Fourteen new species in the Latin American Clade (LAC) of the Ceratocystis fimbriata complex recently were distinguished from C. fimbriata sensu stricto largely based on variation in ITS rDNA sequences. Among the 116 isolates representing the LAC, there were 41 ITS haplotypes. Maximum parsimony (MP) analysis of ITS sequences produced poorly resolved trees. In contrast, analyses of mating-type genes (MAT1-1-2 and MAT1-2-1) resolved a single MP tree with branches of high bootstrap and posterior probability support. Four isolates showed intragenomic variation in ITS sequences. Cloning and sequencing of PCR products from a single haploid strain identified two or more ITS sequences differing at up to 16 base positions and representing two described species. Isolates from introduced populations that appeared to be clonal based on microsatellite markers varied at up to 14 bp in ITS sequence. Strains of seven Brazilian ITS haplotypes and an isolate from Ipomoea batatas (on which the species name C. fimbriata was based) were fully interfertile in sexual crosses. These analyses support three phylogenetic species that differ in pathogenicity: C. platani, C. cacaofunesta and C. colombiana. Five ITS species (C. manginecans, C. mangicola, C. mangivora, C. acaciivora, C. eucalypticola) appear to be ITS haplotypes that have been moved from or within Brazil on nursery stock. The taxonomic status of other species delineated primarily by ITS sequences (C. diversiconidia, C. papillata, C. neglecta, C. ecuadoriana, C. fimbriatomima, C. curvata) needs further study, but they are considered doubtful species.

Fourteen new species in the Latin American Clade (LAC) of the Ceratocystis fimbriata complex recently were distinguished from C. fimbriata sensu stricto largely based on variation in ITS rDNA sequences. Among the 116 isolates representing the LAC, there were 41 ITS haplotypes. Maximum parsimony (MP) analysis of ITS sequences produced poorly resolved trees. In contrast, analyses of mating-type genes (MAT1-1-2 and MAT1-2-1) resolved a single MP tree with branches of high bootstrap and posterior probability support. Four isolates showed intragenomic variation in ITS sequences. Cloning and sequencing of PCR products from a single haploid strain identified two or more ITS sequences differing at up to 16 base positions and representing two described species. Isolates from introduced populations that appeared to be clonal based on microsatellite markers varied at up to 14 bp in ITS sequence. Strains of seven Brazilian ITS haplotypes and an isolate from Ipomoea batatas (on which the species name C. fimbriata was based) were fully interfertile in sexual crosses. These analyses support three phylogenetic species that differ in pathogenicity: C. platani, C. cacaofunesta and C. colombiana. Five ITS species (C. manginecans, C. mangicola, C. mangivora, C. acaciivora, C. eucalypticola) appear to be ITS haplotypes that have been moved from or within Brazil on nursery stock. The taxonomic status of other species delineated primarily by ITS sequences (C. diversiconidia, C. papillata, C. neglecta, C. ecuadoriana, C. fimbriatomima, C. curvata) needs further study, but they are considered doubtful species.

Ceratocystis fimbriata has been associated with decline disorders of several fruit and forest trees. In 2006 this pathogen was isolated for the first time from declining mango trees in Pakistan. It has also recently been isolated from samples of declining shisham trees and pathogenicity tests have confirmed that it is indeed responsible for the decline disorders observed on shisham tress in Pakistan. This is the first record of C. fimbriata in association with shisham decline and the first time it is demonstrated to be the etiological agent of this important disease.

Oidium mangiferae Berthet was found to be associated With the powdery mildew disease of mango. The air- borne conidia are released from the old tissue harboring the dormant fungal hyphae under favorable weather conditions, which produce the disease. Proper forecasting of release of airborne innoculum significantly reduced the required number of sprays needed for chemical control. Spore traps were used to monitor the concentration of airborne conidia during the months of February, March and April 1996 and l997. Daily temperature and relative humidity were noted and the spore counts from the spore traps were correlated to the meteorological data. There was a positive trend between rising temperature, lowering relative humidity and number of spores in the air alter a low temperature, high humidity and cloudy spell of weather. The maximum spore occurrences were noted around 25°C and relative humidity of 40-60%. It took 5-8 days for the emergence of disease symptoms after the first detection of airborne conidia. Ten fungicides were tested on three mango varieties (Langra, Dashehari, and Anwar Retol). The preventive sprays at the stage of first detection of air born conidia were effective in controlling the disease. Optimal timing of two sprays of fungicide were sufficient to provide preventive control (>90%). The susceptibility of inflorescence varied with its developmental stage. Proper forecasting reduced the number of sprays from 7 to 2 or 3. There was no varietal difference in incidence of the disease or response to fungicide applications. During the course of this study, we identified seedling plants which consistently showed resistance to powdery mildew.

Mango (Mangifera indica) is a popular fruit in Pakistan and ranks second to citrus. Pakistani mangoes have a large export potential in overseas markets that has yet to be realized. In Pakistan, important fruit trees such as citrus, mango, guava, etc. are facing a decline. Among these fruits, mango decline has been addressed strongly as they are important foreign exchange earnings and export items. In the case of mango, the decline has different forms, generally known as progressive, slow decline, or dieback; quick dieback, and sudden death. This type of condition is most common in poorly managed orchards that do not follow correct nutrition, plant protection, or irrigation techniques. Such a drop can be easily addressed if orchards are cultivated using the greatest possible production methods. The updated studies on the occurrence of mango decline are necessary to become a reference for further research and management strategies. Therefore, the present study was designed for disease estimation in the mango-growing areas of the Punjab province of Pakistan. According to the results, maximum mean disease severity of 2.70 was observed in district Bahawalpur followed by Khanewal (2.30), Multan (2.11), and Muzaffar Garh (2.00). The minimum disease severity (1.90) was recorded in Rahim Yar Khan district. Similarly, the maximum mean disease incidence (100%) was found in Khanewal followed by Bahawalpur (99.30%), Muzaffar Garh (96.00%), and Multan (96.00%) while the minimum disease incidence (90.00%) was observed in Rahim Yar Khan. The disease index which gives the actual picture of the disease was found to be the maximum in Bahawalpur (53.30%) followed by Khanewal (46.50%), Rahim Yar Khan (39.10%), and Muzaffar Garh (37.30%) while the minimum disease index of 36.89 was found in Multan district. This information will serve as the baseline information for research and management strategies in mango decline.