Incidence Of Scald Research Articles

Superficial scald incidence in ‘Abate Fetel’ pears in relation to maturity, ethylene production and antioxidant capacity

Superficial scald incidence in ‘Abate Fetel’ pears in relation to maturity, ethylene production and antioxidant capacity

Effect of repeated low oxygen stress (RLOS) on superficial scald incidence on ‘Packham’s Triumph’ pears

Effect of repeated low oxygen stress (RLOS) on superficial scald incidence on ‘Packham’s Triumph’ pears

Antioxidants of blushed and unblushed sides in relation to superficial scald of ‘NY2’ (RubyFrost®) apples treated preharvest with 1-methylcyclopropene and aminoethoxyvinylglycine

The effects of plant growth regulators (PGRs) and harvest date on antioxidant contents at harvest and superficial scald development in ‘NY2’ apple during storage have been studied. Aminoethoxyvinylglycine (AVG, ReTain®) and 1-methylcyclopropane (1-MCP, Harvista™) were sprayed two and one weeks, respectively, before the first of three weekly harvests. The apples were stored at 0.5 °C for 20 weeks + 7 d at 20 °C. At harvest, color and index of absorbance difference (IAD) values, and contents of total phenolics, anthocyanins, chlorophylls, carotenoids, ascorbic acid (TAA), dehydroascorbic acid (DHA) glutathione (GSH), reduced glutathione (GSSG) and total antioxidant activity of blushed and unblushed sides of the apple were measured. The antioxidant contents increased with later harvest dates. Chlorophyll and GSSG were higher in unblushed than blushed skin tissues, while all antioxidant contents were highest in blushed skin tissues. Superficial scald incidence was highly correlated with less mature fruit, lower fruit anthocyanin, higher chlorophyll content at harvest. α-Farnesene, conjugated trienols (CTols), and IAD value index were measured at 0, 1, 2, 4, 6, 10, 15, and 20 weeks at 0.5 ⁰C for fruit from harvest 1. Scald incidence and severity was higher in AVG-treated fruit than untreated or 1-MCP treated fruit and did not decrease at later harvest dates. Using harvest management and preharvest application of plant growth regulators is a promising strategy to improve the nutritional value of 'NY2′ apples, reduce physiological disorders, and maintain fruit quality.

A hydroxypropyl methylcellulose (HPMC)-based coating inhibits ethylene-dependent quality changes and reduces superficial scald incidence and blue mould severity during postharvest handling of two apple varieties

The search of new alternatives to substitute postharvest treatments based on synthetic chemicals has gained attention on recent years due to social pressure and stricter legislative policies. Consequently, edible coatings from natural sources have risen as potential solutions to retain postharvest fruit quality. Among these, coatings based on hydroxypropyl methylcellulose (HPMC) have shown potential in preserving fruit quality after harvest. However, scarce studies have explored into their effects on the physiology of climacteric fruits. In this context, the effect of a novel HPMC-based edible coating on fruit postharvest physiology and quality was evaluated in two apple cultivars: ‘Golden Reinders’ and ‘Granny Smith’. In both cultivars, the HPMC-based coating was able to preserve some initial quality attributes, such as firmness and colour, while reducing superficial scald and the severity of blue mould caused by Penicillium expansum. Coated fruit showed reduced ACS activity and ethylene production, delaying changes in ethylene-dependent parameters such as colour and firmness during two different postharvest scenarios: shelf life after harvest and after 3 months of cold storage. Other ripening-associated traits such as starch index, soluble solids content (SSC), and total titratable acidity (TTA) were not affected by the coating application. The coating altered the levels and composition of volatile organic compounds (VOCs), yet without affecting the overall consumer acceptance in most of the studied scenarios. Changes in fruit physiology promoted by the coating, including the decrease of α-farnesene levels and its oxidation products, together with enhanced accumulation of ethanol may reduce the superficial scald incidence in ‘Granny Smith’ and the severity of blue mould rot in the two studied cultivars. Overall, the use of the HPMC-based coating in apples could be useful for maintaining fruit quality and reducing postharvest losses related to mould development and physiological disorders without compromising taste perception.

Metabolome and transcriptome profiling in different bagging pear fruit reveals that PbKCS10 affects the occurrence of superficial scald via regulating the wax formation.

Superficial scald is a physiological disorder of fruit, which is easy to occur during long-term cold storage after harvest. Different preharvest bagging treatments (no bagging, polyethylene bagging and non-woven fabric bagging) were used to explore the occurrence mechanism of superficial scald. UHPLC-MS analysis, GC-MS analysis and RNA-seq revealed the influence of the wax of 'Chili' on the occurrence of superficial scald. The wax content and wax components (Lupeol, lup-20(29)-en-3-one, heptacosane, 9-octadecenoic acid, eicosanoic acid, cis-11-eicosenoic acid) were significantly higher in the fruit bagged with non-woven fabric (NWF, with low incidence of superficial scald) than that in fruit bagged with polyethylene (PE, high incidence of superficial scald). Transcriptomics and qRT-PCR data identified a wax synthesis gene, PbKCS10, which exhibited high expression levels in fruit with low of superficial scald. The results of gene function showed that PbKCS10 reduced the occurrence of superficial scald by increasing the wax formation.

Superficial scald development in ‘Granny Smith’ and ‘Nicoter’ apples: The role of key volatile compounds when fruit are stored under dynamic controlled atmosphere

A positive correlation of α-farnesene and its oxidation metabolites with superficial scald is commonly reported in apples stored in air or controlled atmosphere (CA) systems, where O2 levels are above the lower oxygen limit (LOL) tolerated by the fruit. Nevertheless, the LOL can be monitored by the dynamic controlled atmosphere (DCA) techniques and to provide different physiological responses. Therefore, this study aimed to evaluate key volatile metabolites from ‘Granny Smith’ and ‘Nicoter’ (‘Kanzi®’) apples stored under dynamic controlled atmosphere (DCA) monitored by respiratory quotient (RQ), i. e. at extremely low oxygen partial pressures (ELO) and correlate their emissions with the incidence of superficial scald (SS). The volatile compounds (VCs) were isolated by solid phase microextraction (HS-SPME) and analyzed by gas chromatography. For the first time, higher concentrations of α-farnesene and its oxidation metabolites (6-methyl-5-hepten-2-one, and 6-methyl-5-hepten-2-ol) were negatively correlated with SS in DCA-RQ. This is likely due to the higher levels of ethanol in fruit stored under this condition having an inhibitory effect on SS incidence even when α-farnesene, 6-methyl-5-hepten-2-one, and 6-methyl-5-hepten-2-ol accumulate. Additionally, SS is more correlated to internal ethylene concentration (IEC) than α-farnesene accumulation and their metabolites, even when fruit were stored under ELO, where ethylene action is reduced.

Short-term storage of ‘Honeycrisp’ apples at 0.5 oC does not improve control of bitter pit without increasing low temperature-induced physiological disorders

‘Honeycrisp’ apples are conditioned at 10 °C for 7 d before storage at 3 °C to reduce development of low temperature disorders such as soft scald. Conditioning, however, can result in greater risk of bitter pit development. A strategy to compromise between two types of disorder by storing fruit for short periods at 0.5 °C before being transferred to 3 °C showed promise in earlier research. Here, this strategy has been investigated over three years. Fruit were conditioned or not conditioned for 1 week at 10 °C before being stored at 0.5 or 3 °C. Fruit stored at 0.5 °C were moved to 3 °C after 1, 2, 3, 4, or 6 weeks in year 1; 5 weeks in year 2; and 1, 2, 3, 4, 6, or 8 weeks in year 3. Fruit quality and incidence of physiological disorders assessed after 16 weeks in years 1 and 2, and 20 weeks in year 3, plus 4 d at 20 °C. Internal ethylene concentration (IEC) and concentrations of acetaldehyde, ethanol and ethyl acetate of the fruit were measured during storage in year 3. Storage at 0.5 °C for different durations before transferring fruit to 3 °C in different years did not inhibit bitter pit or soft scald development compared with 0.5 or 3 °C with or without conditioning for 1 week at 10 °C. Fruit quality was not affected by storage temperature manipulation in any year. Bitter pit incidence correlated negatively with that of soft scald, and positively with IEC. Acetaldehyde, ethanol and ethyl acetate concentrations reached a maximum at 6–8 weeks of storage, but were not consistently related to treatment differences on soft scald incidence. However, volatile accumulations were associated with increasing severity ratings when fruit were categorized by disorder severity. Cavities and vascular browning of fruit were increased by short-term periods at 0.5 °C in year 3. Previous research suggesting that temperature manipulations could be used to manage soft scald and bitter pit incidence was not supported by this study.

Multiple factors affecting occurrence of soft scald and fungal decay in apple during storage

Some apple cultivars are highly susceptible to soft scald, a physiological disorder that can lead to large losses. The effect of harvest time, gradual cooling regimes and storage conditions on soft scald and fungal decay was investigated in two common apple cultivars, ‘Aroma’ and ‘Frida’ in a three year trial 2018–2020. Further, possible relationships between weather conditions during the growing season and 28 d before harvest and soft scald incidence along with fungal decay after storage were studied. The year with the highest rainfall had the highest incidence of soft scald and fungal decay. Our results suggest that the relative humidity during a period of 28 d before harvest was important for later development of soft scald in ‘Frida’, and together the results from ‘Frida’ and ‘Aroma’ showed a moderate correlation between relative humidity and soft scald. Gradual cooling showed conflicting results, and no treatment consistently lowered soft scald incidence. Gradual cooling led to inconclusive results, and storage in ambient air led to higher incidence of soft scald as compared to some investigated ULO storage conditions. Advanced maturity was associated with soft scald development and more fungal decay in one out of three years in ‘Aroma’, but did not affect incidence in ‘Frida’. The etiology of soft scald seems to be dependent of multiple factors.

Pb4CL2 Inducing Lignin Accumulation in Superficial Scald ‘Chili’ (Pyrus bretschneideri) Pear Fruit

Superficial scald of pear fruit is a physiological disorder that easily occurs during cold storage and seriously affects pear eating quality and commodity value. It is important to study the mechanism of superficial scald disorder. Our previous study reported that the incidence of superficial scald of calcium chloride (CaCl2)-treated pear fruit during storage was significantly lower than that of untreated fruit. In this study, we found that the accumulation of lignin in CaCl2-treated fruit was significantly lower than that of untreated fruit. The expression of the Pb4CL2 gene in the lignin synthesis pathway was downregulated in the CaCl2-treated fruit. The lignification level of the fruit overexpressing Pb4CL2 was significantly higher than that of the empty vector fruit. Therefore, we speculate that downregulation of Pb4CL2 after CaCl2 treatment plays an important role in CaCl2 inhibiting superficial scald disorder by affecting lignin accumulation in pear fruit.

Impact of sowing dates on the yield efficiency of upland rice cultivars

The choice of cultivars adapted to different regions and the determination of the best sowing dates are indispensable tools for crop development. This allows the installation of the crop in times favorable to its development, as well as cultivars that manage to reach their maximum yield potential. The objective of this study was to determine the best sowing dates and the cultivars that can adapt to the low-altitude Cerrado region and have the best development and yield efficiency. The experiment was conducted on a typical clayey dystrophic Red Latosol soil. The experimental design was in randomized blocks in a factorial scheme, comprised by four sowing dates during the spring/summer season (October, November, December, and February) and in each sowing date there were eight upland rice cultivars (BRS Esmeralda, ANa 6005, ANa 5015, IPR 117, IAC 203, IAC 500, ANa 7211 and BRSGO Serra Dourada) with four replicates. Sowing in October and November benefited the aerial dry mass and the spikelets fertility however, sowing in November provided higher plant height, which caused lodging in plants. Sowing in December caused the incidence of scald, mainly affecting the cultivar ANa 7211. For all cultivars, sowing in October favored the yield efficiency of upland rice in the low-altitude Cerrado, followed by sowing in November. The cultivars which demonstrated higher yield efficiency in the conditions of the region were BRS Esmeralda and ANa 5015.

Exogenous putrescine and 1-methylcyclopropene prevent soft scald in ‘Starkrimson’ pear

‘Starkrimson’ pears are susceptible to soft scald disorder after long-term cold storage. In the present study, the role of putrescine (PUT) and 1-methylcyclopropene (1-MCP) in the development of scald disorder, fruit softening, and ripening behaviors were initially investigated in ‘Starkrimson’ pear during 9 d of shelf life at 20 °C after 90 d storage at 1 °C. PUT (1 mM) reduced scald incidence to 36.9 % and partially suppressed ethylene production, and the treated fruit properly softened within 6 d of its shelf life; 1-MCP (300 nL L−1) prevented scald formation, but the treated fruit exhibited ripening obstacles with limited ethylene and CO2 production. The underlying molecular and biochemical mechanisms were further investigated, and, of the genes monitored，the most similar impact between PUT and 1-MCP treatments was their inhibitory effects on laccase activity and the transcription of related laccase-encoding genes, including PcLAC7, PcLAC9, and PcLAC15. Additionally, 1-MCP largely influenced the transcription of the genes involved in hormone biosynthesis and transduction, including ethylene, abscisic acid, and jasmonic acid, while PUT exhibited a limited influence on these genes. Unlike PUT, 1-MCP exclusively influenced the transcription of genes involved in starch and sucrose, respiratory, and cell wall metabolism, resulting in delayed ripening and enhanced firmness of fruit. In summary, exogenous applications of PUT and 1-MCP were both capable of preventing soft scald in ‘Starkrimson’ pear; 1 mM PUT could be employed as a beneficial treatment for reducing scald disorder accompanied by a proper ripening process during shelf life.

Epidemiology of severe scald in 0–5–year-old children at the Department of Plastic and Reconstructive Surgery, Gauhati Medical College and Hospital – A 5-year retrospective study

Background: The 0–5-year-old age group has the highest incidence of scalds. In assessing a child with scalds, it will be beneficial to look at the interactions between the host, substance, mechanism, and environment. These factors have an effect on the degree, percentage, distribution, and pattern of injury sustained by the child. Subjects and Methods: This retrospective study comprised children aged 0–5 years who were admitted to the Burn Unit of the GMCH, Guwahati, with scald wounds between January 1, 2017, and December 31, 2021, for a period of 5 years. After receiving ethical committee approval, the records of the patients were gathered from the medical records department of GMCH, Guwahati, during this time period. Results: Majority of the incidences were found in male children aged 9–12 months. Scalds commonly occur in rural areas and indoor at home. The upper lower class had the most scald injuries and parents had a poor educational status. The most common substance was hot water in a vessel. The most common mechanism was for a child to pull a hot water down over themselves. In descending order, children suffered a significantly higher proportion of scalds to the hand, chest, and face. Conclusions: Children should be closely supervised by elders or parents, particularly in the kitchen while at home. Parents and caregivers should receive preventive education and training. All kitchen practices, such as floor cooking, low-level shelves, and keeping hot liquids in easily accessible places, should be avoided to prevent childhood scalds.

Liver Dysfunction in Sternness Burn Injury in Association to Age Estimate: A Conceivable Role of Antioxidant Biomarker and Tumor Necrosis Factor Alpha

Background: Burn injuries represent one of the greatest public health problems that induce significant patient morbidity and mortality. Scalds are the most common cause of burn injuries which is known to have long term grave consequences on general health. Aim: The current study was performed to identify the age of scald burn from histopathological changes and TNF-α immunoexpression. As well, study the probable relation between the scald age and the hepatic function impairment. Materials and Methods: A total number of 40 adult male albino rats were used in the study. Eight kept as control group I. Thirty-two rats were exposed to scald injury involving 20% of total body surface area (TBSA). Histopathological examination for the scald area, liver, and skin TNF-α immunohistochemistry was performed. Liver function tests and liver tissue malondialdehyde (MDA) were also determined. The study was carried out after 2, 7 days, 1 and 3 months of scald incidence. Results: Progressive histopathological changes and elevated liver enzymes were observed in the early scald ages while manifestations of healing and improvement in liver parameters, started to occur after 1 and 3 months of scald infliction in comparison with the other periods. There was a highly significant (P < 0.001) increase in malondialdehyde level and TNF-α expression in scald injured groups after 2 and 7 days compared with control group I. Conclusion: Overall, the results showed the ability to identify the age of scald injury using routine histopathological examination. Also, scald injury involving 20% of TBSA may cause long term impairment of hepatic function. Moreover, the proinflammatory results revealed that TNF-α may consider as mediators in the post-burn pathophysiological process. Furthermore, our results declare a significant correlation between MDA levels and the degree of burn complications, including shock and remote organ damage.

Physiological and biochemical mechanism of resveratrol inhibiting superficial scald in ‘Dangshansuli’ pears

ABSTRACT The effects of resveratrol (RES) and diphenylamine (DPA) on superficial scald of ‘Dangshansuli’ pears (Pyrus bretschneideri Rehd.) were studied. Pears treated with RES or DPA were stored in cold storage for 210 d and then transferred to shelf life (20 ± 0.5°C) for 5 and 10 d. Compared to the control, RES and DPA maintained the firmness and soluble solid content (SSC) and decreased α-farnesene and its auto-oxidation. RES and DPA decreased membrane lipid peroxidation and oxidative damage but increased auto-oxidant enzyme activities during cold storage. During later storage, RES and DPA significantly regulated energy levels. After cold storage and shelf life, RES and DPA significantly inhibited the scald incidence and scald index. Hence, RES and DPA inhibit scald in slightly different ways. RES can inhibit scald by two pathways, namely, by decreasing α-farnesene and its auto-oxidation products and by decreasing membrane lipid peroxidation and oxidative damage through improvements in energy metabolism and antioxidant capacity. RES has the potential to be a substitute of DPA to effectively control the scald of ‘Dangshansuli’ pears.

Impact of Hot Water and Modified Atmosphere Packaging Treatments on the Postharvest Quality of Pomegranate Fruit cv. Hicaznar

Hot water (HW) and modified atmosphere packaging (MAP) treatments were evaluated to maintain postharvest quality of pomegranate fruit (Punica granatum cv. ‘Hicaznar’). Pomegranates were subjected to hot water (HW) treatment (at 50 °C for 3 min) and packaged with or without MAP bags. Fruit was then kept at 6 °C for 6 months and at 20 °C for 7 days after cold storage period. The untreated and unpackaged fruit was served as a control treatment (C). MAP and HW+MAP treatments was more effective in reducing weight loss, fungal decay and husk scald, compared to HW and C treatments. The lightness and red color intensity of husk and aril (higher values of L* and C* and lower values of h°) were maintained better in the packaged fruit with MAP (MAP + HW+MAP treatments). The unpackaged fruit from HW and C treatments became unmarketable while those from MAP and HW+MAP treatments were still marketable after 6 months of cold storage and shelf life period. Although fungal decay incidence was low in HW-treated fruit, relatively high scald incidence and weight loss had adverse effect on overall visual acceptability of HW-treated fruit. Hot water dipped pomegranate fruit cv. ‘Hicaznar’ (50 °C for 3 min) could be kept in MAP bags for 6 months at 6 °C and for 7 days 20 °C without adverse effect on quality.

Effects of 1-methylcyclopropene and gaseous ozone on Listeria innocua survival and fruit quality of Granny Smith apples during long-term commercial cold storage

This study evaluated the impact of 1-methylcyclopropene (1-MCP), an ethylene synthesis inhibitor, followed by long-term commercial cold storage with low-dose gaseous ozone on the microbiological safety and quality of fresh apples. Granny Smith apples were inoculated with or without Listeria innocua, treated with or without 1.0 mg/L 1-MCP for 24 h, then subjected to commercial cold storage conditions including refrigerated air (RA, 0.6 °C, control), controlled atmosphere (CA, 2% O2, 1% CO2, 0.6 °C), and CA with 51–87 μg/L ozone gas for up to 36 weeks. RA storage reduced L. innocua on apples by up to 3.6 log10 CFU/apple. CA had no advantage over RA in controlling Listeria. Continuous ozone gas application resulted in an additional ∼2.0 log10 CFU/apple reduction of L. innocua (total reduction up to 5.7 log10 CFU/apple) and suppressed native bacteria and fungi. Treatment with 1-MCP had a minor impact on survival of L. innocua or background microbiota on apples, while it significantly delayed fruit ripening and reduced the incidence of superficial scald and internal browning. In summary, 1-MCP treatment followed by CA storage with low-dose continuous ozone gas can effectively control Listeria on fresh apples and delay fruit ripening.

Management of ethylene production, superficial scald and fruit quality in ‘Granny Smith’ apple using organic oils and ozonised cold storage

Ethylene management during storage of organically grown apples is challenging due to limited number of treatment and storage options that are available for organic produce. In this study the effects of fumigation with lemon and cinnamon oils on ethylene production, superficial scald incidence, and fruit quality in 'Granny Smith apples' placed in cold storage with and without application of ozone were evaluated. The fruit were fumigated with 3 µL L‑1 lemon or cinnamon oil for 24 h while untreated fruit were used as a control. Following the treatments, the fruit were put into cold storage at 0±2, with and without ozone for 100 or 150 days. After each storage period, ethylene production, superficial scald incidence, and fruit quality parameters were recorded. The fruit fumigated with lemon oil was significantly reduced climacteric ethylene peak rates after 100 and 150 days cold storage. The mean rate at which the ethylene climacteric peak developed was significantly reduced in fruit stored in ozonised cold storage compared to the peak level in fruit stored without ozone for 100 days. The climacteric ethylene peak was significantly delayed in the fruit cold stored with ozone (8.78 d) as compared to without ozone (3.89 d) following 100 days storage. Fruit firmness was significantly higher in fruit fumigated with lemon or cinnamon oil compared to control fruit for both storage times. Lemon or cinnamon oil fumigation significantly reduced superficial scald in the cold-stored fruit with or without ozone. The fruit fumigated with lemon oil or cinnamon oil following 150 days cold storage resulted in significantly higher levels of ascorbic acid and antioxidant capacity compared to control fruit. Overall, lemon oil fumigation was more effective in suppressing ethylene production in 100 and 150 day cold-stored fruit than cinnamon oil. Notably, fumigation with lemon or cinnamon oil were effective in reducing superficial scald and maintaining quality in 100 and 150 days cold-stored fruit.

A DNA test for high incidence of soft scald and soggy breakdown postharvest disorders in Malus domestica Borkh

The ‘Honeycrisp’ apple, an economically important cultivar and breeding parent, is prone to soft scald and soggy breakdown postharvest physiological disorders. Phenotypic evaluation of soft scald is time consuming and costly, making it an excellent target for DNA-informed breeding. The objective of this study was to develop a DNA test for a soft scald and soggy breakdown quantitative trait locus (QTL) on linkage group two (LG2) that was characterized in a previous study. ‘Honeycrisp’ is homozygous for the undesirable high disorder incidence haplotype (HDI) at this QTL. In this study, sixteen single nucleotide polymorphism markers were evaluated for their associations with the HDI haplotype in a set of 132 unique cultivars and important breeding parents. A DNA test was successfully developed utilizing KASP™ (Kompetitive Allele Specific PCR) chemistry to identify the number of HDI haplotypes in individuals. This test had a 100% accuracy for detecting homozygous unfavorable HDI individuals and has an expected 88% accuracy over all three haplotype copy groups across the evaluated germplasm. This DNA test is a promising tool for minimizing the chances of selecting individuals that exhibit high incidence of soft scald postharvest disorder in ‘Honeycrisp’-related germplasm.

Scald Burns, Children a Vulnerable Vicitm

This retrospective study spans over a period of two years and included 18 scald cases all of them were accidental in nature. Majority of the reported cases were children who sustained scalds of more than 50% of the area of the body. Analysis of the data was done on the bases of age, gender, site where incidence took place, nature of injury, causative agent, duration patient survived and manner of death. There were 18 male cases and 6 female cases, all died due to incidence of scald. All reported cases were domestic in nature. Upper part of the body was affected in majority of the cases and boiling water was the main source of scalds. The surface area affected in all cases was more than 50% which was calculated with the help of rule of nine. The cause of death in majority of the cases was septicemia. Aim: The aim of the study is to explore of causative factors of wet burns in young age group. Methodology: This study is based on retrospective data which was conducted between the years January 2000 to December 2002. During this time period total of 16 cases of death due to hot liquid i.e. scalds were reported for autopsy nearly all of them belonged to young age group. Results: The reported cases in our study were males (67.8%) and females (32.2%), the ratio of male to female was 2:1. The common age group effected was children ranging from 1-12 years (59.01%), followed by adults in the age group of 35 -45 (17.12%) years. Majority of the incidences were domestic in nature72.2%. more than 70% of the incidences took place at home and more than 85% of the body area affected was thorax. Hot boiling water was the main cause of scalds. Conclusion: Scalds appear to be one of the most common type of burns encountered in children, the major contributing factor is the ignorance on the part of the mother. All studies have proven one common thing that onus of responsibility rest on the shoulders of the parents, who should take the responsibility and be more vigilant so that such incidences should be avoided. Key Words: Scalds, wet burns, adolescents.

Distribution, phylogeny, and pathogenicity of Xanthomonas albilineans causing sugarcane leaf scald in Mexico

Disease outbreaks attributed to leaf scald of sugarcane caused by Xanthomonas albilineans were recently reported in southern Mexico. In this study, the distribution of leaf scald was investigated in the main sugarcane producing-states in Mexico. The disease was found in eight of 14 sugarcane-growing states and in 12 of 31 fields. In contaminated fields, incidence of leaf scald based on symptomatic plants ranged from 3 to 15%. The causal agent was identified by phylogenetic reconstruction using a single concatenated sequence of four genes (16S rRNA, fusA, leuS, and rpiA). Twelve X. albilineans isolates from different locations in Mexico produced disease symptoms after inoculation into stalks of susceptible variety Mex 69–290. Microscopic examination of infected stalks revealed structural changes within vascular and non-vascular tissues. These alterations reflected acute disease development and highlighted the importance of selecting varieties resistant to X. albilineans in breeding programs in Mexico.