(64(2):99-108)Breeding of White-glutinous Maize Hybrid ‘Tainung No. 6’

玉米新品種「台農6 號」 (TAWXH97-02)，係2000 年搜集的白糯種原wxpop10 及wxpop12 族群，在2002–2004 年經人工自交5 代所育成S5 世代之自交系wxpop10-84 與wxpop12-28 雜交而成之單交種。2007年春作從220 個組合經組合力檢定後，根據植株、果穗外觀、產量及初步品評後選留9 個新組合。2007 年秋作進行9 個新品系產量比較試驗，2008 年春作–2009 年秋作在台中市霧峰區與雲林縣崙背鄉進行新品系區域試驗，2 年4 期作共8 個地點之區域試驗，平均顯示含苞葉鮮果穗產量14,600 kg ha-1 較對照品種 (「玉美珍」)11,400 kg ha-1 平均增產29.4%，去苞葉鮮果穗產量9,920 kg ha-1 較對照品種「玉美珍」7,920 kg ha-1 平均增產26.8%。株型與穗型外觀整齊、果穗長12 cm，穗徑粗大、行數12 居多，鮮果穗產量高、黏質及皮厚薄適中等特性。TAWXH97-02 經行政院農委會農業試驗所2013 年第58 次研發成果管理委員會審查同意以「台農6號」命名及品種權申請，又於2014 年4 月23 日經行政院農業委員會糧食作物及草類植物品種審議委員會第24 次會議審議通過「台農6 號」品種權，2014 年6 月12 日取得植物品種權證書。品種性狀特性為白糯質，單交種。植株第1 葉葉鞘紅色，上位穗所在葉片與莖的夾角度小且葉片姿態呈反曲，莖無Z 字型 (或極微Z字型)，支持根紅色，植株中段葉鞘綠色，株高 (210–300 cm) 為高，上位穗著生高度 (81–120 cm) 為高。雄穗開花期屬中至晚熟，雄穗穎花護穎基部深紅色，雄穗穎花護穎基部以外為淡紅色，花藥淡紅色，雄穗主軸長(23–29 cm)，雄穗側枝長度 (17–24 cm) 為中等，雄穗主軸中段小穗著生密度為疏，主軸下段與側枝角度為中等，雄穗主軸下段側枝形狀呈稍曲，雄穗一次側枝數為中等。雌穗吐絲期屬晚至極晚熟，花絲淡粉紅色，雌穗數少，穗梗長 (12.1–18 cm)，果穗長 (19.8–26.4 cm)，雌穗直徑 (3.1–5.0 cm) 中等，果穗呈圓錐至圓筒型。籽粒行數少，籽粒類馬齒型，籽粒頂端與周邊白色，穗軸白色，籽粒排列筆直，千粒重小 (164–215 g)。 ‘Tainung No. 6’, a single-cross white-glutinous maize hybrid, was bred from the hybridization of wxpop10-84 and wxpop12-28 population after 5 generations of artificial inbred during 2002 to 2004. From 220 lines of combining ability test in the spring season of 2007, 9 lines were selected from the evaluation of plant height, ear appearance and yield. 9 new lines were planted in fall season of 2007 for advanced trial, and regional trial was conducted in the spring season of 2008 and the fall season of 2009 at two locations. The results of regional trial showed that the average fresh ear yield of ‘Tainung No.6’ was 14,600 kg ha.-1, higher than White Pearl 11,400 kg ha-1, and the ear fresh yield without husk was 9,920 kg ha.-1, higher than of White Pearl 7,920 kg ha-1. Plant height and ear shape of ‘Tainung No.6’ were uniform, and the length of ear was 20 cm with 12 row. In 2013, TAWXH97-02 was permitted to apply variety right by Taiwan Agricultural Research Institute (TARI), then it was registered as ‘Tainung No.6’ by the committee of variety right on 6 June 2014. The agronomic traits of ‘Tainung No.6’ are as follows. It is a white-glutinous type and single hybrid variety. The color of first leaf sheath is medium red, and angle between blade and stem is small. The leaf blade is curve in shape and the degree of zig-zag is absent or very small. Anthocyanin coloration of brace roots is medium red, and anthocyanin coloration of sheath is absent or weak green. The plant height is long and the position of upmost ear is high. As for the agronomic traits of tassel, days to tasseling is medium to late, and anthocyanin coloration at the base of glume is strong dark red. Anthocyanin coloration of glume excluding base is weak pink and anthocyanin coloration of filaments/silks is weak pink. Main axis is long and length of side branches is medium. The density of ears is loose. Angle between main axis and lateral branches is medium and lateral branches is slightly curve in shape. The number of primary lateral branches is medium. As for the agronomic trait of ear, the time of silks emergence (silking) is late to very late and the intensity of anthocyanin coloration of silks is weak pink. Ear number is few and the length of peduncle is long. Ear length is long and ear diameter is medium. Ear shape is conical-cylindrical. As for the agronomic traits of kernels, the number of rows is few and the type of kernels is dent-like. The color of top and dorsal side is white, and the intensity of anthocyanin coloration of glumes of cob is weak white. The row of kernel is straight and 1,000-kernel weight is small