Wyniki wyszukiwania - Biblioteka Nauki

1

Effects of altitude and leaf age on leaf shape in an alpine shrub: the relevance for the leaf area estimation model

100%

Li Q. , He X. , Huang X. , Zhang L.

Polish Journal of Ecology

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2022

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tom Vol. 70, nr 1

33--43

EN

Nondestructive methods to estimate leaf area (LA) by leaf length (L) and/or width (W) are useful in plant physiology and ecology studies. However, both environmental and ontogenic factors may influence leaf size and/or shape, which may alter the coefficient of LA models. We carried an investigation along an altitudinal gradient in the Sergyemla Mountains, southeast Tibet. In August 2009, we selected nine sites at about every 50 m in altitude from 4,250 m to 4,640 m a.s.l. A total of 4,245 different leaf-aged Rhododendron aganniphum var. schizopeplum (a dominant overstory species) leaves were measured. Compared with the single dimensional models, the two-dimensional model encompassing both L and W (model 5) reflected higher R2 (0.98–0.99) and lower MSE (1.19–3.21) across different leaf age groups for each site, implying that such model could provide the best fit for LA estimation. Analysis of covariance further illustrated that two leaf dimensions model was irrespective of leaf age effects in eight out of the nine sites. Leaf shape (L:W ratio) varied between sites and tended to decrease at higher altitudes (4500–4640 m a.s.l.), leading to significant differences in coefficients of the two-dimension model between every two adjacent sites. For overstory species in alpine habitats, altitude rather than leaf age may affect leaf shape which alters the coefficients of LA estimation models. Since leaf shape of different species (overstory species versus understory ones) may show different responses to a certain environmental gradient, researchers must pay attention to the variation of leaf shape when estimating species-specific LA by measuring L and W, especially when leaves of the top overstory species were collected at different sites.

2

Variation and correlations of leaf traits of two Taxus species with different shade tolerance along the light gradient

84%

Liu W. , Li S. , Su L. , Su J.

Polish Journal of Ecology

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2013

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tom 61

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nr 2

EN

The variations in leaf traits of Taxus species in different light conditions are still poorly understood. We sampled leaves of Taxus yunnanensis W. C. Chang L. K. Fu and Taxus chinensis var. mairei (Lemée and Lév.) W. C. Cheng and L. K. Fu along an illumination gradient (full daylight, 40–60% full daylight, <10% full daylight), and analyzed how seven leaf traits and their correlations changed under different light conditions. The leaf trait that showed the greatest variation was specific leaf area (SLA) for T. yunnanensis, followed by leaf dry mass (LM) for both taxa. The smallest variation was in leaf width (LW) for both taxa. Plasticities of all leaf traits in both taxa were higher than 50%, and those of leaf area (LA), LM and SLA were greater than 80%. The light gradient was positively correlated with leaf length (LL), LM, leaf dry matter content (LDMC), and leaf length to width ratio (LWR). LW and SLA were negatively correlated with the light gradient. Analyses of relationships among leaf traits showed that LM of T. yunnanensis, T. chinensis var. mairei and both taxa was positively correlated with LL, LW, LA, LDMC, and LWR, and negatively correlated with SLA under all light conditions. We concluded that leaf traits and their relationships were affected by light conditions.

3

Analiza genetyczna długości i szerokości liścia flagowego i podflagowego u żyta ozimego (Secale cereale L.)

51%

Kubicka H. , Dec D.

Biuletyn Instytutu Hodowli i Aklimatyzacji Roślin

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2001

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tom 218-219

351-360

PL

W pracy analizowano sposób dziedziczenia długości i szerokości liścia flagowego i podflagowego u dwóch linii wsobnych żyta ozimego (Secale cereale L.): L176 i L260 pokolenia S12, charakteryzujących się pod względem tych cech skrajnymi wartościami. W tym celu obserwowano rozszczepienie roślin w pokoleniach F1, F2 i krzyżówkach wstecznych, uzyskanych po skrzyżowaniu tych linii. W pokoleniu F1 rośliny miały długość i szerokość liścia flagowego i podflagowego pośrednią w stosunku do form rodzicielskich. Natomiast w pokoleniu F2 wystąpiło rozszczepienie wskazujące, że długość liścia flagowego i podflagowego uwarunkowana była trzema genami o addytywnym efekcie działania. Szerokość liścia flagowego i podflagowego była determinowana dwoma addytywnymi genami. Zaobserwowano, że wraz ze wzrostem wielkości liścia flagowego zwiększał się liść podflagowy.

EN

The inheritance of length and width of flag and subflag leaves was studied in two S12 generation inbred lines of winter rye (Secale cereale L). The lines (L176 and L260) showed extremally different values of the investigated leaf characters. Segregation was analysed in the F1, F2 generations and in back-cross progeny of hybrids between the lines. In comparison to the parental forms, the length and width of the flag and subflag leaves in the F1 generation was intermediate. The F2 segregation indicated determination of the character by three genes with additive effect. The width of the flag and subflag leaves was determined by two additive genes. Size of the flag leaf was positively correlated with that of the subflag one.

4

Podatnosc wiechliny lakowej na brunatna plamistosc w zaleznosci od dynamiki wzrostu roslin i szerokosci liscia w warunkach fitotronowych

51%

Czembor E.

Biuletyn Instytutu Hodowli i Aklimatyzacji Roślin

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2003

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tom 228

345-354