Journal of Taiwan Agricultural Research

Author:Guang-Jauh Shieh and Fu-Sheng Thseng

Abstract:

The objective of this study was to determine if the combining ability of inbred lines derived from six Tainan-white (TNW) populations at early generation (S₂) of inbreeding were similar to that at later generations. The selfing lines (S₂ to S₅) were crossed following a half-diallel mating design and produced 15 F₁ hybrids for each generation. A total of 60 hybrids were planted at Lunpei in fall crop season of 1997, to determine the correlation between S₂ and advanced generations in phenotypic expressions, and to compare the combining abilities of inbred lines among different generations. The result showed that the heterotic pattern and combining ability in the early generation (S₂) were similar to that in advanced generations. There existed significant correlations between the hybrids derived from the S₂ and S₅ generation for ear dry weight and grain dry weight in maturity. It indicated that the yield ability of S₅ hybrids could be precisely predicted from that of S₂ hybrids. Thus it suggests that early testing was effective for predicting the combining abilities expressed at later inbreeding generations. It was also that the additive effects (GCA effect) of inbred lines maybe a main contribution to the relationships between the S₂ to S₅ generation hybrids for ear dry weight and grain dry weight.

Key words:Tainan-white, Maize, Inbred lines, F₁ hybrids, Yield

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