Host range of Secusio extensa (Lepidoptera: Arctiidae), and potential for biological control of Senecio madagascariensis (Asteraceae)

Secusio extensa (Lepidoptera: Arctiidae) was evaluated as a potential biological control agent for Madagascar fireweed, Senecio madagascariensis (Asteraceae), which has invaded over 400 000 acres of rangeland in the Hawaiian Islands and is toxic to cattle and horses. The moth was introduced from southeastern Madagascar into containment facilities in Hawaii, and host specificity tests were conducted on 71 endemic and naturalized species (52 genera) in 12 tribes of Asteraceae and 17 species of non‐Asteraceae including six native shrubs and trees considered key components of Hawaiian ecosystems. No‐choice feeding tests indicated that plant species of the tribe Senecioneae were suitable hosts with first instars completing development to adult stage on S. madagascariensis (78.3%), Delairea odorata (66.1%), Senecio vulgaris (57.1%), Crassocephalum crepidioides (41.2%), and at significantly lower rates on Emilia fosbergii (1.8%) and Erechtites hieracifolia (1.3%). A low rate of complete larval development also was observed on sunflower, Helianthus annuus (11.6%), in the tribe Heliantheae. However, sunflower was rejected as a potential host in larval‐feeding and adult oviposition choice tests involving the primary host S. madagascariensis as control. Although larvae died as first instars on most test species, incomplete development and low levels of feeding were observed on nine species in the tribes Heliantheae, Cardueae and Lactuceae. Larvae did not feed on any non‐Asteraceae tested, including species with similar pyrrolizidene alkaloid chemistry, crops, and six ecologically prominent native species. Because all species of Senecioneae are non‐native and weedy in Hawaii, these results indicate that S. extensa is sufficiently host‐specific for introduction for biological control. High levels of feeding damage observed on potted plants indicate that S. extensa can severely impact the target fireweed as well as D. odorata, a noxious weed in native Hawaiian forests.     

中国蕨类植物孢子形态的研究Ⅲ.金星蕨科1.毛蕨属

利用扫描电镜对中国产毛蕨属51种植物孢子形态进行了研究。结果表明：该属孢子为单裂缝,两侧对称,极面观为椭圆形,赤道面观为肾形,由周壁形成表面纹饰。表面纹饰可分为3种类型：(1)周壁具流苏状的翅状纹饰,表面有突起或穿孔,有19种属于此类型;(2)鸡冠状纹饰,有11种属于此类型;(3)刺状纹饰,有10种属于此类型。另外有11种具有上述纹饰的混合纹饰,被认为是中间类型。孢子的形态特征可作为该属的分类学和孢粉学研究的资料。     

Optimization of the extraction of phenolic compounds from Cyclosorus extensa with solvents of varying polarities

The leaves of Cyclosorus extensa are used in the preparation of rice beer in Assam, India. The optimal conditions of time and temperature of fermentation for extraction of bioactive compounds from the dried leaves were obtained using response surface methodology. The central composite rotatable design was used and 13 experimental runs based on two-factor-five-level design were generated and performed for each of the solvents. The independent variables were extraction time (12 and 48?h) and temperature (25 and 55°C). The responses studied were total polyphenol content, radical scavenging activity, antibacterial activity, and antifungal activity. The analysis of variance of the test data was performed and the sequential sum of squares, F-value, R², and adjusted R² were deduced. The predicted models for all the response variables were adequately fitted to the observed experimental data (p?≤?0.001). The maximum extraction of bioactive compounds under the optimum conditions of extraction temperature and time for hexane, ethyl acetate, methanol, and distilled water were found to be 25°C for 29.43?h, 28.28°C for 41.27?h, 43.95°C for 29.61?h, and 55.00°C for 48.00?h, respectively. It was also observed that the solubility of the polyphenols was higher in methanol, followed by ethyl acetate, and the highest antibacterial activity against Escherichia coli was shown by the ethyl acetate extracts.     

湖北黄州龙王山渐尖毛蕨种群分布格局研究

调查湖北黄冈黄州龙王山渐尖毛蕨在不同生境条件下的种群密度和盖度。采用相邻格子法计算渐尖毛蕨种群分布的偏离系数,并进行t检验,判断种群分布类型;应用双项轨迹方差法分析种群格局规模。结果表明,渐尖毛蕨种群呈集群分布,形成的斑块直径大小约为3.0~3.5 m,且随着干扰的减少,斑块数目呈现少→多→少,其大小呈现大→小→大的变化趋势。     

渐尖毛蕨和齿牙毛蕨的配子体发育研究

采用混合土培养渐尖毛蕨和齿牙毛蕨的孢子,显微镜下观察记录了它们的孢子萌发及配子体发育过程.结果表明:两者的孢子均为深褐色,极面观为椭圆形,赤道面观为半圆形,单裂缝;渐尖毛蕨的孢子萌发所需时间较渐尖毛蕨短,但两者萌发类型均为书带蕨型;丝状体阶段均发达;原叶体边缘均可产生少量毛状体;成熟原叶体均呈心脏形;由原叶体发育成幼孢...     

广西毛蕨属（金星蕨科）植物新资料

报道了广西毛蕨属Cyclosorus植物6个新记录种:三都毛蕨C.sanduensis,学煜毛蕨C.houi,缩羽毛蕨C.abbreviatus,毛囊毛蕨C.hirtisorus,巨型毛蕨C.subelatus,秦氏毛蕨C.chingii,并提供了广西产该属植物的分种检索表。     

Spore morphology of pteridophytes from China Ⅲ. Thelypteridaceae 1. Cyclosorus Link.

Spore morphology of 51 species of Cyclosorus in the Thelypteridaceae from China was investigated using scanning electron microscopy (SEM). The spores are monolete, bilaterosymmetric, ellipsoidal in polar view, and kidney-shaped in equatorial view. On the basis of the variation in their surface ornamentation, the spores fall into three main types. Type I: The surface of spores is echinate or perforate with fimbriate wings. 19 species belong to this type. Type Ⅱ: The surface of spores is cristate. 11 species belong to this type. Type Ⅲ: The surface of spores is echinulate. 10 species belong to this type. The remaining 11 species have spores with mixed surface ornamentation of the above three types, which are considered as intermediate types. The results are valuable for a better understanding of the taxonomy and palynology of the genus Cyclosorus.     

渐尖毛蕨(金星蕨科)四个新异名

根据标本研究和野外观察,将疏羽毛蕨、拟渐尖毛蕨、慈利毛蕨和光叶毛蕨处理为渐尖毛蕨的异名。     

Modelling the distribution of a potential invasive tropical fern,Cyclosorus afer in Nigeria

In this study, we predicted the distribution of Cyclosorus afer in Nigeria using the Maximum Entropy (Maxent) technique. We used 95 occurrence points in one State to extrapolate its spread in other States in Nigeria. Three sites of sizes 500 × 500 m² separated by minimum distance of 1,000 m² were sampled in the study area. Seven bioclimatic and elevation variables were selected for the model. Maxent model was run using standard settings with 70% of the occurrence data as training and remaining 30% as test data. The result showed that Maxent performed better than random prediction due to the area under curve for receiver operating characteristics of training (0.990) and test data (0.987) closer to 1. The sensitivity of the Maxent model for occurrence data of C. afer was found to be 100%. The model predicted higher probability of occurrence covering an area of 26019.11 km² in 4 States of Nigeria. Jackknife evaluation of the model revealed that the environmental predictors of C. afer in Nigeria are annual mean temperature, mean temperature of driest quarter, precipitation seasonality, Precipitation of driest quarter and precipitation of coldest quarter. These variables all showed higher gain and contributions to the model.