Browsing by Author "Hedderley D"

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    Nitrous Oxide Treatment after Pollination Induces Ploidy Changes in Statice (Limonium sp.)
    (MDPI (Basel, Switzerland), 2024-08-01) Cordoba-Sanchez J; Funnell K; Hedderley D; Roskruge N; Morgan E; Neri D
    The production of statice (Limonium sp.) plants with higher ploidy through induction of whole-genome duplication (WGD) via the spindle disrupter nitrous oxide (N2O) was examined as a strategy to increase the germplasm diversity of the species. Furthermore, the impact of the resulting ploidy changes on the morphological features of the progeny was examined. Intraspecific crosses between diploid plants of Limonium sinuatum (L.) Mill and L. perezii (Stapf) Hubb. were conducted daily for seven consecutive days, with subsequent exposure to N2O. Within the resulting progeny, between 16% and 35% of plants were polyploid when N2O was applied between one and four days after pollination. A comparative analysis between diploid and tetraploid progeny was conducted, using a selection of 10 L. sinuatum (5 diploids and 5 tetraploids) and 7 L. perezii (4 diploids and 3 tetraploids) genotypes. The results revealed differences between tetraploids and their diploid counterparts for most of the evaluated characteristics. Tetraploid plants of L. sinuatum and L. perezii exhibited pollen grains 1.5 times larger in plan area; the leaves and main floral stem diameter were 1.2 and 1.5 times thicker for L. sinuatum and L. perezii, respectively, the guard cell length was 1.4 times greater for both species, while the stomatal density was 0.6 times lower for L. perezii and 0.8 for L. sinuatum. The leaf area and main floral stem wings were affected by the ploidy increase only for L. sinuatum. In this regard, tetraploid plants of L. sinuatum displayed leaves 1.8 times bigger and main floral steam wings 2.4 times wider in comparison to diploid plants. In conclusion, the production of tetraploid Limonium plants using N2O shortly after pollination creates new diversity for breeding. These findings underscore the potential for leveraging polyploidy as a strategy to enhance desirable traits in Limonium species.
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    The Efficacy of New Zealand Greenshell™ Mussel Powder Supplementation in Supporting Muscle Recovery Following Eccentric Exercise-Induced Muscle Damage in Healthy, Untrained Adult Males
    (MDPI (Basel, Switzerland), 2023-05-15) Lomiwes D; Barnes M; Shaw O; Ngametua N; Sawyer G; Burr N; Hedderley D; Kanon A; Bear T; Carroll A; Bentley_Hewitt K; Tian HS; Miller MR; Nieman DC
    Unaccustomed eccentric exercise results in muscle damage limiting physical performance for several days. This study investigated if Greenshell™ mussel (GSM) powder consumption expedited muscle recovery from eccentric exercise-induced muscle damage (EIMD). Methods: Twenty untrained adult men were recruited into a double-blind, placebo-controlled, cross-over study and were randomly assigned to receive the GSM powder or placebo treatment first. Participants consumed their allocated intervention for four weeks then completed a bench-stepping exercise that induced muscle damage to the eccentrically exercised leg. Muscle function, soreness and biomarkers of muscle damage, oxidative stress and inflammation were measured before exercise, immediately after exercise and 24, 48 and 72 h post exercise. GSM powder promoted muscle function recovery, significantly improving (p < 0.05) isometric and concentric peak torque at 48 h and 72 h post exercise, respectively. Participants on the GSM treatment had faster dissipation of soreness, with significant treatment × time interactions for affective (p = 0.007) and Visual Analogue Scale-assessed pain (p = 0.018). At 72 h, plasma creatine kinase concentrations in the GSM group were lower (p < 0.05) compared with the placebo group. This study provides evidence for GSM powder being effective in supporting muscle recovery from EIMD.