000			08057nam a22001937a 4500
005			20250325151941.0
020			_a0412553309
082			_aRef 631.5 B65s 1995
100			_aBos, Izak
245			_aSelection methods in plant breeding
260			_aLondon _bChapman & Hall _c1995
300			_ax, 347 pages : _billus.
490			_aPlant Breeding Series 2
500			_a1 Introduction – 2 Population genetic aspects of cross-fertilization – 2.1 Introduction – 2.2 Panmixis and diploid chromosome behaviour – 2.3 Panmixis and autotetraploid chromosome – 3 Inbreeding – 3.1 Introduction – 3.2 One locus, two alleles – 3.3 Two or more loci, each with two alleles – 3.4 Self-fertilization and autotetraploid chromosome behaviour – 3.5 Self-fertilization and cross-fertilization – 4 Assortative mating and disassortative meaning – 4.1 Introduction – 4.2 Repeated backcrossing – 5 Population genetic effects of selection with regard to sex expression – 5.1 Introduction – 5.2 The frequency of male sterile plants in the case of complete seed-set of such plants – 5.3 The frequency of male sterile plants in the case of incomplete seed-set of such plants – 6 Random variation of allele frequencies – 6.1 Introduction – 6.2 The effect of the mode of reproduction on the probability of fixation: an example – 6.3 The effect of the mode of reproduction on the effective number of reproducing plants – 7 Selection – 7.1 Introduction – 7.2 The maintenance of genetic variation – 7.3 Artificial selection for a trait with qualitative variation – 8 Quantitative variation – 8.1 Introduction – 8.2 Phenotypic value and genotypic value – 8.3 Components of the genotypic value – 9 Effects of the mode of reproduction on the expected genotypic value – 9.1 Introduction – 9.2 random mating – 9.3 Self-fertilization – 9.4 Inbreeding depression and heterosis – 10 Effects of the mode of reproduction on the genetic variance – 10.1 Introduction – 10.2 Random mating – 10.3 Self-fertilization – 11 Applications of quantitative genetic theory in plant breeding – 11.1 Prediction of the response to selection – 11.2 The estimation of quantitative genetic parameters – 11.3 Breeding value – 11.4 Prediction of the ranking of crosses – 11.5 Diallel crosses – 12 Selection for several traits – 12.1 Introduction – 12.2 The association between the phenotypic or genotypic values for traits with quantitative variation – 12.3 Indirect selection – 12.4 Procedures for estimating the coefficient of phenotypic, environmental or genetic correlation – 12.5 Index selection and independent-culling-levels selection – 13 Genotype x environment interaction – 13. 1 Introduction – 13.2 The statistical analysis; stability parameters – 13.3 Applications in plant breeding – 13.4 Statistical selection procedures and ordering procedures – 14 The disclosure of the genotypic value in the case of heterogenous growing conditions – 14.1 Introduction – 14.2 Single-plant evaluation and elimination of effects of a plant-to-plant trend in soil fertility – 14.3 Evaluation by means of plots and elimination of effects of a plot-to-plot trend in soil fertility – 15 The detrimental effects of allocompetition on the efficiency of selection – 15.1 Introduction – 15.2 Single-plant evaluation and reduction of the detrimental effect of allocompetition – 15.3 Evaluation by means of plots and reduction of the detrimental effect of allocompetition – 16 The optimum number of replications – 17 The size and shape of the test plots – 17.1 Introduction – 17.2 How to measure soil heterogeneity – 17.3 The optimum plot size from an economic point of view – 17.4 Causes of the low efficiency of selection – 18 The optimum generation to start selection in self-fertilizing crops – 18.1 Introduction – 18.2 Reasons to start selection in an early segregating generation – 18.3 Reasons to start selection in an advanced generation – 19 Experimental designs for plant breeding.
520			_a"Selection procedures used in plant breeding have gradually developed over a very long time span, in fact since settled agriculture was first undertaken. Nowadays these procedures range from very simple mass selection methods, sometimes applied in an ineffective way, to highly complicated schemes for (reciprocal) recurrent selection. Such procedures differ in cost as well as in genetic efficiency. In contrast to the genetic efficiency, costs depend on the local conditions encountered by the breeder. The genetic progress per unit of money invested consequently varies from site to site. This book considers only the genetic efficiency, i.e. the rate of progress to be expected when applying certain procedures. If a breeder has a certain breeding goal in mind, a selection procedure should be chosen. A wise choice requires a well-founded opinion about the response to be expected from any procedure that might be applied. Such an opinion should preferably be based on models that are most appropriate when considering the crop and the trait to be improved. Sometimes little knowledge is available about the genetic control of expression of the trait. This applies particularly to the quantitative variation underlying many traits. It is, therefore, important to be familiar with methods for the elucidation of the inheritance of traits. This means, in fact, that the breeder should be able to develop population genetic and quantitative genetic models that describe the observed mode of inheritance as satisfactorily as possible. The genetic models are generally based on the simplifying of assumptions. Quite often one assumes: - a diploid behaviour of the chromosomes; - an independent segregation of the pairs of homologous chromosomes at meiosis, or, more rigorously, independent segregation of the alleles at the loci controlling the expression of the considered trait; - independence of these alleles with regard to their effects on the expression of the trait; - a regular mode of reproduction within plants as well as among plants belonging to the same population; or - the presence of not more than two alleles per segregating locus. Such simplifying assumptions are made as a compromise between, on the one hand, the complexity of the actual genetic control, and, on the other hand, the desire to keep the model simple. As the assumptions deviate more from the real situation, decisions made on the basis of the model will be less appropriate. The decisions concern choices with regard to: - selection methods, e.g. mass selection versus half sib family selection; - selection criteria, e.g. grain yield per plant versus yield per ear; - experimental design, e.g. testing of each of N entries in a single plot versus testing each of only 1/2N entries in two plots; or - data adjustment, e.g. moving mean adjustment versus adjustment on the basis of plots with standard varieties. In fact such decisions are very often made on subjective grounds (experience, tradition, intuition). This explains why breeders who deal in the same region with the same crop work in divergent ways. Indeed, their breeding goals may differ, but these goals themselves are often based on a subjective judgement about the ideotype (ideal type of plant) to be pursued. In this book concepts from plant breeding, population genetics, quantitative genetics, probability theory and statistics are integrated. The reason for this is to help provide a basis on which to make selection more 'professional', in such a way that the chances of being successful are increased. Success can, of course, never be guaranteed because the best theoretical decision will always be made on the basis of incomplete and simplified assumptions. Nevertheless, the breeder will hopefully be in a better position when making any decision!"
650			_aPlant breeding.
700			_aCaligari, Peter
942			_cBK
999			_c5738 _d5738