抽穗至收穫期間氣象變因對水稻米質（TNG 71）之影響

Effect of Climatic Conditions during Heading to Harvest Stage on Quality of Rice Cultivar TNG 71

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》 61卷3期 (2012/09) Pp. 222-240

https://doi.org/10.6156/JTAR/2012.06103.06

摘要

為探討抽穗至收穫之穀粒充實期間氣象環境變化對稻米品質的效應，以釐清影響米質的關鍵生育期主要氣象變因之作用及其影響，本研究以良質稻種台農71號（TNG 71）為試料，在台中市霧峰區的行政院農業委員會農業試驗所農場進行多個栽植期的田間試驗。研究期間自2006年12月起至2009年8月止總計41個栽植期，累加各栽植期自抽穗至收穫所量測的日均溫（ADMAT）、日最高溫（ADMAXAT）、日最低溫（ADMINAT）、日照時數（ADSH）與日射量（ADIR）等五項氣象因子測值，以分析此五個氣象變因對米質的影響。又將41個栽植期劃分兩部分，其一為1月至6月的上半年，共有22個栽植期，其二為7月至12月的下半年，計有19個栽植期，藉以進一步分析上、下半年氣象因子對米質的差異影響。經由相關矩陣分析結果，此5項計算累加值的氣象變因兩兩之間皆為顯著相關，上半年之此5項氣象變因之間泰半具有較高的相關係數，顯示試驗期間上半年的氣象變因之間具有較密切之連結。對於影響米飯食味品質的米粒化學組成與外觀品質，其與41個栽植期的氣象變因之相關性分析顯示，糙米的粗蛋白質含量與此5項氣象變因皆呈顯著正相關，其游離脂肪酸則與ADMAXAT及ADSH呈顯著正相關；而白米的粗蛋白質含量與ADMAT、ADMAXAT及ADSH呈顯著正相關，其直鏈性澱粉與ADMINAT則呈顯著負相關，白米的白度與ADMAT、ADMAXAT、ADSH及ADIR等氣象變因具有顯著負相關，其透明度則與此5項氣象變因均呈極顯著負相關。白米的完整粒比例與ADMAT、ADMAXAT、ADMINAT及ADSH等氣象變因之間為顯著負相關，其非完整粒比例則與ADMAT及ADMINAT為顯著正相關。穀粒的粒長與ADIR呈顯著負相關，粒厚則與ADIR呈顯著正相關。除白米粗蛋白質含量、穀粒長度及穀粒長/穀粒寬之比值之外，概以上半年較下半年具有較高相關程度。由多元線性迴歸分析結果，建立米粒化學組成及物理特性與氣象變因之間的三元線性迴歸方程式，發現概以ADMINAT、ADSH及ADIR乃影響本試區米粒化學組成及物理特性的3項最主要氣象變因。綜合試驗結果，顯見良質稻種台農71號於抽穗至收穫期間的氣象因子變化將會影響米粒的化學組成及物理特性，各項米質性狀各有其不同的主要影響氣象變因與權重。為求穩定稻米品質勢必篩檢合適的栽植地區或栽植期，藉由選擇穩定的栽植期氣象環境來減緩氣象變因的負作用或調適氣候變遷的負面影響。

關鍵字

米質 ； 氣象變因 ； 關鍵生育期 ； 化學組成 ； 物理特性

並列摘要

Climatic conditions during heading to harvest stage are important factors affecting quality of rice (Oryza sativa). The objective of this study was to determine effects of major climatic variables during the key growth stage from heading to harvest on quality of rice by conducting multiple-year field experiments at the experimental farm of Taiwan Agricultural Research Institute at Wufeng, Taichung, Taiwan, using a widely cultivated variety TNG 71. The variety TNG 71 was grown for a total of 41 crops from December 2006 to August 2009 with 22 crops produced in the first half year and 19 crops produced in the second half year. For each crop season, accumulated values of daily mean air temperature (ADMAT), daily maximum air temperature (ADMAXAT), daily minimum air temperature (ADMINAT), daily sunshine hours (ADSH), and daily irradiance (ADIR) were collected during heading to harvest stage. These five climatic variables were used for analysis of quality traits of rice. Results of correlation matrix analyses showed that correlation coefficients among climatic variables were generally higher in the crop of first half year than those in the crop of second half year, suggesting a more stable climatic environment and hence a closer link between variables in the first half year during the experimental period of 2006-2009. From pooled data, crude protein of brown rice was correlated with all the five climatic variables and free fatty acid content was positively correlated with ADMAXAT and ADSH. In milled rice, crude protein was positively correlated with ADMAT, ADMAXAT and ADSH, while amylose was negatively correlated with ADMINAT. The whiteness of milled rice was negatively correlated with ADMAT, ADMAXAT, ADSH and ADIR, and the transparency of grain kernel was negatively correlated with all the climatic variables. The ratio of head rice was negatively correlated with ADMAT, ADMAXAT, ADMINAT and ADSH, while the ratio of non-head rice was positively correlated with ADMAT and ADMINAT. The grain length was negatively correlated with ADIR, whereas grain thickness was positively correlated with ADIR. Except crude protein, the correlations of length and length width ratio of grains with climatic variables were generally higher in the crop of first half year than in the crop of second half year. Results of multiple linear regression analyses showed that, ADMINAT, ADSH and ADIR were the three major climatic variables accounted for variations of chemical and physical components of rice. This study indicates that changes in climatic conditions during the period of heading to harvest are important factors affecting chemical components and physical characteristics of rice grains. Thus, selection of suitable location for cultivation of rice and planting season are some strategies for minimizing negative impacts of climatic factors on rice quality.

並列關鍵字

Rice quality ； Climatic variable ； Key growth stage ； Chemical composition ； Physical characteristics