(52(3):191-206)Variation of Seedling Characters of Shiokari Rice and Its Dwarf Near-Isogenic Lines under Deep Seeding Condition

本試驗以Shiokari及17個水稻矮性近同源系為材料進行深播5、7 cm條件下秧苗特性之研究。結果得知深播5 cm下，矮性近同源系d-1、d-2、d-18k及d-42t幼苗之出土明顯受到抑制，而d-6則促進出土，其餘矮性近同源系之出土能力則與Shiokari相似；除d-1伸長第1葉節間外，各矮性近同源系主要以中胚軸、鞘葉節間、不完全葉節間共同伸長促使幼苗出土；其他幼苗性狀長度則因不同的矮性基因導入而產生差異。深播7 cm下，矮性近同源系sd-1、d-6、d-12、d-14及d-52促進幼苗出土，而d-1則抑制出土，其餘矮性近同源系之出土能力則與Shiokari相似；除d-1伸長第2葉節間外，各矮性近同源系主要以不完全葉節間及第1葉節問共同伸長促使幼苗出土；其他幼苗性狀長度則因不同的矮性基因導入而產生差異。Shiokari與其矮性近同源系大部分深播 (5、7 cm) 下幼苗仍以第1葉型式出土，當播種愈深第1葉出土的比率愈高，且亦會有些許幼苗以第2葉型式出土。主成分分析圖得知，在深播5 cm下Shiokari與其矮性近同源系主要分布在第一象限，而深播7 cm下則主要分布在第四象限，但矮性近同源系並不全散佈於輪迴親之附近。透過主成分分析及遺傳型相關結果得知深播下矮性基因對幼苗生育具有多效性作用。In order to understand the seedling characters of different dwarf genes expressed under 5 and 7 cm seeding depth, Var. Shiokari and its seventeen dwarf near-isogenic lines were used for investigation. The results were that the emergence ability of d-1, d-2, d-18k and d-42t was significantly inhibited at 5cm seeding depth, but d-6 was enhanced, and no significant difference was found among the rest dwarf near-isogenic lines with Shiokari. All dwarf near-isogenic lines were emerged with the elongated of mesocotyle, however, coleoptile internode and incomplete leaf internode however d-1 was found emerged by its 1st leaf internode. At 7cm seeding depth, the emergence ability of sd-1, d-6, d-12, d-14 and d-52 were enhanced however d-1 was inhibited and no difference found among the rest dwarf near-isogenic lines with Shiokari. All dwarf near-isogenic lines were emerged by the elongation of incomplete internode and the 1st leaf internode however d-1 was found emerged by the 2nd leaf internode. Each dwarf genes had different effects along with various degrees on seedling characters at both seeding depth. Most seedlings of Shiokari and its dwarf near-isogenic lines emerged by the 1st leaf. It was found the emerged ratio of the 1st leaf was increase and which the seeding depth however the emergence of 2nd leaf was also observed on some seedings. Through principal components analysis, it was found that Shiokari and its most near-isogenic lines were distributed in 1st quadrant at 5cm seeding depth however the distribution in 4th quadrant was found while seeding depth at 7cm. It was observed that the distribution of dwarf near-isogenic lines were not scattered near Shiokari. Conclusion from principal components analysis and genotypic correlation, it was found that dwarf genes had pleiotropic effects on seedling growth under deep seeding culture