Hybrid Variety of Indica Rice and Its Yield Potential

Abstract

In a series of testcrosses, none of the varieties was found to restore the CMS of Reimei A (rufipogon), but many restored that of Chen-shan 97A (WA). Hybrid sterility seemed to limit the transfer of Rf-gene from an IR line to a japonica variety, Reimei. A row ratio of 4 : 1 or 6: 1=A : B was found suitable for mechanical planting of A and B or and Rf lines in the hybrid seed production. Chen-shan 97 A, B gave a seedset percentage higher than 30 % or an yield of 1,288 kg/ha for seed production. The amount of hybrid seed produced for the first time in Taiwan was low, 562 kg/ha, which could be raised by increasing the row number of A line and by synchronizing the parental flowering times. Introduced hybrid variety Shan-you 6 gave a high yield of 9.5 t/ha in the first crop, but only about 6 t/ha in the second crop. The yield increase over the control vaiety as performed by the introduced and developed hybrid varieties seemed to he in the range of 20%-30% in the first crop and less than 10% in the second crop. 本文報告秈稻雜種品種之育成及其產量潛力。多次檢驗交配結果顯示，現有育成系統、品系或品種均未能恢復 Reimei A ( rufipogon) 之雄不稔性，但有多數品種（系）恢復 Chen -shan 97A ( WA) 之不稔性。秈稉型間雜種不稔性似限制稔性恢復基因從一個 IR 品系轉移至稉型的 Reimei。生產雜種種子所需 A 、 B 系統或 A 、 Rf 系統之種植行數比，以 4 : 1 或 6 : 1 = A : B 或 A : Rf 較適合於機械插秧 6 雄不稔品種 Chen-shan 97A , B 有 30 ％以上之結實率，種子生產量達 1,288 公斤／公頃。目前的雜種品種種子生產量低，僅有 562 公斤／公頃，有可能以增加 A 系統之行數及同步化兩親的開花期來將之大幅提高。引進雜種品種汕優 6 號在第一期作產量達 9.5 公噸／公頃，第二期作 6 公噸／公頃。引進及育成雜種品種的一般產量潛力似比對照品種高約 20%～ 30%（第一期作）及 10 ％以下（第二期作）