Chromosome numbers of Thai Rubiaceae

Chromosome numbers for 14 taxa of indigenous Thai Rubiaceae are presented. They include first counts for 3 genera: Aphaenandra (A. uniflora), Prismatomeris (P. tetrandra subsp. malayana) and Tarennoidea (T. wallichii) ; all show diploidy on x=11. The remaining counts are first counts for species: Argostemma diversifolium, A. neurocalyx and A. pictum, Coptosapelta flavenscens, Gardenia saxtilis, Ixora sp., Morinda sp., Mussaenda sanderiana, Oxyceros horridus, Rothmannia wittii (first count for an Asiatic species of the genus) (all diploid on x=11), and Canthium sp. (tetraploid on x=11). The poor state of karyological knowledge of indigenous Thai Rubiaceae is discussed, and a table including all relevant known chromosome counts is presented. Chromosome data are only known for 38 genera (ca. 41% of all Rubiaceae genera occurring in Thailand); chromosome numbers are often only available for one or few taxa of each genus [in sum, for only about 50 (or for roughly 10% of all) taxa]. Of only 14 genera (ca. 15%), chromosomes were counted from Thai material (for the others, counts originate from elsewhere, i.e. refer to more widely distributed taxa also extending into Thailand).     

New Rubiaceae from the Brazilian Planalto

Three new species from Brazil,Hindsia irwinii, Manettia irwinii, andMitracarpus pusillus, are described. A new section,Brevicalyx, is erected for Hindsia irwinii, and another new section,Irwinianthus, forManettia irwinii.     

Studies in Pacific Rubiaceae: VI-VIII

These studies deal with HawaiianHedyotis andGouldia, and withCoprosma in Juan Fernández. The speciesCoprosma oliveri is described as new, as isGouldia terminalis (Hook. & Arn.) Hillebr. var.pubistipula, and three forms ofHedyotis acuminata (Cham. & Schlecht.) Steud.     

Phylogeny of the Gardenieae (Rubiaceae)

The phylogeny of Gardenieae (Rubiaceae) is evaluated using 70 morphological and anatomical characters and 81 terminal taxa. After successive reweighting of the characters and modified bootstrap tests the following is concluded. The position of the Diplosporinae genera Argocoffeopsis, Calycosiphonia, Cremaspora and Tricalysia with the genera belonging to the tribes Aulacocalyceae, Coffeeae, Octotropideae and Pavetteae, suggests that this subtribe does not belong in Gardenieae. Posoqueria is nested among outgroup genera and consequently is not a member of the tribe. Robbrecht & Puff's informal 'tetrad group' is monophyletic. Likewise, their 'Alibertia group' is supported as monophyletic, although slightly rearranged. On the other hand, their 'Aidia group' must he greatly expanded with several genera in order to be monophyletic, but the monophyly of this group is weakly supported. Several disputed genera should be included in Gardenieae ( Anomanthodia, Amaioua, Brachytome , and supposedly Bertiera ). Most inferred groups, however, exhibit low bootstrap values and should he viewed with caution.     

Self-compatibility in distylousHedyotis salzmannii (Rubiaceae)

Hedyotis salzmannii (Rubiaceae) is distylous. Experimental pollination revealed that both morphs are self-compatible. However, the thrum morph proved to be more self-compatible. Hand cross-pollination between different plants of the same floral form produced less seed-sets per pollination than hand cross-pollination between pin and thrum or thrum and pin pollination. Two species ofHymenoptera, oneApidae and oneHalictidae, and two species ofDiptera (Syrphidae) were observed as pollinators.     

Isochorismate hydroxymutase from Rubiaceae cell suspension cultures

The enzyme catalysing the isomerisation of chorismic to isochorismic acid (isochorismate hydroxymutase E.C. 5.4.99.6) has been detected in protein preparations of various cell suspension cultures derived from plants of Rubiaceae species.Abbreviations OSB o-Succinylbenzoic acid - Tris Tris(hydroxymethyl)aminomethane - DEAE Diethylaminoethyl cellulose     

Intrusive hair sclereids in Jovetia (Rubiaceae)

In the genus Jovetia , many outer cells from the multiseriate epidermis develop into hairs while at the same time differentiating as sclereids. In the upper epidermis, these show intrusive growth to the bottom of the palisade parenchyma and even below. In the lower epidermis, they remain epidermal or show slight penetration of the underlying parenchyma.     

An unusual homostyle inHedyotis caerulea (Rubiaceae)

Hedyotis caerulea, a spring flowering herb widely distributed in eastern North America, has distylous flowers that differ by a number of morphological and physiological traits. The presence of a strong incompatibility system is indicated by the fact that intramorph crosses or self-pollinations produced little or no seed and intermorph crosses produced copious seed. An unusual homostyle was located that had most floral characters intermediate between pin and thrum flowers, although its pollen size was that of pin. The homostyle was only moderately self-compatible, and its pollen did not behave as pin pollen on thrum stigmas. It appears that, despite their intermediate position and morphology, the homostyle stigmas were fundamentally pin. Although the exceptional rarity of the homostyle suggests that it is an inadaptive failure, workers should watch for its further occurrence since additional study of it may provide insights into the genetic and physiological basis of heterostyly in theRubiaceae.     

Review of the Neotropical Isertieae (Rubiaceae)

All neotropical genera previously included in the tribe Isertieae A. Rich. ex DC. are considered. The tribe Isertieae is here delimited by the following characters: absence of rhaphides, valvate aestivation of the corolla, cordiform or discoid placenta, fleshy indehiscent fruit, and seed coat cells with pitted walls. As so delimited, the tribe definitely includes the neotropical generaIsertia Schreb.,Gonzalagunia Ruiz & Pav.,Amphidasya Standl.,Raritebe Wernh.,Sabicea Aubl., andMussaenda L. as well as some paleotropical genera not here considered. The following neotropical genera are excluded from tribe Isertieae:Hippotis Ruiz & Pav.,Pentagonia Benth.,Sommera Schlecht.,Tammsia Karst.,Coccocypselum P. Browne,Schradera Vahl,Didymochlamys Hook, f., andXerococcus Oerst. The position of four genera,Striolaria Ducke,Patima Aubl.,Habroneuron Standl., andNeosabicea Wernh., remains uncertain due to a lack of material.     

Iridoid glucosides from Randia spinosa (Rubiaceae)

An iridoid glucoside: randinoside, along with five known iridoids: galioside, deacetylasperulosidic acid methyl ester, scandoside methyl ester, geniposide and gardenoside, were isolated from the stems of Randia spinosa. The structures were determined by spectroscopic analysis, including 2D NMR techniques.     

Microsatellite markers for Duperrea pavettifolia (Rubiaceae)

? Premise of the study: The development of microsatellite primers for Duperrea pavettifolia will be the foundation for mating system analysis and conservation research. ? Methods and Results: Nineteen microsatellite markers were developed and characterized in two wild populations by using the Fast Isolation by AFLP of Sequences COntaining repeats (FIASCO) protocol. Polymorphisms were evaluated in 24 individuals from two natural populations. Eleven of these primers generated polymorphic loci. ? Conclusions: These microsatellite markers will be useful in future investigations into the population genetics and mating system of D. pavettifolia.     

Pollen morphology of the Gardenieae-Gardeniinae (Rubiaceae)

Pollen grains of 107 species of 61 genera of the Gardeniinae were investigated by scanning electron and light microscopy. The subtribe is europalynous and grains occur either as monads, tetrads or massulae. Grains are porate, colporate or rarely pororate. The majority of the genera has 3-zonoaperturate pollen grains. However, deviating numbers of apertures occur in Byrsophyllum (4–8) and Pseudomantalania (4–5). Pantoporate pollen occurs in Randia . The average equatorial size (E) of monads varies between 13 μm in Anomanthodiu to 59 μm in Posoqueria . The tetrads vary from 37 μm in Casasia to 61 μm in Calochone and Euclinia . The exine is usually reticulate, but also foveolate, rugulate, perforate and psilate exine occurs in the subtribe. The thickness of the exine is only 0.3 μm in tetrad grains of Randia armata and in the pantoporate monad grains of R. ruiziana , whereas the thickest exine occurs in Posoqueria (2.8 pm) and Euclinia (2.9 μm). Tectal excrescenses are generally absent. However, three genera with pollen in tetrads, namely Euclinia, Gardenia and Oligoco-don , show this feature. Contrary to the subtribe most genera are fairly stenopalynous, but in the neotropical genera Alibertia and Randia several different types of pollen are encountered.     

Palynological characters and their phylogenetic signal in Rubiaceae

In the 1990s Rubiaceae became a hot spot for systematists, mainly due to the comprehensive treatment of the family by Robbrecht in 1988. Next to the exploration of macromolecular characters to infer the phylogeny, the palynology of Rubiaceae finally received the attention it deserves. This article aims to present a state-of-the-art analysis of the systematic palynology of the family. The range of varíation in pollen morphology is wide, and some of the pollen features are not known from other angiosperm taxa; e.g., a looplike or spiral pattern for the position of apertures in pantoaperturate grains. We compiled an online database at the generic level for the major pollen characters and orbicule presence in Rubiaceae. An overview of the variation is presented here and illustrated per character: dispersal unit, pollen size and shape, aperture number, position and type, sexine ornamentation, nexine pattern, and stratification of the sporoderm. The presence/absence and morphological variation of orbicules at the generic level is provided as well. The systematic usefulness of pollen morphology in Rubiaceae is discussed at the (sub)family, tribal, generic, and infraspecific levels, using up-to-date evolutionary hypotheses for the different lineages in the family. The problems and opportunities of coding pollen characters for cladistic analyses are also treated.