Recurrent selection for yield and other quantitative characters in wheat

René Cortázar S.1 y Ernesto Hacke E.1

Selection for yield in the segregating generations has a low efficiency; this delays selection till the breeding material becomes homozygote. The probability to obtain,at this advanced time,homozygote genotypes for all the genes for yield that differenciate the parents, is minima!. One can only select the best, among individuals that have only a part of the genes coming from the parents. By means of recurrent selection, one could raise significantly the proportion of individuals with a higher number of genes for any quantitative character. In this paper, the way to obtain this objective is described, using two methods: a. with gametocides (Ethrel); and b. using a line with polen sterility, due to a dominant gene. At the La Platina Exp. Sta. (INlA, Santiago), recurrent selection is being applied in wheat, with three objectives: a. gene concentration for horizontal resistance to Puccinia striiformis and P. graminis; b. yield improvement; and c. gene concentration for resistance to BYDV. These programs are under way only for the last two years.

1 Estación Experimental La Platina (INlA), Casilla 439, Correo 3, Santiago, Chile.