congeladas por cinco meses. O teste de germinação foi realizado a uma temperatura constante de 30 °C. O delineamento utilizado foi inteiramente casualizado, composto por 20 matrizes, 4 repetições e 25 sementes por parcela. As características de germinação avaliadas foram porcentagem de germinação, índice de velocidade, tempo médio de germinação e índice de sincronização. As sementes cortadas são mais eficientes para determinar o teor de água. Todas as variáveis biométricas são representativas para a seleção de lotes vigorosos, com ênfase no diâmetro geométrico, área superficial e esfericidade das sementes. As sementes das espécies foram classificadas como ortodoxas e com dormência física. A protrusão da raiz primária é a melhor característica morfológica para avaliação da germinação em laboratório. As matrizes 7, 16 e 10 apresentaram características superiores para dados dendrométricos e tecnológicos, sendo indicadas para marcação, monitoramento fenológico e plantio.

ABSTRACT The study on the native species of fast growth and nodulation capacity, Ormosia discolor, intends to conserve genetic resources and make available seed lots of high vigor for seed orchards. This work evaluates the physical and physiological characteristics of seeds from 20 O. discolor trees as a subsidy for selecting superior mother trees. Twenty matrices selected from a population in the state of Amazonas were inventoried. Physical tests were performed on the seeds collected, including water content, biometrics, the weight of one thousand seeds, and coat permeability test. For vigor estimates and classification regarding seed storage, the seeds were frozen for five months. The germination test was carried out at a constant temperature of 30 °C. It was used a completely randomized design consisting of 20 mother trees, 4 replicates, and 25 seeds per plot. The germination characteristics evaluated were germination percentage, speed index, mean germination time, and synchronization index. Cut seeds are more efficient for determining water content. All biometric variables are representative for the selection of vigorous lots, with emphasis on geometric diameter, surface area, and sphericity of seeds. Species seeds were classified as orthodox and as having physical dormancy. The protrusion of the primary root is the best morphological characteristic for evaluating germination in the laboratory. The mother trees 7, 16, and 10 showed superior characteristics for dendrometric and technological data, being indicated for marking, phenological monitoring, and planting.

Abstract This article sought to assess the genetic diversity within and between natural populations of Astrocaryum acaule by means of AFLP markers. Ninety individuals were sampled in three populations located in Manaus (state of Amazonas) across regions with different intensities of anthropogenic activity. Two clusters were differentiated by means of dendrograms and Bayesian cluster analysis, the first consisting of individuals from the Tarumã-Açu population in an intensely agricultural region, and the second, of populations from UFAM and Tupé conservation areas. The physical isolation of A. acaule populations has resulted in good conservation of its genetic identity, since anthropogenic activity is an important modifier of the genetic diversity of natural populations. Genetic diversity was higher within populations (74.58%) than between them (25.42%), which means that we have to collect representative samples from each of the genetically distinct groups for genetic conservation of the species. Therefore, in situ conservation is recommended.

Abstract Euterpe precatoria (Açaí-do-Amazonas) produces fruits of which the fresh pulp is consumed. It is almost exclusively collected by extractivist farmers, because no selected genotypes are available for the establishment of plantations. For the domestication and breeding of the species, mating system studies are needed for strategy formulation. This study evaluated the mating system of a natural population of E. precatoria. Thirteen progenies were genotyped with 13 microsatellite loci by capillary electrophoresis in an automated DNA sequencer. Estimates of single-locus and multilocus outcrossing rates were 1.0, and paternity correlation was low ( r ^ p ( m )>= 0.293). Euterpe precatoria families consist mainly of half-sibs and the reproductive strategy of the species is allogamy.

RESUMO Sacha inchi (Plukenetia volubilis) é nativa da região amazônica e suas sementes tem um alto teor de ácidos graxos mono e poliinsaturados, tornando-a interessante para a indústria farmacêutica e cosmética. O objetivo deste estudo foi analisar a diversidade genética de sacha inchi e caracterizar os acessos com base em características fenotípicas. Foi realizada coleta e biometria de frutos e sementes de 25 acessos do banco de germoplasma de sacha inchi da Embrapa Amazônia Ocidental em Manaus-AM. Os dados foram submetidos a análise de variância, distância de Mahalanobis, correlação canônica e diversidade genética por análise de variância molecular (AMOVA). Houve diferenças significativas entre as médias das variáveis analisadas, contudo, não houve correlação canônica significativa para os grupos de variáveis. De acordo com AMOVA, aproximadamente 60% da variação observada esteve dentro de acessos. Os resultados mostram variabilidade entre acessos, sendo importante explorar a variação intra-acessos para obter melhores resultados em programas de melhoramento.

ABSTRACT Sacha inchi (Plukenetia volubilis) is native to the Amazon region and has a high seed content of mono and polyunsaturated fatty acids, making it interesting for the pharmaceutical and cosmetic industry. The purpose of this study was to analyze sacha inchi genetic diversity and describe accessions based on phenotypic characteristics. Fruits and seeds of 25 accessions from the sacha inchi genebank of Embrapa Amazônia Ocidental in Manaus, Amazonas state, were sampled and biometrically measured. The data were subjected to analysis of variance, Mahalanobis distance, canonical correlation, and genetic diversity among and within accessions by analysis of molecular variance (AMOVA). There were significant differences among the means of the analyzed traits, but no significant canonical correlation for the groups of traits. According to AMOVA, approximately 60% of the observed variation was within accessions. The results showed variability among accessions, and that the variation within accessions should be explored to obtain best results in breeding programs.

Abstract Annatto (Bixa orellana) is a tropical crop native to the Americas with Amazonia as the likely center of origin of domestication. Annatto is important because it produces the dye bixin, which is widely used in the pharmaceutical, food, cosmetic and textile industries. A total of 32 microsatellite loci were isolated from a microsatellite-enriched genomic library, of which 12 polymorphic loci were used to characterize four populations of B. orellana and B. orellana var. urucurana, the wild relative. Higher genetic diversity estimates were detected for the wild populations when compared to the cultivated populations. Also, higher apparent outcrossing rates were found for the two wild than the cultivated populations. These results indicate a mixed mating system for the species. All markers described herein have potential to be used in further studies evaluating the genetic diversity, population dynamics, domestication, breeding, and conservation genetics of annatto.

RESUMO: Corynespora cassiicola é um ascomiceto cosmopolita amplamente conhecido como fitopatógeno em diversas culturas e, mais recentemente, como patógeno emergente em humanos. Na região Norte do Brasil é responsável por perdas significativas em cultivos tanto em casa de vegetação como em campo aberto. Neste estudo foi avaliada a variabilidade genética de 60 isolados de Corynespora cassiicola procedentes de diferentes hospedeiras e municípios do Amazonas, usando marcadores moleculares AFLP. Foram identificados sete grupos genéticos de acordo com dendrograma obtido pelo método de agrupamento UPGMA, indicando significativa variabilidade entre os isolados. Três isolados de diferentes hospedeiras (isolado 28, obtido de mamoeiro; isolado 55, obtido de pepineiro; e isolado 58, proveniente de tomateiro) permaneceram como indivíduos únicos em grupos distintos, sugerindo variação genética marcante em comparação com os demais e possível especificidade pela hospedeira de origem.

ABSTRACT: Corynespora cassiicola is a cosmopolitan ascomycete widely known as phytopathogen in several crops, and more recently as an emerging pathogen in humans. In this study the genetic variability of 60 isolates of Corynespora cassiicola from different hosts and cities of Amazonas was evaluated, using AFLP molecular markers. Seven genetic groups were identified according to a dendrogram obtained by the Unweighted Pair Group Method using Arithmetical Averages, indicating significant variability among the isolates. Three isolates of different hosts (28, obtained from papaya; 55, obtained from cucumber; and 58, from tomato) remained as single individuals in distinct groups, suggesting marked genetic variation in comparison to the other isolates and possible specificity by the host.

RESUMO Sacha inchi (Plukenetia volubilis L.) é uma espécie com benefícios nutracêuticos tradicionalmente consumida por populações indígenas e urbanas amazônicas. Estudos de diversidade genética e do sistema reprodutivo são necessários para a conservação e uso dos recursos genéticos da espécie. Objetivou-se estimar parâmetros de diversidade genética e do sistema reprodutivo de sacha inchi, utilizando-se marcadores Amplified Fragment Length Polymorphism (AFLP). Um total de 360 progênies de 30 subamostras da espécie foram analisadas, com três combinações de primers AFL. Foram estimadas, dentre outros parâmetros, a porcentagem de variação entre e dentro de famílias e a taxa de cruzamento. Os marcadores AFLP foram eficientes na diferenciação genética das progênies, revelando 251 (98,82 %) fragmentos polimórficos. A análise de variância molecular mostrou que a maior parte da variação ocorre entre famílias (57,16 %). No entanto, a diferenciação genética dentro destas foi considerável (42,84 %), podendo ser explorada em programas de melhoramento. A estimativa da taxa de cruzamento multiloco foi alta (0,957), indicando se tratar de uma espécie predominantemente alógama. Por outro lado, 33,7 % dos cruzamentos ocorreram entre indivíduos aparentados. A estimativa para cruzamentos biparentais revelou que as progênies são constituídas principalmente por meios-irmãos (66,9 %) e irmãos-completos (28,8 %). Para fins de melhoramento e conservação genética ex situ, sementes de sacha inchi devem ser coletadas de um grande número de plantas matrizes.

ABSTRACT Sacha inchi (Plukenetia volubilis L.) is a species with nutraceutical benefits traditionally consumed by Amazonic indigenous and urban communities. Studies on the genetic diversity and mating system are required to preserve and make the best use of the genetic resources for this species. This study aimed to estimate the genetic diversity and mating system parameters of sacha inchi progenies using Amplified Fragment Length Polymorphism (AFLP) markers. A total of 360 progenies from 30 accessions of sacha inchi were analyzed using three AFLP primers combinations. The percentage variation between and within families and the crossing rate, among other parameters, were estimated. The AFLP markers were efficient in genetically differentiating progenies, revealing 251 (98.82 %) polymorphic fragments. The analysis of molecular variance showed that the strongest variation occurs between progenies (57.16 %). However, the genetic differentiation within progenies was considerable (42.84 %), and could be exploited in breeding programs. The estimated population outcrossing rate was high (0.957), indicating it is a predominantly allogamous species. On the other hand, 33.7 % of the crosses occurred between related individuals. The estimate for biparental crosses revealed that the progenies consisted mainly of half-siblings (66.9 %) and full-siblings (28.8 %). For purposes of breeding and ex situ genetic conservation, sacha inchi seeds should be collected from a large number of parent plants.

Abstract The objective of this study was to analyze the genetic diversity among and within populations of Brazil nut by Amplified Fragment Length Polymorphism markers. Five populations with 30 plants each of the state of Amazonas, Brazil, two populations from the Farm Aruanã (Aruanã Carolina and Aruanã Brastor), in Itacoatiara, one from the municipality of Parintins and two from the municipality of Manaus (Instituto Federal do Amazonas - IFAM and Manaus Airport) were evaluated. Four primer combinations were used and 306 polymorphic bands (93.3%) were obtained. Genetic differentiation within and among populations was tested by analysis of molecular variance. The presence of genetic divergence was greater within populations (51.88%) than among populations (48.11%) and the Fst value was 0.48. Two groups were formed by interpopulation grouping: the first consisted of populations from plantations in Aruanã Carolina, Aruanã Brastor and Manaus IFAM, and the second of natural populations from Parintins and Manaus Airport.

Resumo: O objetivo deste trabalho foi avaliar os efeitos dos agentes solidificantes ágar e phytagel e do carvão ativado no cultivo in vitro de duas variedades de maná cubiu (Solanum sessiliflorum): Thaís e Santa Luzia. As características fitotécnicas analisadas incluíram número de folhas, número de raízes, comprimento de parte aérea e raiz, e massa de matéria fresca de parte aérea e raiz. Independentemente da variedade, o phytagel foi superior ao ágar como meio de cultura. Observou-se maior número de folhas e comprimento da parte aérea na variedade Santa Luzia, na ausência de carvão. A variedade Thaís apresentou maior comprimento da parte aérea e da raiz na presença de carvão.

Abstract: The objective of this work was to evaluate the effects of the solidifying agents agar and phytagel and of activated charcoal on the in vitro cultivation of two maná cubiu (Solanum sessiliflorum) varieties: Thaís and Santa Luzia. The phytotechnical characteristics analyzed included number of leaves, number of roots, shoot and root length, and fresh matter of shoot and root. Regardless of the variety, phytagel was superior to agar as a culture medium. A greater number of leaves and longer shoots were observed in the Santa Luzia variety, in the absence of charcoal. The Thaís variety showed longer shoots and roots in the presence of charcoal.