广东设施葡萄林下大球盖菇优质高效栽培技术

本研究针对广东设施葡萄林下大球盖菇的优质高效栽培技术进行了系统探讨。基于广东地区独特的亚热带气候条件与设施葡萄种植特点,以及大球盖菇的生物学特性,集成了种植季节选择、菌种优选、场地准备、培养料配制发酵、播种覆土管理、出菇期管理、采收加工以及病虫害防治等多个关键环节,实现了资源高效利用、环境友好与经济效益的有机统一。该技术为广东乃至相似气候区域提供了可复制、可推广的林下食用菌种植模式,有助于推动农业科技创新、农民增收、生态改善和乡村振兴战略实施。

The pressure compensation technology of deep-sea sampling based on the real gas state equation

Compressed gas is usually used for the pressure compensation of the deep-sea pressure-maintaining sampler.The pressure and volume of the recovered fluid sample are highly related to the precharged gas. To better understand the behavior of the gas under high pressure, we present a new real gas state equation based on the compression factor Z which was derived from experimental data. Then theoretical calculation method of the pressure and volume of the sample was introduced based on this empirical gas state equation. Finally, the proposed calculation method was well verified by the high-pressure vessel experiment of the sampler under 115 MPa.

Genetic variation in growth traits and stem–branch characteristics and their relationships to Eucalyptus clones

Eucalyptus has become an important genus in China because it displays adaptability to a wide range of site conditions and produces pulp wood and veneer on short rotations. The aim of this study was to estimate genetic parameters and relationships and consider impli- cations for development of clonal forestry. We assessed growth traits, stem-branch characteristics, crown diameter and height of fresh branch for 20 Eucalyptus hybrid clones in China measured at the age of 44 months. Analysis of variance showed that there were significant differences in growth traits, height of fresh branch and stem straightness among clones. Significant differences in height, volume, crown diameter, height of fresh branch and branch size among replicates were also recorded. Coefficients of vari- ation ranged from 9.84 to 28.54 % for growth traits, 12.03 to 17.25 % for stem-branch characteristics, 18.26 % for crown diameter and 11.73 % for height of fresh branch. Estimates of repeatabilities for height, diameter at breastheight over bark, volume, crown diameter, height of fresh branch, stem straightness and branch size at clone mean level were 0.86, 0.80, 0.80, 0.54, 0.85, 0.77 and 0.44 respectively. Diameter at breast height over bark and height had strongly positive phenotypic and genotypic correlations with volume, ranging from 0.96 to 1.00. The positive genotypic and phenotypic correlations between growth traits and other studied traits suggested that fast growing clones always had bigger crown diameter, higher height of fresh branch, straighter stems and relatively smaller branches.

Age Trends and Correlations of Fiber Traits in Clone of Eucalyptus Urophylla×E.Grandis in Guangdong Province

Growth traits and wood properties were assessed for DH32-29,a clone of Eucalyptus urophylla×E.grandis,at the age of two to six in Guangdong,China.Analysis of variance of studied traits showed that there were significant differences(1%level)on Fiber Length and Fiber Width among ages,with F value ranging from 12.73 to 18.91,indicating clear differences between ages.The Fiber Length increased from 0.58 mm at 2-year to 0.60 mm at 3-year,061 mm at 4-year,0.72 mm at 5-year and 0.79 mm at 6-year,meanwhile the annual Fiber Length increment among ages increased from 0.02 to 0.01,0.11 and 0.07 mm,respectively.However,Mean Curl,Kink Index and Kink Angle were not found any trend by age.In general,the correlations between same traits were different with different ages.The biggest negative correlations(-0.78)was found between Fiber Length and Fine Percentage at 4-year while the biggest positive correlations(0.98)was found between Kink Index and Kink Angle at 2-year and 4-year.

Heterosis Estimation for Growth Traits and Wood Properties of Eucalyptus urophylla under Two Sites in Southern China

Heterosis is a quicker,cheaper and easier method for increasing plantation production,and heterosis studies can provide the basis for exploitation of valuable hybrid combinations in breeding programs.Growth traits,wood properties,and bark percentage were assessed for 6×6 full diallel progenies of E.urophylla in southern China measured at age 4 years.Analysis of variance showed that there were significant differences on all studied traits except dynamic modulus of elasticity among combinations.The mean diameter at breast height,wood basic density,and dynamic modulus of elasticity were 9.40 to 12.20 cm,0.45 to 0.47 g cm-3,and 5.04 to 5.72 GPa,respectively.The coefficients of variation ranged from 18.18%to 50.43%for growth traits,9.07%to 55.24%for wood properties and 22.26%to 23.93%for bark percentage.The heterosis estimation on diameter at breast height,wood basic density,and dynamic modulus of elasticity were-24.07%to 18.74%,-14.23%to 9.17%and-25.53%to 16.28%.U22×U56 generally had higher heterosis of growth traits and wood properties through three sites.Same combinations had different original and reciprocal heterosis estimation at two sites even on same traits.The combinations of same parents always had similar original and reciprocal heterosis estimation.

Growth Traits of Toona Ciliata under Different Fertilization Levels in Guangdong Province

Toona ciliate,which belongs to Toona of Meliaceae,is a rare and native timber species in China.However,little progress has been made in the cultivation of Toona ciliate.The height and diameter at breast height of Toona ciliata were assessed for fertilization cultivation techniques aged 1 year.Analysis of variance showed that there were significant differences on height among different treatments and replicates and the difference on diameter at breast height among different replicate was also significantly.Treatment with 200 g urea(N>46.5%)+60 g superphosphate(P2O5>12.0%)+100 g potassium chloride(K2O>60.0%)could improve the height and diameter at breast height of Toona ciliate.In summary,more fertilizer could not always improve the growth traits and the site location could affect the growth significantly,therefore more test trials should be carried out before diffusion.

Present Situation of Eucalypts Breeding and Future Prospect in China

Breeding is the major procedure in forest research.The basic goal in all of breeding program is to expand the frequency of favorable alleles or the frequency of specific combinations of favorable alleles in the breeding populations through recurrent selection in order to improve the performance of individual plants.During the past three decades,an increase in research on breeding has improved Eucalyptus productivity,and to some extent our standing of their effects on tree growth and on wood properties.Unfortunately,very little information about breeding on the review of Eucalyptus grown in China has been published even though this species was introduced some 120 years ago.This paper reviews the available information regarding research status and prospect of breeding under Chinese ecological conditions and to outline some suggestions to them.According to the present research situation of breeding,we would recommend that:generalizing empirical and useful practices;developing highvalue products;creating more clones for demand;carrying out intensively research over different species and clones for different cultivation goals at different sites over time;above all,applying breeding strategy,especially for multiple generations and interspecific hybrid breeding.

Comparing the Seedling Growth of Six Precious Species in Southern China

Seedling stage is an important period for forestry.The aim of this study was to estimate the growth trend of six local precious species and consider their implications for silviculture on forestry.We assessed height,diameter near ground and crown width at 1,4,6 and 8-month.The variance analysis indicated that there were significant differences between species on all traits except diameter near ground and crown width at 8-month.There were no significant differences on height and crown width at all ages among replicates whereas there were significant differences on diameter near ground at 1 and 4 months,differences on diameter near ground at 6 months and no difference on diameter near ground at 8-month.The significant differences among interaction of species and replicates on diameter near ground at 1-months,4-month,6-month and crown width at 8-month were also found.Dalbergia odorifera had a higher growth period after 6-month.Aquilaria sinensis(Lour.)Spreng,Swietenia mahagoni(L.)Jacq.,Hopea hainanensis Merr.et Chun,Homalium hainanense Gagnep.and Cassia siamea Lam.had the same growth trend on all traits at the whole time.

Eucalypts in China:Research History,Present Situation and Future Prospect

Silviculture is the major procedures in forest research.Silviculture is traditionally focused on various aspects of tree planting,such as tree selection,site preparation,irrigation and fertilization and so on,and the role of silviculture at that time is to manage forests scientifically for continuous production of goods and services while meeting biological and economic requirements.During the past three decades,an increase in research on silviculture has improved Eucalyptus productivity and on wood properties.But,very little information about this procedure on the review of Eucalyptus grown in China has been published even though this species was introduced many years.This paper reviews the available information regarding research history and progress of silviculture under Chinese ecological conditions and to outline some suggestions to them.

Effects of Cooking Temperature and Storage Time on the Quality of Macadamia Nut Oil

The purpose is to study the influence of cooking and storage habits on the quality of macadamia nut oil,so as to provide reference for macadamia nut processingenterprises and consumers.Macadamia oil was treated at 100℃,200℃,300℃,microwave heating,45℃constant temperature storage,natural light for different times,and its acid value,peroxide value,squalene,sterol and fatty acid content were detected according to the national standard method.The results showed that the acid value and peroxide value increased with time.The acid value and peroxide value of macadamia oil cooked at 300℃and stored under natural light were higher than those heated by microwave and stored at 45℃,and increased rapidly with the increase of cooking and light time.The acid value was as high as 0.77 mg/g,with an increase of 63.8%,and the peroxide value was as high as 6.18 mg/g,with an increase of 43.7%.As for squalene,it decreased in varying degrees with heating time and storage time.Squalene in macadamia oil cooked at 300℃and stored under natural light were lower than those heated by microwave and stored at 45℃constant temperature,respectively,and decreased rapidly with the increase of cooking and light time,with the reduction ranges of 38.6%and28.4%respectively;Stigmasterol was not detected in macadamia oil.But in macadamia oil the content ofβ-sitosterol was 0.132 g/100 g,and the content did not change significantly in each treatmentgroup.In the experimental treatment group,the content of fatty acids in macadamia oil had different trends.After treatment at 300℃for 20 minutes,the content of oleic acid decreased by 75.66%,the content of palmitic acid decreased by 75.28%,and thecontent of palmitic acid decreased by 74.12%.In conclusion,low temperature heating,microwave heating and storage away from light can better preserve the quality of macadamia oil,this study will provide a theoretical basisfor the rational utilization of macadamia oil as cooking oil.

Microstructure and mechanical properties of directionally solidified Al-rich Ni_(3)Al-based alloy under static magnetic field

The influence of a longitudinal static magnetic field on microstructures and mechanical properties of Ni_(3)Al-based alloy during directional solidification at the growth speed of 25μm/s and 100μm/s has been experimentally investigated.Results reflected that the utilization of a 0.5 T magnetic field refines the Ni Al dendrites at both speeds of growth.When applying a high magnetic field,the columnar-to-equiaxed transition(CET)occurred at growth speed of 25μm/s and dendrite networks formed at growth speed of 100μm/s.Tensile property results indicated that the refinement of dendrites enhanced both plasticity and ultimate tensile strength of Ni-Al alloy.The change of microstructures and mechanical properties should be attributed to the combined action of the thermoelectric magnetic convection(TEMC)in mushy zone together with the thermoelectric magnetic force(TEMF)acting on the solid.When applying a low magnetic field(0.5 T),the TEMF is too small to fragment the dendrites,and the refined dendrites is mainly due to the TEMC in the interdendritic regions.At a lower growth speed,the TEMF is supposed to strong enough to fragment the dendrites and induce the occurrence of CET under 2 or 4 T.When the growth speed increased to 100μm/s,no obvious CET was observed,but a vertical secondary convection is induced by the circulation in the parallel plane,which promotes the growth of secondary and tertiary branches,leading to the formation of abnormally developed high order dendrites.The hierarchical dendritic structure was suggested to provide a channel for rapid crack propagation and thus degraded the mechanical properties.