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1

Jak przedluzyc piekno cietych kwiatow

100%

Lukaszewska A. J.

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nr 07

33-34

2

High temperatures applied at fall forcing disturb ovule development in Syringa vulgaris L. "Mme Florent Stepman"

84%

Jedrzejuk A. , Lukaszewska A. J.

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nr 5

EN

Under natural conditions, Syringa vulgaris blooms in May but it may be forced to produce blooming panicles in autumn, winter and early spring. To break winter dormancy, plants require high temperatures, the range of which depends on the forcing date. Forcing in November requires exposure to temperatures of ~37C. Such an exposure may affect the development of both male and female flower organs. In this work we have followed the anatomical changes in the ovule development in buds collected from plants forced in autumn, and compared them to those in plants blooming under natural conditions in May. From the earliest identifiable stages, in flowers forced in November the ovule development was delayedrelative to the normal development pattern. Ultimately, most of the ovules (83%) degenerated before the differentiation of the embryo sacs was completed. We believe that it is the high temperatures required during autumn forcing that affect the development of female gametophytes, leading to the formation of defective structures which often degenerate. This in turn may reduce the esthetic appeal of the inflorescences and reduce their commercial value.

3

Troche wiosny zima

83%

Lukaszewska A. J.

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nr 01

12-13

4

Drought response of two bedding plants

67%

Chylinski W. K. , Lukaszewska A. J. , Kutnik K.

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nr 5

EN

Bedding plants are an important part of the urban public space and private gardens. However, they are not always properly watered and suffer from drought stress, especially when grown in containers. In this trial a response to water stress of two commonly used species, impatiens (Impatiens walleriana Hook) and geranium (Pelargonium hortorum L. H. Bailey) were compared. The former is highly herbaceous and prone to wilting whereas the latter has hairy leaves and is better adapted to drought. Plants were grown at three levels of soil water content (SWC): 80% (control), 60% (mild stress) and 30% (severe stress). Drought was maintained during three 10 day cycles, separated by 10 day periods of normal watering. In both species roots were significantly longer in plants grown at 30% SWC as compared to 80% SWC while plant height and flower number were reduced by drought only in impatiens. The initial relative water content (RWC) was lower in geranium and decreased less in response to drought than in impatiens. Ammonium content in leaves of both species increased significantly under stress but the ranges of increase were different in both species. There was a significant increase in the free amino acids content in leaves of impatiens as compared to geranium but this rise was more time than drought dependent. The reduction in the a + b chlorophyll concentration in leaves of impatiens was significantly time and stress dependent while no reaction in geranium was observed. The above results show that changes in leaf RWC merit further attention as a possible indicator of plant response to drought stress in ornamental plants but additional studies are needed before this or other parameters can be used to evaluate new bedding plants for introduction into urban growing conditions, or as selection criteria in breeding for adaptation to demanding growing conditions.

5

Senescence of cut leaves of Zantedeschia aethiopica and Z. elliottiana. Part I. Chlorophyll degradation

67%

Skutnik E. , Rabiza-Swider J. , Wachowicz M. , Lukaszewska A. J.

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tom 03

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nr 2

EN

Chlorophyll degradation occurring during leaf senescence in under control of plant hormones. Changes in the chlorophyll content and the effects of BA (benzyladenine) and GA₃ (gibberellic acid) on this process were analyzed during senescence of cut leaves of Zantedeschia aethiopica Spr. and Zantedeschia elliottiana Engl., two species grown for the florists’ green. Both growth regulators were applied as 24 h pulse treatment: 0.25 mmol·dm⁻³ and 0.1 mmol·dm⁻³ for GA₃ and BA, respectively. Gibberellic acid was more effective than benzyladenine in delaying senescence of both Zantedeschia species leaves by retarding chlorophyll loss. A standard preservative solution used to prolong longevity of cut flowers (8-HQC /citrate of hydroxyquinoline/ +2% S /sucrose/) radically accelerated chlorophyll loss of Z. aethiopica leaves but had no effect on pigment degradation in leaves of Z. elliottiana. However, in both species the preservative diminished the positive effect of GA₃ treatment on final chlorophyll content.

PL

Degradacja chlorofilu zachodząca w trakcie starzenia się ciętych liści regulowana jest przez fitohormony. W doświadczeniach analizowano zmiany zawartości chlorofilu w trakcie starzenia się ciętych liści dwóch gatunków stosowanych jako zieleń cięta (Zantedeschia aethiopica Spr. i Zantedeschia elliottiana Engl.) i wpływ BA (benzyloadeniny) i GA₃ (kwasu giberelinowego) na ten proces. Roztwory obu regulatorów wzrostu aplikowano w formie 24-godzinnego kondycjonowania (BA – 0,1 mmol·dm⁻³; GA₃ –0,25 mmol·dm⁻³). Kwas giberelinowy okazał się skuteczniejszy od benzyloadeniny w opóźnianiu rozkładu chlorofilu w przypadku obu gatunków, zwiększając tym samym ich trwałość. Pożywka standardowa, używana w celu przedłużenia pozbiorczej trwałości ciętych kwiatów, (8-HQC /cytrynian 8-hydroksychinoliny/ + 2% S /sacharoza/) istotnie przyspieszyła degradację chlorofilu w ciętych liściach Z. aethiopica, nie mając jednocześnie wpływu w przypadku Z. elliottiana. W obu jednak przypadkach pożywka osłabiła pozytywny wpływ GA₃ na końcową zawartość chlorofilu.

6

Zastosowanie STS w produkcji roslin ozdobnych

67%

Lukaszewska A. J.

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nr 2

29-30