屏東地區期作性水稻品種間生理差異之研究

Abstract

為瞭解本省水稻主要栽培地區之一的屏東地區水稻品種在第一、二期作所呈現生理反應之差異，作為改善栽培方法及分期育種之參考資料。太試驗選擇外表型差異大之14品種種值於自然條件下，在生育期間每隔13天取樣調查，比較一二期作之葉面積指數，葉綠素含量，葉片氮含量，根活性，光合能力，產量及產量構成要素之差異。茲將所得結果摘要於下。 1.供試14品種，生育期間稻根對α-NA氧化能力之變異，稍有不同。稉稻根活性不一定比利I稻高，視品種及生育期不同而異。供試品種生育後期，一期作根活性均高於二期作。 2.一期作生育後期葉綠素含量除臺中65號、陸奧錦兩品種外，均高於二期作。 3.供試14品種一期作之葉面積指數，抽穗期後，均高於二期作。二期作在抽穗期葉面積指數已達最高，然後迅速遞減。二期作葉面積指數與產量之相關係數為0.75。 4.一期作有7個品種在生育後期葉片氮含量較高，但一、二期作生育期間葉片氮含量變遷差異不明顯。 5.單位葉面積之乾物生產量所代表之光合能力，二期作較一期作強。 6.第一期作高產品種依序為奎農67號(7,080kg/ha)、臺中秈3號(6,700kg/ha)、低腳烏尖(6,64Ckg/ha)，二期作為臺中秈3號(3,960kg/ha)、高雄秈7號(3,832kg/ha)、臺農67號(3,460kg/ha)。二期作低產主要係穗數、每穗粒數減少及結實率降低。 Leaf chlorophyll content, leaf N content, root activity, leaf area index, photosynthetic capacity, yield and yield components of 14 rice varieties of the first and the second crops in Pingtung area were investigated and compared. Results obtained are summarized as follows 1. The α-naphthylamine oxidizing ability of rice root differed with varieties and growing period. Root oxdizing ability in the late growing period of the first crop was higher than that of the second crop. 2. Except Taichung 65 and Mutsuniskiki, leaf chlorophyll content in the late growing period of the first crop was higher than that of the second crop. 3. The leaf area indice of all tested varieties after heading in the first crop were higher than those in the second crop. In the second crop, the leaf area index reached the maximum in the heading time and then decreased abruptly. The correlation coefficient between leaf area index and yield of the second crop was 0.75. 4. The leaf N content during late growing period was higher in the first crop. N contents of 7 vaieties did not fluctuated obviously in the first and second crops. 5. The photosysthetic capacity, presenting by dry matter production per unit leaf, was higher in the second crop than that the first crop. 6. The grain yield of the first crop: Tainung No. 67 (7,080kg/ha) ; Taichung Sen No. 3 (6,700 kg/ha) ; Ti-eChun-Wu-Chien (6,640kg/ha). The second crop : Taichung Sen No. 3 (3,960kg/ha) ; Kaohsiung Sen No. 7 (3,832 kg/ha) ; Tainung No. 67 (3,460 kg/ha). The lower grain yield of the second crop was mostly due to low panicle number, low grain per spikelat and low fertility.