Origins of the regional feeding abilities in the tiger swallowtail butterfly: ecological monophagy and the Papilio glaucus australis subspecies in Florida

Summary The Highlands County, Florida populations of the eastern tiger swallowtail butterfly, Papilio glaucus L., represent a putative subspecies, P. g. australis Maynard. The only foodplant ever reported in southern half of Florida is sweetbay, Magnolia virginiana L. (Magnoliaceae). In fact, there are apparently no other reported foodplants for the polyphagous tiger swallowtail species which exist in southern Florida. These ecologically monophagous P. g. australis populations were studied in order to determine whether or not significant behavioral and biochemical adaptations in the larvae are detectable as a result of the ecological specialization on sweetbay. These results suggest an emphatic yes. On sweetbay, neonate larval survival of these Florida populations is the best of any other population tested from across North America. In addition, penultimate instar larval growth rates are significantly faster on sweet bay than any other foodplant tested. Furthermore, these biochemical adaptations to sweetbay by P. g. australis in Florida are accompanied by a significantly poorer neonate survival and growth performance on northern foodplants (most notably the Salicaceae and Betulaceae). Reciprocal inabilities of the northern subspecies, P. g. canadensis, and the western P. rutulus to utilize sweetbay are described, as well as the reciprocal inabilities of two congeneric and sympatric (Florida) species, Papilio palamedes and Papilio troilus, that have specialized on another bay (redbay, Persea borbonia; of the Lauraceae). It remains uncertain to what degree such apparent negative genetic correlations in foodplant adaptations represent a driving force in the formation of host races or species, especially since so little is known about oviposition preferences of Papilio glaucus across North America. In Florida we have an apparently strict ecological monophagy coupled with a degree of reproductive isolation that has resulted in its tentative classification as a subspecies, P. g. australis. The role of foodplants in the speciation process can be significant even for P. glaucus, the most polyphagous of all 563 species of world Papilionidae. It remains uncertain whether the significant differences in detoxication and biochemical processing abilities observed in this study were evolved in parapatry or allopatry. Disjunct populations of P. alexiares in Mexico retain some ability to detoxify sweetbay, as do some individuals in most P. glaucus glaucus populations tested from ten different states north of Florida.     

A new species of Talauma (Magnoliaceae) from Bolivia

Talauma boliviana is described as new and illustrated. This species, first collected in 1989, is the only Magnoliaceae known from Bolivia. It seems to be most closely related toT. sambuensis of northwestern Colombia and eastern Panama.     

15-Acetoxycostunolide from Magnolia sieboldii

A new germacranolide isolated from M. sieboldii was shown to be 15-acetoxycostunolide by spectroscopic and chemical methods. ¹H NMR spin decoupling and NOE experiments in the presence of a lanthanide shift reagent were used for structure elucidation.     

云南48种木兰科野生植物资源遗传多样性研究

为了解云南省木兰科（Magnoliaceae）野生植物资源的遗传多样性,利用ISSR分子标记技术对48种木兰科野生植物资源进行研究。结果表明,10对引物共扩增出151条带,均为多态性条带,多态性条带百分率为100%。总的观测等位基因数（N_a）为2.000 0,有效等位基因数（N_e）为1.564 5,Nei’s基因多样性指数（H）0.337 9,Shannon’s信息指数（I）为0.510 1。总的基因多样性指数（H_t）为0.368 0,属间基因多样性指数（D_st）为0.251 9,占68.4%,基因分化系数（G_st）为0.684 0,基因流（N_m）为0.231 0。UPGMA聚类分析将48种木兰科植物划分为7个类群,各类群并非按照属聚在一起,而是不同属植物相间分布,长喙厚朴（Magnolia rostrata）、素黄含笑（Michelia flaviflora）和球花含笑（M.sphaerantha）可能为云南省木兰科植物中的原始种。48种木兰科野生植物总体具有较高的遗传多样性,但属间遗传变异较高,基因流较小,存在遗传漂变的风险,聚类结果与刘玉壶的分类系统存在分歧,这从分子水平为木兰科植物间的起源、进化与分类提供了重要依据。     

Sesquiterpenoids from the Chinese endangered plant Manglietia aromatica

One new bourbonane-type (1) and one new cadinane-type (2) sesquiterpenoids, along with one known aromodendrane-type (3) and five known megastigmane-type (4–8) compounds, were isolated from the leaves and twigs of Manglietia aromatica, a Chinese endangered plant that has not been previously phytochemically investigated. The structures and absolute configurations of the new isolates, (1R,4S,5S,6S,7S,10S)-4-hydroxy-bourbon-8-one (1) and (1R,6S,7S)-1-hydroxy- cadin-4,9-dien-8-one (2), were established by means of spectroscopic methods and a combination of experimental and calculated electronic circular dichroism (ECD). Among the isolates, compound 2 was found to show a moderate inhibitory effect against the human protein tyrosine phosphatase 1 B (PTP1B) enzyme, a target for the treatment of type-II diabetes and obesity, with an IC₅₀ value of 83.5 μM.     

Plastid and nuclear phylogenomic incongruences and biogeographic implications of Magnolia s.l. (Magnoliaceae)

Magnoliaceae, an assemblage of early diverged angiosperms, comprises two subfamilies, speciose Magnolioideae with approximately 300 species in varying numbers of genera and monogeneric Liriodendroideae with two species in Liriodendron L. This family occupies a pivotal phylogenetic position with important insights into the diversification of early angiosperms, and shows intercontinentally disjunct distribution patterns between eastern Asia and the Americas. Widespread morphological homogeneity and slow substitution rates in Magnolia L. s.l. resulted in poorly supported phylogenetic relationships based on morphology or molecular evidence, which hampers our understanding of the genus’ temporal and spacial evolution. Here, based on the newly generated genome skimming data for 48 Magnolia s.l. species, we produced robust Magnolia phylogenies using genome-wide markers from both plastid genomes and single nucleotide polymorphism data. Contrasting the plastid and nuclear phylogenies revealed extensive cytonuclear conflicts in both shallow and deep relationships. ABBA-BABA and PhyloNet analyses suggested hybridization occurred within sect. Yulania, and sect. Magnolia, which is in concordance with the ploidy level of the species in these two sections. Divergence time estimates and biogeographic reconstruction indicated that the timing of the three tropical Magnolia disjunctions coincided with the mid-Eocene cooling climate and/or late Eocene climate deterioration, and two temperate disjunctions occurred much later, possibly during the warm periods of the Miocene, hence supporting the boreotropical flora concept of Magnolia s.l.     

广东木莲的一个新异名

根据对广东木莲Manglientia kwangtungensis（Merr．）Dandy和毛桃木莲M.moto Dandy大量标本的研究,将毛桃木莲处理为广东木莲的一个异名。     

国产木兰科6属植物柱头表面形态比较

用扫描电镜对中国产木兰科单性木兰属、木兰属、木莲属、含笑属、拟单性木兰属和观光木属的42种植物柱头表面形态进行观察.结果表明,42种木兰科植物的柱头均为干柱头,包含单细胞乳突型和多细胞乳突型两类.单性木兰属和观光木属植物是单细胞乳突型;木莲属、含笑属和拟单性木兰属植物是多细胞乳突型;木兰属中木兰亚属植物两型均有,而玉兰亚属则均为多细胞乳突型.结合其他证据,本文支持单性木兰属、木莲属、含笑属、拟单性木兰属和观光木属的建立,并认为在系统学问题较复杂的木兰属中,玉兰亚属是一个相对独立的单系类群,将其独立成属也不无道理,而木兰亚属可能不是一个单系类群,还需要进一步的深入研究,积累更多的性状数据.     

木兰科3个杂交组合及其亲本的核型研究

研究了木兰科（Magaoliaceae）3个杂交组合的亲本和杂交后代的核型。结果表明,云南含笑（Michelia yunnanensis）、灰岩含笑（Michelia calcicola）及其杂交组合A的核型分别为2n=2x=38=36m＋2sm、2n=2x=38=34m＋4sm和2n=2x=38=26m＋12sm;紫花含笑（Michelia crassipes）及其与云南含笑杂交组合C的核型分别为2n=2x=38=32m＋6sm和2n=2x=38=24m＋12sm＋2st;山玉兰（Mognolia delavayi）、广玉兰（Mognolia grondiflora）及其杂交组合U的核型分别为2n=2x=38=28m＋10sm、2n=6x=114=88m＋lOsm＋16st和2n=4x=76=57m＋15sm＋4st。杂交组合的核型与理论核型存在明显的差异,可能是在杂交组合的形成过程中,来自亲本的染色体发生了结构变异。