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• An Analysis of Rotational Line Mating Using Computer Simulation

  35-39

  Szilvia Szőke

  István Komlósi

  Views:

  134

  In a simulation examination, we analyzed the effect of the family size and the rate of pairing on the survival of rare genes, to keep the level of variation of the genepool and to avoid the loss of alleles.
  The population size was 360 animals. In the simulation, we calculated on the basis of a discrete population. We placed the 360 animals into different clusters, with 3 types of frequencies of alleles and 3 types of groups. We assumed 2, 3 or 4 alleles in 8 loci. We generated 15 generations using the same mating and selection system used in practise. The simulation was written with Scilab 2.7.2 software, and evaluated with SPSS software.
  There were significant changes in the effect of family size on the genetic variation in the following cases: when the base population had the same gene frequencies in all loci, and when the gene frequencies were between 0.125-0.75. In these cases, we found that the smaller families (10 animals/cluster) were better than the larger families (30 or 90 animals/cluster). The first generation where there accured a loss of alleles was averagely earliest in larger families (90 animal/cluster). This average was 3.37 generations. When we are searched the effects of the different rates of pairing we found those cases most favourable when the ratio of males and females was 1:2 or 1:4 as compared to 1:9. The first generation where there was a loss of alleles was averagely earliest at the ratio of pairing male and females of 1:9 (the mean was 3.05 generations) when the frequency of the rarest allele was 0.0069.
  The recently introduced rotating-random mating system is an eligible method for small populations for the preservation of genes.

• Study of a Turkey Population for Gene Preservation

  48-52

  Szilvia Szőke

  István Komlósi

  Edit Korom

  Márton Ispány

  Sándor Mihók

  Views:

  173

  Genetic variability is very important in small populations. We examined an indigenous bronze turkey population which is bred for gene conservation in order to see if the current mating system maintains genetic variability. The present generation was surveyed using microsatellite markers and a computer model was used to simulate changes in the population over 100 generations.
  The data was analysed using the concept of entrophy from information theory instead of genetic variance so that we could more accurately measure genetic variability.
  The results indicate that the breeding method currently in use, rotational line mating, is acceptable with respect to preserving genetic variability, but new selection methods may provide additional protection against the loss of alleles.

• Computer simulation modeling of Leaf Area Index (LAI) in maize

  5-8

  Károly Bakó

  László Huzsvai

  Views:

  159

  This study presents a PHP-based model capable of calculating maize leaf area index. The model calculates LAI from emergence to 75% silking. The basis of calculation is represented by the daily average temperature values. The usability of the model was tested using three years' temperature and LAI data series from the values obtained by the weather station set up at the Látókép Experiment Site of the University of Debrecen, Centre for Agricultural Sciences between 1994 and 1996. During the running of the model, it was observed that temperature affects the intensity of leaf development to a various extent.