水稻分蘗之生理研究(四)不同節位葉片形態性狀與稻榖產量間之相關

Abstract

本試驗採用本省歷年來育成之9個稉稻與2個秈稻品種爲材料，於第一、二期作在田間栽培，以單一大分蘖爲樣品，測定抽穗期各節位葉片之長度、寬度與面積，計算各節位葉片諸項性狀與劍葉或第3葉性狀之比值，以及與成熟期稻榖產量間之關係。水稻葉片長度以劍葉最短，第3葉最長，各節位葉片長度間的相對關係有明顯的品種間及期作間差異，即高產品種具有較高的第3葉與劍葉長度比值，而第一期作第2至4葉相對於劍葉之長度顯著超過二期作之相對長度；單一葉面積性狀也有相似的表現，一期作水稻分蘖第2至4葉之單葉面積又較二期作爲高。水稻單一分蘖稻穀屋量在一期作與葉片形態性狀之間相關較不明顯，在第二期作則與 第3、4葉長度、第2至4葉長度與劍葉長度比值、除劍葉外之單葉面積與總葉面積、第2至4葉面積與劍葉面積比值均呈顯著或極顯著之正相關，顯示葉面積爲限制產量的因子。本試驗結果認爲葉片形態性狀影響群體的葉片立體結構，因期作而有不同，爲期作產量差異的生理原因之一；而 第3葉片長度及其與劍葉長度之比值與稻榖屋量具有相關，或可用爲高產 育種選拔時之指標，值得再予詳細研究探討。 Large tillers of 9 japonica and 2 indica rice cultivars were used in this experiment. Length, width, and area of leaf blades at different node positions of the culm were measured at heading stage. Measurements of various leaf blade characters were also compared to those of the flag leaf or 3rd leaf from the top. Their relationship with grain yield was then determined. Experimental results indicated that ratios of individual leaf length to flag or 3rd leaf length were different among cultivars or between crop seasons. High-yielding cultivars tended to have higher ratio of 3rd leaf length to flag leaf length. Ratios of the 2nd to 4th leaf length to flag leaf length were higher for the 1st than for the 2nd crop rice. Single leaf area of the 2nd to 4th leaf was higher for the 1st crop rice as compared to tillers of rice grown in the 2nd crop season. No clear relationship was observed between grain yield and leaf morphological characters in the 1st crop season. However, length of the 3rd and 4th leaves, ratios of the 2nd to 4th leaf length to flag leaf length, single leaf area (except for flag leaf) and total leaf area, and ratios of the 2nd to 4th leaf area to flag leaf area were all significantly correlated with grain yield in the 2nd crop. It is assumed that changes in leaf geometry caused by dimension characters were important in causing yield difference between crops. Length of the 3rd leaf and its ratio to flag leaf length were suggested as possible indexes for breeding high-yielding varieties as they were significantly correlated to most leaf morphological as well as yield characters.