Pineapple Disease Research Articles

IMPLICATIONS OF THE USE OF EXCESS COIR DUST MULCH IN PINEAPPLE CULTIVATION ON THE MEALYBUG WILT DISEASE OF PINEAPPLE

IMPLICATIONS OF THE USE OF EXCESS COIR DUST MULCH IN PINEAPPLE CULTIVATION ON THE MEALYBUG WILT DISEASE OF PINEAPPLE

Genetic and biochemical characterization of the pathway in Pantoea citrea leading to pink disease of pineapple.

Pink disease of pineapple, caused by Pantoea citrea, is characterized by a dark coloration on fruit slices after autoclaving. This coloration is initiated by the oxidation of glucose to gluconate, which is followed by further oxidation of gluconate to as yet unknown chromogenic compounds. To elucidate the biochemical pathway leading to pink disease, we generated six coloration-defective mutants of P. citrea that were still able to oxidize glucose into gluconate. Three mutants were found to be affected in genes involved in the biogenesis of c-type cytochromes, which are known for their role as specific electron acceptors linked to dehydrogenase activities. Three additional mutants were affected in different genes within an operon that probably encodes a 2-ketogluconate dehydrogenase protein. These six mutants were found to be unable to oxidize gluconate or 2-ketogluconate, resulting in an inability to produce the compound 2,5-diketogluconate (2,5-DKG). Thus, the production of 2,5-DKG by P. citrea appears to be responsible for the dark color characteristic of the pink disease of pineapple.

GdhB, a gene encoding a second quinoprotein glucose dehydrogenase in Pantoea citrea, is required for pink disease of pineapple.

The pink disease of pineapple, caused by the bacterium Pantoea citrea, is characterized by a dark coloration on fruit slices after canning. A glucose dehydrogenase (Gdh) encoded by the gdhA gene has been implicated in the colour formation activity of P. citrea. In this paper it has been shown that P. citrea contains a second, homologous gdh gene and its product, GdhB, represents the main source of Gdh activity in this organism. Unlike gdhA, gdhB is constitutively expressed during the exponential phase of growth and is induced in stationary phase. A previously isolated chemical mutant, CMC6, which is deficient in Gdh activity and pink disease formation, failed to express gdhB during the stationary phase of growth. The CMC6 mutant can be complemented by a 54 bp DNA fragment located upstream of gdhA. This fragment, which contains an operator-like 11 bp inverted repeat, strongly enhances the expression of gdhA, probably by titrating away a negative effector of its expression. These results illustrate the complex interplay operating between the two gdh genes and emphasize the role of glucose metabolism in the pathway leading to pink disease.

Characterization of pUCD5000 Involved in Pink Disease Color Formation byPantoea citrea

Pantoea citrea,the causal agent of pink disease of pineapple, harbors a cryptic plasmid of 5229 bp, designated pUCD5000. On the basis of nucleotide and amino acid sequence analyses, pUCD5000 contains both replication and mobilization loci (bomandmobCABD) that are similar to those in plasmids pSW100 and pSW200 inPantoea stewartiiand pEC3 inErwinia carotovorasubsp.carotovora.The survival ofP. citreaon pineapple does not depend on pUCD5000. However, full pink coloration development, which is characteristic of the pink disease, appears to require this plasmid.

Analysis of Patterns of Pineapple Mealybug Wilt Disease in Sri Lanka.

Mealybug wilt disease of pineapple has a complicated etiology, which is not yet fully understood. As a result, assessments of the disease in the field, such as those that are made in the context of evaluation of disease control methods, are usually based on symptomatology. Field assessments, based on symptoms of mealybug wilt disease, were made in the Kurunegala and Gampaha districts of Sri Lanka. These data were fitted to statistical probability distributions as a method of summarizing the spatial pattern of disease incidence. Most plots showed aggregated patterns of diseased plants, but there were some exceptions. Summarizing patterns of disease incidence by means of fitting statistical probability distributions provides a basis for significance testing in cases where factors affecting disease incidence are the subject of field experimentation. Some examples of this methodology are given.

First Report of a Closterovirus-Like Particle Associated with Pineapple Plants (Ananas comosus cv. Smooth Cayenne) Affected with Pineapple Mealybug Wilt in Cuba.

Pineapple mealybug wilt (PMW) was first described in Hawaii in 1910 and has since spread wherever pineapple is cultivated. PMW is currently one of the most important field diseases of pineapple in Cuba, causing up to 40% crop loss. Leaves of plants affected with PMW turn bronze-red and lose turgidity, and the tips curve down. Root system size is decreased and fruits are unmarketable because the flesh is fibrous and sour. Leaves from wilt-affected pineapple plants were selected from the Experimental Station "Tomás Roig" at Ciego de Avila, Cuba. Asymptomatic plants derived from meristem tissue and cultivated under greenhouse conditions were also collected. Both samples were analyzed by several virus purification procedures and finally purified with a protocol modified from Gunashinge and German (1). Partially purified samples from symptomatic and asymptomatic plants were negatively stained and examined by a JEOL (JEM-2000 EX) transmission electron microscope at a magnification of ×30,000. Sixteen, long, flexuous, rod-shaped, viruslike particles (estimated length 1,200 to 1,450 nm; width about 12 nm) were observed in symptomatic leaves, using electron microscope micrographs. These particles were similar to those of the pineapple clostero-like virus found in Hawaii (1) and Australia (2). Particles were observed from symptomatic plants but not from plants propagated by primary meristem culture. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of viral proteins indicated that the coat protein has a molecular mass of approximately 23 kDa. This is the first report of closterovirus-like particles associated with pineapple plants (Ananas comosus cv. Smooth Cayenne) affected with PMW in Cuba.

Studies on Pantoea citrea, the Causal Agent of Pink Disease of Pineapple

AbstractThe causal agent of pink disease of pineapple has been identified as Pantoea citrea, a member of the Enterobacteriaceae. Comparative physiological and biochemical analyses demonstrated that P. citrea isolated from diseased pineapple fruit in the Philippines possesses features identical to those of an American Type Culture Collection type strain of P. citrea and not to those of P. ananas, P. herbicola (formerly Erwinia herbicola), and P. stewartii (formerly Erwinia stewartii). P. citrea induces the production of compounds in pineapple which become pink to reddish‐brown upon cooking the fruit, pulp, or juice. This distinct colour is not induced by Escherichia coli, Agrobacterium tumefaciens, Burkholderia gladioli, Pseudomonas fluorescens, Gluconobacter oxydans, Acetobacter aceti, and Acinetobacter calcoaceticus. Like other well characterized bacteria pathogens, such as Pseudomonas syringae pv. phaseolicola, P. citrea elicits the hypersensitive response (HR) in tobacco. By contrast, G. oxydans and A. aceti that have been previously implicated as the causal agents of pink disease, do not elicit HR. Although the nature of the pink colour in pineapple produced by P. citrea has not been elucidated, the locus conferring this activity has been located on its chromosome. The pink colour can be restored in an avirulent, pink colour defective mutant strain, CMC6, by complementation in trans with a specific 3.8 kb genomic DNA fragment of P. citrea. This suggests that P. citrea contains the genetic elements that are required for pink disease.

Identification and characterization of a Pantoea citrea gene encoding glucose dehydrogenase that is essential for causing pink disease of pineapple.

Pantoea citrea, a member of the family Enterobacteriaceae, causes pink disease of pineapple, whose symptom is characterized by the formation of pink to brown discolorations of the infected portions of the pineapple fruit cylinder upon canning. Molecular genetic approaches were applied to elucidate the mechanism responsible for this fruit discoloration. A P. citrea mutant strain, CMC6, defective in its ability to cause pink disease and fruit discoloration, was generated by nitrosoguanidine mutagenesis. A DNA fragment that restored these activities was isolated by screening a genomic cosmid library of P. citrea. A large open reading frame of 2,361 bp, identified by nucleotide sequencing of a subclone of the complementing DNA, showed high similarities to identified genes encoding glucose dehydrogenase (GDH) in Escherichia coli, Acinetobacter calcoaceticus, and Gluconobacter oxydans. The predicted amino acid sequence of GDH of P. citrea was identical to known GDHs in these bacteria by 54, 44, and 34%, respectively. GDH of P. citrea has a predicted molecular mass of 86.2 kDa, contains a conserved binding domain for the cofactor pyrroloquinoline quinone, and possesses GDH activity as demonstrated by biochemical assay. GDH is the key branch point enzyme leading to the biosynthesis of gluconate, which in turn serves as the substrate leading to the formation of 2-ketogluconate, 2,5-diketogluconate, 6-phosphogluconate, and 2-keto-6-phosphogluconate. Addition of gluconate to CMC6 restores the juice- and fruit-discoloring activity. Although the pigments formed by heating (or canning) have not been identified, it is clear that GDH is one of the enzymes required for pigment formation leading to pink disease.

POSTHARVEST DISEASES OF PINEAPPLE

POSTHARVEST DISEASES OF PINEAPPLE

Ocorrência do complexo Carpophilus humeralis (Fabricius)-Ceratocystis paradoxa (De Seynes) Moreau em cana-de-açúcar no Estado de São Paulo

Foi constatada a ocorrência do besourinho Carpophilus humeralis (Fabricius) (Coleoptera, Nitidulidae) no Estado de São Paulo, em toletes de cana-de-açúcar com podridão-abacaxi, causada pelo fungo Ceratocystis paradoxa (De Seynes) Moreau. Experimento conduzido com duas variedades de cana, IAC64-257 e NA56-79, tratamento do tolete com fungicida e posição da gema no tolete, demonstrou que a variedade NA56-79 respondeu positivamente ao tratamento com fungicida enquanto a variedade IAC64-257 não apresentou resposta. As gemas da extremidade do tolete foram mais afetadas que as centrais.

Control of Pineapple Disease of Sugarcane with Propiconazole

Control of Pineapple Disease of Sugarcane with Propiconazole

Control of Pineapple Disease of Sugarcane with Propiconazole

Control of Pineapple Disease of Sugarcane with Propiconazole

Nutritional requirements and biochemical activities of pineapple pink disease bacterial strains from Hawaii.

Bacteria which cause pink disease of pineapple, identified on the basis of their nutritional and biochemical activities, were found to belong to three genera. These bacteria include the following species: Gluconobacter oxydans, Acetobacter aceti, and Erwinia herbicola. Several pink disease strains required one to three vitamins for growth. Both G. oxydans strains 303D and 180 required biotin, nicotinic acid, and pantothenic acid for growth; E. herbicola 189 required only nicotinic acid; however, A aceti 295 was able to grow without any added supplements in glucose mineral salts medium. Optimal vitamin concentrations for maximal growth and optimal pH for the maximal number of generations per hour was established for a few pink disease strains.

Diseases of Sugarcane — a Review

Abstract Cane supplies over 60% of the world's commercial sugar. Technologically the industry is highly organised but diseases are a recurrent problem. Ratoon stunting disease is especially serious. Leaf scald (Xanthomonas albilineans) and smut (Ustilago scitaminea) are also important at the moment because of their potential for damage and their ability to cross quarantine boundaries. Red stripe (Pseudomonas rubrilineans), deterioration of harvested cane, eye spot (Drechslera sacchari), pineapple disease (Ceratocystis paradoxa), red rot Glomerella tumucanensis, yellow spot (Cercospora koepkei). Fiji (virus) and mosaic (virus), are other diseases which can also cause economic losses. The effective control of disease needs legislative backing, effective field work in surveying for disease, obtaining clean plants etc., plus suitably resistant varieties. A typical, large, clean-plant scheme is at present in operation in southern Queensland against Fiji disease.

The Interaction of Four Bacteria Causing Pink Disease of Pineapple with Several Pineapple Cultivars

The Interaction of Four Bacteria Causing Pink Disease of Pineapple with Several Pineapple Cultivars

Control of Endogenous Brown Spot of Fresh Pineapple in Postharvest Handling1,2

Abstract In Hawaii, the physiological disease of pineapple [Ananas comusus (L.) Merr. cv. Smooth Cayenne] called endogenous brown spot (EBS), occurs throughout the year. During the development of EBS there is a significant positive correlation between the number of spots and degree of darkening of spots. Correlations between number and degree of darkening of spots with pulp translucence indicated that higher pulp translucency does not necessarily camouflage the spots and thereby reduce the number as well as the degree of darkening of the spots. A heat treatment at 32.3–37.8°C for 1 day controlled EBS in fresh fruits held under refrigeration (7.2°C). In simulated shipping experiments heat treatment was effective when applied in transit in shipping containers before, during, or after refrigeration, the last being most effective. The only detrimental effect of heat treatment was increased fruit-wt loss. This was more than offset by the beneficial effect of the reduction in EBS incidence, and improvement in appearance and flavor of the pulp.

Transmission of the Pineapple Disease Organism of Sugarcane by Nitidulid Beetles in Hawaii12

Urophorus humeralis (F.), Carpophilus hemipterus (L.), and Haptoncus ocularis (Fairmaire) were proven to be important vectors of pineapple disease of sugarcane, Ceratocystis paradoxa (Dade) Moreau in Hawaii. Viable spores were carried on the body surface but not in the feces of U. humeralis. Once it acquired the pathogen, individuals of U. humeralis could make a maximum of 13 transmissions (2-min inoculation period) and remain infective up to 12 days. Nitidulids were attracted to diseased cane, which also proved to be a better food source for both adult and young U. humeralis than healthy sugarcane stalks.

Sexual Compatibility, Morphology, Physiology, Pathogenicity and in vitro Sensitivity to Fungicides of Thielaviopsis paradoxa Infecting Sugarcane and Pineapple in Puerto Rico

A previously unreported race of Thielaviopsis paradoxa was isolated from pineapple fruits with symptoms of black rot disease. Macro- and microconidia resemble in appearance those of T. paradoxa, the causal agent of the pineapple disease of sugarcane. Perithecia were produced in PDA (24°-28° C.) when the pineapple isolate was crossed with the light strain of T. paradoxa from sugarcane. Perithecia are characteristic of Ceratocystis paradoxa (horn-like appendages on the base of the perithecia and long, pointed ostiolar hyphae) and are morphologically indistinguishable from those obtained by crossing two sexually compatible strains from sugarcane. However, the rate of growth of the pineapple isolate, under various temperatures, pHs, and cultural media, was consistently different from those characterizing other strains of the fungus. The pineapple strain attacks sugarcane seedpieces more virulently than isolates obtained from sugarcane. In vitro tests were conducted in the laboratory to determine the relative toxicity of the fungicides benzoic acid, Dowicide A, Benlate, Tecto 60 (TBZ), and Dithane M-45 on pineapple and sugarcane isolates of the fungus. Benzoic acid and Dowicide A appeared to be the most effective of these fungicides for inhibiting mycelial growth of T. paradoxa.

Diseases of Sugarcane and their Control in Puerto Rico

A sugarcane disease survey was conducted over different mill zones of Puerto Rico during the fall of 1969 and the spring of 1970. It covered the plantations of 10 sugar mills. The results obtained to date indicate that the diseases of major importance are ratoon stunting, chlorotic streak, pineapple disease, and root rot caused by a complex of Pythium, Fusarium and nematodes. The specific disease problems are identified in each area. Special attention was given to disease distribution, economic importance, and possible methods of control. Although in general low incidence of ratoon stunting was observed in commercial plantings, data obtained from previous variety tests indicate this malady to be potentially dangerous. Hot water treatment of seedpieces should be conducted to prevent its further spread. The significance of chlorotic streak disease as a factor in yield decline in Puerto Rico has not yet been completely evaluated. The high incidence of this disease, under present conditions, has given rise to concern. Pineapple disease caused by Thielaviopsis paradoxa greatly affects the germination of P.R. 980, especially in areas with poor drainage. Root rots caused by Pythium, Fusarium and nematodes reduced germination of P.O.J. 2878 and H. 328560 by as much as 40 percent in poorly-drained areas.

Management of Pineapple Disease of Sugarcane through Biological Means

Trichoderma harzianum was found an effective antagonist to Ceratocystis paradoxa, the causal organism of pineapple disease of sugarcane. It exhibited a strong antagonism against Ceratocystis paradoxa by overgrowing on it, forming lysed zone and inhibiting its growth. In the present investigation Trichoderma harzianum was found as effective as fungicide (Bavistin 50WP- Carbendazim 50WP) in controlling Ceratocystis paradoxa both in in vitro and in vivo condition. Ceratocystis paradoxa failed to grow on Trichoderma harzianum and Bavistin 50WP treated PDA plates. Trichoderma harzianum and Bavistin treated sugarcane setts showed significantly higher germination (20.34 to 26.17% higher) over control. Trichoderma harzianum and Bavistin treated sugarcane setts showed respectively 40.72 and 62.69% higher yield of cane compared to control. Hence Trichoderma harzianum may be used as bio agent and alternative to Bavistin 50WP (a standard sett treating fungicide of sugarcane) in controlling pineapple disease of sugarcane. Key words: Sugarcane, pineapple disease, biological control. DOI = 10.3329/jard.v5i1.1462 J Agric Rural Dev 5(1&2), 79-83, June 2007