水稻分蘗之生理研究Ⅴ.穀粒充實期間氮含量變化與產量之關係

Abstract

本試驗以大粒型水稻品種Pegonil與中粒型品種臺農67號，及以後者為輪迴親經回交5-6次並自交6-7次且具大粒特性（千粒重為32-34g）後代品系為材料，探討單一大分蘗在抽穗後之氮素累積與利用性狀，以瞭解對產量生理的影響。試驗結果顯示回交後代BC-5之產量高於臺農67號，BC-6產量則與臺農67號相近，又以Pegonil產量最低。抽穗期葉面積及單位面積葉片氮素含量不能反應產量表現，如以抽穗期單位葉面積及單位面積葉片氮素含量為基準計算產量效率，則仍以Pegonil最低，其餘三個品種（系）間的差異較小。回交品系在抽穗後具有較高的相對累積氮素能力，顯示穀粒充實期間的氮素供需較為平衡，可能與高產潛能有關，建議為一值得利用的優良生理性狀。A medium-grain variety, Tainung No. 67, a large-grain variety, Pegonil, and one each of their BC-5 and BC-6 offsprings with grain weight of 32 and 34 mg were used in this experiment. Large tillers were sampled from heading to matrurity to examine the characteristics of N accumulation and distribution, and changes in concentrations of chlorophyll and soluble protein, for elucidating the relationship between grain yield and leaf physiological characters during the period of grain-filling. Experimental results revealed that grain yield was highest for the backcross strain BC-5 followed by Tainung No. 67 BC-6 strain, and Pegonil. N content per unit leaf area at heading was not correlated to grain yield at maturity. Yield efficiency, espressed as grain yield per unit leaf area at heading, was lowest for Pegonil, and no difference was observed among the other three genotypes.