As wild Aquilaria sinensis resources are exhausted and protected, China has established a huge number of plantations of Aquilaria trees and developed artificial induction techniques. However, the current output and quality of artificial induction technology have not yet met the expected results. It has been found that high-oil-containing agarwood may contain particular fungal stains associated with agarwood production. To enhance the quality of agarwood, we recovered and characterized three highly active fungi from high-oil-containing agarwood and inoculated them onto A. sinensis trees using two traditional physical methods. The results showed that fungi extracted from high-oil-containing agarwood can effectively increase the yield and quality of agarwood. During the agarwood formation process, parenchyma cells, xylem rays, and axial parenchyma cells in the xylem gradually undergo apoptosis, thereby promoting the expansion of the color range of agarwood. Nine months after the treatment, the alcohol-soluble extract content in agarwood reached the standard specified in the Chinese Pharmacopoeia (10%), and the proportions of sesquiterpenes and chromones in each treatment were 55.82%, 58.31%, 62.65%, 70.97%, and 13.71%, respectively. These results indicate that fungal induction has a positive impact on the quality of agarwood. In addition, compared to drilling and fungus combined induction, “burning holes and fungi” combined induction demonstrates better results and can further improve the yield and quality of agarwood.

The trunks of ten-year-old Aquilaria sinensis trees were filled with high-pressure nitrogen gas and treated every 7 and 15 days for 3 consecutive months.The wood discoloration area was observed and measured,the content of alcohol-soluble substances was detected,and the chemical composition and relative content of the agarwood were analyzed by GC-MS at 7 and 10 months after treatment.The effect of nitrogen gas filled on the agarwood formation was discussed,which would provide a feasible induction method for artificial agarwood formation.The results showed that nitrogen treatment significantly increased the longitudinal discoloration length and transverse discoloration width of wood trunks,and the results of the treatment filled with nitrogen gas every 7 days （N 7 ） were better than that of the treatment filled with nitrogen every 15 days (N 15 ).Ten months after N 7 treatment,the discoloration area was the largest,and the length of agarwood zone and total discoloration zone in both longitudinal and transverse direction were significantly longer than those of N 15 and CK 1 .Inflating nitrogen treatment could significantly increase the content of alcohol-soluble substances and agarotetrol,and the content of agarwood zone was higher than that of transition zone.The content of alcohol-soluble substances and agarotetrol in agarwood area increased by 14.04%and 28.47%compared with that of N 15 and CK 1 ,respectively,and the content of agarotetrol was 0.12%,which significantly higher than that of N 15 and CK 1 ,seven months after N 7 treatment.The content of alcohol-soluble substances and agarotetrol in each treatment increased with the increase of treatment time.Ten months after N 7 treatment,the content of alcohol-soluble substances and agarotetrol in agarwood zone was 19.37%and 0.30%respectively,which was noticeably higher than that of N 15 and CK 1 .The content of alcohol-soluble substances and agarotetrol in N 15 treatment increased by 9.42%and 51.50%respectively,compared with CK 1 .The volatile component of agarwood in N 7 treatment was the highest,which was rich in25 terpenes,5 chromones and 8 other compounds,and the total relative content of terpenes and chromones reached 66.09%,significantly higher than that of N 15 and CK 1 .

为了建立一套丝瓜种子纯度的快速鉴定方法,采用SSR分子标记对丝瓜杂交一代品种"中丝2号"的纯度进行鉴定,利用24对SSR引物对"中丝2号"丝瓜及其亲本的DNA进行扩增.结果表明:从24对引物中筛选出1对特异性引物ZS-SSR24,能够分别在"中丝2号"母本和父本中扩增出特异的2条多态性条带,大小分别为220 b p和250 b p,F1继承双亲的特异性条带,利用此标记能够鉴定出混在F1中的父本或母本.经田间鉴定,供试丝瓜种子纯度为91.3％,这与分子标记的结果完全吻合,故该标记能够用于"中丝2号"丝瓜品种的纯度鉴定.

Little is known about C-N-P stoichiometries and content in teak（Tectona grandis） plantations in South China,which are mostly sited on hilly areas with lateritic soil,and the effect of slope position on the accumulation of these elements in trees and rhizosphere soils.Here we analyzed the C,N,P content and stoichiometry in leaves,fine roots and rhizosphere soils of trees on the upper and lower slopes of a 12-year-old teak plantation.The Kraft classification system of tree status was used to sample dominant,subdominant and mean trees at each slope position.The results showed that the C,N and P contents in leaves were higher than in fine roots and rhizosphere soils.The lowest C/N,C/P and N/P ratios were found in rhizosphere soils,and the C/N and C/P ratios in fine roots were higher than in leaves.Nutrient accumulation in leaves,fine roots and rhizosphere soils were significantly influenced by slope position and tree class with their interaction mainly showing a greater effect on rhizosphere soils.Leaf C content and C/N ratio,fine root C and P contents,and C/N and C/P ratios all increased distinctly with declining slope position.The contents of organic matter（SOM）,ammonium（NH 4 + -N）,nitrate-nitrogen（NO 3 - -N） and available potassium（AK） in rhizosphere soils were mainly enriched on upper slopes,but exchange calcium（ECa）,available phosphorus（AP）,and pH were relatively lower.Variations in the C,N and P stoichiometries in trees were mainly attributed to the differences in rhizosphere soil properties.N and P contents showed significant positive linear relationships between leaf and rhizosphere soil,and C content negative linear correlation among leaves,fine roots and rhizosphere soils.Chemical properties of rhizosphere soils,particularly C/N and NH 4 + -N,had significant effects on the leaf nutrients in trees on the upper slope.Correspondingly,rhizosphere soil properties mainly influenced fine root nutrients on the lower slope,and soil AK was the major influencing factor.Overall,these results offer new insights for the sustainability and management of teak plantations in hilly areas.

[目的]研究氮气对土沉香结香的诱导作用及对非结构性碳水化合物含量和相关酶活性的影响,探讨土沉香结香与非结构性碳水化合物之间的内在联系.[方法]以11年生土沉香树为材料,采用树干打孔填充氮气和打孔处理,氮气每隔7 d填充1次,连续填充3个月,以不打孔处理为对照,于处理结束后6个月和10个月,从木质部沉香区和过渡区取样测定醇溶性提取物和沉香区沉香四醇含量;于第1次充气后30,60,90,120和150 d钻取树干木芯,测定非结构性碳水化合物(葡萄糖、果糖、蔗糖、麦芽糖等可溶性糖和总糖、淀粉)含量及淀粉相关酶活性,分析醇溶性提取物和沉香四醇含量与非结构性碳水化合物含量的相关性.[结果]①氮气诱导处理下,土沉香木质部沉香区和过渡区醇溶性提取物含量显著高于其他处理(P＜0.05),且沉香区高于过渡区.处理后10个月时,氮气处理下沉香区醇溶性提取物含量最高,达17.28％,显著高于打孔处理和对照.②填充氮气和打孔处理均能诱导土沉香木质部沉香区沉香四醇的形成,且氮气处理的效果更佳.处理后10个月时,氮气处理沉香区沉香四醇含量最高,达0.19％,显著高于其他处理.③氮气处理土沉香木质部各类糖含量随处理后时间的延长变化规律明显不同,其中总糖含量整体低于对照,但葡萄糖和蔗糖含量则高于对照;而果糖含量在处理60 d低于对照,随后上升,处理90 d后高于对照;麦芽糖含量呈波浪式变化,与对照差异不显著.④填充氮气可有效促进土沉香木质部淀粉的分解,处理150 d内淀粉含量始终低于对照.同时淀粉分解酶类活性整体逐渐上升,淀粉合成相关酶活性整体逐渐下降.⑤处理后10个月时土沉香木质部醇溶性提取物和沉香四醇含量与总糖、可溶性糖含量呈正相关,与淀粉含量呈负相关.[结论]树干填充外源氮气可明显加速土沉香木质部组织非结构性碳水化合物代谢,有效促进土沉香结香.

[目的]探究土沉香树干填充CO2诱导结香过程与抗逆防御反应,阐明外源CO2诱导下树体结香效应及生理防御机制.[方法]以11年生土沉香为试验材料,采用随机区组设计,设置4个处理,即每隔7天(T1)和15天(T2)充气1次、树干打孔(CK1)和不作任何处理(CK2),持续处理3个月.充气开始后第30、60、90、120、150天钻取木芯,测定过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量.处理结束后7和10个月取样观察木质部细胞内含物变化,测定结香范围及醇溶性提取物和沉香四醇含量.[结果]1)土沉香树干填充CO2可加速木质部射线薄壁细胞和导管内淀粉的转化,侵填体随诱导时间增长而增多;T1处理结束后10个月时,射线薄壁细胞和导管被完全堵塞;2)与CK1和CK2相比,CO2处理下木质部变色范围增大,其中T1处理变色范围最大,纵向变色长度26.45 cm、横向变色宽度4.17 cm、径向变色深度9.87 cm;3)随诱导时间增长,T1和T2处理结香区的醇溶性提取物和沉香四醇含量逐渐升高,且均显著高于CK1和CK2;4)T1处理第60天POD、CAT活性达到峰值后缓慢下降,但第150天POD活性仍高于CK2,CAT活性与CK2无显著差异;第90天SOD活性下降,而后缓慢上升;MDA含量先下降后升高,第90天达到最低值,且明显低于CK2;第150天时,SOD活性、MDA含量与CK2无显著差异.[结论]1)外源CO2可显著促进木质部射线薄壁细胞内淀粉的转化,增大导管和射线薄壁细胞内侵填体堵塞面积;2)外源CO2可诱导土沉香木质部变色,随诱导时间增长,树干木质部纵向、横向和径向变色长度增长,纵向变色面积增加;3)外源CO2可诱导土沉香形成沉香块且质地细腻,最优处理10个月时的醇溶性提取物含量达21.27％,沉香四醇含量达0.29％,分别是CK1的1.42和2.11倍;4)外源CO2可在短期内诱导POD、CAT抗氧化酶活性升高,降低MDA含量,激活土沉香树体的抗逆防御反应.

为筛选黄瓜嫁接苗愈合期间的适宜光质条件,利用LED光源调制不同光质比例,以白光(W)为对照,探究了嫁接愈合期间红光(R)、蓝光(B)和红蓝混合光(RB,红光光照度∶蓝光光照度=7∶3)对黄瓜嫁接苗生长及生理生化特性的影响.结果表明,B处理可显著促进茎秆及叶柄伸长,叶片伸展,增加嫁接苗全株鲜质量、干质量及可溶性蛋白含量;RB处理有利于嫁接苗单位叶面积的叶片干质量(LMA)及迪克森质量指数(DQI)等幼苗质量评估指标的提高;W及RB处理下嫁接苗总叶绿素含量与R、B处理相比显著提高,可溶性糖含量显著降低.此外,黄瓜第 1 朵雌花开放节位以及 10、15、20 节以内雌花数也受到不同光质处理的影响.RB处理下第 1 朵雌花开放节位最低,R处理不利于黄瓜嫁接苗雌花的分化.综合来看,红蓝混合光最利于嫁接苗壮苗的培育,提升后期高产潜力,宜作为嫁接苗愈合光质.

为探究施肥对柚木(Tectona grandis L.f.)幼林生长及林下植被多样性的影响,以广西4年生的柚木人工林为研究对象,采用随机区组试验设计,开展不同肥种配比组合试验(F1,0.5 kg氮磷钾复合肥+1.0 kg钙肥+1.0 kg硫酸镁肥;F2,1.0 kg氮磷钾复合肥+0.5 kg钙肥+0.5 kg硫酸镁肥;F3,1.0 kg氮磷钾复合肥+0.5 kg硫酸镁肥;F4,1.0 kg氮磷钾复合肥+0.5 kg钙镁磷肥;CK,不施肥).结果表明:施肥显著加快了柚木树高、胸径和单株材积的生长,各指标年均增量分别比不施肥(CK)提高了0.13～0.32 m、0.17～0.26 cm和4.35～9.63 dm3,其中F3配比组合处理生长增量最大,且胸径和材积生长率比CK显著增加了10.35％、10.55％.幼林林下植物相对丰富,植被种类涉及25科39属42种,其中菊科(Compositae)与禾本科(Gramineae)植物为主要优势种.不同处理间林下植被物种Shannon-Wiener指数(H′)、Simpson指数(D)和Pielou均匀度指数(Jsw)差异显著(P<0.05),F1、F3处理的3个物种指数显著高于CK,而各处理Gleason物种丰富度指数(Dg)差异不明显,不同处理间生长及林下植被多样性等12个指标综合评价得分由高到低依次为F3、F1、F4、F2、CK.4年生柚木幼林合理施肥,可以促进林木生长,还可提高林下物种丰富度和多样性;1.0 kg氮磷钾复合肥和0.5 kg硫酸镁肥的低投入配方施肥,更有利于促进柚木人工林生长和群落的稳定.

Appropriate fertilization can enhance forest productivity by maintaining soil fertility and improving the structure of the bacterial community. However, there is still uncertainty surrounding the effects of combined application of organic and inorganic fertilizers on soil nutrient status and bacterial community structure. A fertilization experiment was set up in an eight-year-old teak plantation with five treatments involved: mixed organic and NPK compound fertilizers (OCF), mixed organic and phosphorus fertilizers (OPF), mixed organic, NPK and phosphorus fertilizers (OCPF), mixed NPK and phosphorus fertilizers (CPF) and no fertilization (CK). Soil chemical properties and bacterial communities were investigated, and the co-occurrence pattern of the bacterial community under different fertilization treatments was compared. The results showed that the contents of soil organic matter and nitrate nitrogen, and the soil pH values were the highest after OCPF treatment, which were 20.39%, 90.91% and 8.16% higher than CK, respectively. The richness and diversity of bacteria underwent no obvious changes, but the structure of the soil's bacterial community was significantly altered by fertilization. Of the dominant bacteria taxa, the relative abundance increased for Gemmatimonadetes, Myxococcota, ADurb.Bin063-13 and Candidatus_Koribacter, and decreased for Chloroflexi, Proteobacteria, JG30-KF-AS9 and Acidothermus under OCPF treatment in comparison to CK. The number of nodes and edges, the average degree and the network density of bacterial community co-occurrence networks were the greatest in OCPF treatment, indicating that application of OCPF could make the network structure of soil bacteria more stable and complex. Moreover, soil pH and organic matter were significantly correlated with bacterial community structure and were considered the main influencing factors. These findings highlight that the combined application of organic, NPK and phosphorus fertilizers is highly beneficial for improving soil quality and optimizing bacterial community structure in teak plantations.

[目的]以柚木为研究对象,探究不同施肥处理对叶片光合生理特征及叶绿素荧光特性的影响.[方法]采用随机区组试验设计,设置5种肥料及其配比处理,对比分析不同处理之间柚木的瞬时光合、叶绿素荧光参数及叶绿素含量的差异.[结果]1)施肥处理显著提高了柚木叶片的净光合速率(Pn)、水分利用效率(WUE)、最大荧光(Fm)和PSⅡ最大光化学效率(Fv/Fm),其中,处理5(0.25 kg NPK肥+1.5 kg CaMgP肥)的Pn、Fm和Fv/Fm值均最大,分别比对照提高了142.48％、11.52％和5.73％;叶片Pn值表现为T5>T2>T3>T1>T4>CK.2)处理2(0.25 kg CaMgP肥+2.5 kg有机肥)叶片WUE值最大,为7.32,显著高于其它施肥处理及对照.3)施肥后,柚木叶片初始荧光(Fo)呈下降趋势,光化学猝灭系数(qp)和非光化学猝灭系数(NPQ)变化无明显规律.T2、T3、T5处理的qp值高于CK,T1、T4却低于CK.T5的NPQ值最小,T3最大.除T5外,其它施肥处理叶片的气孔导度(Gs)、蒸腾速率(Tr)、PSⅡ实际光化学效率(ФPSⅡ)和电子传递速率(ETR)变化不大.4)施肥显著提高了柚木叶片的叶绿素含量,并随钙镁磷施肥量的增加而增大,其中,T5增加幅度最大,较对照提高了27.25％,但施肥后叶片类胡萝卜素含量变化呈显著下降趋势.[结论]1)5种肥料和肥量的配施,均可改善柚木幼林的光能利用效率,明显提高叶片净光合速率和叶绿素含量.2)10个光合生理指标的施肥效应综合评价结果表明,0.25kg NPK+1.5kg CaMgP配施效果最佳.

为鉴定与结香相关的关键酶基因和探明土沉香结香的分子机理,本研究以无机盐与激素混合诱导处理后18个月的土沉香为试验材料,采用RNA-Seq技术分别对土沉香未变色白木部位(W样品)、深棕色变色沉香层(R样品)、沉香层与白木之间浅棕色过度部位(H样品)进行转录组分析.经过测序及相关分析共计获得功能注释的Unigene共125329条,占全部Unigene的57.38％.KEGG数据库比对有51592条Unigenes归属到6大类代谢途径中,沉香层形成过程中获得的各途径差异Unigene数量最多.通过KEGG数据库同源检索鉴定17条编码沉香倍半萜合成途径的8个关键酶的Unigene.通过基因表达模式分析表明,与倍半萜化合物合成代谢相关基因在沉香形成期整体上表达模式呈上调,而与倍半萜化合物分解代谢相关的基因则呈下调表达.萜类物质合成代谢途径基因表达模式,与沉香形成过程中沉香层倍半萜类物质的大量积累表型相吻合,有助于更深入地揭示土沉香倍半萜合成的分子机制.

[目的]探究不同间伐强度对柚木人工林土壤理化性质、酶活性及林木生长的影响,为柚木大径材高效培育和林地可持续经营提供理论依据。[方法]以15年生柚木纯林为研究对象,设置轻度、中度、重度间伐和对照4个处理。间伐3.5 a后,测定柚木生长量、土壤理化性质和酶活性等指标,分析不同间伐强度处理下各指标的差异。采用冗余分析法（RDA）分析柚木生长指标及土壤酶活性与土壤理化性质指标之间的关系。[结果]间伐对土壤理化性质及酶活性的影响主要表现在0～20 cm土层,间伐提高了土壤含水率,降低了表层土壤pH值;土壤有机质、碱解氮的含量随间伐强度的增大而增加,中度、重度间伐林分0～20 cm土层有机质含量比对照显著提高了18.2%和19.0%,碱解氮含量显著增加了15.7%和16.6%;间伐后土壤全氮和交换性钙含量也均增加。间伐显著增强了0～20 cm土层的蔗糖酶活性,而脲酶、酸性磷酸酶和过氧化氢酶活性变化无显著差异。柚木林分的平均胸径和单株材积随间伐强度的增大而增加,林分断面积和蓄积也均高于对照;重度间伐处理的林分各生长指标年均增量最大,并显著高于对照,平均单株材积和蓄积增量分别提高了80.0%和90.2%。土壤有机质、有效磷含量与柚木各生长指标呈正相关,田间持水量、土壤密度及总孔隙度是影响土壤酶活性的主要环境因子。[结论]间伐改善了土壤养分和水分状况,促进了柚木生长,林地生产力得到明显提高。间伐提高了与N、P循环相关酶的活性,显著增强了与C循环相关的蔗糖酶活性。对15年生柚木人工林进行间伐,适宜的间伐强度为40%～45%。