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Performance and Genetic Variance among S 1 Lines and Testcrosses of Iowa Stiff Stalk Synthetic Maize
Author(s) -
Walters S. P.,
Russell W. A.,
Lamkey K. R.
Publication year - 1991
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1991.0011183x003100010019x
Subject(s) - heterosis , biology , zea mays , genetic variation , grain yield , selection (genetic algorithm) , population , poaceae , inbred strain , variance components , genetic distance , agronomy , zoology , genetics , mathematics , statistics , gene , demography , hybrid , artificial intelligence , sociology , computer science
Iowa Stiff Stalk Synthetic (BSSSC0) maize ( Zea mays L.) population has been used in two long‐term recurrent selection programs: reciprocal recurrent selection (R) and half‐sib followed by S 2 ‐progeny (S) recurrent selection. Advanced populations after nine cycles of reciprocals recurrent selection [BSSS(R)C9] and seven cycles of half‐sib and three cycels of S 2 progeny selection [BS13(S)C3] were evaluated. Objectives of this study were to compare performance and amount of genetic variation present among S 1 lines from BSSSC0, BSSS(R)C9, BS13(S)C3, and BSSS(R)C9 ✕ BS13(S)C3(C3 ✕ C9) and, also, to compare performance and genetic variation among testcrosses of the S 1 lines by using two testers of different heterotic background, B73 and Mo17. The S 1 lines from BSSS(S)C9 and BS13(S)C3 showed significant increases in grain yield compared with S 1 lines from BSSSC0. The C3 ✕ C9 S 1 lines showed high‐parent heterosis for grain yield. Genetic variance component estimates of S 1 lines were significant in all four populations, and C3 ✕ C9 reflected midparent estimates between the estimates for C3 and C9. Mean grain yield for Mo17 testcrosses was significantly greater than for B73 testcrosses within each of the four populations. Testcrosses involving C3 and a related inbred, B73, showed a nonsignificant grain yield variance estimate. The average yield for the testcrosses of S 1 lines from C3 ✕ C9 for both testers was intermediate between the testcrosses of S 1 lines from C3 and C9; thus, the high‐parent heterosis observed for C3 ✕ C9 S 1 lines was not observed for the testcross means.