Factors involved in the dormancy and germination of Capsella bursa-pastoris (L.) Medik. And Senecio Vulgaris L
TL;DR: A laboratory investigation into the dormancy and germination behaviour of the two species in relation to some of the major factors which are likely to affect seed germination in the soil.
Abstract: bute to the main bulk of the seed population are very similar. Two of the most important of these species are Capsella bursa-pastoris and Senecio vulgaris. We chose them for study in order to gain further insight into the germination characteristics which lead to the success of annual weeds in cultivated or disturbed soil. This paper describes a laboratory investigation into the dormancy and germination behaviour of the two species in relation to some of the major factors which are likely to affect seed germination in the soil. As Koller (1964) has pointed out that there are difficulties in relating petri dish experiments to field conditions. Nevertheless it is believed that laboratory studies under controlled conditions are an essential beginning to an understanding of the behaviour of seeds in response to the complex and fluctuating conditions in the field. In the second paper, an attempt will be made to relate field behaviour to the physiological responses investigated here. MATERIALS AND METHODS Source of seed Seeds were collected in Cheshire in September 1965: those of Capsella bursa-pastoris (L.) Medik. from the Experimental Grounds, Jodrell Bank, and those of Senecio vulgaris L. from Morton's Rose Nursery, Alderley Edge. They were dried to about 800 moisture content in a stream of dry air at room temperature and were then stored in Kilner jars at 4 + 20 C until needed. Occasional checks on viability and dormancy during the 2-year period of these investigations showed that there were no changes, except for a slight loss of dormancy in the case of Senecio.
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TL;DR: Researchers have known for decades that many buried seeds need to be brought to the soil surface before they will germinate, and to understand how germination of buried seeds is controlled, plant biologists have studied the re.
Abstract: The classic studies of Brenchley and Warington (1930) and numerous other investigations have demonstrated that large reserves (pools) of weed seeds accumulate in arable soils. Work reviewed by Kropad (1966) and Roberts (1981) shows that the number of seeds per m2 in the upper 15-25 cm of soil in cultivated fields may be as high as 70,000-90,000, and up to 95% of these may be contributed by annuals. Soil samples collected under vegetation of known age and history suggest that buried seeds of some weedy species may remain viable for 50100 years or more (e.g., Livingston and Allessio 1968, Oosting and Humphreys 1940). Seeds of 3 of 21 species buried in 1879 by W. J. Beal were viable after 100 years (Kivilaan and Bandurski 1981). In another experiment started by J. W. T. Duvel in 1902, buried seeds of 36 of 107 species were viable after 39 years (Toole and Brown 1946). Researchers have known for decades that many buried seeds need to be brought to the soil surface before they will germinate. To understand how germination of buried seeds is controlled, plant biologists have studied the re-
419 citations
TL;DR: The results suggest that the spread potential of C. radicans by seeds would be at least 1,400 to 2,800 seeds plant−1, however, only seeds near the soil surface would be able to germinate.
Abstract: The effects of environmental factors on germination and emergence of Campsis radicans seeds were examined in laboratory and greenhouse experiments. Campsis radicans pods produced numerous, papery, and small seeds (696 seeds/pod; 4 mg/seed). Seeds exhibited dormancy that was relieved (74% germination) after 2 wk of prechilling. Fluctuating temperatures and a 12-h photoperiod were required for maximum germination. Optimum conditions for C. radicans seed germination (74%) were 35/25 C (day/night, 12/12 h) with a 12-h photoperiod. Temperatures below 25/15 C or above 40/30 C were unfavorable for germination. Germination in constant temperatures or in continuous darkness was less than 15%. More than 59% of C. radicans seeds germinated at pH 5 to 9, but at pH 4 or 10 seed germination was totally inhibited. Germination was totally inhibited at osmotic stress higher than −0.2 MPa. Germination was 60% at 40 mM NaCl and 20% at 160 mM NaCl. Emergence was maximum (68%) for seeds that were placed on the soil s...
226 citations
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...Similar results have been reported for Scoparia dulcis (goatweed, Jain and Singh 1989), whereas prechilling overcame the light requirement in Senecio vulgaris (common groundsel, Popay and Roberts 1970)....
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TL;DR: The evidence presented here shows that ethylene performs a relatively vital role in dormancy release and seed germination of most plant species studied.
Abstract: The role of ethylene in the release of primary and secondary dormancy and the germination of non-dormant seeds under normal and stressed conditions is considered In many species, exogenous ethylene, or ethephon – an ethylene-releasing compound - stimulates seed germination that may be inhibited because of embryo or coat dormancy, adverse environmental conditions or inhibitors (eg abscisic acid, jasmonate) Ethylene can either act alone, or synergistically or additively with other factors The immediate precursor of ethylene biosynthesis, 1-aminocyclopropane-1-carboxylic acid (ACC), may also improve seed germination, but usually less effectively Dormant or non-dormant inhibited seeds have a lower ethylene production ability, and ACC and ACC oxidase activity than non-dormant, uninhibited seeds Aminoethoxyvinyl-glycine (AVG) partially or markedly inhibits ethylene biosynthesis in dormant or non-dormant seeds, but does not affect seed germination Ethylene binding is required in seeds of many species for dormancy release or germination under optimal or adverse conditions There are examples where induction of seed germination by some stimulators requires ethylene action However, the mechanism of ethylene action is almost unknown
The evidence presented here shows that ethylene performs a relatively vital role in dormancy release and seed germination of most plant species studied
190 citations
TL;DR: The limitations on the understanding of the regeneration of these plants at the present time are reviewed and the four groups of species are assessed in relation to current ideas about ‘strategies’ of plants.
137 citations
TL;DR: Assuming that biomass production is closely related to seed production, fertilizing conservation headlands will result in reduced viability of populations of rare weeds, and cessation of fertilizer inputs may be required.
124 citations
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Book•
01 Jan 1982
TL;DR: In his Friday evening discourse at the Royal Institution on November 3, Sir Arthur Hill discussed the many ingenious devices for the protection of the seed and equally ingenious arrangements for the escape of the embryo on germination, which are found in plants.
Abstract: Provides a comprehensive overview of the physiology, biochemistry and ecology of the process of seed germination. This revised edition includes extended coverage of the influence of molecular biology on seed science and a new chapter on seed technology and propagation.
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