Changes of Climatic Variables during Grain-filling Stage Affect Yield and Quality of Rice Cultivars Bred from Different Regions in Taiwan

穀粒充實期間氣象因子對台灣不同地區選育稻種之米質與產量影響

何佳勳(Chia-Hsun Ho) ； 楊純明(Chwen-Ming Yang) ； 蕭巧玲(Chiao-Ling Hsiao) ； 賴明信(Ming-Hsing Lai)

《台灣農業研究》 62卷4期 (2013/12) Pp. 321-339

https://doi.org/10.6156/JTAR/2013.06204.03

摘要

由抽穗至收穫之穀粒充實期間氣象環境變化將影響稻米品質與產量，惟對選育自不同氣象環境的稻種將存在品種間差異性，探討與釐清這些差別效應將有助於建立各別地區性策略，以有效因應氣候變遷並穩定地區稻米供給而維護糧食安全。本研究於2008－2010年在行政院農業委員會農業試驗所農場（台中市霧峰區）進行三年期間上、下半年稻作之節氣栽植，三年總計29個栽植期。每個栽植期皆以4個良質稻種為試材，由北往南包括「桃園4號」（「TY4」）、「台農71號」（「TNG71」）、「台稉9號」（「TK9」）及「高雄145號」（「KH145」）等。試驗期間收集試區一級農業氣象測站之氣象測值，計算各稻種各栽植期自抽穗至收穫的穀粒充實期所量測的日均溫、日最高溫、日最低溫、日夜溫差、日照時數與日射量等六項氣象因子測值之平均值（即MDMAT、MDMAXAT、MDMINAT、MDNTD、MDSH、MDIR），以分析六個氣象變因對不同稻種米質性狀與產量之差異影響。由回歸分析顯示，4個良質稻種米質性狀受到穀粒充實期溫度變因（MDMINAT、MDMAT及MDMAXAT）影響，升溫將造成白米直鏈性澱粉、透明度及完整米率逐漸下降趨勢，惟上半年以「TY4」達顯著水準，下半年則4個稻種皆呈現顯著二次曲線關係。又產量與溫度變因之間為二次凸形曲線關係，各稻種有其產量表現之最佳平均值。總合4稻種資料，歸納出上半年栽植期之穀粒充實期最佳MDMINAT為23℃、MDMAT為26.5℃、MDMAXAT為31℃時可獲得最大產量，而下半年則分別為MDMINAT 20℃、MDMAT24℃、MDMAXAT 29℃。另發現下半年各栽植期米質性狀與MDNTD、MDIR均呈現極顯著二次曲線關係，而穀粒產量則與MDNTD呈現極顯著二次回歸相關。綜此顯見不同稻種於穀粒充實期間，氣象環境的改變將影響米粒化學組成、物理特性及產量，而各米質性狀各有其不同之主要影響氣象變因與權重，且溫度上升超過最佳門檻值之後將下降。因此，為穩定稻米品質與產量，勢必篩檢合適栽植地區或栽植期以調適栽植期的氣象環境變化及未來變遷趨勢，尤其在氣候快速變遷情境下更需彈性因應。

關鍵字

穀粒充實期間 ； 氣象變因 ； 不同地區選育稻種 ； 米質 ； 產量

並列摘要

Changes in climatic variables during grain-filling stage are known to affect yield and quality of rice at harvest. However, there exist differential effects on cultivars that bred from varied regions with diversified genetic contexts and environmental conditions. To effectively response to different conditions emerging from changing climate for a stable food supply, it is necessary to further clarify the underlying mechanisms of climatic effects. This study was conducted in years from 2008 to 2010 with a total of 29 cropping seasons based on 24 Solar Terms calendar. Four rice (Oryza sativa L.) cultivars bred from different regions in Taiwan were selected for experiments, and weather data recorded from nearby meteorological station were used for analyses. The mean values of daily mean air temperature, daily maximum air temperature, daily minimum air temperature, day-night temperature difference, daily sunshine hours and daily irradiance during grain-filling stage were calculated as six climatic variables of MDMAT, MDMAXAT, MDMINAT, MDNTD, MDSH and MDIR, respectively. Results showed that temperature variables had a greater weight than irradiance and sunshine hour, and amylose, transparency and head rice rate of milled grains were the quality traits affected by temperature changes. The curvilinear relationships were significant only for 'TY4' in the first-half years (FHY), but were significant for all cultivars in the second-half years (SHY). Temperature variables also had an effect on grain yield, the convex curve patterns indicating that there were optimal temperature regimes. Analyses on the pooled data of 4 cultivars indicated that rice yields reached the plateau at MDMINAT of 23℃, MDMAT of 26.5℃ and MDMAXAT of 31℃ in FHY, and were at MDMINAT of 20℃, MDMAT of 24℃ and MDMAXAT of 29℃ in SHY. Both MDNTD and MDIR had a quadratic relationship with quality traits in SHY, and similar relationship was found in MDNTD with grain yield in SHY. This study demonstrated the differential effects of climatic variables during grain-filling stage on chemical components, physical characters and yield of rice grains in cultivars bred from varied regions. Temperature variables above the threshold values that obtained the maximum yield result in a decline of yield production.

並列關鍵字

Grain-filling stage ； Climatic variable ； Cultivar bred from varied regions ； Rice quality ； Rice yield