Approximately one fifth of the world's plants are at risk of extinction.Of these,a significant number exist as populations of few individuals,with limited distribution ranges and under enormous pressure due to hab...Approximately one fifth of the world's plants are at risk of extinction.Of these,a significant number exist as populations of few individuals,with limited distribution ranges and under enormous pressure due to habitat destruction.In China,these most-at-risk species are described as 'plant species with extremely small populations'(PSESP).Implementing conservation action for such listed species is urgent.Storing seeds is one of the main means of ex situ conservation for flowering plants.Spore storage could provide a simple and economical method for fern ex situ conservation.Seed and spore germination in nature is a critical step in species regeneration and thus in situ conservation.But what is known about the seed and spore biology(storage and germination) of at-risk species? We have used China's PSESP(the first group listing) as a case study to understand the gaps in knowledge on propagule biology of threatened plant species.We found that whilst germination information is available for 28 species(23%of PSESP),storage characteristics are only known for 8%of PSESP(10 species).Moreover,we estimate that 60%of the listed species may require cryopreservation for long-term storage.We conclude that comparative biology studies are urgently needed on the world's most threatened taxa so that conservation action can progress beyond species listing.展开更多
Aims The physiological responses during dormancy removal and multi-phasic germination were investigated in seeds of Paeonia corsica(Paeoniaceae).Methods Seeds of P.corsica were incubated in the light at a range of tem...Aims The physiological responses during dormancy removal and multi-phasic germination were investigated in seeds of Paeonia corsica(Paeoniaceae).Methods Seeds of P.corsica were incubated in the light at a range of temperatures(10-25 and 25/10℃),without any pre-treatment,after W(3 months at 25℃),C(3 months at 5℃)and W+C(3 months at 25℃followed by 3 months at 5℃)stratification,and a GA_(3)treatment(250 mg·l^(−1)in the germination substrate).Embryo growth,time from testa to endosperm rupture and radicle emergence were assessed as separate phases.Epicotyl-plumule emergence was evaluated incubating the germinated seeds at 15℃for 2 weeks,at 5 and 25℃for 2 months on agar water before transplanting to the soil substrate at 10,15 and 20℃and at 15℃for 2 months on the surface agar water with GA_(3).Important Findings Embryo growth,testa rupture,endosperm rupture(radicle emergence)and growth of the epicotyl were identified as four sequential steps in seeds of P.corsica.Gibberellic acid alone and warm stratification followed by 15℃promoted embryo growth and subsequent seed germination.Cold stratification induced secondary dormancy,even when applied after warm stratification.After radicle emergence,epicotyl-plumule emergence was delayed for ca.3 months.Mean time of epicotyl-plumule emergence was positively affected by cold stratification(2 months at 5℃)and GA_(3).P.corsica seeds exhibited differential temperature sensitivity for the four sequential steps in the removal of dormancy and germination processes that resulted in the precise and optimal timing of seedling emergence.展开更多
基金Funding (No. U1302262) to W.B. Sun from the NSFC-Yunnan joint fund on key projects is gratefully acknowledgedThe Royal Botanic Gardens, Kew receives grant-in-aid from Defra+1 种基金This joint work was undertaken under the Memorandum of Agreement (2014e24) on Plant and Fungal Science between the Chinese Academy of Sciences and the Trustees of the Royal Botanic Gardens, KewHWP thanks Darwin Initiative Project 21-003 on cycads for funding
文摘Approximately one fifth of the world's plants are at risk of extinction.Of these,a significant number exist as populations of few individuals,with limited distribution ranges and under enormous pressure due to habitat destruction.In China,these most-at-risk species are described as 'plant species with extremely small populations'(PSESP).Implementing conservation action for such listed species is urgent.Storing seeds is one of the main means of ex situ conservation for flowering plants.Spore storage could provide a simple and economical method for fern ex situ conservation.Seed and spore germination in nature is a critical step in species regeneration and thus in situ conservation.But what is known about the seed and spore biology(storage and germination) of at-risk species? We have used China's PSESP(the first group listing) as a case study to understand the gaps in knowledge on propagule biology of threatened plant species.We found that whilst germination information is available for 28 species(23%of PSESP),storage characteristics are only known for 8%of PSESP(10 species).Moreover,we estimate that 60%of the listed species may require cryopreservation for long-term storage.We conclude that comparative biology studies are urgently needed on the world's most threatened taxa so that conservation action can progress beyond species listing.
基金The National Basic Research Programme of China(973Programme,2007CB411600)the Ministry of Science and Technology of China(2005DKA21006)the Millennium Seed Bank Project of the Royal Botanic Gardens,Kew,UK,which receives grant-in-aid from the DEFRA,UK
基金Sardinia Regional Government:financial support of Marco Porceddu PhD scholarship(P.O.R.Sardegna F.S.E.Operational Programme of the Autonomous Region of Sardinia,European Social Fund 2007-2013-Axis IV Human Resources,Objective l.3,Line of Activity l.3.1.)supported by Ente Foreste della SardegnaThe Royal Botanic Gardens,Kew,receives grant in-aid from Defra,UK.
文摘Aims The physiological responses during dormancy removal and multi-phasic germination were investigated in seeds of Paeonia corsica(Paeoniaceae).Methods Seeds of P.corsica were incubated in the light at a range of temperatures(10-25 and 25/10℃),without any pre-treatment,after W(3 months at 25℃),C(3 months at 5℃)and W+C(3 months at 25℃followed by 3 months at 5℃)stratification,and a GA_(3)treatment(250 mg·l^(−1)in the germination substrate).Embryo growth,time from testa to endosperm rupture and radicle emergence were assessed as separate phases.Epicotyl-plumule emergence was evaluated incubating the germinated seeds at 15℃for 2 weeks,at 5 and 25℃for 2 months on agar water before transplanting to the soil substrate at 10,15 and 20℃and at 15℃for 2 months on the surface agar water with GA_(3).Important Findings Embryo growth,testa rupture,endosperm rupture(radicle emergence)and growth of the epicotyl were identified as four sequential steps in seeds of P.corsica.Gibberellic acid alone and warm stratification followed by 15℃promoted embryo growth and subsequent seed germination.Cold stratification induced secondary dormancy,even when applied after warm stratification.After radicle emergence,epicotyl-plumule emergence was delayed for ca.3 months.Mean time of epicotyl-plumule emergence was positively affected by cold stratification(2 months at 5℃)and GA_(3).P.corsica seeds exhibited differential temperature sensitivity for the four sequential steps in the removal of dormancy and germination processes that resulted in the precise and optimal timing of seedling emergence.
