Topcrosses in the selection of testers and inbred lines S3 for the yield and bromatological quality of silage maize

Abstract

The study aiming to evaluate the combining ability of maize partially inbred lines (S3) in crosses with testers of narrow genetic base aiming at the selection of the inbred lines, testers and topcross hybrids. Three simple lattice trials with 81 treatments were carried out in the 2014/2015 and 2015/2016 growing seasons. For each growing season, trials were used to evaluate the topcross hybrids obtained in combination with the testers AG8088, DKB330 (single-cross hybrids) and 9.H33.3 (line). The hybrid AG8088 and line 9.H3.33 were the best testers for grain yield. The line 9.H3.33 was the best tester for the traits related to yield and quality of silage maize. The inbred lines that stood out for their combining abilities and capacity of generating great topcross hybrids with the testers (i.e., 201-23.2, 201-59.1, 201-80.2, 201-81.5, 203-195.3, 201-100.4, 201-145.4, 201-169.3, 202-155, 202159, 203-23, 203- 31, 203-32, 203-38, 203-75, 203-98, 203-111, 203-135, 203-139, 203-150, 203-188, 203-235, and 203-237) should be maintained in the UEM silage maize breeding program. Progenies 201-59.01, 201-100.4, 203-135, 203-150, 203-235 and 203-254 were selected as tester lines of progenies derived from selfing of the testers AG8088 and DKB330 to improve the silage maize quality. The topcross hybrids 201-95.3 x 9.H3.33, 203-71 x 9.H3.33, 203-72 x 9.H3.33, 203-88 x 9.H3.33, 203-139 x 9.H3.33, and 203-150 x 9.H3.33 were selected for good performance for agronomic and bromatological silage maize traits. These hybrids are indicated for evaluations in more environments, with a view to recommending commercial cultivars for grain and silage production in the future.