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Effectiveness of Early‐Generation Selection for Tillering Capacity in Spring Wheat
Author(s) -
Hucl P.,
Baker R. J.
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/cropsci1991.0011183x003100040020x
Subject(s) - tiller (botany) , biology , heritability , hybrid , ideotype , agronomy , seeding , grain yield , irrigation , poaceae , yield (engineering) , zoology , crop , genetics , materials science , metallurgy
The tillering process is one of the major determinants of grain yield in wheat ( Triticum aestimm L.). A restricted tillering (oligoculm) ideotype has been proposed for maximizing grain yield. This study was conducted to estimate the heritability and effectiveness of selection for tillering capacity in oligoculm and nonoligoculm spring wheat crosses. Eight populations derived from crosses among high tillering ('Neepawa', ‘Ingal’), low tillering (‘Ko Fong’, ‘Siete Cerros’), and oligoculm (M1417) parents were evaluated at Saskatoon, SK. The F 1 , F 2 , and the F 2 ‐derived F 3 , F 4 , F 5 , and F 6 lines were tested under dryland conditions. The 10 highest‐ and 10 lowesttillering F 7 lines from each of the oligoculm crosses were grown under irrigation at Saskatoon and Outlook, SK. Tiller production of F 1 hybrids did not differ significantly ( P = 0.05) from their midparent values in 16 of 18 hybrid‐environment combinations. Heritability estimates for tillers per plant were, on average, much higher for the oligoculm crosses. At commercial seeding rates, high‐ and low‐tillering F 4 lines differed significantly in spikes per square meter in eight out of nine populations. High‐ and low‐tillering selections in oligoculm F 4 populations differed, on average, by 19% for spikes per square meter, compared with 12% in nonoligoculm crosses. Limited May and June precipitation during the evaluation of the F, and F 6 generations resulted in few (4 of 16) significant differences in spikes per square meter between high‐ and low‐tillering groups. Averaged across 2 yr (1987,1989), the low‐tillering selection group in oligoculm crosses yielded 7% less than the high‐tillering group. Early‐ generation divergent selection for tillering capacity was more effective in oligoculm than in nonoligoculm crosses.