Use of recurrent selection in middle late synthetic maize population

I. Results of the first cycle in synthetic “1/2005”
N. Petrovska, V. Valkova
Abstract. The present study shows the results of a completed first cycle of recurrent selection in a middle late synthetic population “1/2005” and the inbred line PAU 1617 is used as a recurrent parent. The aim of the improving selection is to obtain synthetic inbred lines which are later to be used as parental forms for receiving hybrids of this maturity group. The experimental work was carried out in the period 2009 – 2011 when two hundred and twenty-two testcrosses were tested. After the data were analyzed, sixty-two inbred progeny variants displaying the best results have been included for crosspollination and a new cycle of breeding. The genetic variability in the synthetic has been preserved as the selected progeny represents 28 % of the initially chosen ones. The index of variability after recurrent selection is 16,9 % which allows efficient testing in the subsequent stages of the improving selection. As a direct outcome of the research, three crosses have been pointed out – PAU 1617 x 15/5, PAU 1617 x 63/2 and PAU 1617 x 111/4. They exceed in grain yield the foreign standard in the maturity group by 9.2, 2.3 and 3.4%, respectively. Grain moisture is lower than that of the standards in the trials, by 2.8, 0.7 and 4.8 %, respectively. They are still tested in varietal and ecological trials.