Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "index method" wg kryterium: Temat


Wyświetlanie 1-2 z 2
Tytuł:
What to divide leaves into ten parts for? The proposition of shape indices of leaf blade
Autorzy:
Meissner, W
Zolkos, K.
Powiązania:
https://bibliotekanauki.pl/articles/41355.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
leaf blade
roundness index
asymmetry index
leaf blade measurement
statistical method
Opis:
In this paper the method of creating indices for description leaf blade roundness and asymmetry, based on division of the leaf into 10 equal parts perpendicularly to the long axis was proposed. Along each division line the distance between the midrib and the leaf edge was measured separately for the left and right site of the blade. Sum of all 18 measurements, 9 on each side, may be treated as an index of the roundness of the leaf blade. Differences between sums of all measurements of the left and right leaf site could be a base for calculations of various asymmetry indices, including indicators of fluctuating asymmetry. Indices obtained by this method are quite sensitive and may be analysed using standard statistical methods.
Źródło:
Dendrobiology; 2008, 60; 29-33
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of phenotypic and genetic selections in Scots pine (Pinus sylvestris L.) single tree plot half-sib progeny tests
Autorzy:
Kowalczyk, J
Powiązania:
https://bibliotekanauki.pl/articles/41778.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Scotch pine
Pinus sylvestris
genetic selection
phenotypic selection
selection index
heritability
genetic gain
genetic diversity
progeny test
statistical method
Opis:
The study was carried out in three Scots pine (Pinus sylvestris L.) single tree plot half-sib progeny tests planted in 1984–86. Phenotypic selection was done in two ways: F about 0.5% to 1% of the total number of trees were chosen by the author on the basis of their appearance only, and Fbis on the basis of diameters at breast height and heights measurements and observations scored for individual trees. The best trees were selected on the basis of the index value weighing traits by their economic value. Genetic selection was performed based on both family index value (Wf) and tree index value (WT), weighing traits by heritability and economic value. This was done in four different ways: (A) The best trees were selected only on the basis of their index value (WT) with no attention paid to the family; (B) About 10 to 12 trees were selected in the best families, (both (Wf) and (WT) were taken into consideration); (C) The best 30% of the families (Wf) were selected and then equal numbers of best trees were selected (WT); (D) The same number families (Wf) as in the phenotypic selection were selected and within these families equal numbers of best trees (WT). The number of trees that were genetically selected was always the same as the number of phenotypically selected ones (selection type F). The selections were compared using a calculated expected genetic gain and the relative loss of effective population size. As expected, phenotypic selection resulted in the lowest genetic gain. Phenotypic selection generally conserved genetic variability, while genetic selection reduced it, especially when genetic gain was maximised. Phenotypic selection type F generally identifies the good families. The agreement of genetic selection with the phenotypic selection is low (0% to 19%) at the individual tree level. This is slightly better with phenotypic selections using measurements data (Fbis). Phenotypic selection is recommended only where information concerning pedigrees is not available. It can provide a simple and cheap way of obtaining material for future selection. Genetic selection method (A) where best trees were selected without any restrictions provided highest genetic gain and cause the greatest loss of genetic diversity.
Źródło:
Dendrobiology; 2005, 53; 45-56
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies