Seed dormancy,germination and storage behavior of Magnolia sinica,a plant species with extremely small populations of Magnoliaceae

Magnolia sinica is one of the most endangered Magnoliaceae species in China.Seed biology information concerning its long-term ex situ conservation and utilization is insufficient.This study investigated dormancy status,germination requirements and storage behavior of M.sinica.Freshly matured seeds germinated to ca.86.5%at 25/15℃but poorly at 30℃;GA3 and moist chilling promoted germination significantly at 20℃.Embryos grew at temperatures(alternating or constant)between 20℃and 25℃,but not at 5℃or 30℃.Our results indicate that M.sinica seeds possibly have non-deep simple mor-phophysiological dormancy(MPD).Seeds survived desiccation to 9.27%and 4.85%moisture content(MC)as well as a further 6-month storage at-20℃and in liquid nitrogen,including recovery in vitro as excised embryos.The established protocol ensured that at least 58%of seedlings were obtained after both cold storage and cryopreservation.These results indicate that both conventional seed banking and cryopreservation have potential as long-term ex situ conservation methods,although further optimized approaches are recommended for this critically endangered magnolia species.

Dormancy Breaking and Storage Behavior of Garcinia cowa Roxb. （Guttiferae） Seeds： Implications for Ecological Function and Germplasm Conservation

Abstract: The dormancy breaking and storage behavior of Garcinia cowa Roxb. seeds were investigated. The seeds of G. cowa had 8–11 months dormancy in their natural habitat. Seeds were matured and dispersed at the end of the rainy season (mid-late August to late September) and were scatter-hoarded by rodents as food for winter after the seeds had fallen to the ground. Seedlings often emerged in the forest during the rainy season (May to August) the following year. Intact seeds of G. cowa failed to germinate after being sown at 30 °C for 120 d and the mean germination time (MGT) of seeds cultured in a shade (50% sunlight) nursery was 252 d. The most effective method of breaking dormancy was to remove the seed coat totally, which reduced the MGT to 13 d at 30 °C. Germination was also promoted by partial removal of the seed coat (excising the hilum and exposing the radicle) and chemical scarification (immersion in 1% H2O2 for 1 d). Unscarified seeds take up water rapidly in the first 96 h, but water was absorbed by the outside seed coat, without penetrating through it. The moisture content (MC) of G. cowa seeds was high (50% in fresh weight) at shedding. The seeds could tolerate desiccation to some extent, until the MC reached approximately 40%; below that, the viability decreases rapidly and all seeds died at approximately 17% of MC. Seed viability decreased rapidly when seeds were chilled at 4 °C; germination was 2% after storage for 1 week. Even stored at 10 °C, seeds began to be damaged after 4 weeks. Seed storage for 1 yr revealed that in both dry (relative humidity (35 ± 5)%) and moist (wet sand) storage conditions, seed viability declined, but germination percentages for seeds stored under moist conditions are better than for seed stored under dry conditions. Because of their low tolerance to desiccation, marked chilling sensitivity and relatively short lifespan, G. cowa seeds should be classified into the tropical recalcitrant category. The ecological implications of dormant recalcitrant seeds and cues on storing recalcitrant seeds were discussed.

Physiological Changes in Red Onion Bulbs at Different Storage Temperature

Onion bulbs were stored at five different temperatures to know the storage behavior of onion bulbs. Indian red onion bulbs were kept without wrapping at ambient conditions (25℃ ± 3℃ and 75% RH) and within polyethylene pouch at 2.5℃, 6℃, 7℃ and 13℃ for 60 days of storage period. Weight loss, total soluble solids (TSS), number of sprouted and rotten bulbs were measured at an interval of 10 days throughout storage. The greatest decrease (23.25%) in weight was observed throughout storage for onions stored at ambient conditions. TSS was observed to increase in all samples until 40 days of storage and then decreased up to 60 days. Lowest TSS (14.89 ?Bx) was found in onion stored at ambient conditions at the end of storage. Maximum sprouted (67.25%) and rotten (17.78%) onions were observed for onions stored at 13℃, whereas minimum sprouted and rotten onions were found at 2.5℃ at 60 days of storage. Results also recommend lowest temperatures (2.5℃ - 6℃) for prolong storage life of onion with no detrimental effects.

Embedding antimony nanoparticles into metal–organic framework derived TiO_(2)@carbon nanotablets for high-performance sodium storage

Titanium dioxide (TiO_(2)) has been widely investigated as a candidate for anode materials of sodium-ion batteries (SIBs) due to its low cost and high abundance.However,the intrinsic sluggish ion/electron transfer rate hinders its practical applications for high energy density storage devices.In contrast,antimony(Sb) shows high specific theoretical capacity (660 m Ah/g) as well as excellent electron conductivity,but the large volume variation upon cycling usually leads to severe capacity fading.Herein,with the objective of achieving high-performance sodium storage anode materials,Ti O_(2)@C-Sb nanotablets with a small amount of Sb content (6.4 wt%) are developed through calcination Ti-metal–organic framework (MIL-125)derived TiO_(2)@C/SbCl3 mixture under reductive atmosphere.Benefitting from the synergetic effect of welldispersed Sb nanoparticles as well as robust porous TiO_(2)@C substrate,the TiO_(2)@C-Sb shows enhanced electron/ion transfer rate and predominantly pseudocapacitive sodium storage behavior,delivering a reversible capacity of 219 m Ah/g at 0.5 A/g even after 1000 cycles.More significantly,this method may be commonly used to incorporate other alloy-based high-theoretical materials into MIL-125-derived TiO_(2)@C,which is promising for developing high-energy-density TiO_(2)-based energy storage devices.

Understanding and quantifying capacity loss in storage aging of Ah-level Li metal pouch cells

Promoting industry applications of high-energy Li metal batteries(LMBs)is of vital importance for accelerating the electrification and decarbonization of our society.Unfortunately,the time-dependent storage aging of Ah-level Li metal pouch cells,a ubiquitous but crucial practical indicator,has not yet been revealed.Herein,we first report the storage behaviors and multilateral synergistic aging mechanism of Ah-level NCM811jjLi pouch cells during the 120-day long-term storage under various conditions.Contrary to the conventional belief of Li-ion batteries with graphite intercalation anodes,the significant available capacity loss of 32.8%on average originates from the major electrolyte-sensitive anode corrosion and partial superimposed cathode degradation,and the irreversible capacity loss of 13.3%is essentially attributed to the unrecoverable interface/structure deterioration of NCM with further hindrance of the aged Li.Moreover,principles of alleviating aging have been proposed.This work bridges academia and industry and enriches the fundamental epistemology of storage aging of LMBs,shedding light on realistic applications of high-energy batteries.