Umbu Tree Research Articles

UMBU TREE (Spondias tuberosa Arr. Cam. - Anacardiaceae): FROM EXTRACTIVE TO PLANTED CULTURE IN BRAZIL

Umbu tree (Spondias tuberosa Arr. Cam.) is botanical species native to the Caatinga that plays significant cultural and economic role in Northeast Brazil. The aims of this study to evaluate the trend in umbu fruit production over a period of 21 years and to discuss the cultivation of the species, associated with its socioeconomic and environmental advantages in the semiarid region of Northeast Brazil. Data on extractive production and the monetary value of umbu fruit were obtained from the official platform of the Brazilian Institute of Geography and Statistics. Silvicultural aspects cultivation, management, and its market was obtained from specialized literature. Descriptive statistics on the data set and a trend analysis through regression model fitting was carried out using JMP® software. A downward trend in umbu tree fruit was estimated for most states, except for Alagoas, Paraíba, and Rio Grande do Norte. Alagoas was the only one with the best average variation (74.6%) in production and price (US$ 0.83) per kg of production via extractivism. The cultivating through plantations for commercial fruit umbu production is an alternative to overcome the declining trend in extractivism, ensuring continuation of family income and environmental protection of umbu tree populations in their natural habitats.

SNP-based analysis reveals high genetic structure and diversity in umbu tree (Spondias tuberosa Arruda), a native and endemic species of the Caatinga biome

SNP-based analysis reveals high genetic structure and diversity in umbu tree (Spondias tuberosa Arruda), a native and endemic species of the Caatinga biome

Gas exchange in umbu tree accessions

The objective of this work was to evaluate gas exchanges in umbu tree accessions. A 5 × 7 × 2 split-split plot experiment was carried out in a completely randomized design (five accessions – BRS-68, EPAMIG-05, BGU-61, BGU-75, and BGU-50 × seven evaluation dates × two reading times – 8 a.m. and 2 p.m.) with three repetitions. The lower leaf temperatures recorded in BRS-68 and EPAMIG 05 accessions favor higher net photosynthetic rates, water use efficiency and instantaneous carboxylation efficiency compared to BGU 61 accession. Umbu tree regulates transpiration by reducing stomatal conductance under high vapor pressure deficit, although the tree increases transpiration as a defense strategy against heat stress, even with a reduction in stomatal conductance. High temperatures limit instantaneous carboxylation efficiency, photosynthetic rate, and the ratio of photosynthesis to radiation incident on the leaf. Transpiration varies directly with stomatal conductance, while intrinsic water use efficiency varies inversely with internal CO2 concentration.

Brazil plum fruit (Spondias tuberosa) stored under refrigeration with different types of packaging

The objective of this work was to evaluate the use of packaging to maintain quality and extending the postharvest life of umbu tree fruits in different storage periods, stored at 14 ° C and 90% UR. The experimental design used was completely randomized, in a 4 x 4 factorial scheme, with four evaluation periods (0, 4, 8 and 12 days after storage) and four packaging systems (PET, PET with holes, PVC and LDPE), with four replicates and four fruits per experimental unit. The physical and chemical characteristics were evaluated, such as, objective color of the peel, firmness of the intact fruit, soluble solids, titratable acidity, pH and loss of fresh mass. The results were submitted to analysis of variance and regression, using the SISVAR software program. The characteristics of the quantitative factor (types of packaging) were compared by the Tukey’s test at 5% probability, while for those of the qualitative factor (storage period), the adjustment was made to the regression model. There was a significant interaction between packaging and storage periods only for loss of mass. The luminosity characteristic was significant only for the type of packaging. For the other variables such as chroma, HUE angle, firmness, titratable acidity and pH, there was no significant interaction between the factors tested, having significance only for storage period. For soluble solids, there was no significance for packaging and storage period. The PVC and PET packaging were effective in delaying the loss of mass, and withering of the fruits up to 12 days, which kept under refrigeration at 14°C. It was verified that along the storage time, physical and chemical changes occur in the umbu tree fruits.

Variação colorimétrica e correlação de parâmetros biométricos entre matrizes de umbu

Abstract The umbu tree is an endemic species and is found in the Brazilian semi-arid. Umbu is highly appreciated for its socioeconomic importance and significant diversity of quality attributes. This study aims to explore the color-related variations between umbu matrices, and to evaluate the correlation between the main biometric attributes of quality. With this, 14 matrices were explored at the commercial ripening stage and submitted to colorimetric analysis (a*, b*, C* and L*) and determination of biometric parameters (fruit mass, length, width, shape, firmness, percentages of peel, seed, pulp, and yield). The colorimetric parameters were evaluated by the Scott-Knott mean test and dendrogram, and biometrics were submitted to linear correlation analysis. It was observed that in the peel green predominates, compared to the pulp, and the lowest luminosity indexes (L*) consist of the fruits with hairy peel. The saturation (C*) has a direct relationship with parameter b*; in addition, the dendrogram indicates the formation of four groups between the matrices. The correlation analysis of biometric parameters showed significant tendencies. Therefore, the results reinforce that the parameters evaluated can provide an important tool in selecting and quality control these fruits, since the required characteristics change according to their commercial purpose.

Resposta fotossintética de umbuzeiro ao deficit de pressão de vapor

Abstract The objective of this work was to evaluate the photosynthetic response to vapor pressure deficit (VPD) in umbu (Spondias tuberosa) tree accessions. The experiment was carried out in a completely randomized design in a 5×7×2 factorial arrangement (five umbu accessions – BRS-68, EPAMIG-05, BGU-61, BGU-75, and BGU-50 –, seven evaluation times, and two reading times – at 8 a.m. and 2 p.m.) in split-split plots in time. Leaf temperature increased with air temperature. The variation of stomatal conductance and transpiration with the VPD was not significant. Net photosynthesis rate, carboxylation efficiency, and instantaneous water-use efficiency decreased with increasing VPD in all accessions, except in BRS-68, whose rates remained positive.

Research Article Development and transferability of microsatellite loci for <i>Spondias</i> <i>tuberosa</i> (Anacardiaceae: Sapindales), a species endemic to the Brazilian semi-arid region

The umbu tree (Spondias tuberosa) is one of the best known plants of the Brazilian semi-arid region; it has great potential for the fruit market due to excellent consumer acceptance. This tree is not presently cultivated; fruit commercialization is based on extrativism. Consequently, there has been little research on the genetics of this species. Our objective was to develop, evaluate and transfer single sequence repeat (SSR) loci to S. tuberosa to support work on genetic resources and agronomic improvement of this species. SSR loci for the umbu tree were developed from a new enriched genomic library and evaluated by PCR. Fourteen SSR loci developed for S. radlkoferi were evaluated for use in S. tuberosa, as well as 18 SSR loci previously identified for this species. DNA was extracted from leaf tissue of eight umbu trees available that are part of a germplasm collection located in Petrolina, PE, Brazil. Of the 14 pairs of primers that were tested, six yielded amplicons, and two showed polymorphism in the genotyped samples. All SSR loci of S. radlkoferi transferred to the umbu tree species, yielding amplicons; however, only four were polymorphic in this sample. Among the eighteen available species-specific SSR loci, six were polymorphic for these eight trees. Among the 38 loci that we evaluated, 12 were polymorphic in the sample, including two new loci for S. tuberosa. The number of alleles ranged from 2 to 12, and 10 of them were moderately to highly informative (PIC>0.50), while nine had heterozygosity greater than 0.50. The six new SSR loci and the 14 SSR loci transferred from S. radlkoferi increase the number of available loci for population studies, germplasm collection and resource management for the development of new umbu tree cultivars.

Enraizamento de estacas de umbuzeiro potencializado pela aplicação de ácido ácido indol-3-butírico (AIB)

The umbu tree is a species of the genus Spondias of big expression in the semiarid region, since it is present in all the Brazilian northeast. However, the lack of a propagation protocol is one of the barriers to commercial cultivation of this species. In this sense, the objective of this study was to evaluate the effect of the treatment in the matrix plant with zinc in the promotion of rooting of umbu tree cuttings treated with indolebutyric acid (IBA). It was adopted a completely randomized design with nine treatments at levels determined by the matrix “Central Box Compound” for zinc concentrations (0, 5.8, 20, 34.2 and 40 mg L-1) and combinations with concentrations of AIB (0; 872.35; 3000, 5127.65 and 6000 mg L-1) and four replicates. Each experimental unit consisted of 12 stakes. Treatment of matrix plants with zinc does not affect the development of roots and shoots of umbu tree cuttings. Indolbutyric acid promotes better development and rooting of umbu tree cuttings at the concentration of 6000 mg L-1. However, there is less growth of the aerial part of the cuttings with the use of this vegetal regulator.

Características físicas e químicas de acessos de umbuzeiros (Spondias tuberosa Arr. Cam)

The caatinga is a biome rich in biodiversity occupying an area of about 11% of the national territory, in asemi-arid climate, with typical Brazilian xerophytic vegetation, and. The umbu tree (Spondias tuberosa Arr. Cam.) is an endemic species of this type of vegetation that presents great economic importance, as an alternative source of income, especially in drought periods.Thus, this work had the objective to characterize, physically and chemically, the umbu fruits. Ten fresh fruits of umbu were used, from 10 trees in five municipalities in the state of Bahia, Brazil (Anagé, Belo Campo, Brumado, Caraíbas and Macarani), totaling 100 fruits per municipality. The evaluations were carried out at the Plant Breeding and Production Laboratory of the State University of Southwest of Bahia in March 2016. The following biometric characteristics were analyzed: length, diameter, fruit and endocarp thickness, fruit mass, peel mass, pulp mass, endocarp mass, and also total soluble solids, pH and titratable total acidity. Data of independent samples were submitted to analysis of variance and the means were compared by the t test, at 5% probability. Variability of the physical and chemical characteristics was observed. The fruits from the municipality of Macarani stand out in relation to length, width, fruit thickness, total fruit mass, peel mass, pulp yield, pH and soluble solids which confer desirable quality for in natura consumption and industrial processing.

An AFLP estimation of the outcrossing rate of <i>Spondias tuberosa</i> (Anacardiaceae), an endemic species to the Brazilian semiarid region

The umbu tree (Spondias tuberosa) is one of the most important endemic species to the Brazilian tropical semiarid region. The umbu tree has edible fruits with a peculiar flavor that are consumed in natura or in a semi-industrialized form, such as jams, candies and juices. The majority of endemic species to Brazilian semiarid region have not been studied or sampled to form germ-plasm collections, which increases the risk of losing genetic variability of the adapted species to xerophytic conditions. The aim of this study was to estimate outcrossing rates in S. tuberosa using a multilocus mixed model in order to guide genetic resources and breeding programs of this species. DNA samples were extracted from 92 progenies of umbu trees, which were distributed among 12 families. These trees were planted by seed in 1991 in Petrolina, PE, Brazil. The experimental design was a randomized block, with a total of 42 progenies sampled in three regions. The experimental units were composed by five plants and five replications. The outcrossing rate was estimated by the multilocus model, which is available in the MLTR software, and was based on 17 polymorphic AFLP bands obtained from AAA_CTG and AAA_CTC primer combinations. The observed heterozygotes ranged from 0.147 to 0.499, with a maximum frequency estimated for the AAA_CTC 10 amplicon. The multilocus outcrossing estimation (t(m)) was 0.804 +/- 0.072, while the single-locus (t(s)) was 0.841 +/- 0.079, which suggests that S. tuberosa is predominantly an outcrossing species. The difference between t(m) and t(s) was -0.037 +/- 0.029, which indicates that biparental inbreeding was nearly absent. The mean inbreeding coefficient or fixation index (F) among maternal plants was--0.103 +/- 0.045, and the expected F was 0.108, which indicates that there was no excess of heterozygotes in the maternal population. The outcrossing estimates obtained in the present study indicate that S. tuberosa is an open-pollinated species. Biometrical models applied to this species should therefore take into account the deviation from random outcrossing to estimate genetic parameters and the constitution of broad germplasm samples to preserve the genetic variability of the species. Outcrossing rates based on AFLP and the mixed-mating model should be applied to other studies of plant species in the Brazilian semiarid region.

Estimativas de polinização cruzada em população de Spondias tuberosa Arruda (Anacardiaceae) usando marcador AFLP

O umbuzeiro é uma das espécies mais importantes do semiárido brasileiro, devido à sua capacidade de produzir frutos em ambiente de estresse hídrico. O objetivo deste estudo foi estimar taxas de polinização cruzada em umbuzeiro (<img border=0 src="/img/revistas/rarv/v35n3s1/a13form02.jpg" />), considerando-se a frequência de heterozigotos observada e esperada nas populações maternal e de descendentes (M1), respectivamente, e a estimativa de multilocos (M2), de forma a orientar programas de preservação e melhoramento genético da espécie. Amostras de DNA extraído de uma população maternal de 96 plantas, estabelecidas no campo em 1991, em Petrolina, PE, bem como DNA de um indivíduo descendente de cada planta-mãe, foram analisadas para 16 bandas polimórficas das combinações de primer de AFLPAAA_CTG e AAA_CTC. No M1, considerou-se a frequência de heterozigotos estimada pela raiz quadrada de 1 menos a frequência de ausência de fragmentos AFLP, tanto para a população maternal (frequência observada) quanto para a população de descendentes (frequência esperada), enquanto no M2 a estimativa foi obtida por estimativa multilocos (<img border=0 src="/img/revistas/rarv/v35n3s1/a13form02.jpg" />m). As estimativas de <img border=0 src="/img/revistas/rarv/v35n3s1/a13form02.jpg" />no M1 variaram de 1,74 a 0,50, com média de 1,063. Como valores de <img border=0 src="/img/revistas/rarv/v35n3s1/a13form02.jpg" />acima de 1,0 são biologicamente inaceitáveis, ficou demonstrado que M1 não foi apropriado para estimar <img border=0 src="/img/revistas/rarv/v35n3s1/a13form02.jpg" />. As frequências de óvulos e pólen para 15 locos de AFLP foram iguais, indicando boa adequação do modelo de acasalamento misto no M2. A taxa <img border=0 src="/img/revistas/rarv/v35n3s1/a13form02.jpg" />m obtida pelo M2 foi de 0,719, próxima de estimativas prévias com isoenzimas em outras populações da espécie. Os resultados indicam que o umbuzeiro é predominantemente de polinização cruzada e há necessidade de amostras amplas para preservar a variabilidade genética da espécie.

Water relations and organic solutes production in four umbu tree (Spondias tuberosa) genotypes under intermittent drought

In order to evaluate changes in leaf water potential (ψw) and solute accumulation induced by intermittent drought, an research was performed under greenhouse conditions using four umbu tree genotypes (GBU 44, GBU 48, GBU 50 and GBU 68) and two water treatments (control and stressed by withholding water), with four replicates. The ψw was measured in four-hour intervals during a 24-hour period at the first stomatal closure and at the end of the experimental period. Carbohydrates, amino acids, protein and proline contents were also evaluated in leaves and roots. Significant differences were found in most of the studied parameters. The lower ψw hour was between 800 h and 1200 h. GBU 50 reduced significantly ψw in stressed plants at 800 h, while control plants reduced at 1200 h . GBU 68 presented the higher ψw. The extending of the stress induced reductions to carbohydrates in the leaves of all genotypes, increases in amino acids to GBU 44 and 48, and reductions of 40% and 43% to GBU 50 and 68, respectively; results also showed alterations in proline content. In the roots, increases in carbohydrates were observed only in GBU 48. Alterations in amino acids, protein, and proline were verified. Umbu trees presented isohydric behavior maintaining high leaf water potential and a great variability in organic solutes accumulation in response to drought with marked differences among the genotypes.

Stomatal changes induced by intermittent drought in four umbu tree genotypes

Transpiration (E), diffusive resistance (r s) and anatomical parameters were measured in plants of four grafted umbu tree genotypes (GBUs 44, 48, 50 and 68) in order to evaluate alterations induced by intermittent drought and possible genotypic variations. Transpiration measurements were taken daily until stomatal closure by withholding water. Measurements were also taken, when the plants were re-watered and the watering was interrupted again. This cycle was repeated for a period of 31 days (stress period). The control plants were also irrigated daily. A regular pattern in the stomatal opening/closing mechanism was observed throughout the watering period, exhibiting intra-specific differences. Stomatal behavior of GBU 44 and GBU 68 were influenced by air temperature (Tar), relative humidity (RH) and vapor pressure deficit (VPD), whereas GBU 50 was influenced by photosynthetically active radiation (PAR). GBU 48 was not influenced by these environmental factors. Anatomical alterations in response to drought were observed in stomatal density (SD), reductions in the stomatal index (SI) and stomatal aperture size (SA). The anatomical features of the GBU 48 genotype remained unaltered. There was an inversion in tissue proportion in GBU 44 under stress conditions, reducing the spongy parenchyma and increasing palisade parenchyma thickness. The inverse occurred with GBU 68, while the remaining genotypes were unaltered. The results found in this study suggest that GBU 68 is the most drought-sensitive genotype and anatomical changes induced by intermittent drought are not enough to explain the physiological differences between genotypes.

Variabilidade genética do umbuzeiro no Semi-Árido brasileiro, por meio de marcadores AFLP

O objetivo deste trabalho foi avaliar a distribuição da variabilidade genética do umbuzeiro (Spondias tuberosa), no Semi-Árido brasileiro, por meio de marcadores AFLP, para subsidiar estratégias de prospecção e conservação da espécie. Foram analisados 68 indivíduos de umbuzeiro de 15 ecorregiões, pelo dendrograma UPGMA e pela dispersão em escala multidimensional (MDS), com o coeficiente de Jaccard de 141 bandas polimórficas de AFLP. A análise da variância molecular foi realizada pela decomposição total entre e dentro das regiões ecogeográficas. O dendrograma apresentou valor cofenético de 0,96, e o gráfico MDS apresentou 0,25 para a falta de ajustamento. A variabilidade genética do umbuzeiro foi estimada em 0,3138, o que indica grande variação entre os grupos de indivíduos. Agrupamentos específicos foram observados em seis regiões ecogeográficas, enquanto nas demais regiões observaram-se pares entre alguns indivíduos, sem formação de agrupamentos específicos por local de amostragem, o que indica que a variabilidade genética do umbuzeironão está uniformemente distribuída no Semi-Árido. Sugerem-se estratégias para o estabelecimento de maior número de áreas para conservação in situ ou amostragens de menor número de indivíduos, em várias unidades de paisagens, para conservação ex situ da variabilidade genética do umbuzeiro.

Fruit Flies (Diptera: Tephritidae) Associated with Umbu (Spondias tuberosa) in the Semiarid Region of Bahia, Brazil

Arr. Cam. (Anacar-diaceae), is a xerophytic tree species endemic tothe northeastern Brazilian semiarid region in thestates of Piaui, Paraiba, Pernambuco, Bahia, andin the northern part of Minas Gerais (Silva et al.2004). It occurs in the Caatinga biome, which ischaracterized by a semiarid climate and a mosaicof vegetation types varying from dry thorn forestto open shrubby vegetation (Costa et al. 2007).Deforestation has recently increased in Caatingaas a result of an expanding human populationand the demand for timber and land for cattleranching (Coimbra-Filho & Câmara 1996). Fewstudies have focused on the contribution of Caat-inga´s biota to biodiversity in Brazil (Leal et al.2005), and it is considered one of the least knownbiomes in Brazil regarding terrestrial host-depen-dent invertebrates (Lewinsohn et al. 2005).The umbu tree is important from an economicand social standpoint to many populations in Bra-zil’s northeast due to its edible fruit and high tol-erance to drought. Rural communities in thesemiarid region can increase their incomethrough selective extraction of umbu fruit, espe-cially during the prolonged drought periods (Cav-alcanti et al. 2006; Santos 1999). The fruit is around, ovoid, or oblong drupe, 2-3.5 cm long andweighs 10-20 g. The fruit has a thin skin, a largeseed, and high content of moisture, ascorbic acid,and iron. The pulp has a very distinct flavor andaroma and its consumption has been increasingin recent years in several regions in northeasternBrazil, not only for the fresh market but also forthe processing industry (Narain et al. 1992; San-tos 1999).Inventories carried out at a regional level inthe states of Maranhao (Oliveira et al. 2000) andRio Grande do Norte (Araujo et al. 2005) indi-cated that there were fruit flies associated withumbu fruit. A paucity of studies on possible fruitflies in Bahia prompted the current considerationof which fruit fly species and parasitoids might beassociated with umbu fruit in the semiarid regionof Bahia.Umbu fruit were collected in southwestern Ba-hia. Our study site was a 3-ha area on a 10-hafarm located in Manoel Vitorino, Bahia, at 290 mabove sea level (14°21´S, 40°11´W). Climate issemiarid, which corresponds to the BSh climatictype of Koppen, with an annual average tempera-ture of approximately 28°C with little variation.Annual average rainfall usually totals less than800 mm and is concentrated from Jan throughMar (Rodrigues 2005). The farm hosts nativeumbu trees at an average density of about 30trees per hectare. The phenology of 30 umbu treeswas verified through monthly observations in2005 in 3 study parcels of 1 ha each at 200 m spac-ing. Three distinct periods were identified: vege-tative rest from Apr through Aug, flowering fromSep through Nov, and fruiting from Dec throughMar. We collected 770 ripe or ripening umbu fruit,410 from the canopies and 360 that had fallen onthe ground, totaling 10.68 kg in Jan 2006, Jan,Nov and Dec 2007, and Jan 2008. The collectedfruits were counted, weighed, placed in individualplastic containers with a layer of vermiculite, andcovered with voile cloth until larvae emerged andpupated. Puparia were removed weekly. All pu-paria obtained were placed in 30-mL plastic con-tainers with a layer of vermiculite at the bottomand covered with voile cloth until adults emerged.Voucher specimens were deposited at the Labo-ratorio de Entomologia, UESC, Ilheus, Bahia,Brazil.Altogether, 328 fruits (42.6%) were infested bytephritid larvae, corresponding to an infestationrate of 0.65 ± 0.93 (SD) puparia/fruit and 47 pu-paria/kg. The number of puparia per fruit rangedfrom 1 to 4. We obtained 502 puparia from the in-fested fruit, from which 361 adults emerged, rep-resenting a pupal viability of 71.2%. All adultsreared were

Efeito do ácido indolbutírico e raizon no enraizamento de estacas herbáceas e lenhosas de umbuzeiro

The umbu tree can be propagated assexually, but few information are had that the species can be propagation by cutting. The objective of the present research was to evaluate the effect of different concentrations of IBA (indolbutiric acid) and Raizon 05 ® in the rooting of cuttings herbaceous and hardwoody of umbu tree. The experimental design used was block at random, with four concentrations of IBA (0; 500; 1000 and 2000 mg L -1 ) and one of Raizon 05 ® and two types of cuttings (herbaceous and hardwoody). After the treatment of the cuttings with Metiltiofan (Thiophanate methyl a 0,05% i.a.) for one minute, these were immersed in the solutions of IBA by ten minutes, or in contact with Raizon 05 ® , soon afterwards took place the planted in plastic tubets containing medium vermiculite. The material was transported for greenhouse with 50% of light reduction with overhead irrigation of the type under intermittent mist, with intervals of 5 minutes and duration of 10 seconds. The analyzed variables were: rooting percentage and surviving cuttings and mass of the matter dries of the root. It can be ended that: the woody cutting presented better results in relation to the herbaceous cuttings for the survival; the percentage largest of rooting was verified in herbaceous cuttings with the application of 500 mg L -1 of IBA, providing 33.33% of rooted cuttings.

Chemical composition of umbu (Spondias tuberosa Arr. Cam) seeds

The umbu tree (Spondias tuberosa Arr. Cam) is an important fruit tree the economy of the semi-arid northeastern region of Brazil. With the objective of finding use for the seeds, physical and chemical characterizations of the seeds from 2 cultivars in 2 maturation stages were carried out and their fatty acid and mineral profiles determined. The results showed no differences between the seeds analyzed. The yield was about 10% and the dimensions as follows: length from 1.48 to 2.11 cm and width from 0.76 to 1.16 cm. The average lipid content was 55% of which 69% was unsaturated and the average protein content was 24%. The seeds were a good source of the following minerals: P, K, Mg, Fe and Cu. The overall results indicated that the oil or the seeds could be used for food stuffs if no toxic agents were found.

Gas exchange of the umbu tree under semi-arid conditions

A study was carried out at Embrapa Semi-Árido, Petrolina-PE, Brazil, aiming to understand the gas exchange process of the umbu tree (Spondias tuberosa Arr. Cam.) in the dry and rainy seasons. Stomatal conductance, transpiration, photosynthesis and internal CO2 concentration were obtained with a portable infrared gas analyzer (IRGA). During the dry season the umbu tree showed a much lower stomatal conductance early in the morning, as soon as the vapor pressure deficit increased, apparently affecting CO2 assimilation more than transpiration. The highest values were detected around 6:00 am but decreased to the lowest points between 10:00 am and 2:00 pm. During the rainy season, however, stomatal conductance, transpiration and photosynthesis were significantly higher, reaching the highest values between 8:00 and 10:00 am and the lowest around 2:00 pm. It was also observed at 4:00 pm, mainly during the rainy season, an increase on these variables indicating that the umbu tree exhibits a two-picked daily course of gas exchange.

Variabilidade genética de procedências e progênies de umbuzeiro via metodologia de modelos lineares mistos (REML/BLUP)

O umbuzeiro (Spondias tuberosa Arruda), espécie nativa do semi-árido brasileiro, é um dos recursos genéticos mais importantes para a produção de frutos destinados ao consumo in natura e à industrialização. No melhoramento de espécies perenes, o uso de técnicas de avaliação genética com base em modelos mistos do tipo REML/BLUP (máxima verossimilhança restrita /melhor predição linear não viciada) é fundamental para a predição de valores genéticos aditivos e genotípicos de indivíduos com potencial para seleção, tanto em nível intrapopulacional como interpopulacional. Este procedimento vem sendo aplicado com sucesso no Brasil, no melhoramento de várias espécies frutíferas e florestais. O presente trabalho teve como objetivos estudar a variabilidade genética, estimar parâmetros genéticos e realizar a predição de valores genéticos dos indivíduos, utilizando a metodologia REML/BLUP a partir da avaliação de procedências e progênies de umbuzeiro. O ensaio foi instalado em delineamento de blocos ao acaso, com arranjo hierárquico desbalanceado, constituído de três procedências e 42 progênies. Foram avaliados os caracteres altura de plantas (ALP), maior diâmetro de copa (MAC), menor diâmetro de copa (MEC), diâmetro do colo (DIC) e número de ramos primários (NRP), os quais são correlacionados à produção de frutos. Os resultados obtidos permitem afirmar que, no umbuzeiro, aos nove anos de idade, a maior parte da variabilidade genética encontrada concentra-se dentro de populações. Os caracteres MEC e MAC apresentaram, respectivamente, valores de herdabilidade individual no sentido restrito de 0,08 e 0,14 e ganhos de 6% e 9%, respectivamente, com a seleção dos dez melhores genitores.

EFEITO DO ESTÁDIO DE MATURAÇÃO DO FRUTO E DO TEMPO DE PRÉ-EMBEBIÇÃO DE ENDOCARPOS NA GERMINAÇÃO DE SEMENTES DE UMBUZEIRO (Spondias tuberosa Arr. Câm.)

O umbuzeiro é uma fruteira nativa do Nordeste brasileiro, cujos frutos são usados na alimentação humana, tendo, portanto, grande potencial de exploração agroindustrial. A lenta germinação das sementes limita a produção de mudas, daí a realização deste trabalho que objetivou estudar o efeito dos diferentes estádios de maturação do fruto e tempos de pré-embebição dos endocarpos em água na germinação das sementes de umbu. Os frutos foram despolpados manualmente, e os endocarpos pré-embebidos em água destilada substituída a cada 24 horas. Utilizou-se o delineamento experimental inteiramente ao acaso, em fatorial (4´4´2), sendo os fatores: estádios de maturação dos frutos (verde, de vez, maduro e maturação avançada), tempos de pré-embebição dos endocarpos em água (0, 48, 96 e 144 horas) e tipos de umbuzeiros (azedo e doce), com quatro repetições e dez endocarpos/parcela. Os endocarpos foram semeados em bandejas de isopor contendo Areia Quartzosa Distrófica. Pelos resultados, concluiu-se que o tipo de umbu e o estádio de maturação do fruto influenciaram na germinação. Entretanto, a pré-embebição dos endocarpos em água não influenciou na germinação das sementes de umbuzeiro.