|Title:||大豆雜交後裔各世代產量選拔效果及遺傳力之研究||Other Titles:||Heritability Estimates and Effectiveness of Selection for Yield in Various Generations of Two Soybean Crosses||Authors:||詹國連
|Issue Date:||5-Sep-1976||Publisher:||農業試驗所||Journal Volume:||25||Journal Issue:||3||Start page/Pages:||206-213||Source:||中華農業研究||Abstract:||
Two soybean crosses, P1 200492 (P1) × Shih-Shih (P2), and Tainung No. 4 (P3) × Flambeau (P4) were grown 200 and 41 plants in the F2 generation in Summer crop 1974 and 32 and 26 lines in the F3 and 48 and 36 lines in the F4 generation in Spring and Summer crops 1975, respectively. The study reported herein was conducted to estimate the heritabilities and predicted gains for the two segregating populations under visual selection for seed yield on single plant performance of each progeny studied. The predict gain was then compared with the actual mean performance differential between the progeny of the selected parent and the population mean, and the close agreements between the predict and actual gains was reffered to as the effectiveness of visual seed yield selections. The results are summarized as follows:
1. The F1 hybrids gave an average of 45% and 69% heterosis for seed yield per plant over their respective high parent, and of 89% and 82% higher than their mid—parent value in the two crosses evaluated. The average seed weight per plant, however, decreased definitely from F2 generation downward to F5 generation in both crosses.
2. Heritabilities for seed yield per plant estimated varied greatly between F2 and F3 generations in both crosses, and F2 generation gave the highest heritability estimates (25 .5% and 28.5%) while the F3 generation had the lowest with 3.6% and 7.6%. Heritability estimated from F4 generation were 24.8% and 24.6%, nearly close to the F2 generations. Since F3 generations were grown in spring season which provided the most favourable vegetation environment, the lowest heritability for F3 probably resulted in having larger environmental variance large enough to cover the express of its true heritability.
3. The disagreements were found between actual and predict gains for visual seed yield selection per plant, and the former were overall generations larger than the later in both crosses. This result showed that the sampled mean in F2, F3, and F4 generations were not from the same populations. It was concluded that there was no genetic progress to be expected from the visual selection for seed yield based on single plant performance in progeny studied.
|Appears in Collections:||1.台灣農業研究(1950～迄今)|
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