Sugar beet seeds of three varieties (Jastra, Jamira, PNMono1) were rubbed, primed, washed and primed after rubbing. All used methods of seed treatment changed pericarp characteristics such as water potential, density, moisture and content of chemicals resulting in electrical conductivity of water extract from the seeds. Seed treatments also improved the ability and rate of germination. Their efficiency was more significant in an excess and shortage of water in germination medium than in optimum water conditions. The lower the initial seed vigour, the larger the vigour improvement. Seed priming had the best effect on the course of germination. Primed seeds were most resistant to different moisture conditions during germination. The largest differences in germination ability after four days in different water conditions were 5.1 and 7.4% for primed and primed after rubbing seeds, respectively, while the difference for control ones was 26.8%. Priming also caused an increase in seed respiration intensity. Rubbing and washing removed chemicals from the pericarp, which resulted in an increase in water potential, and consequently in vigour improvement.Keywords: sugar beet; seeds; germination; vigour; treatment; priming; washing; rubbingThe introduction of monogerm sugar beet varieties and drilling to stand had a catastrophic influence on the plant population through poor establishment. Accordingly, an improvement of the course of germination and field emergence was necessary.A series of experiments was conducted to evaluate the effectiveness of different technologies of pre-sowing treatment of three sugar beet varieties differing in their ploidy level. There was also an attempt to explain the results of seed treatments. This study tries to explain how some fruit properties affect germination and field emergence.Pericarp and botanical seed characteristics determine the properties of sugar beet fruit. The pericarp consists of three layers: the two inner ones consist of thick-wall sclereids containing crystals of salts. In the presence of water they form an osmotic solution which has a low water potential. Just before radicle emergence the level of the water potential of seed pericarp is about -1.0 MPa. If this level is achieved faster, seed germination will be faster (Podlaski and Chrobak 1997) The process of rubbing removes the most porous, outer layer of parenchyma resulting in an increase in pericarp density and removal of a part of chemicals. Similar effects can be obtained by seed washing.In the last years seed companies have exerted an enormous pressure on researchers to develop new, effective technologies of seed quality improvement, especially seed priming. Priming consists in wetting seeds to the moisture level that enables early processes leading to germination but is too low for radicles to emerge. It is obvious that priming changes mostly the properties of botanical seed. In 2002 primed seeds were sown on 30% of the area under sugar beet in Great Britain. As a result an improvement of germination and ...

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Endophytes produce a wide range of compounds with high application potential, mainly in medicine and agriculture. In this study, we test the hypothesis that endophytic bacteria produce indole-3-acetic acid (IAA), have positive influence on plant root development and are possible to application as plant-growth promoters. Endophytic bacteria were isolated from 3 native growing plant species: Chelidonium majus L., Elymus repens L., Solidago gigantea L. All endophytic strains produced IAA and the highest levels of IAA were observed for Pseudomonas azotoformans P3 strain. Triticale seed bacterization did not affect the seed germination, but had significant influence on root length and the longest roots were obtained after seed treatment with Pseudomonas sp. strains. Triticale roots were longer only in seedlings grown from seeds treated with endophytic strains producing high IAA levels (more than 22 µg ml -1 ). Our results suggest that endophytic Pseudomonas sp. strains isolated from Elymus repens L. can be used as plant-growth promoter.