Physically, physiologically and conceptually hidden: Improving the description and communication of seed persistence

AbstractSeed size is a good predictor of seed persistence in soil for British, Argentinean, Iranian and – to some extent – New Zealand species. It has been suggested that seed shape should also be linked to the ease of burial and, thus, to seed persistence, even if some studies failed to show this. The relationship between seed size and shape and persistence in soil was analysed for 259 species of the Italian flora, belonging to a wide range of habitats, from alpine pasture to limestone prairies and meadows of the Prealps, and from woodlands to Mediterranean maquis and garigues. Seed size was related to persistence in soil in the same way as in most other floras examined. Furthermore, seed shape was highly related to persistence in soil among the species analysed, when considered both altogether and divided among the different habitats. Our results suggest that not only seed size, but also seed shape, are key factors in determining seed fate and seed persistence in soil.

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Gamba grass (Andropogon gayanus Kunth.) seed persistence and germination temperature tolerance

The Rangeland Journal ◽

10.1071/rj17125 ◽

2018 ◽

Vol 40 (5) ◽

pp. 463 ◽

Cited By ~ 1

Author(s):

Faiz F. Bebawi ◽

Shane D. Campbell ◽

Robert J. Mayer

Keyword(s):

Seed Viability ◽

Temperature Tolerance ◽

Burial Depth ◽

Soil Seed Banks ◽

Seed Persistence ◽

Dry Tropics ◽

Andropogon Gayanus ◽

Wide Range ◽

Higher Temperature ◽

National Significance

Gamba grass (Andropogon gayanus Kunth.) is a highly invasive, naturalised Weed of National Significance in Australia due to its economic, environmental and social impacts. It outcompetes native pastures and fuels intense fires in northern Australian rangelands. To aid management of current infestations and to better understand its potential distribution, this study determined the germination response of gamba grass under a range of constant (13°C−48°C) and alternating (11/7°C–52/42°C) temperature regimes and quantified the potential longevity of soil seed banks. The effect of different soil types, levels of pasture cover and burial depths on seed longevity was investigated in the Dry Tropics of northern Queensland. Germination of gamba grass occurred under a wide range of both constant (17°C−39°C) and alternating day/night temperatures (16/12°C–47/39°C), although the level of germination declined at the lower and higher temperature ranges. At the cooler temperatures, seed viability was not affected, but seeds went into a state of dormancy. The highest level of seed viability was recorded at the lowest constant temperature regime (13°C) and at the two lowest alternating temperatures (11/7°C and 16/12°C). A gradual but variable decline in viability occurred thereafter with increasing temperatures. At the higher temperature range (e.g. constant temperatures of 39°C−43°C and alternating temperatures of 47/39°C) both dormancy and loss of seed viability were occurring, but once alternating and constant temperatures reached above 47/39°C and 43°C all seeds were rendered unviable after 9 and 6 weeks respectively. In the Dry Tropics of northern Queensland, viability of seeds was <1% after 12 months and nil after 24 months, irrespective of soil type or vegetation cover. However, burial depth had a significant effect, with surface located seeds exhibiting a faster rate of decline in germination and viability than seeds buried below ground (i.e. 2.5–10 cm). These findings have implications for the duration of control/eradication programs (i.e. seed persistence) and also suggest that gamba grass has the potential to greatly expand its current distribution into the relatively cooler southern latitude areas of Australia.

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Factors determining seed persistence of Chondrilla juncea L. (skeleton weed) in southern Western Australia

Austral Ecology ◽

10.1111/j.1442-9993.1988.tb00969.x ◽

1988 ◽

Vol 13 (2) ◽

pp. 211-224 ◽

Cited By ~ 10

Author(s):

F. D. PANETTA

Keyword(s):

Western Australia ◽

Seed Persistence ◽

Chondrilla Juncea

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Seed persistence of three species, Carex stricta, Carex hystericina and Phalaris arundinacea, in a restored wetland

Flora ◽

10.1016/j.flora.2021.151971 ◽

2021 ◽

pp. 151971

Author(s):

Julia L. Bohnen ◽

Susan M. Galatowitsch ◽

Laura G. Perry

Keyword(s):

Phalaris Arundinacea ◽

Restored Wetland ◽

Carex Stricta ◽

Seed Persistence ◽

Carex Hystericina

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Natural Far Red Irradiation and Weed Seed Persistence in the Soil

Basic and Applied Aspects of Seed Biology - Current Plant Science and Biotechnology in Agriculture ◽

10.1007/978-94-011-5716-2_33 ◽

1997 ◽

pp. 297-302

Author(s):

A. Doroszewski

Keyword(s):

Weed Seed ◽

Seed Persistence

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Seedbank persistence and emergence pattern of Argemone mexicana, Rapistrum rugosum and Sonchus oleraceus in the eastern grain region of Australia

Scientific Reports ◽

10.1038/s41598-021-97614-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sudheesh Manalil ◽

Bhagirath Singh Chauhan

Keyword(s):

Surface Layer ◽

Winter Season ◽

Seed Viability ◽

Annual Rainfall ◽

Argemone Mexicana ◽

Emergence Pattern ◽

Seed Persistence ◽

Rapistrum Rugosum ◽

Persistence Behavior ◽

Mesh Bag

AbstractA thorough understanding of the emergence pattern and persistence of weed seeds is a prerequisite in framing appropriate weed management options for noxious weeds. In a study conducted at the University of Queensland, Australia, the emergence and seed persistence behavior of three major weeds Sonchus oleraceous, Rapistrum rugosum, and Argemone mexicana were explored with seeds collected from Gatton and St George, Queensland, Australia, with an average annual rainfall of 760 and 470 mm, respectively. Seed persistence was evaluated by placing seeds at the surface layer (0 cm) or buried at 2 and 10 cm depths enclosed in nylon mesh bags and examined their viability for 42 months. In another study, the emergence pattern of four populations, each from these two locations, was evaluated under a rainfed environment in trays. In the mesh-bag study, rapid depletion of seed viability of S. oleraceous from the surface layer (within 18 months) and lack of seed persistence beyond two years from 2 and 10 cm depths were observed. In trays, S. oleraceous germinated 3 months after seeding in response to summer rains and there was progressive germination throughout the winter season reaching cumulative germination ranging from 22 to 29% for all the populations. In the mesh-bag study, it took about 30 months for the viability of seeds of R. rugosum to deplete at the surface layer and a proportion of seeds (5 to 13%) remained viable at 2 and 10 cm depths even at 42 months. Although fresh seeds of R. rugosum exhibit dormancy imposed due to the hard seed coat, a proportion of seeds germinated during the summer months in response to summer rains. Rapid loss of seed viability was observed for A. mexicana from the surface layer; however, more than 30% of the seeds were persistent at 2 and 10 cm depths at 42 months. Notably, poor emergence was observed for A. mexicana in trays and that was mostly confined to the winter season.

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