S1 AND S2 LINES ALTERNATE COMBINED SELECTION AND PURE LINE IN S0 SELFED PLANTS IN WHEAT

Abstract

The S1 and S2 lines alternate combined selection (ACS) method starts with the evaluation of S1 families derived from S0 self-pollinated selected plants. Since self-pollination occurs as a natural process in autogamous species, it is posible the self-pollination and evaluation at the same time in a single-plant selection plot (SI), from which the selected plants integrate the S1 families of the ACS. In this study, the incorporation of the SI in the ACS was developed. The expected response with respect to grain yield was estimated, and the observed response recorded in a population of the first cycle in wheat (Triticum aestivum L.). The ACS significatively increased grain yield in 25.8 % per cycle and 5.9 % of this amount was atributated to the SI. Agreement between expected and observed selection response was 84.4 %. SI improved 27 % the total expected response of the ACS; however, the genetic and operative efficiency of SI in ACS depended on the amount of seed obtained from each pollination and on the availability of agricultural regions with two planting seasons per year.