Passion Fruit Crop Research Articles

Azamora penicillana occurrence in sour passion fruit in the state of Minas Gerais

Abstract Azamora penicillana (Walker) (Lepidoptera: Pyralidae) is popularly known as exotic passionflower caterpillar, passionflower web, cloak or pouch. It is considered an emergent pest of passion fruit crop due to damages caused to the plant and management difficulties related to insect habit. This species is recorded for the first time infesting passion fruit in the state of Minas Gerais attacking leaves, fruits and branches. Pest attacks have been widely reported throughout the orchard.

Characterization of Cowpea aphid-borne mosaic virus in Passiflora edulis ‘Catarina’ in the southern coast of Santa Catarina State, Brazil

ABSTRACT: CABMV is a limiting virus for passion fruit crop in Brazil, its main producing country. This virus has been reported in all producing states of the country, with the state of Santa Catarina (SC) in 2017 standing as the third largest passion fruit producer. In 2017, it reached 8.4% of the national production. The southern coast is the main responsible for the increase in production, which has been supplying the domestic market. However, in that same year, this region recorded the first symptom expressions in plants and fruits. The evaluation of the samples collected in the municipalities of Sombrio, Praia Grande and São João do Sul, southern coast of SC, was performed by using a mechanical transmission to indicator plants, PTA-ELISA and RT-PCR, and by sequencing. The evaluation results were positive for CABMV and negative for CMV in PTA-ELISA. In RT-PCR, there was the formation of a 700bp ca band, expected size for Potyvirus, whose sequence comparison with those deposited in GenBank reveled 98% identity with the isolates from São Paulo State. The occurrence of the virus in the southern coast of SC did not reach a serious decrease in passion fruit production due to the union of producers, who adopted preventive management measures to control the virus, whose effect led to a consolidation of the passion fruit production chain in the region.

Integrated management of Colletotrichum gloesporioides in yellow passion fruit (Passiflora edulis f. flavicarpa Degener)

Anthracnose (Colletotrichum gloeosporioides) is one of the most limiting diseases of yellow passion fruit, reducing crop production by more than 80%. This research aimed to assess anthracnose management strategies on yellow passion fruit crop sanitation and yield. We assessed the effect of alternating fungicide applications (//) every 15 days with foliar nutrients on the severity of anthracnose and crop yield in a commercial crop in San Isidro district (Montería), located at coordinates 8°44'52.7'' N, 75°52'53.2''W and 75m.a.s.l. We conducted this research in two experiments; in the first, we assessed the response of the disease index (DI) after the application of the following treatments: T1=Manazeb (Mancozeb) // Potassium phosphite (Foscrop), T2=Mancozeb // Potassium (Terramin potassium), T3=Mancozeb // Calcium (Terramin calcium), T4=Trichoderma spp. (Fitotripen) // Copper oxychloride, T5=Azoxystrobin (Amistar) // Mancozeb, and T6=Control sprayed with water. In the second experiment, we selected the best treatments, as follows: T1 = Amistar // Mancozeb; T2 = Terramin potassium // Mancozeb, and T3 = Control. We evaluated DI, percent of affected fruits, number of fruits/ha, and yield (Kg/ha). The results from the first experiment showed that T1 and T5 controlled anthracnose, reducing the levels of severity by 39.69% compared to the control (T6). In the second experiment, T1 decreased the levels of foliage severity by 29.04% and increased the number of fruits/ha and yield by 200% compared to the control. Overall, the fungicide application of Azoxistrobin alternating with Manazeb constitutes an effective alternative to control anthracnose in yellow passion fruit cultivation.

STINK BUG POPULATION FLUCTUATION AND CONTROL IN SOUR PASSION FRUIT ORCHARDS IN SOUTHERN BRAZIL

ABSTRACT Sour passion fruit (Passiflora edulis Sims, 1818) crops in Brazil are drawing attention due to the national production, and the increasing consumption of this fruit as fresh and processed products. However, fruit losses due to damages caused by stink bugs (Hemiptera: Coreidae) are concerning to fruit growers in southern Brazil. The objective of this study was to evaluate the population fluctuation and control of stink bugs in P. edulis crops grown in the 2013-2014 and 2014-2015 crop seasons in Araquari, SC, Brazil, using natural and synthetic insecticides. The stink bug population was evaluated using the 0.25 m2 frame technique. The evaluations were carried out weekly during the two crop seasons. The species and distribution of stink bugs in the different parts of the plant were evaluated. The insecticides and rates used were: Neenmax (azadirachtin 1.0%) at 10 mL L-1; Orobor N1 (N-citric acid 1.0% + 0.20% B) at 2 mL L-1; and Decis 25 EC (deltamethrin 2.5%) at 1 mL L-1, diluted in aqueous solution. Specimens of three stink bug species where found: 86% Diactor bilineatus (Hemiptera: Coreidae); 13.5% Holhymenia histrio (Hemiptera: Coreidae), and 0.5% Nezara viridula (Hemiptera: Pentatomidae). The D. bilineatus species presented higher frequency, constancy, and dominance during the evaluated crop seasons; 64% of the stink bugs were found on fruits, 18.5% on leaves, 7.3% on floral buds, 5.8% on flowers, and 4.4% on branches. The use of azadirachtin or deltamethrin was efficient to reduce the stink bug infestation and the number of P. edulis withered fruits.

Evaluation of Fusarium wilt disease in passion fruit species inoculated with Fusarium oxysporum f.sp. passiflorae

AbstractOne of the main diseases that reduces production of passion fruit crops is Fusarium wilt, caused by the fungus Fusarium oxysporum f.sp. passiflorae (FOP). The use of resistant rootstocks, such as the species Passiflora cincinnata, is one of the management strategies used to control this disease. The objective of this work was to evaluate the pathogenicity of different isolates of FOP on P. edulis and P. cincinnata in order to identify its potential for use in areas with a history of the disease. Thirteen isolates of the fungus were used, and the inoculums were produced at a concentration of 106 CFU/ml. Seedlings were produced in coconut fibre, and the root system was then immersed for five minutes in the conidial suspension before being replanted in the 770‐ml pots. Inoculated seedlings of P. edulis and P. cincinnata at the three‐leaf stage were daily evaluated from the second day after inoculation (DAI) until day 90. All isolates were pathogenic in both Passiflora species; however, the incidence, severity and mortality were higher in P. edulis. There was a statistically significant difference for the incubation period of the FOP 23 and FOP 57 isolates, being higher in P. edulis. We concluded that P. cincinnata was susceptible to FOP.

Primer reporte de begomovirus infectando cultivos de ají (<i>Capsicum</i> spp.) en Colombia

Virus del género Begomovirus infectan cultivos de importancia económica en todo el mundo, incluyendo ají. A la fecha, en Colombia no hay reportes de la presencia de begomovirus infectando este cultivo, por lo que el objetivo de esta investigación fue identificar la presencia de virus de este género en ají empleando estrategias moleculares. Se colectaron 197 muestras de ají en diez municipios del Valle del Cauca. Se extrajo el DNA genómico total vegetal y mediante PCR se detectó la presencia de begomovirus. Para establecer la identidad molecular del virus se amplificaron fragmentos de 1,4 kb de muestras colectadas en Palmira y Vijes. Los fragmentos fueron clonados, secuenciados y analizados. Se encontró que el 85,7 % de las muestras de ají evaluadas fueron positivas para begomovirus. Los análisis de secuencia de los fragmentos virales de 1,4 kb arrojaron una identidad de 91,8 % entre ellos y los de secuencia de nucleótidos de los virus aislados en Vijes y Palmira mostró que éstos presentan los valores de identidad más altos (87,2 % y 86,6 %) con el virus de la distorsión de la hoja de maracuyá, un begomovirus aislado de maracuyá en Colombia. Estos análisis estarían indicando que este begomovirus aislado de ají podría ser una nueva especie. De acuerdo con la literatura, este es el primer reporte de un begomovirus infectando cultivos de ají en Colombia.Virus del género Begomovirus infectan cultivos de importancia económica en todo el mundo, incluyendo ají. A la fecha, en Colombia no hay reportes de la presencia de begomovirus infectando este cultivo, por lo que el objetivo de esta investigación fue identificar la presencia de virus de este género en ají empleando estrategias moleculares. Se colectaron 197 muestras de ají en diez municipios del Valle del Cauca. Se extrajo el DNA genómico total vegetal y mediante PCR se detectó la presencia de begomovirus. Para establecer la identidad molecular del virus se amplificaron fragmentos de 1,4 kb de muestras colectadas en Palmira y Vijes. Los fragmentos fueron clonados, secuenciados y analizados. Se encontró que el 85,7 % de las muestras de ají evaluadas fueron positivas para begomovirus. Los análisis de secuencia de los fragmentos virales de 1,4 kb arrojaron una identidad de 91,8 % entre ellos y los de secuencia de nucleótidos de los virus aislados en Vijes y Palmira mostró que éstos presentan los valores de identidad más altos (87,2 % y 86,6 %) con el virus de la distorsión de la hoja de maracuyá, un begomovirus aislado de maracuyá en Colombia. Estos análisis estarían indicando que este begomovirus aislado de ají podría ser una nueva especie. De acuerdo con la literatura, este es el primer reporte de un begomovirus infectando cultivos de ají en Colombia.

Mapping of the current land use in part of the Irrigated Perimeter Nilo Coelho, Petrolina-PE, Brazil

The objective of this study was to quantify and spatialize the agricultural composition and current land use in part of the Irrigation perimeter Nilo Coelho from the Landsat 8 satellite digital image classification. At first we performed the unsupervised classification image related to January 2014, identifying the separability within natural vegetation, water bodies, agricultural crops and anthropized areas. Then the supervised classification Maxver model was performed where it was observed that the fruit classes “Grape” (5.41%) “Acerola” (3.75%), “Coconut” (6.14%) “Guava” (6.17%), “Banana” (2.29%) and “Mango” (8.18%) showed dominance in the study area. These classes stood out in terms of yield in the area, pointing out that in that expansion which occurs in an area with agricultural crops in the irrigated Nilo Coelho, crops of mango, coco, guava, acerola, banana and grape also grow. In addition, we observed the emergence of new areas with passion fruit crops, melon, watermelon, corn, beans, onions, pumpkin, sweet potatoes, tomatoes, bell peppers, among other crops. Furthermore, we also found the occurrence of pastures containing buffel and elephant grasses, intercropping or not. The estimated overall accuracy was 80.52%, and the mapping defined as very good, with Kappa index equal to 0.7783.

Initial vegetative growth and survival analysis for the assessment of Fusarium wilt resistance in Passiflora spp.

In Brazil, diseases caused by soil-borne pathogens such as Fusarium oxysporum f. sp. passiflorae are major constraints to the yellow passion fruit crop. We report the use of the survival analysis technique to assess the resistance of Passiflora spp. to Fusarium wilt in field conditions in a coastal tableland region of Brazil. Fifty genotypes were evaluated comprising the species Passiflora edulis, P. alata, P. gibertii, P. nitida, P. setacea,P. cincinnata, and backcross [(P. edulis x P. cincinnata) x P. edulis] and three graft combinations of P. edulis onto P. nitida, P. gibertii or P. alata. Plant growth and Fusarium wilt incidence were evaluated using 30 plants of each genotype in a completely randomized design. The highest growth speed indexes (GSI) were observed in P. cincinnata (BGP077) and P. edulis (BRS-GA) grafted onto P. gibertii (BGP008) with 12.04 and 11.96, respectively. Conversely, P. nitida (BGP390) had the lowest growth rate (4.10). Plants of P. gibertii, P. nitida and P. setacea did not present Fusarium wilt symptoms until 15 months after planting and presented the same median survival time with 466 days. Among P. edulis genotypes, Fusarium wilt incidence varied within three reaction groups, with the highest median survival time of 286 days. P. alata and P. cincinnata plants had high Fusarium wilt incidence (median survival time 250 and 252, respectively), similar to P. edulis, with 80% of symptomatic plants at 15 months after planting and median survival time of 240 days. Interspecific backcross hybrids differed from genotypes and intraspecific hybrids of P. edulis despite the similar median survival time among all of them (239–252 days). Grafting P. edulis onto wild species did not decrease Fusarium wilt incidence in relation to the most resistant group of P. edulis genotypes.

Complete genome sequence of a Passion fruit yellow mosaic virus (PFYMV) isolate infecting purple passionfruit (Passiflora edulis f. edulis)

Purple passion fruit (Passiflora edulis f. edulis), also known as gulupa, is a vine plant of the familiy Passifloraceae, which in recent years has gained importance in the world fruit market due to its exotic nature and excellent organoleptic properties. Although the demand for gulupa in Colombia has increased significantly to become one of the most important fruit exports, the cultivated area has been in decline since 2009 due to the impact of plant diseases. Cucumber mosaic virus (CMV), soybean mosaic virus (SMV) and cowpea aphid borne mosaic virus (CABMV) are amongst the main viruses found infecting gulupa in Colombia. To further characterize the virome of gulupa, a deep sequencing transcriptome study was performed from a producing region in eastern Antioquia. Based on the results of next-generation sequencing (NGS), we report the genome sequence of a tymovirus infecting this plant. Phylogenetic analysis revealed this virus to be a close relative of Passion fruit yellow mosaic virus (PFYMV), Cassia yellow mosaic-associated virus (CYMaV) and Calopogonium yellow vein virus (CYVV). To date, only a 1115 nt segment comprising the RdRP-CP region of PFYMV has been reported; this sequence shares 84.79% and 95.24% identities at the nucleotide and amino acid levels with the purple passionfruit tymovirus suggesting that the detected virus is a PFYMV isolate (PFYMV_Antioquia). Finally, RT-qPCR and Sanger sequencing using specific primers confirmed the presence of PFYMV in different purple passionfruit crops in Antioquia. This is the first complete genome sequence of a PFYMV isolate reported in the world.

Agricultural area losses and pollinator mismatch due to climate changes endanger passion fruit production in the Neotropics

Pollinator diversity and abundance are declining in the agricultural landscapes of some parts of the world along with the pollination services they provide. Among an array of reasons, climate change has been pointed out as a major player and studies suggest strong negative impacts on agricultural pollination toward the end of the 21st century. In this study, we investigated for the first time the concomitant effect of climate changes on a tropical crop, passion fruit (Passiflora edulis), and its two main pollinator bee species (Xylocopa frontalis and X. grisescens) in the Neotropics considering two of the IPCC environmental scenarios, RCP 4.5; RCP 8.5 (Representative Concentration Pathways), and in the years 2060 and 2080. We have shown that the climate changes may lead to changes in the natural ranges of Xylocopa bees, with considerable loss of habitable area (X. frontalis, RCP 4.5 = −27.3 to −15.4%; RCP 8.5 = −57.7 to −47.9%; X. grisescens, RCP 4.5 = −15.4 to −27.81%; RCP 8.5 = −23.5 to −35.3%), as well as for cropping passion fruit (RCP 4.5 = −44. 9 to −51.3%; RCP 8.5 = −42.9 to −64.8%), for years 2060 and 2080, respectively. We also predicted a potential reduction between 31.9% and 54.9% in the overlapping of the remaining suitable areas for the bees and passion fruit, increasing the potential spatial mismatch between the crop and its pollinators. Based on the models forecast of climate changes, we conclude that the suitable areas to co-occurrence of passion fruit crop and its effective pollinators will be largely affected in the Neotropics and steps to mitigate the effects of the climate changes should be taken to ensure viable population of pollinators in the remaining suitable areas for both bees and the crop.

Pathogenicity and transmission of fungi detected on Passiflora alata seeds

ABSTRACT: Passion fruit is usually propagated by seeds because of the ease and lower cost in seedling production. However, the seed is the most efficient agent for the spread of pathogens. The damages from seed-borne diseases occur mainly during the germination stages or at the formation of seedlings in nurseries. Considering the need for knowledge on the pathology of sweet passion fruit seeds, the objective was to evaluate the transmission and pathogenicity of the fungi Alternaria sp., Botrytis fabae, Cladosporium cladosporioides, Fusarium spp. and Lasiodiplodia theobromae, known as potentially pathogenic to this crop, and isolated from sweet passion fruit seeds. Therefore, tests on seed health, germination and seedling emergence in a sterilized commercial substrate were conducted using seeds from this species, inoculated with those fungal isolates. Leaves, stems and fruit from this plant were also inoculated with the same fungi. Alternaria sp., Fusarium spp. and L. theobromae were identified in seedlings obtained from inoculated seeds, confirming the transmission of these fungi by seeds. L. theobromae was also considered the most harmful fungus to passion fruit crop, as it causes seed rot and other disease symptoms on the leaves, stem and fruit. These findings inferred that healthy seeds of sweet passion fruit are essential for producing seedlings and to prevent the spread of the diseases caused by these fungi to exempt areas.

Histological and electron microscopy observations on the testis and spermatogenesis of the butterfly Dione juno (Cramer, 1779) and Agraulis vanillae (Linnaeus, 1758) (Lepidoptera: Nymphalidae)

Lepidopteran species present an interesting case of sperm polymorphism and testicular fusion. The study of these features are of great importance in understanding the reproductive biology of these insects, especially in the case of those considered pests. Dione juno and Agraulis vanillae stand out as the most important pests of passion fruit (Passiflora sp.) crops in Brazil. Therefore, the objective of the present study was to characterize the testes and germ cells of Dione juno and Agraulis vanillae at different life stages, using light microscopy and scanning and transmission electron microscopy, to understand the maturation mechanisms of the male gametes in these species. The study showed that the larvae of both species have a pair of brown kidney-shaped testes, covered by epithelial cells which divide the organ into four follicles. The testes are full of spermatogonia which begin to differentiate in the third larval instar. In the fifth larval instar, spermatozoa can be observed. When they enter the prepupal stage the testes begin a fusion process that is completed in the adult insects, where they present as spherical organs divided into eight follicles, containing all the cells of the germ line. Spermatogenesis occurs centripetally, and in both species, sperm dimorphism is observed, where two different types of spermatozoa are formed, eupyrene (nucleated) and apyrene (anucleate), which differ in morphology and function. Apart from contributing to scientific basic research on the reproductive biology of these insects, the present study provides important data that can aid in research on the physiology, systematics, and control of these species.

Do flexible pollen foraging habits of Xylocopa frontalis (Apidae, Xylocopini) contribute to nest management in passion fruit crops?

Xylocopa bees provide efficient pollination services for yellow passion fruit orchards. Passion fruit is solely a nectar source for pollinators, and the use of pollen sources from the surroundings of crop areas is essential to sustain these pollinator populations. This study aimed to assess the food niche breadth of Xylocopa frontalis in the use of pollen sources in a breeding area and in two yellow passion fruit crops. We evaluated larval food samples from nests maintained in the breeding area and after their transference to crop areas. Based on pollen analysis, we verified differences in the food niche breadth and a shift in pollen sources among the study areas. In addition, although X. frontalis can be considered a plastic species regarding pollen sources, we observed that they concentrate foraging activities on few pollen sources, considering both cells and the areas studied. Information regarding pollen foraging habits performed by X. frontalis can contribute to the design more appropriate nest management strategies and maintain its populations in passion fruit crops in the long-term.

Desenvolvimento, florescimento e análise morfoanatômica do maracujazeiro-amarelo enxertado em espécies silvestres do gênero passiflora

Soil diseases reduce the lifetime of the yellow passion fruit crops, forcing the practice of shifting cultivation. The use of tolerant rootstocks could help control premature demise of plants, providing healthier crops, uniform and long-lived. This paper has aimed quantify the influence of two species of wild passionfruit Passiflora mucronata Lam and P. gibertii NE Brown as rootstocks on the agronomic characteristics of yellow passion fruit. The morphological and anatomical analysis of graft region highlighted the cellular redifferentiation resulting in the connection of the graft and the rootstock hypo and epibioto tissues. The changes in characteristics such as plant height, number of nodes, occurrence rate of nodes, accumulation of thermal units to flowering also discussed. It was observed that P. mucronata as rootstock positively influenced the number of nodes, plant height, the number of flowers and the rate of occurrence of nodes. The wild species used as rootstock developed flower buds prematurely. The specie P. mucronata showed the best performance as rootstock.

Dissimilarity based on morphological characterization and evaluation of pollen viability and in vitro germination in Passiflora hybrids and backcrosses

Brazil is considered the main center of the genetic diversity and greatest worldwide producer of passion fruit. Passionfruit woodiness virus (Cowpea aphid born mosaic virus) is an important pathogenic agent of the passion fruit crop, causing severe losses in yield. Wild species of Passiflora are valuable sources of genetic resistance to this disease. Interspecific crosses are a promising method to incorporate resistance genes in commercial species (Passiflora edulis Sims.), despite problems with male sterility in developed hybrids. The objective of the present work was to study the dissimilarity based on morphological characteristics, and the viability and in vitro germination of pollen grains of progenitors, F1 hybrids, as well as progenies of the first generation of backcross BC1 [(P. edulis × P. cincinnata) × P. edulis]. Analysis of the severity of the viral disease showed that most genotypes were considered as susceptible to highly susceptible. The resistant hybrids did not show symptoms of foliar deformation. Cluster analysis showed two major groups; one represented by P. cincinnata and the second group by the hybrids and recurrent progenitor P. edulis. Morphological characterization of the hybrids showed phenotypic variation as to the color and shape of flowers, although the descriptors used were not able to show these differences. As expected, the progenitors (P. edulis and P. cincinnata) presented higher percentages of pollen viability, followed by the BC1-H45 progenies. The progenies of the BC1 will also be evaluated in the future with molecular markers aiming to accelerate the selection of hybrids with higher percentages of the genome of the recurrent parent.

Bigger and sweeter passion fruits: effect of pollinator enhancement on fruit production and quality

AbstractBrazil stands out as the world’s largest producer of yellow passion fruit, a species of economic interest which, due to its self-incompatibility, depends on pollinators for fruit formation. The main pollinators of passion fruit are large solitary bees of the genus Xylocopa, commonly known as carpenter bees, which are potential candidates for management. Passion fruit crops exhibit a low density of pollinators and, consequently, a reduction in production. To improve management techniques of X. frontalis and X. grisescens, the general aim of this study was to evaluate the effect of pollinator enhancement on pollination services in passion fruit crop areas. Our results demonstrated that pollinator enhancement was an efficient way to minimize pollination deficit in passion fruit crops, as it promoted the production of a bigger and sweeter fruits. Data obtained in our study are essential to consolidate management techniques for carpenter bees in passion fruit crops.

Hymenopterous parasitoids of Dasiops (Díptera: Lonchaeidae) infesting cultivated Passiflora spp. (Passifloraceae) in Cundinamarca and Boyaca, Colombia

Dasiops spp. are the most important pest in cultivated Passiflora plants. Larvae of these fruit flies are herbivores, feeding on flower buds and fruit of yellow passionfruit, sweet granadilla, banana passionfruit and purple passionfruit crops located in Cundinamarca and Boyaca, Colombia. Geographic distribution, natural abundance and percentage of parasitoidism for every Dasiops species by each plant species were determined. Aganaspis pelleranoi (Hymenoptera: Figitidae) was found to be a parasitoid of D. inedulis (14.19-50.00%), infesting flower buds of yellow passionfruit and fruit of sweet granadilla (7.41%). Microcrasis sp. (Hymenoptera: Braconidae) was found to be parasitizing both D.gracilis (0.83-3.13%) and D. inedulis (0.83%) in purple and yellow passionfruit. Trichopria sp. and Pentapria sp. (Hymenoptera: Diapriidae) were found to be parasitizing D. inedulis (40.00% and 4.17-20.00%, respectively) and D. gracilis (1.69-22.22% and 1.67-29.17%, respectively) in purple passion fruit. Dasiops caustonae was found to be infesting banana passionfruit only in Boyaca, naturally parasitized by Pentapria sp. (11.11-33.33%). Because Pentapria sp. had a wide geographical distribution as an idiobiont of Dasiops spp. pupae, in all of the assessed cultivated Passiflora species, despite a high selection pressure by chemical control distributed at regular calendar intervals, it would be a crucial strategy in pest management control. Collecting fallen flower buds and fruit infested by Dasiops spp. is important to truncate the life cycle of fruit flies and allow emergence of parasitoids. This simple cultural strategy could have important implications in reducing production costs, increased crop yields and environmental care.

English

Soil fungi, Fusarium oxysporum FO and F. solani FS (teleomorph: Nectria hematococca), are pathogens of economic importance passion fruit crops. The present work was developed in order to standardize the methodology of inoculation, as an initial step to confirm the etiology of diseases associated with Fusarium wilt and collar rot. Strains of FO for A14, A16, A22, A27, A29, A32, A34, A48, A54, A64 and FS A11, A23, A62, A63 were used; they were obtained from symptomatic crops of P. edulis. Inoculations were carried with and without wounds, on seedlings of two and four months of P. edulis. To assess incidence and severity, a scale designed for symptoms and growth variables was used. An incubation period of 14 to 19 days for FO, and was found highly virulent strains (A54, A64, A34). The symptoms are characterized by vascular wilt corresponded to a pattern of descending necrosis. Cross sections showed discoloration in vascular vessels and roots showed necrotic processes that lead to delayed development of seedlings. FS causes disease but the evolution in most strains is very low and exceeds 100 days. Wounds are further evidence for the fungus required in the plant tissue. Symptoms are manifested in the collar area with redness, mild canker associated with cracking and dry appearance on the injury.   Key words: Pathogenicity, collar rot, Fusarium wilt, passion flower, Passiflora edulis, Koch´s postulates.

Effect of two wild rootstocks of genus Passiflora L. on the content of antioxidants and fruit quality of yellow passion fruit

The nutritional importance of the fruit of passionfruit has prompted studies to assess its composition and antioxidant content and to evaluate it as a functional food in fresh fruit and concentrated juice markets. Currently, the use of wild species as rootstock has been recommended mainly for their positive effects such as tolerance to disease attack and maintenance of fruit quality of grafted cultivars. The aim of this study was to determine the effect of wild species of Passiflora gibertii N.E. Br. and Passiflora mucronata Lam as rootstock on the content of antioxidants and fruit quality of Passiflora edulis f. flavicarpa. The experimental design was completely randomized with four treatments and 25 replications, with a total of 100 experimental units. As a control treatment, plants of P. edulis from seed and grafted on the same species were used. Significant correlations were observed among the contents of β-carotene, ascorbic acid, luminosity values, chroma and hue angle. For the combination P. edulis/P. gibertti, the contents of β-carotene and ascorbic acid were highly correlated with luminosity, chroma and hue angle of fruit juice. A similar behavior was observed for the combination P. edulis/P. mucronata Lam. The content of β-carotene in the fruit showed no statistical differences (p < 0.05), indicating no significant rootstock effect on the variables evaluated. The results indicate a potential wild rootstock use for its positive effects on grafted plants while maintaining the commercial quality of the fruits of passionfruit crops.

Resistance to Fusarium solani and characterization of hybrids from the cross between P. mucronata and P. edulis

The development of resistant cultivars is an alternative to control phytosanitary problems affecting passion fruit crops. This study was conducted to obtain progenies through interspecific crosses between Passiflora edulis × Passiflora mucronata, perform the genetic assessment of the progenies obtained, and evaluate and select genotypes resistant to Fusarium solani. When P. mucronata was used as female parent, 516 seeds were obtained, with 20 % germination and survival of nine hybrid genotypes. On the other hand, in the reciprocal cross, 9 seeds were obtained and only one genotype survived. Due to the small number of genotypes obtained, 10 hybrid genotypes and their parents P. edulis (susceptible) and P. mucronata (resistant) was propagated by cuttings. Nine plantlets of each genotype were taken to the field in a randomized block design, with three replications, aiming at morphological characterization. Twenty quantitative and 7 qualitative descriptors were assessed. Nine clones of each individual were kept in a greenhouse, inoculated with F. solani, and assessed 76 days after inoculation. Later, the fungus was re-isolated. The offspring genotypes of the cross in which P. edulis was the female parent did not flourish. For most quantitative and qualitative traits, hybrids were similar to P. mucronata. The genotypes studied formed six groups. Resistance to the fungus was detected in the genotypes of P. mucronata, from Bahia, and two hybrid genotypes. The resistant hybrid can be backcrossed with P. edulis and/or used as rootstock for sour passion fruit.