Being a parasitoid of parasites: host finding in the tick wasp Ixodiphagus hookeri by odours from mammals

The parasitic wasp Ixodiphagus hookeri Howard (Hymenoptera: Encyrtidae) parasitizes larvae and nymphs of a number of tick species worldwide. Ticks themselves are parasitic on vertebrate hosts. To study the specificity and reliability of vertebrate odours used by I. hookeri for host location, we conducted bioassays in a four‐chamber olfactometer. Wasps were arrested by carbon dioxide and by odours from roe deer faeces and odours from hair of roe deer and wild boar. Odours from faeces of cattle, rabbit, and field mouse as well as odours from hair of cattle and field mouse had no effect. Odours from faeces of the host tick species Ixodes ricinus L. (Acari: Ixodidae) were attractive only up to a distance of 1 cm. Thus, I. hookeri reacts to general (carbon dioxide) and specific vertebrate odours from wild boar and deer. Examination of freshly shot specimens demonstrates that deer and wild boars are infested with a sufficient number of tick nymphs to tap the full reproductive potential of an I. hookeri female, which makes cues from these mammal species reliable. These results indicate that I. hookeri locates its hosts using specific and reliable mammal odours and that ticks are parasitized on their vertebrate hosts. The implications of this host‐finding strategy and its benefits for the parasitoid are discussed.     

Revisions of the Genera Lathraea and Christisonia (Orobanchaceae) in China

The present paper deals with taxonomic studies on the genera Lathraea Linn. and Christisonia Gard. (Orobanchaceae) in China. In the genus Lathraea, only a single species in China, L. japonica Miq., is recongnized in the paper. It occurs in southern Shaanxi, southern Gansu, southeastern Sichuan, northern Guizhou and northern Guangdong, also in Japan. L. miqueliana Franch. et Sav., L. chinfushanica Hu et Tang and L. japonica Miq. var. miqueliana (Franch. et Sav.) Ohwi are treated as new synonyms of L. japonica Miq. in this paper. In the genus Christisonia, the most of collections from China, which were identified as C. sinensis G. Beck before, are treated as a new synonym of C. hookeri C. B. Clarke. A few collections of this genus from China, which were mistakenly described as Gleadovia lepoense Hu snd G. kwangtungense Hu, should be transferred to Christisonia hookeri C. B. Clarke. It is distributed in southeastern and south China, westwards to the Himalayas.     

Studies on the Karyotype of 5 Samples of Allium Sect. Bromatorrhiza Ekberg

The karyotypes of 5 samples in Allium Sect. Bromatorrhiza Ekberg were analysed in this paper. In Allium wallichii Kunth, the first sample is a diploid, with genome formula is AA and karyotype formula is K(2n)=2x=14=2m(SAT)+2m+10sm. The second is an autotetraploid, with genome formula AAAA, karyotype formul K(2n)=4x=28=2m(SAT)+6m+20sm. These two karyotypes belong to “3A”. The two karyotypes of A. wallichii Kunth are similar in morphology, though different in ploidy. In Allium hookeri Thwaites, the first sample is a dibasic autoallotriploid. Its genome formula is AAB₁; the basic number of the genome A is 7 and that of the genome B₁ is 8. The karyotype formula is K(2n)=2x+x'=22=(12sm+2t)+(1m+4sm+1st+2t). The second is also an autoallotriploid. The genomes in pairs are similar to those in the first sample in size and morphology of chromosomes. However, the unpaired genome differs from the first one apparently. Therefore, its genome formula is AAB₂, and karyotype formula is K(2n)=2x+ x'=22=(12sm+2t)+(3m+1sm+2st+2t). The third is doubling of the first karyotype. It is an autoallohexaploid, with genome formula AAAAB₁ B₁ and karyotype formula K(2n)=4x+2x'= 44= (24sm+4t) + (2m+8sm+2st+4t). These three karyotypes belong to “3A”.     

云南美登木悬浮培养细胞的化学成分(英)

利用组织培养方法以云南美登木 (MaytenushookeriLose .)未木质化的茎和嫩叶为材料诱导出愈伤组织 ,经过继代培养建立了悬浮细胞培养系。培养物的乙酸乙酯提取物显示抗橙色青霉 (PenicilliumavellaneumUC_4 376 )生长的生物活性。对培养物进行化学成分研究 ,分离鉴定了 9个化合物 :2 ,3_diacetoxylmaytenusone (1)、角鲨烯 (squa lene ,2 )、β_谷甾醇 (β_sitosterol,3)、2′ ,3′,4′_triacetylsitoindosideⅠ (4)、salaspermicacid (5 )、美登酮酸 (maytenonicacid ,6 )、2α_羟基美登酮酸 (2α_hydroxy_maytenonicacid ,7)、6 ,11,12_trihydroxy_8,11,13_abietrien_7_one (8)和 11,12_dihydroxy_8,11,13_abietrien_7_one (9) ,其中化合物 1为新化合物。通过 2DNMR对化合物 5 - 7的NMR数据进行了全指定 ,并修正了化合物 5和 6的部分碳谱数据指定。     

云南美登木悬浮培养细胞的化学成分

利用组织培养方法以云南美登木(Maytenus hookeri Lose.)未木质化的茎和嫩叶为材料诱导出愈伤组织,经过继代培养建立了悬浮细胞培养系.培养物的乙酸乙酯提取物显示抗橙色青霉(Penicillium avellaneum UC-4376)生长的生物活性.对培养物进行化学成分研究,分离鉴定了9个化合物:2,3-diacetoxyl maytenusone (1)、角鲨烯 (squalene,2)、β-谷甾醇 (β-sitosterol,3)、2′,3′,4′-triacetylsitoindoside Ⅰ (4)、salaspermic acid (5)、美登酮酸 (maytenonic acid,6)、2α-羟基美登酮酸(2α-hydroxy-maytenonic acid,7)、6,11,12-trihydroxy-8,11,13-abietrien-7-one (8)和11,12-dihydroxy-8,11,13-abietrien-7-one (9),其中化合物1为新化合物.通过2D NMR对化合物5-7的NMR数据进行了全指定,并修正了化合物5和6的部分碳谱数据指定.     

川西高山林线交错带两种地被物分解的木质纤维素酶活性特征

以川西高山林线交错带两种优势地被物锦丝藓和高山冷蕨为对象,对针叶林和林线中锦丝藓植物残体及高山冷蕨凋落叶分解的质量损失和木质纤维素酶活性特征进行研究.结果表明： 锦丝藓和高山冷蕨的质量损失率在雪被期和生长季均表现为林线高于针叶林,而酶活性整体上表现为针叶林显著高于林线.两种地被物不同季节的质量损失有显著差异,雪被期林线和针叶林的锦丝藓质量损失率占全年的69.8%和83.0%;生长季林线和针叶林的高山冷蕨质量损失率分别占全年的82.6%和83.4%.高山冷蕨凋落叶在生长季节快速分解,与其生长季节末较高的纤维素酶活性相吻合,说明纤维素和半纤维素的酶解作用可能是凋落物前期质量损失的主要原因.多元线性回归分析表明,环境因子和凋落叶初始质量能共同解释酶活性变异的45.8%～85.1%,两种地被物分解过程中酶活性主要受到雪被期冻融循环的影响.     

藏药西藏棱子芹抗炎镇痛药效学研究

本文采用二甲苯致小鼠耳廓肿胀法、棉球致小鼠肉芽肿法观察藏药西藏棱子芹的抗炎作用,采用热板法、醋酸扭体法观察藏药西藏棱子芹的镇痛作用。结果表明藏药西藏棱子芹能明显抑制二甲苯所致小鼠耳廓肿胀和棉球所致小鼠肉芽肿;能提高小鼠对热板疼痛的阈值,减少小鼠扭体反应的次数,延长醋酸所致小鼠扭体反应的潜伏时间。藏药西藏棱子芹具有显著的抗炎镇痛作用,值得开发研究。     

宽叶韭及其近缘种不同居群的黄酮类化合物薄层层析研究

对宽叶韭的１３个居群及其变种木里韭和近缘种峨眉韭的叶片进行了黄酮类化合物的薄层层析（ＴＬＣ）分析,发现不同居群的木里韭、峨眉韭和具有相同生活习性的宽叶韭的层析图谱类型不受生态环境和染色体倍性的影响;依据层析图谱,宽叶韭可明显分为三个类型且与宽叶韭的生活习性相吻合,表明宽叶韭可能发生了种内分化。