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Yang X.-H.,Beijing Forestry University | Yu Y.-H.,Guangxi University | Wu Y.-J.,Guangxi Forestry Research Institute | Qin J.-L.,Guangxi Institute of Meteorological Disaster Reducing Research | Luo Y.-Q.,Beijing Forestry University
Journal of Economic Entomology | Year: 2013

Endoclita signifier Walker (Lepidoptera: Hepialidae) has become a new wood borer pest in Eucalyptus plantations in southern China. This article documents survey results of its geographic distribution and host plant range in Guangxi and its morphological measurements, life cycle and behavior. In total, 83 Eucalyptus growing counties were surveyed. E. signifier was found in 59 counties. Host plants included 31 species in 16 families and 24 genera. Four Eucalyptus hybrid species were recorded as its host plant with E. grandis × E. urophyllo and E. urophylla × E. grandis infested the heaviest. The infestation of Eucalyptus trees 1-2 yr old was heavier than that of older trees. Most individuals of E. signifier took 1 yr to complete a generation, overwintering as larvae in tunnels in wooden stems, and pupating in February of the following year. Adults emerge, mate, and lay eggs in April, and the eggs hatch in late April or early May. Adult emergence peaks between 17:00-18:59 hours. Mating flights last under 30 min at dusk and the copulation duration was 24 h. Moths were large, weighting and average of 3.4 g. Eggs and newly hatched larvae were very small, weighing only 0.127 ± 0.001 mg and 0.093 ± 0.017 mg, respectively. The larvae have two distinct development stages. One stage spends 1-2 mo living in the forest litter, the second stage then moves to woody stems where it feeds for ≈10 mo. Larvae start boring into hosts between June and November, mainly in July and August. This study indicated that E. signifier, a highly polyphagous native species, has shifted host to exotic Eucalyptus and can cause significant damage to plantations. © 2013 Entomological Society of America.

Wang P.,Nanjing Agricultural University | Wang P.,Guangxi Forestry Research Institute | Wang H.,Nanjing Agricultural University | Zheng Y.,CAS Institute of Botany | And 3 more authors.
Scientia Horticulturae | Year: 2014

Centipedegrass (Eremochloa ophiuroides) is an important warm-season turfgrass native to the warm temperate and tropical regions of China. Seed yield, vegetative characters and cold tolerance are important horticultural traits affecting the widespread application of this species. To elucidate the genetic mechanisms of these characteristics, we constructed genetic maps based on a population of 87 F1 plants from a cross between two ecotypes (E142 and E022) that significantly differed for the traits. Two types of molecular markers, sequence-related amplification polymorphisms (SRAPs) and expressed sequence tags from wheat [Triticum aestivum] (TaESTs), were employed to construct the genetic maps. The genetic map of E142 spanned a total genetic distance of 878.48cM and contained 82 polymorphic loci, with an average genetic distance of 12.92cM per marker. The genetic map of E022 covered a total genetic distance of 566.25cM and contained 69 polymorphic loci, with an average genetic distance of 9.93cM per marker. A total of 14 QTLs, comprising eight for seed yield, five for vegetative traits and one for cold tolerance, were detected on nine linkage groups: seven linkage groups of the E142 genetic map and two linkage groups of the E022 genetic map. Each of these QTLs explained 8.71-23.61% of the phenotypic variation. The results presented here will enhance the understanding of the genetic basis of seed yield, vegetative traits and cold tolerance in centipedegrass and enable further marker-assisted breeding in the species. © 2014 Elsevier B.V.

Zhou C.-M.,CAS Institute of Botany | Huang Y.-Q.,CAS Institute of Botany | Gu D.-X.,CAS Institute of Botany | Ren S.-Q.,Guangxi Forestry Research Institute | And 2 more authors.
Chinese Journal of Ecology | Year: 2015

Large-scale plantations of Eucalyptus urophylla × Eucalyptus grandis have been recently developed in southern China, especially in Guangxi Province. For sustainable forest and water resource management of these plantations, attention is increasingly paid to their water use efficiency. Sap flow measurement provides a powerful tool for quantifying plant water use, and it is widely employed to estimate the ecological and hydrological outcomes of plant growth. However, a potential error might occur if one applies the sap flow measurements of the outermost layer of these trees to the entire trunk or an entire plantation without considering the radial distribution of xylem sap flow density. Hence, we determined the radial distribution of xylem sap flow density in trunks of 4-year-old E. urophylla × E. grandis using the Granier thermal dissipation probe (TDP) method at the Qipo Forest Farm, Guangxi Province. We found that despite similar diurnal variation of sap flow at different depths of the trunk, sap flow at the 0-20 mm depth constituted bulk of the flow, which changed with seasons, while that of the 20-40 mm depth remain relatively stable. The curve regression analysis showed a significant exponential correlation in daily mean sap flow density (R2>0.90, P = 0.00) between the 0-20 and 20-40 mm depths. Radial distribution pattern of sap flow of, E. urophylla × E. grandis showed a declining pattern with steep slope. The mean monthly sap flow density showed significant changes in the daytime, but it was relatively stable at night. Our findings will be helpful in accurately assessing the water use efficiency of this widely planted Eucalyptus hybrid by more precise calculation of its seasonal sap flow density, having significant implications for land management. © 2015, Editorial Board of Chinese Journal of Ecology. All rights reserved.

Grant J.C.,Southern Cross University of Australia | Nichols J.D.,Southern Cross University of Australia | Yao R.L.,Southern Cross University of Australia | Yao R.L.,Guangxi Forestry Research Institute | And 3 more authors.
Forest Ecology and Management | Year: 2012

Understanding depth distribution of roots may help develop an understanding of plant productivity and the limits to productivity by indicating which parts of the soil profile are being accessed for water and nutrients. The subtropical east coast of Australia provides climatic and soil conditions that produce some of the highest plant productivity rates in the country. This has been recognised by the hardwood plantation industry and over the last decade a substantial estate of plantations has been established with plans for further expansion. However, two of the major species used, Eucalyptus dunnii and Corymbia citriodora subsp. variegata, have had little published research directly related to root depth distribution in the area. We examined root depth distribution in established plantations of E. dunnii and C. citriodora subsp. variegata under three contrasting soil types using the techniques of soil trench profile and coring. The results showed that the fine roots of C. citriodora subsp. variegata are at lower densities in poorly structured subsoils than the roots of E. dunnii. The root densities of both species in the subsoils of a Vertosol soil (with high levels of reactive, shrink-swell clays) were lower than for the other soil types. In native vegetation Vertosols are often colonised by grasses with few, scattered trees from a limited range of species. Our findings show lower levels of root growth in the Vertosols, particularly into the subsoil and this is likely to be the reason that productivity on these, otherwise fertile soils, is restricted. © 2011 Elsevier B.V.

Li D.-W.,Guangxi Forestry Research Institute | Wang G.-Q.,China Agricultural University | Wei S.-G.,Guangxi University
Zootaxa | Year: 2010

A new genus and three new species of eriophyid mites from Guangxi Zhuang Autonomous Region, South China are described and illustrated: Calliparus lanceolarus n. gen., n. sp. infesting Glochidion lanceolarium (Roxb.) Voigt (Euphorbiaceae); Colopodacus glochidion n. sp. infesting Glochidion sp. (Euphorbiaceae) and Neocosella laurifolia n. sp. infesting Genianthus laurifolius (Roxb.) Hook.f. (Asclepiadaceae). All species described here are vagrants on the undersurface of host leaves. Copyright © 2010 Magnolia Press.

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