Arbuscular mycorrhizal fungi increased early growth of two nontimber forest product species Dyera polyphylla and Aquilaria filaria under greenhouse conditions

Nontimber forest products (NTFPs) represent an important source of income to millions of people in tropical forest regions, but some NTFP species have decreased in number and become endangered due to overexploitation. There is increasing concern that the planting stocks of Dyera polyphylla and Aquilaria filaria are not sufficient to sustain the yield of NTFPs and promote forest conservation. The objective of this study was to determine the effect of two arbuscular mycorrhizal (AM) fungi, Glomus clarum and Gigaspora decipiens, on the early growth of two NTFP species, D. polyphylla and A. filaria, under greenhouse conditions. The seedlings of both species were inoculated with G. clarum or G. decipiens, or uninoculated (control) under greenhouse conditions. Percentage of AM colonization, plant growth, survival rate, and nitrogen (N) and phosphorus (P) concentrations were measured after 180 days of growth. The percentage of AM colonization of D. polyphylla and A. filaria ranged from 87 to 93% and from 22 to 39%, respectively. Colonization by G. clarum and G. decipiens increased plant height, diameter, and shoot and root dry weights. Shoot N and P concentrations of the seedlings were increased by AM colonization by as much as 70–153% and 135–360%, respectively. Survival rates were higher in the AM-colonized seedlings at 180 days after transplantation than in the control seedlings. The results suggest that AM fungi can accelerate the establishment of the planting stocks of D. polyphylla and A. filaria, thereby promoting their conservation ecologically and sustaining the production of these NTFPs economically.     

Characterization of an oviposition stimulant from the surface of sweet potato Ipomoea batatas storage roots for the sweet potato weevil, Cylas formicarius elegantulus

An improved laboratory bioassay was used to characterize an oviposition stimulant from the surface of sweet potato Ipomoea batatas (L.) Lam. storage roots for the sweetpotato weevil, Cylas formicarius elegantulus (Summers). Filter paper discs impregnated with a methylene chloride surface extract of sweet potato storage roots induced significantly (p<0.05) higher oviposition on root cores than those treated with solvent only. Significantly higher oviposition was also observed in the nonpolar fractions, especially one that contains a tentatively identified triterpenoid present in susceptible cultivars.

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Caractérisation d'une substance extraite de la surface des racines tubéreuses d'Ipomoea batatas induisant la ponte de Cylas formicarius elegantulus

Résumé La caractérisation des substances extraites de la surface des racines tubéreuses d'I. batatas Lam et stimulant la ponte de C. formicarious elegantulus Summers, a été effectuée à partir d'une technique améliorée. Différents substrats ont été essayés: extraits au chlorure de méthylène ou péridermes intacts de cultivars résistants ou sensibles, racines tubéreuses après élimination du périderme, morceaux de Solanum tuberosum ou de papier filtre présentés au milieu de plaques à 24 plots pour culture de tissus. Le meilleur substrat s'est révélé être de petits disques de papier filtre (diamètre 0,4 cm), fixés au milieu d'un morceau de racine avec encore un peu de périderme sur lequel le coléoptère pouvait pondre. Cette méthode a été utilisée dans les tests ultérieurs pour caractériser la nature du stimulant.Des disques de papier filtre inhibés d'extraits au chlorure de méthylène du contenu des structures superficielles de racines tubéreuses de cultivars sensibles induisent une ponte significativement plus importante (p<0,05) sur les morceaux de racines par comparaison avec ceux traités au chlorure de méthylène pur. Une ponte significativement plus importante a aussi été obtenue avec des fractions non-polaires, particulièrement celles qui contiennent un triterpènoïde de cultivars dont l'identification a été tentée.

     

内蒙古典型草原灌丛化对生物量和生物多样性的影响

通过样方调查,研究了内蒙古典型草原不同退化程度草地中小叶锦鸡儿 (Caragana microphylla Lam.)灌丛斑块空间分布格局、草地生物量及生物多样性特征。结果表明,从轻度到中度、重度退化草地,草本植物生物量呈减少趋势,小叶锦鸡儿生物量呈增加趋势,总生物量呈先减少后增加趋势;灌丛斑块生物多样性呈增加趋势,草地斑块生物多样性呈先减少后增加趋势,其中轻度退化草地中灌丛斑块生物多样性低于草地斑块,中度和重度退化草地中灌丛斑块生物多样性高于草地斑块。本研究认为,内蒙古典型草原灌丛化过程中,生态系统可能存在草本植物占优势或小叶锦鸡儿占优势这样两种稳定状态,这两种状态能维持较高生物量和生物多样性,而在由草本植物占优势向小叶锦鸡儿占优势转化的过渡阶段,系统不稳定,仅能维持较低生物量和生物多样性。     

沉香的质量评价及药理活性研究进展

目前国内市场提供的沉香来源广泛,品种繁杂,包括国内沉香和进口沉香,而进口沉香来源的国家地区又各有不同,本文对国内外沉香的质量评价及主要药理活性进行了研究总结,旨为沉香药材的应用以及进一步深入研究提供一定的参考。     

Screening of <i>Bacillus subtilis</i> HAAS01 and Its Biocontrol Effect on <i>Fusarium</i> wilt in Sweet Potato

Fusarium wilt, a disease caused by Fusarium oxysporum f.sp batatas (Fob) is an important disease in sweet potato production. Using endophytic bacteria for biological control of sweet potato diseases is one of the important ways. A Bacillus subtilis with antagonistic effect on Fusarium wilt of sweet potato was isolated from soil by confrontation culture. According to the biological characteristics, 16S rDNA sequence analysis, and physiological and biochemical analysis, the Bacillus subtilis HAAS01 was named. A pot experiment was conducted for the biological control experiment of strain HAAS01, and the endogenous hormone content, antioxidant enzyme activity, soluble protein content, and related gene expressions of sweet potato plants were detected. The results showed that the HAAS01 strain could promote the production of endogenous hormones and resist the infection of plant diseases together with defensive enzymes and upregulation of related gene expressions. In summary, Bacillus subtilis HAAS01 was effective in controlling Fusarium wilt of sweet potato and has potential for application and development.     

Selection<Emphasis Type="Italic">of nptll</Emphasis> transgenic sweetpotato plants using G<Subscript>418</Subscript> and paromomycin

We have used two aminoglycosides, G₄₁₈ and paromomycin, to develop a reliable selection system fornptll transgenic sweet-potato (Ipomoea batatas (L.) Lam.). Embryogenic calli derived from shoot apical meristems were bombarded with gold particles coated with pCAMBIA2301, which contained thenptll andgusA genes. When compared on a kill curve that was based on calli proliferation and cell viability, G₄₁₃-selection proved to be more efficient and had fewer escapes than kanamycin. These bombarded expiants were then selected on G₄₁₈-containing media. The total time required from bombardment to plant establishment in soil was seven to nine months. Multiple copies of the transgene were integrated into the sweetpotato genome. Northern analysis confirmed transgene expression in the regenerated plants, and a paromomycin assay demonstrated that thenptll gene was functionally expressed in transformed sweetpotato. These molecular analyses and assays all showed that selection with G₄₁₈ and paromomycin is reliable. So far, we have produced 69 transgenic events with this system, at a transformation frequency of approx. 1.1%. That efficiency is based on the number of transgenic plants obtained and the amount of calli bombarded. Thus, this selection method that combines G₄₁₈ with paromomycin is now available for selectingnptll transgenic sweetpotato.     

无机盐、激素与真菌联合诱导土沉香抗逆能力的研究

为了探究无机盐、激素与真菌联合诱导土沉香(Aquilaria sinensis)抗逆性及其与结香前期木芯变色长度之间的相关关系,以10年生土沉香为材料,采用均匀试验设计,开展了3种无机盐、3种激素及3种真菌组合试验。结果表明:(1)土沉香树体POD和SOD活性和MDA含量呈先升高后降低趋势,CAT活性在诱导后1天最高,随后呈下降趋势;(2)无机盐与真菌处理下土沉香的抗逆能力大于激素与真菌处理,其中无机盐与真菌组合试验的处理4(1.0%CaCl2+0.5%FeSO4+2.0%NaCl+黑绿木霉∶腐皮镰孢∶龙眼焦腐(1∶1∶1))和激素与真菌组合试验的处理2(0.01%茉莉酸甲酯+0.1%乙烯利+0.2%水杨酸钠+黑绿木霉∶腐皮镰孢∶龙眼焦腐(1∶1∶1))分别为同类处理最高;(3)土沉香抗逆能力高低与木芯变色长度存在显著正相关性;(4)理论上,土沉香抗逆能力最强诱导组合分别为0.93%CaCl2+0.53%FeSO4+2.5%NaCl+黑绿木霉∶腐皮镰孢∶龙眼焦腐(1∶1∶1)和0.005%茉莉酸甲酯+0.006%乙烯利+0.2%水杨酸钠+黑绿木霉∶腐皮镰孢∶龙眼焦腐(1∶1∶1)。     

几种提取白木香茎干总RNA方法的比较

目的:通过比较多种RNA提取方法,确定白木香茎干RNA提取的有效手段,为白木香伤害形成沉香药材的分子研究奠定基础。方法:取2年生白木香茎,分别用CTAB法、TRIzol法、异硫氰酸胍-SDS法、Qiagen试剂盒和Nor gen试剂盒法提取总RNA,通过琼脂糖凝胶电泳和紫外分光光度法测定其产量与质量,并通过cDNA合成及小样本克隆测序检查RNA的可用性。结果:异硫氰酸胍-SDS法及Norgen试剂盒法提出的RNA条带清晰,完整性好;D260nm/D280nm值可达2.0左右,纯度较高,其产量足够应用于cDNA合成;其他方法不能提出RNA。结论:异硫氰酸胍-SDS法及Norgen试剂盒法可用于白木香茎干RNA提取。     

白木香内生真菌的分离及分子鉴定

对采自广东省信宜市的白木香进行了内生真菌分离培养,共获得50个菌株,通过rDNA中内转录间隔区(ITS)序列鉴定其为20个种,其中确定至种名的有7属8种,仅确定至属名的有8种,不能确定种属的有4种,其中A20菌株(Fimetariella rabenhorstii)为国内首次报道。刺盘孢菌(Colletotrichum)共分离到17株,占分离总数的34%,为白木香优势种群;镰刀菌(Fusarium)共分离到11株,是结香部位的优势种群。白木香内生真菌分布部位的专一性不明显,茎中分离的数量及种类最多,叶中最少;5年龄内生真菌的多样性较好,10月龄的多样性较低。