Seed Cryopreservation, Germination, and Micropropagation of Eastern Turkeybeard, Xerophyllum asphodeloides (L.) Nutt.: A Threatened Species from the Southeastern United States

Xerophyllum asphodeloides (Xerophyllaceae), known as eastern turkeybeard, is an herbaceous perennial found in eastern North America. Due to decline and destruction of its habitat, several states rank X. asphodeloides as “Imperiled” to “Critically Imperiled”. Protocols for seed cryopreservation, in vitro germination, sustainable shoot micropropagation, shoot establishment in soil, and seed germination are presented. Seeds from two tested sources were viable after 20 months of cryopreservation. Germination of isolated embryos in vitro was necessary to overcome strong seed dormancy. Shoot multiplication and elongation occurred on ½ MS medium without PGRs. Shoots rooted in vitro without PGRs or with 0.5 mg/L NAA or after NAA rooting powder treatment and placement in potting mix. When planted in wet, peaty soil mixes, shoots grew for two months and then declined. When planted in a drier planting mix containing aged bark, most plants continued growth. In the field, plant survival was 73% after three growing seasons. Safeguarding this species both ex situ and in situ is possible and offers a successful approach to conservation. Whole seeds germinated after double dormancy was overcome by incubation under warm moist conditions for 12 weeks followed by 12 weeks cold at 4 °C and then warm.

The Effect of Red Palm Oil Concentration towards Characteristics and Biodegradability of PLA-Starch Film

Polylactic acid (PLA) is a biodegradable polymer that had been used as a substitute for conventional petroleum based plastics. Plasticizers were added into the solution of PLA and starch (PLA/S) to increase the flexibility and degradability of the produced film. PLA/S films need plasticizers that able to improve the degradation process. Red palm oil (RPO) were incorporated into PLA/S blends. The films were casted into petri dish via casting method. The films were characterized based on the color, thickness and chemical composition (Fourier-transform infrared spectroscopy). The performance of the films was analyzed based on tensile strength and biodegradation percentage. The films were yellowish in color with the addition of RPO. The FTIR shows that the increment of RPO concentration modified the intermolecular interaction between the PLA/S molecules. The tensile strength of PLA decreased with the addition of starch. The biodegradability test was done by using soil burial method where the samples were buried in peaty soil for 12 days. The films produced from these combinations resulted in a good biodegradable activity. The films with high concentration of RPO and presence of starch degraded 100% within 12 days. RPO can be used as the plasticizer with further improvement.

Late Quaternary (≥MIS 3 to MIS 1) stratigraphic transitions in a highland Beringian landscape along the Kuskokwim River, Alaska

Stratigraphic records extending to Marine Oxygen Isotope Stage (MIS) 3 (57,000–29,000 cal yr BP) or older in Beringia are extremely rare. Three stratigraphic sections in interior western Alaska show near continuous sedimentological and environmental progressions extending from at least MIS 3, if not older, through MIS 1 (14,000 cal yr BP–present). The Kolmakof, Sue Creek, and VABM (vertical angle bench mark) Kuskokwim sections along the central Kuskokwim River, once a highland landscape at the fringe of central and eastern Beringia, contain aeolian deposition and soil sequences dating beyond 50,000 14C yr BP. Thick peaty soil, shallow lacustrine, and tephra deposits represent the MIS 3 interstade (or older). Sand sheet and loess deposits, wedge cast development, and very thin soil development mark the later MIS 3 period and the transition into the MIS 2 stade (29,000–14,000 cal yr BP). Loess accumulation with thicker soil development occurred between ~16,000–13,500 cal yr BP at the MIS 2 and MIS 1 transition. After ~13,500 cal yr BP, loess accumulation waned and peat development increased throughout MIS 1. These stratigraphic sequences represent transitions between a warm and moist period during MIS 3, to a cooler and more arid period during MIS 2, then a return to warmer and moister climates in MIS 1.

Carabid beetles in peatlands - what are bog species? Clear definitions of tyrphobiontic and tyrphophilic species as used in the "Bavarian bog species basket"

Peatland species are endangered because of peat extraction and drenching of peatland in many regions, and thus are of great conservation concern. Often times, the trait of being "tyrphobiontic" or "tyrphopilous" is defined differently in the literature, yielding ambigous results. Frequently, studies of peatland fauna do not clearly define which species are characteristic of peatlands, instead focussing on other traits like red data book status etc. The group of peatland specialists should be definied by their affinity to the habitat trait of peaty soil. For many species, further factors are also relevant, like habitat tradition, elevation and regional climate, vegetation types etc., but peaty soil is a common denominator. The "Bavarian bog species basket" lists all species from different species groups that are bog species, grouping them into three clearly defined categories of peatland affinity. For carabids, a list of all 26 species in that basked is presented, and examples provided how these differ in their affinity to different bog habitats, and to bog habitats overall.