7-Polyacylated delphinidin 3,7-diglucosides from the blue flowers of Leschenaultia cv. Violet Lena

The triacyl anthocyanins, Leschenaultia blue anthocyanins 1 and 2 (LBAs 1 and 2) were isolated from the blue flowers of Leschenaultia R. Br. cv. Violet Lena (Goodeniaceae), in which LBA 1 was present as a dominant pigment. The structure of LBA 1 was elucidated to be delphinidin 3-O-[6-O-(malonyl)-beta-D-glucopyranoside]-7-O-[6-O-(4-O-(6-O-(4-O-(beta-D-glucopyranosyl)-trans-caffeoyl)-beta-D-glucopyranosyl)-trans-caffeoyl)-beta-D-glucopyranoside] by application of chemical and spectroscopic methods. Since LAB 2 was isolated in small amount, its structure was tentatively assigned as either delphinidin 3-(malonylglucoside)-7-[(glucosyl-p-coumaroyl)-(glucosylcaffeoyl)-glucoside] or delphinidin 3-(malonyl-glucoside)-7-[(glucosyl-caffeoyl)(glucosyl-p-coumaroyl)-glucoside]. This is the first report of the occurrence of 7-polyacylated anthocyanins in the family of Goodeniaceae, although others have been found in the families of the Ranunculaceae, Campanulaceae, and Compositae. Moreover, delphinidin 3-glycoside-7-di-(glucosylcaffeoyl)-glucoside has been reported only in the flowers of Platycodon grandiflorum (Campanulaceae). From a chemotaxonomical viewpoint, the Goodeniaceae may be closely related to the Campanulaceae.     

Mimicking a semi-arid tropical environment achieves dormancy alleviation for seeds of Australian native Goodeniaceae and Asteraceae

Background and Aims: Seed physiological dormancy (PD) limits the use and conservationof some of Queensland's (Qld) native forb species. It was hypothesisedthat optimum dormancy-alleviating treatments would reflect environmentalconditions that seeds experience in situ, and this premise wastested for PD seeds of four species native to south-west Qld. Methods: High temperatures and increased rainfall during summer are characteristicof this semi-arid tropical environment. Ex situ treatments weredesigned to mimic conditions that seeds dispersed in springexperience during the summer months before germinating in coolerautumn temperatures. Seeds received between 4 and 20 weeks ofa dry after-ripening (DAR), warm stratification or dry/wet cyclingtreatment (DAR interspersed with short periods of warm stratification),in darkness, before being transferred to germination test conditions.In addition, natural dormancy alleviation of one of the Goodeniaceaespecies was investigated in situ. Key Results: Dry/wet cycling resulted in higher levels of germination ofActinobole uliginosum (Asteraceae), Goodenia cycloptera andVelleia glabrata (Goodeniaceae) when compared with constantDAR or stratification, while Goodenia fascicularis (Goodeniaceae)responded better to short durations of warm stratification.Long durations of DAR partially alleviated PD of A. uliginosum;however, stratification induced and maintained dormancy of thisspecies. Modifications to the dry/wet cycling treatment andgermination test conditions based on data collected in situenabled germination of G. cycloptera and V. glabrata to be furtherimproved. Conclusions: Treatments designed using temperature, relative humidity andrainfall data for the period between natural seed dispersaland germination can successfully alleviate PD. Differences betweenthe four species in conditions that resulted in maximum germinationindicate that, in addition to responding to broad-scale climatepatterns, species may be adapted to particular microsites and/orseasonal conditions.     

Growth and abundance of desert annuals in an arid woodland in Oman

Given the role of Scaevola plumieri as a major pioneer species in the dune environment, as well as the need forindigenous sand stabilisers for South Africa’s coastal dunes, the reproductive phenology was unravelled as a firststep to establish the potential usefulness of the species in dune stabilisation programmes. In the highly variablecoastal environment the plants must cope with many problems for successful reproduction to take place. Theplants of S. plumieri overcome these difficulties through vegetative reproduction, but sexual reproduction is byno means insignificant. Numerous peduncles, each carrying multiple buds, were produced per stem, but only fewdeveloped into ripe seeds. Several of the flowers were unfertilised and of the seeds produced many were infectedand/or aborted. There was a strong effect of dune position on the reproductive phenology of S. plumieri. Thestems situated at the landward face of the foredunes showed an overall higher reproductive performance numberof buds, flowers, unripe seeds, ripe seeds. The phenogram showed that the reproduction of stems at the landwardside of the foredunes started on average 34 days earlier and showed a tendency for a longer reproductionperiod. For the duration of the different stages in the reproduction sequence, the bud stage’ took the shortesttime and the ‘ripe seed stage’ longest time. Between the different sample years, the production of the number ofpeduncles, buds, flowers and seeds was the similar; only differences in reproduction time (duration) of the differentstages were observed for the bud, flower an unripe seeds stage between the sample years.     

Morphological and physiological responses of Scaevola sericea (Goodeniaceae) seedlings to salt spray and substrate salinity

The effects of substrate salinity and salt spray upon seedlings of Scaevola sericea were examined in this study. Three levels of substrate salinity: 0.0 ppt, 3.0 ppt, and 10.0 ppt were examined in conjunction with three levels of salt spray: zero, medium (200 mg m^-2mdd^-1), and high (1200–1500 mg-m^-2mdd^-1). Leaf surface area, root to shoot ratio, as well as leaf, stem, and root mass decreased significantly (P 0.05) with increasing substrate salinity. Biomass accumulation was very low at 10.0 ppt substrate salinity, suggesting that higher levels of substrate salinity cannot be tolerated by the seedlings. Salt spray had a substantial effect on several of these variables, however its effects were less pronounced than those of substrate salinity. Cell sap osmolarity, leaf thickness, and leaf specific mass increased significantly (P 0.05) with both increasing substrate salinity and salt spray levels. Leaf carbon isotope ratios (δ^l3C) became more positive with increasing salinity, indicating an enhancement of the intrinsic water use efficiency of the seedlings at higher salinities. Scaevola sericea is one of the dominant plants found at the leading edge of strand communities in the Hawaiian archipelago and throughout much of the tropical Pacific. Since substrate salinity and salt spray increase with proximity to the ocean, the two factors may act together to limit the seaward expansion of S. sericea in coastal habitats.     

On the Mechanisms of Secondary Pollen Presentation in the Campanulales-Asterales-Complex1

Families of the Campanulales-Asterales-complex are characterized by special mechanisms for secondary pollen presentation: pump mechanism, brushing mechanism, deposition mechanism, cup mechanism and combination of cup mechanism with brushing mechanism. These different mechanisms are based on three successive events: elongation of the filaments, opening of the anthers, elongation of the style. The diversity of the mechanisms arises through different auxiliary structures such as an indusium, hairs or an anther tube, and the relative rate and time of filament and style growth. An advantage of secondary pollen presentation lies in the prolongation of the male phase of anthesis through portioned pollen release. A probable phylogeny of the different mechanisms of secondary pollen presentation is proposed (Fig. 7).