Genetic Variation of Soybean Hybrid Populations by Natural Selection in Spring Crop Season at Four Locations－I. Frequency Distributions for Certain Agronomic Characters in F2 Generation

Abstract

In spring crop season 1983, two F2 soybean (Glycine max) hybrid populations, KS8×TN15 (Population A) and TN15×T175 (Population B) were planted in four locations of Taiwan for studying the frequency distributions and breeding parameters of eleven characters in F2 populations. The distribution patterns showed late flowering in Tainan and Taichung locations, whereas those in Pingtung and Hsinchu flowered earlier. All characters studied distributed continuously but varied among locations. The standard deviations of plant height, nodes on main stem, days to flowering and days to maturity tended to be increased from south toward north. The results suggested that some differentiation in F2 populations under various locations were involved. 使用 KSS × TN15（A 集團）及 TN15 × T175（B 集團）兩個大豆雜種集團之 F2種子，於 1983 年春作分別播種於臺灣四個地區，探討 F2集團之農藝性狀，在四個不同栽培地區之集團分布型及各種育種介量。 兩個F2集團之分布型，在臺南及臺中地區偏向晚開花，在屏東及新竹偏於早開花。所有調查性狀均呈連續性之分離，且分布型在不同栽培地區間均有顯著差異。而株高、分枝數、主莖節數、開花期及成熟期等性狀之集團的分散度，一般呈現由南向北增大之趨勢。其他性狀也因地區有顯著差異。由此結果，可推測 F2雜種集團因不同栽培環境之影響，似乎地區間已有分化之現象。