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Ceratocystis wilt disease surveys were conducted in three selected Malaysian Acacia mangium plantations. These completed surveys revealed the occurrence of the wilt disease, with the incidence of infection ranging from 7.5% to 13.6%. Signs of wood-boring insects, bark peeling due to squirrel activity, and pruning wounds were often associated with this disease. The fungus most frequently isolated from the diseased trees was the Ceratocystis fungus. The analysis on the morphological characteristics has identified the fungus as Ceratocystis fimbriata complex. Phylogenetic analysis based on the sequences of the ITS, and concatenated sequences of EF1α-βT regions grouped the isolates within the C. fimbriata sensu stricto, in comparison to other C. fimbriata isolates. Pathogenicity tests were conducted on six to nine-month-old healthy A. mangium seedlings by inoculating these seedlings with eight out of the 16 isolates. The results demonstrated that all the isolates were pathogenic, with mortality beginning as early as two weeks after inoculation. However, an ANOVA test indicated a significant difference between the pathogenicity levels among the fungal isolates. The results also showed that pathogen aggressiveness was not correlated with geographical origin. A host range test was also conducted by using C. fimbriata SSB3 and FRIM1162 isolates against several forest plantation species. The findings suggested that only A. mangium was susceptible to C. fimbriata. The other species remained healthy with no symptoms of infection even after seven weeks of treatment, as compared to the A. mangium species, where between 38 to 60% of the inoculated plants had died. This study provides new information on the status of Ceratocystis wilt disease, especially on the occurrence and effects on A. mangium plantation, by giving insights on how to control and manage this ferocious plant pathogen in the future.

In this study, the effects of stem canker disease caused by Chrysoporthe deuterocubensis on the chemical properties and durability of a Eucalyptus hybrid (E. urophylla x E. grandis) were investigated. Eleven-year-old healthy and infected trees were collected. The samples were grouped into four different classes based on the infection severity: healthy (class 1), moderately infected (class 2), severely infected (class 3), and very severely infected (class 4). The changes in chemical properties were evaluated via chemical analysis and Fourier transform infrared spectroscopy (FTIR) analysis. A resistance test against fungal decay (Pcynoporus sanguineus and Caniophora puteana) and termite (Coptotermes curvignathus) was also performed. The results showed that reductions in cellulose and hemicellulose content from 53.2% to 45.4% and 14.1% to 13.9%, respectively, were observed in the infected samples. Meanwhile, the percentages of lignin and extractives increased from 18.1% to 20.5% and 14.6% to 20.2%, respectively. The resistance against fungi and termites varied between severity classes. Generally, infected wood behaved better than healthy wood in terms of durability against fungi and termites. The durability classes for both tests were significantly improved, from resistant to highly resistant and poor to moderately resistant, respectively. These results suggest that E. urograndis that is infected by C. deuterocubensis might have a better potential use in lumber production with regard to its durability and processing cost compared to pulp and paper products. [ABSTRACT FROM AUTHOR]

Aquilaria is a tropical forest tree, producer of the famed and expensive agarwood. Aggressive collection of agarwood put strain on the natural stands of Aquilaria species, sparking efforts to domesticate the tree and cultivate agarwood in plantations. However, tree domestication progress is hampered by the scarcity of genomic resources that is crucial for breeding programs. In this study, the complete chloroplast (cp) genome sequences from eight Aquilaria species were analyzed in silico. For identification of the simple sequence repeats (SSRs), MISA PERL script which had a repeat length of 12 for mononucleotides (mono-), 6 for dinucleotides (di-), 4 for trinucleotides (tri-), 3 for tetranucleotides (tetra-), pentanucleotides (penta-), and hexanucleotides (hexa-), respectively, along with frequency were utilized. From a total of 312 SSRs that were discovered, merely 50 (16%) were found localized within the coding region while the majority (84%) were within the intergenic regions, with an average of one SSR per 4.5 kb. The mean length of the SSRs were 11.63 bp. Mono- repeats were the predominant motifs (29.2%), followed by tetra- (28.8%), di- (20.5%), tri- (19.9%), and penta- (1.6%). Whereas the most recurring motifs were A/T (97.8%) for mono-, AT/AT (87.5%) for di-, AAT/ATT (48.4%) for tri-, and AAAT/ATTT (45.6%) for tetra-. GO analysis using the REVIGO software identified four molecular functions, six biological processes and three cellular components. In conclusion, findings of this study offer a scientific foundation for future phylogenetics, evolutionary genetics, diversity studies and breeding programs on Aquilaria species. [ABSTRACT FROM AUTHOR]

Known for its durable timber quality, Neobalanocarpus heimii (King) Ashton is a highly sought after tree species endemic to the Malay Peninsula. Due to its scarcity and high value, the tree is classified under the IUCN Red List categories of Vulnerable. In this study, we assembled the complete chloroplast (cp) genome of N. heimii using data from high-throughput Illumina sequencing. The Chengal cp genome is 151,191 bp in size and includes two inverted repeat regions of 23,721 bp each, which is separated by a large single copy region of 83,801 bp and a small single copy region of 19,948 bp. A total of 130 genes were predicted, including 37 tRNA, 8 rRNA, and 85 protein-coding genes. Phylogenetic analysis placed N. heimii within the order Malvales. [ABSTRACT FROM AUTHOR]