Soil seed bank and seed dormancy in wild populations of lima bean (Fabaceae): considerations for in situ and ex situ conservation

The soil seed bank in a 5-y-old Sahelian fallow was studied through seed extraction and compared with germinations recorded either in controlled conditions, ex situ in a glasshouse, or in the field. The influence of phosphorus fertilizer and mulch application during the preceding crop period, and that of seasonal grazing regimes applied the last 2 y of fallowing, were assessed on the composition of the seed stock. Ctenium elegans, Fimbristylis hispidula, Merremia pinnata and Phyllanthus pentandrus accounted together for 75% of extracted seeds, 72% of ex situ, and 62% of in situ seedlings. Mulch treatment was correlated with the first axis of the canonical correspondence analyses performed on the seedling datasets. Mulch and phosphorus fertilizer treatments held similar responses, as they both favoured the seed bank of erect dicotyledons such as P. pentandrus and Cassia mimosoides. On the whole, the effects of grazing remained modest compared with the residual effects of past crop management practices. However, seedling densities increased as a result of dry-season grazing, while the soil seed bank decreased with wet-season grazing. Grazing also reduced the spatial heterogeneity of the seed bank rather than the overall number of species.

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Longevity of seeds and soil seed bank of the Cerrado tree Miconia chartacea (Melastomataceae)

Seed Science Research ◽

10.1017/s0960258515000173 ◽

2015 ◽

Vol 25 (4) ◽

pp. 386-394 ◽

Cited By ~ 3

Author(s):

Diego F. Escobar E. ◽

Victor J. M. Cardoso

Keyword(s):

Seed Bank ◽

Low Temperatures ◽

Rainy Season ◽

Storage Time ◽

Soil Seed Bank ◽

High Water ◽

Ex Situ ◽

High Water Content ◽

Storage Test

AbstractMiconia chartacea is a widely distributed tree in Brazil, occurring at altitudes ranging from 300 m to 1900 m in the Caatinga, Cerrado and Atlantic Forest biomes. In this work we attempted to classify M. chartacea seeds regarding their behaviour during storage and their germination syndrome and to determine, from a storage test in Cerrado soil and laboratory conditions in situ and ex situ, the longevity of seeds, as well as the capacity of the species to form a soil seed bank. The results suggested that M. chartacea seeds form a transient soil seed bank in the Cerrado and can be classified as orthodox in terms of storage behaviour, although the seeds are dispersed with a relatively high water content. The life span of seeds was favoured in soil-stored seeds in comparison with dry storage at 25°C, whereas storage at low temperatures prevented a decrease of the seed's germinability with storage time (330 d). M. chartacea seeds are dispersed during the dry season and germinate during the next rainy season, which can be classified as an intermediate–dry germination syndrome. Seeds of this species are dispersed in the Cerrado when temperatures and soil moisture are relatively low, which favours the formation of a soil seed bank, considering that the seeds tolerate desiccation and their longevity is favoured by low temperatures. A transient seed bank type is favoured by the loss of viability in storage at warm temperatures linked to the rainy season, and the predictable seasonal variations in climate in the region, with germination being restricted to the beginning of the rainy season.

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Status of the Ex Situ and In Situ Conservation of Brazilian Crop Wild Relatives of Rice, Potato, Sweet Potato, and Finger Millet: Filling the Gaps of Germplasm Collections

Agronomy ◽

10.3390/agronomy11040638 ◽

2021 ◽

Vol 11 (4) ◽

pp. 638

Author(s):

Marcelo B. Medeiros ◽

José F. M. Valls ◽

Aluana G. Abreu ◽

Gustavo Heiden ◽

Suelma Ribeiro-Silva ◽

...

Keyword(s):

Finger Millet ◽

Ex Situ Conservation ◽

Gap Analysis ◽

In Situ Conservation ◽

Germplasm Collection ◽

Crop Wild Relatives ◽

Wild Relatives ◽

Ex Situ ◽

The Status

This study presents the status of ex situ and in situ conservation for the crop wild relatives of rice, potato, sweet potato, and finger millet in Brazil, and the subsequent germplasm collection expeditions. This research is part of a global initiative entitled “Adapting Agriculture to Climate Change: Collecting, Protecting, and Preparing Crop Wild Relatives” supported by the Global Crop Diversity Trust. Species of the primary, secondary, and tertiary gene pools with occurrences reported in Brazil were included: Oryza alta Swallen, O. grandiglumis (Döll) Prod., O. latifolia Desv., O. glumaepatula Steud., Eleusine tristachya (Lam.) Lam., E. indica (L.) Gaertn., Solanum commersonii Dunal, S. chacoense Bitter, Ipomoea grandifolia (Dammer) O’Donell, I. ramosissima (Poir.) Choisy, I. tiliacea (Willd.) Choisy, I. triloba L., and I. cynanchifolia Meisn. The status of the ex situ and in situ conservation of each taxon was assessed using the gap analysis methodology, and the results were used to plan 16 germplasm collection expeditions. Seeds of the collected material were evaluated for viability, and the protocols for seed germination and cryopreservation were tested. The final conservation score, resulting from the gap analysis and including the average of the ex situ and in situ scores, resulted in a classification of medium priority of conservation for all the species, with the exception of I. grandifolia (high priority). The total accessions collected (174) almost doubled the total accessions of these crop wild relatives incorporated in Embrapa’s ex situ conservation system prior to 2015. In addition, accessions for practically absent species were collected for the ex situ conservation system, such as Ipomoea species, Eleusine indica, and Solanum chacoense. The methods used for dormancy breaking and low temperature conservation for the Oryza, Eleusine, and Ipomoea species were promising for the incorporation of accessions in the respective gene banks. The results show the importance of efforts to collect and conserve ex situ crop wild relatives in Brazil based on previous gap analysis. The complementarity with the in situ strategy also appears to be very promising in the country.

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Floristic diversity of the soil weed seed bank in a rice-growing area of Brazil: in situ and ex situ evaluation

Acta Botanica Brasilica ◽

10.1590/s0102-33062013000300001 ◽

2013 ◽

Vol 27 (3) ◽

pp. 465-471 ◽

Cited By ~ 6

Author(s):

Mário Luiz Ribeiro Mesquita ◽

Leonaldo Alves de Andrade ◽

Walter Esfrain Pereira

Keyword(s):

Seed Bank ◽

Ex Situ ◽

Floristic Diversity ◽

Weed Seed

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Conservation and Change: A Comparison of In situ and Ex situ Conservation of Jala Maize Germplasm

Crop Science ◽

10.2135/cropsci2005.06-0116 ◽

2006 ◽

Vol 46 (1) ◽

pp. 428-436 ◽

Cited By ~ 19

Author(s):

Elizabeth B. Rice ◽

Margaret E. Smith ◽

Sharon E. Mitchell ◽

Stephen Kresovich

Keyword(s):

Ex Situ Conservation ◽

Ex Situ ◽

Maize Germplasm

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In Situ and Ex Situ Conservation of Coconut Genetic Resources

Coconut Biotechnology: Towards the Sustainability of the ‘Tree of Life’ ◽

10.1007/978-3-030-44988-9_4 ◽

2020 ◽

pp. 51-75

Author(s):

Roland Bourdeix ◽

Steve Adkins ◽

Vincent Johnson ◽

Lalith Perera ◽

Sisunandar

Keyword(s):

Genetic Resources ◽

Ex Situ Conservation ◽

Ex Situ

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Ex situ conservation of genetic resources of field elm (Ulmus minor Mill) and European white elm (Ulmus laevis Pall)

Genetika ◽

10.2298/gensr0403221a ◽

2004 ◽

Vol 36 (3) ◽

pp. 221-227

Author(s):

Jelena Aleksic ◽

Sasa Orlovic

Keyword(s):

Genetic Resources ◽

Ex Situ Conservation ◽

Ex Situ ◽

In Vitro Production ◽

Ulmus Minor ◽

Conservation Of Genetic Resources ◽

Ulmus Laevis ◽

Vitro Production

Principles of the conservation of genetic resources of elms (Ulmus spp) do not differ fundamentally from the general principles accepted for the conservation of genetic resources of other common Noble Hardwoods. Efficient conservation can best be achieved through appropriate combination of in situ and ex situ methods, which have distinct advantages. Besides that, ex situ conservation is employed when emergency measures are needed for rare endangered populations and when populations are too small to be managed in situ (e.g. risks of genetic drift and inbreeding). The aim of our research is ex situ conservation of genetic resources of field elm {Ulmus minor Mill) and European white elm (Ulmus laevis Pall) through establishment of field genebanks. Sampling was conducted in one population of field elm and one population of white elm. Plant material (buds) from 8 trees of field elm and 10 trees of white elm was used for in vitro production of clones. Obtained clones will be used for establishment of field genebanks on the experimental estate of the Institute of Lowland Forestry and Environment.

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