(35(3):235-243)Variability of Milling Quality and Grain Appearance of Rice Varieties

以引自日本及本省育成之稉稻與引自IRRI、本省傳統及本省育成之秈稻計59個水稻品種供試。在力求均一之栽培管理與收穫調製條件下，調查參試水稻品種之碾米品質及米粒外貌等二大類品質性狀共計10項，以探討水稻碾米品質及米粒外貌之品種間變異。就型間言，碾糙率、白米率、完整白米率、糙米容重量、糙米粒寬、粒米千粒重、白堊質米出現頻度及白質堊面積大小等8性狀之表現以稉稻較佳；秈稻則有較長之粒長與較大之長寬比。就稉稻言，引自日本諸品種之平均碾米率、白米率、完整白米率、糙米容重量、白堊質米出現頻度及白堊質面積大小等6性狀均較本省育成者為優。顯示本省稉稻品種，在碾米品質及米粒外貌方面尚須繼續加以改良。秈稻方面，本省育成品種之完整米率，白堊質米出現頻度及白堊質面積大小等3性狀之表現均優於引自IRRI及本省傳統之品種，顯示本省秈稻育種在此3性狀之改良確有實績。 This study was intended to provide some basic imformatiom on the variability of milling quality and grain appearance of rice varieties. A total of 10 grain quality characters relating to milling quality and grain appearance were evaluated, under uniform field practices and postharvest handling operations, for 59 rice varieties including japonica (Japan and Taiwan improved varieties) and indica (IRRI, Traditional, and Taiwan improved varieties) types. In general, the mean performance of some characters of japonica type such as brown rice rate, total milled rice rate, headrice rate, brown rice volume weight (0.11), brown rice grain width, brown rice 1,000-grain weight, the occrruence frequency of chalky endosperm and the opaque area of chalky endosperm were better than those of indica type. On the other hand, indica type was characterized by longer grain length and larger length/width ratio. Among japonica rice varieites, the mean values of brown rice rate, total milled rice rate, head rice rate, brown rice volume weight, the occurrence frequency of chalky endosperm and the opaque area of chalky endosperm of Japan varieties were better than those of Taiwan improved variaties. Among indica rice varieties, the mean performance of head rice rate, the occurrence frequency of chalky endosperm and the opaque area of chalky endosperm of Taiwan improved varieties were better than those of IRRI or Traditional varieties