Wyniki wyszukiwania

1

Changes in quail blastodermal cell status as a result of selection

100%

Sawicka D., Samek K., Chojnacka-Puchta L., Witkowski A., Knaga S., Debowska M., Bednarczyk M.

Folia Biologica

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2015

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tom 63

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nr 1

2

Production of an MHC class II B molecular probe in the turkey, Meleagris gallopavo

100%

Jones Dukes M. D., Locklear C. C., Buchholz R., Hecht S. J., Findley A. M.

Journal of Applied Genetics

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2003

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tom 44

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nr 3

3

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Comparison of phenotypic and genetic selections in Scots pine (Pinus sylvestris L.) single tree plot half-sib progeny tests

84%

Kowalczyk J.

Dendrobiology

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2005

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tom 53

45-56

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.

4

Environmental stability and heritability estimates for grain yield and test weight in triticale

84%

Barnett R. D., Blount A. R., Pfahler P. L., Bruckner P. L., Wasenberg D. M., Johnson J. W.

Journal of Applied Genetics

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2006

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tom 47

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nr 3

Hexaploid triticale has many advantages over both parental species for both grain and forage production in certain environments. Additional information on environmental stability and heritability would be desirable to develop appropriate selection strategies in the production of superior widely-adapted cultivars. The grain yield of 22 diverse genotypes grown at four ecologically-distinct geographical locations [Quincy, FL, USA (approximate geographical coordinates (AGC) = 30°N 84°W, approximate elevation (AE) = 58 m), Plains, GA, USA (AGC = 32°N 84°W, AE = 76 m), Bozeman, MT USA (AGC = 45°N 111°W, AE = 1458 m), and Aberdeen, ID, USA (AGC = 42°N 112°W, AE = 1360 m)] was measured in two years with winter and spring planting dates only at Bozeman and Aberdeen. Test weight (grain weight in a given volume) was determined for two years at Bozeman and Aberdeen at both planting dates and one year at Quincy. Stability analyses indicated that significant (P <0.01) variation in means, regression coefficients, and deviation mean squares of the genotypes were present for both characters. Realized heritability (h²) estimates were as follows: grain yield ranged from -0.02 to 0.80 with a mean of 0.57; test weight ranged from 0.63 to 1.05 with a mean of 0.93. The results indicated that substantial genetic variation is present and selection for widely-adapted cultivars would be effective for both characters especially test weight.

5

Ocena postepu hodowlanego pod wzgledem wartosci przetworczej materialow wyjsciowych ziemniaka wytworzonych w latach 1999-2007

67%

Domanski L., Flis B., Jakuczun H., Zimnoch-Guzowska E.

Biuletyn Instytutu Hodowli i Aklimatyzacji Roślin

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2009

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nr 252

275-283

6

Substrate preferences in chicken selected for and against feather pecking behaviour

67%

Kjaer J. B., De Jong I. C.

Animal Science Papers and Reports. Supplement

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