Leaf blight caused by Calonectria spp. is an important disease occurring on Eucalyptus trees grown in plantations of Southeast Asia. Symptoms of leaf blight caused by Calonectria spp. have recently been observed in commercial Eucalyptus plantations in FuJian Province in Southeast China. The aim of this study was to identify these Calonectria spp. employing morphological characteristics, DNA sequence comparisons for the β-tubulin, histone H3 and translation elongation factor-1α gene regions and sexual compatibility. Four Calonectria spp. were identified, including Ca. pauciramosa and three novel taxa described here as Ca. crousiana, Ca. fujianensis and Ca. pseudocolhounii. Inoculation tests showed that all four Calonectria spp. found in this study were pathogenic on two different E. urophylla × E. grandis hybrid clones, commercially utilised in eucalypt plantations in China.

The Botryosphaeriaceae is a species-rich family that includes pathogens of a wide variety of trees, including Eucalyptus species. Symptoms typical of infection by the Botryosphaeriaceae have recently been observed in Eucalyptus plantations in South China. The aim of this study was to identify the Botryosphaeriaceae associated with these symptoms. Isolates were collected from branch cankers and senescent twigs of different Eucalyptus spp. All isolates resembling Botryosphaeriaceae were separated into groups based on conidial morphology. Initial identifications were made using PCR-RFLP fingerprinting, by digesting the ITS region of the rDNA operon with the restriction enzymes CfoI and KspI. Furthermore, to distinguish isolates in the Neofusicoccum parvum ⁄ N. ribis complex, a locus (BotF15) previously shown to define these species, was amplified and restricted with CfoI. Selected isolates were then identified using comparisons of DNA sequence data for the ITS rDNA and translation elongation factor 1-alpha (TEF-1a) gene regions. Based on anamorph morphology and DNA sequence comparisons, five species were identified: Lasiodiplodia pseudotheobromae, L. theobromae, Neofusicoccum parvum, N. ribis sensu lato and one undescribed taxon, for which the name Fusicoccum fabicercianum sp. nov. is provided. Isolates of all species gave rise to lesions on the stems of an E. grandis clone in a glasshouse inoculation trial and on the stems of five Eucalyptus genotypes inoculated in the field, where L. pseudotheobromae and L. theobromae were most pathogenic. The five Eucalyptus genotypes differed in their susceptibility to the Botryosphaeriaceae species suggesting that breeding and selection offers opportunity for disease avoidance in the future.

Many species in the Cryphonectriaceae cause diseases of trees, including those in the genera Eucalyptus and Syzygium. During disease surveys on these trees in southern China, fruiting structures typical of fungi in the Cryphonectriaceae and associated with dying branches and stems were observed. Morphological comparisons suggested that these fungi were distinct from the well known Chrysoporthe deuterocubensis, also found on these trees in China. The aim of this study was to identify these fungi and evaluate their pathogenicity to Eucalyptus clones/species as well as Syzygium cumini. Three morphologically similar fungal isolates collected previously from Indonesia also were included in the study. Isolates were characterized based on comparisons of morphology and DNA sequence data for the partial LSU and ITS nuclear ribosomal DNA, btubulin and TEF-1a gene regions. After glasshouse trials to select virulent isolates field inoculations were undertaken to screen different commercial Eucalyptus clones/species and S. cumini trees for susceptibility to infection. Phylogenetic analyses showed that the Chinese isolates and those from Indonesia reside in a clade close to previously identified South African Celoporthe isolates. Based on morphology and DNA sequence comparisons, four new Celoporthe spp. were identified and they are described as C. syzygii, C. eucalypti, C. guangdongensis and C. indonesiensis. Field inoculations indicated that the three Chinese Celoporthe spp., C. syzygii, C. eucalypti and C. guangdongensis, are pathogenic to all tested Eucalyptus and S. cumini trees. Significant differences in the susceptibility of the inoculated Eucalyptus clones/ species suggest that it will be possible to select diseasetolerant planting stock for forestry operations in the future.

The genus Chrysoporthe includes important pathogens of plantation-grown Eucalyptus spp. and has been reported from several tree genera in the order Myrtales in tropical and subtropical areas of the world. During disease surveys in South China, fruiting structures typical of Chrysoporthe spp. were observed on cankers on Eucalyptus spp. and Syzygium cumini trees. The aim of this study was to confirm the identity of the Chrysoporthe cubensis infecting the Eucalyptus spp. and S. cumini and to test the pathogenicity of the fungus. Following glasshouse trials to select virulent isolates, field inoculations were undertaken to screen different commercial Eucalyptus genotypes for their susceptibility to the fungus. Isolates were characterized based on their morphology and DNA sequence data for the β-tubulin and internal transcribed spacer regions of the ribosomal DNA. Results showed that the putative pathogen represented the Asian form of C. cubensis, which occurred on numerous different Eucalyptus spp. and hybrid clones as well as S. cumini. Field inoculations showed that all six of the Eucalyptus genotypes tested are susceptible to infection by C. cubensis. Significant differences were observed between them, providing prospects to select disease-tolerant planting stock in the future.

Eucalypt plantations in China currently exceed 4.5 Mhm 2 , and this country has the third largest area of such plantations after India and Brazil. China's eucalypt industry now comprises a complex, multifaceted industry including seedling propagation, fertilizer production and supply, plantation silviculture, harvesting and transport, wood processing for products including lumber, pulp and paper, and wood-based panels, as well as bioenergy production and various forest byproducts and non-wood forest products. In 2015, the combined value of output of this whole industry was around 300 billion CNY. Chinese research and development (R&D) has been instrumental in supporting growth and development across the whole breadth of the country's eucalypt industry. In this report, recent advances in this R&D are reviewed under six key topics: (1) advanced propagation technology; (2) genetic resources and breeding; (3) targeted silviculture; (4) eucalypt disease and pest management; (5) enhancing plantation ecology and sustainability; and (6) wood processing and byproduct technology. R&D has greatly facilitated expansion and proliferation of all parts of China's eucalypt industry. This industry is now of major importance to China's economy; it involves tens of thousands of growers and companies that provide livelihoods for hundreds of thousands of people.

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& Context Processing young, small eucalypt logs into veneer is a burgeoning industry across southern China. However, plantations supplying these logs were mostly established for pulpwood; little information is available on variation and selection among commercial eucalypt clones/varieties in regards to suitability for veneer production. & Methods Tree growth and log form were assessed on 11 eucalypt clones from a 5-year-old trial in southern China. Logs from these were rotary peeled for veneer; recovery percentages plus a range of quality and value traits were assessed on the outturn. & Results Tree volumes, green veneer recovery ratios (%), veneer quality grades, log value, and value m −3 varied significantly among both clones and log positions up the stem. The clone with the best veneer recovery ratio (50.5 %) provided nearly twice that of the poorest clone (28.4 %). Average veneer value log −1 by clone ranged from RMB 6.7 (US$1) up to RMB 15.1 (US$2) and average value m −3 by clone ranged from 589 RMBm −3 (US$88) up to 925 RMBm −3 (US$139). Overall, sweep was the key factor influencing veneer recovery ratio and value. Knots, especially dead knots, holes and splitting were major factors influencing veneer quality grade. Middle and upper logs had significantly higher veneer recoveries, grades, and values m −3 than the lower logs. & Conclusions Excellent potential exists for selecting among eucalypt clones, and even among log positions within trees, for optimizing veneer production.

China's plywood production grew rapidly over the past 15 years from around 9 M m 3 yr −1 in the mid 1990s to over 55 M m 3 yr −1 by 2011. Associated with this has been a proliferation of small-scale eucalypt veneer mills processing young (≤ 5 yrs) small diameter logs (mostly ≤ 12 cm small end diameter); by 2011 there were over 5000 such mills in China with a collective capacity to process well over 15.0 M m 3 yr −1 of logs. We review key characteristics of this eucalypt veneer industry with special focus on three key regions for eucalypt veneer production in China. Factors that have spurred and facilitated the rapid growth of this industry are reviewed along with future challenges likely to emerge for China's eucalypt veneer industry.La production de contreplaqué en Chine s'est accrue rapidement durant les quinze dernières années, de 9 M m 3 yr −1 au milieu des années 1990 à plus de 55 M m 3 yr −1 en 2011. Il faut ajouter à cela la prolifération de scieries de petite envergure produisant le placage d'eucalyptus à partir de jeunes (≤ 5 ans) bûches de petit diamètre (pour la plupart ≤ 12 cm au diamètre le plus étroit). En 2011, il existait plus de 5000 telles scieries en Chine, possédant une capacité collective de produire largement plus de 15.0 M m 3 yr −1 de rondins. Nous examinons les caractéristiques clé de cette industrie de plaqué d'eucalyptus en nous concentrant tout spécialement sur trois régions clé pour cette production en Chine. Les facteurs ayant poussé et facilité la croissance rapide de cette industrie sont examinés ainsi que les futurs défis à l'horizon pour cette industrie du plaqué d'eucalyptus en Chine.La producción de contrachapado en China ha crecido rápidamente en los últimos 15 años, desde aproximadamente 9 millones de m 3 año −1 a mediados de los 90 hasta más de 55 millones de m 3 año −1 en 2011. Asociada a este crecimiento está la proliferación de aserraderos de pequeña escala de chapa de eucalipto que procesan trozas jóvenes (≤ 5 años) de pequeños diámetros (≤ 12 cm en punta delgada). Para el 2011 ya se contaba con más de 5000 de estos aserraderos en China, con una capacidad de procesamiento colectiva de más de 15 millones de m 3 año −1 de madera en troza. Revisamos aquí las características más importantes de la industria de chapa de eucalipto en este país, centrándonos en particular en tres regiones claves para la producción de chapa de eucalipto en China. Se revisan también los factores que han estimulado y facilitado el rápido crecimiento de esta industria, junto con los futuros retos a los que probablemente se enfrentará la industria de chapa de eucalipto en China.