The Effect of Water Stress on the Physiological Characteristic of Sorghum (Sorghum b/color L.)

為探討高粱在生殖期間在缺水逆境下之生理反應，及其對產量影響，本試驗採用臺中5號及其親本2R與80B為材料。植株在孕穗期予以2、4或8天之斷水處理；試驗結果顯示：葉片之葉面積，葉綠素含量、可溶性蛋白質含量、硝酸還原酵素活性、澱粉含量和比葉重隨斷水處理時間加長而減少，NAR、預存物質含量、及乾物重亦呈現類似表現；然而，葉片總糖含量卻表現相反結果。不同品系在孕穗期經不同斷水處理之生理反應在各生育時期表現不一，品系在生育末期若能維持較高生理活性將有較大乾物重表現。 Taichung No. 5, 2R and 80B were used in this study to investigate the physiological responses to water stress during reproductive stage of sorghum and their effects on yield. Two days, four days and eight days under water stress treatments were used on booting stage. The results showthat the leaf area, chlorophyll contents, soluble protein contents,nitrate reductase activity, starch contents and specific leaf weight (SLW) are decrease in accordance with the incease of time of water deficit treatment. Net assimilation rate (NAR) preservation and and dry weightalso express same tendency. Whereas, total sugar contents of leaf express opposite responses. Different sorghum genotypes show diffent physiological responses on diffent growth stage under various water stress treatment. The genotype which maintain high physiological activity of the late growth stage will have better dry weight