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This study aims to gain insights into the allelopathic effects (by using leaf extracts) of the notorious invasive Solidago canadensis L. on seed germination of the associated Pterocypsela laciniata (Houtt.) C. Shih under different nitrogen (N) forms added: inorganic (NO3--N and NH4 -N), organic (urea-N), and mixed N (a mixture of the three N forms at 1:1:1 ratio). Among the two used concentrations of S. canadensis leaf extracts the higher exhibited inhibitory allelopathic effects on seedling height and biomass, germination potential, germination index, and vigor index of P. laciniata. N demonstrated positive effects on seed germination of P. laciniata. The effects of mixed and organic N on the seedling biomass of P. laciniata were more pronounced than those of inorganic N and control treatment. The vigor index of P. laciniata under mixed N was significantly higher than those under single N form and control treatment. Thus, organic and mixed N showed higher ecological effects on seed germination of P. laciniata than inorganic and single N form. All N forms could alleviate the inhibitory allelopathic effects of S. canadensis on seed germination of P. laciniata. Overall, the inhibitory allelopathic impact of S. canadensis on seed germination of native species may be attenuated under increased and diverse N deposition, thus it could prevent its further invasion.
In the present investigation the seeds of Pigeon pea (Cajanus cajan (L.) Millsp) were treated with different doses of gamma radiation (05KR, 10KR, 15KR, 20KR, 25KR, 30KR, 35KR, 40KR, 45KR, and 50KR) and concentration of Ethyl Methane Sulphonate (05mM, 10mM, 15mM, 20mM, 25mM, 30mM, 35mM, 40mM, 45mM, and 50mM) for studying seed germination, seedling height, (shoot and root), seedling injury, seedling vigour index, and seedling survival of plants at 30th day. The seed germination percentage was decreased with increased in the concentration/doses when compared to control. The LD50 (Lethal dose) value was determined based upon the seed germination percentage. The 50 percentage of seed germination and reduction was observed in 20KR of gamma rays and 25mM of EMS and it is considered as LD50 value for both the treatments. The decrease in seed germination was more prominent with gamma rays than that of EMS treatments. The seedling parameters of gamma rays and EMS treated seedlings were progressively decreased with increase dose/concentration in all mutagenic treatments when compared to control. The maximum seedling parameters were observed in 05KR of gamma rays and 05mM of EMS. Minimum seedling parameters were observed in 50mM of EMS and 50KR of gamma rays respectively.
Germination of flax seeds (Linum usitatissimum L., cv. Szafir) at 5oC was enhanced by continuous white light, gibberellin A3 (GA3), kinetin and benzylaminopurine. GA3 and kinetin at physiological concentrations (10-8-10-6 M) improved significantly germination in darkness. Stimulatory effect of benzylaminopurine was visible only in the light. Almost no effect of zeatin and isopentenyladenine (2iP) on germination was observed. Possible causes of this differences were suggested.
Milk thistle (Silybum marianum (L.) Gaertn.) is an important medicinal plant. Achenes of milk thistle contain sylimarin, protecting liver cells against toxic compounds. The aim of the research was to find an optimum method of evaluation of milk thistle seed germination. Ten seed samples were tested. The seeds were germinated: on top of blotter paper, on top of blotter paper after seed disinfection, between pleated blotter paper, in rolled blotter paper and in sand. Germination at the first and final counts, the percentages of abnormal seedlings and dead seeds were determined. The correlation coefficients between seed germination, evaluated with various methods, and seedling emergence were calculated. Moreover, fungi associated with seeds and diseased seedlings were identified. The lowest percentage of normal seedlings was observed after germination on the top of blotter. Highly significant positive correlations were noted between seedling emergence and seed germination at the final count evaluated in rolled paper, between pleated paper and in sand. The fungi from genera:Alternaria, Fusarium, Penicillium, Trichoderma, Ulocladium and Verticillium were frequently identified on seeds and seedlings. Infestation with fungi significantly affected milk thistle seed germination and plant emergence. Germination in rolled blotter paper may be recommended for evaluation of milk thistle seed germination, as the most practical and significantly correlated with seedling emergence.
Submerged aquatic vegetation (SAV) is often difficult to restore due to their low seedling survival rates. Therefore, we hypothesized that the elodeid macrophytes serve as effective “nursery” areas to promote success for seedlings of other SAV. However, the high density of the elodeid community may inhibit the establishment of other SAV. An experiment was conducted to explore this “nursery effect” as a restoration approach to increase the success of seed restoration. Two elodeid species were pre-planted into mesocosms to create three levels of “nursery beds” i.e., bare, sparse (approx. 100 g m⁻²) and dense (approx. 200 g m⁻²). Seeds of Vallisneria spiralis were then placed into these beds to test the seed germination and growth of V. spiralis seedlings. After three months, seed germination was lower in the bare treatment than in the sparse and dense treatments. The growth of V. spiralis seedlings was greater in the sparse treatment than in the bare and dense treatments. These results revealed that the established elodeid bed had a positive effect on the seed restoration of V. spiralis but that the restoration efficiency was significantly reduced by the high-density cover of the elodeid community.
Laser stimulation is a non-expensive and environmentally safe way of the improving of seeds quality. The objective of the study was to determine the effect of He-Ne laser irradiation on the germination parameters of scorzonera seeds. Seeds were characterized with different quality expressed by germination capacity. Experimental material consisted of 4 lots of scorzonera seeds having initial germination capacity between 50.8 and 93.0%. Seeds were treated with laser He-Ne light of surface power density of 3 mW·cm-2 and the time of exposition of 0 (control), 1, 5, 10 and 30 minutes. After pre-sowing stimulation of seeds the following parameters were estimated: germination energy, germination capacity, mean germination time, speed of germination, hypocotyl length, length of radicle, fresh and dry weight of seedling, field emergence, mean emergence time and speed of emergence. Pre-sowing laser treatment resulted in increasing of the several parameters such as germination energy, germination capacity, speed of germination, hypocotyl and radicle length, as well as fresh and dry weight of seedlings. Laser light stimulation was the most effective in the case of low quality seeds (initial germination capacity of 50.8%). Irradiation of the seeds belonging to this group also resulted in the increase of the seedling emergence and the speed of emergence.
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Astragalus penduliflorus Lam. is an alpine-subalpine species. Several isolated populations occur in Europe: in the Alps, Pyrenees, Carpathians and in central Sweden. Astragalus penduliflorus is considered as critically endangered species in Poland, growing only at the locality in the Smytnia Valley, in the Western Tatra Mountains. The population is at risk, due to the limited reproduction caused by law rate of seed germination, periodically shortened vegetation period that prevent seed development and gnawing the aerial plant parts by deer. The aim of the study was to explain the reason for the poor germination of A. penduliflorus seeds. As a result of mechanical scarification, 100% of A. penduliflorus seeds germinated, which proved that these seeds are characterized by a water-impermeable seed coat, which classified them as hard seeds that go through physical dormancy. Results obtained in this work can be used for effective reproduction and active conservation of threatened A. penduliflorus.
Vicia hirsuta (L.) Gray S.F. (tiny vetch) is a common and persistent segetal weed. Tiny vetch seeds and pods reach different stages of maturity during the crop harvest season. Some seeds that mature before cereal harvest are shed in the field and deposited in the soil seed bank, while others become incorporated into seed material. The objective of this study was to describe selected aspects of tiny vetch seed ecology: to determine the rate of individual reproduction of vetch plants growing in winter and spring grain crops and to evaluate the germination of seeds at different stages of maturity, subject to storage conditions. The seeds and pods of V. hirsuta were sorted according to their development stages at harvest and divided into two groups. The first group was stored under laboratory conditions for two months. In the autumn of the same year, the seeds were subjected to germination tests. The remaining seeds were stored in a storeroom, and were planted in soil in the spring. The germination rate was evaluated after 8 months of storage. Potential productivity (developed pods and flowers, fruit buds) was higher in plants fruiting in winter wheat than in spring barley. Vetch plants produced around 17-26% more pods (including cracked, mature, greenish-brown and green pods) and around 25% less buds in winter wheat than in spring barley. Immature seeds were characterized by the highest germination capacity. Following storage under laboratory conditions and stratification in soil, mature seeds germinated at a rate of several percent. After storage in a storeroom, seeds at all three development stages broke dormancy at a rate of 72- 75%. The high germination power of tiny vetch seeds stored in a storeroom indicates that this plant can be classified as an obligatory speirochoric weed species.
In the years 2011-2012, thirteen cultivars and breeding lines of Chinese origin adzuki bean (Phaseolus angularis W.H. White) were evaluated for their selected breeding characters and seed protein content in the climatic conditions of Central Europe. In the field experiment, the evaluation included seedlings emergence, number of pods per plant, number of seeds per pod and plant health status. In the laboratory research, the assessments included seed germination as well as seed dry matter and total protein contents. In Western Poland climatic conditions, it was possible to produce seeds of adzuki bean. However, in cold and wet years, they did not set seeds. The tested materials differed in plant emergence, earliness, number of pods per plant, number of seeds per pod and plant health status. The produced seeds had germination capacity from 0 to 54% and no symptoms of bean weevil (Acanthoscelides obtectus Say) damage. They also had from 20.01 to 31.91% of total proteins in d. m., which proved they could be a valuable source of plant protein. Amongst the evaluated materials, one breeding line (marked with the letter J) turned out to be the best, whereas the other one (marked Z1) was also interesting for further breeding work.
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