河姆渡·罗家角出土稻谷外稃双峰乳突的扫描电镜观察研究

The Study on the Bi-Peak-Tubercle on Lemma of Hemudu and Luojia-jiao Ancient Excavated Rice Grains with Electric Scanning Microscope

以8个籼稻品种和8个粳稻品种作对照,对较完整的太湖地区河姆渡出土稻谷(6950±130BP)和罗家角出土稻谷(7040±130BP)进行扫描电镜观察.发现距/深比以10,峰角度以80°,垭角度以155°为界限指标,可将水稻的双峰乳突分为“锐型”和“钝型”两种基本类型.小于上述指标的为“锐型”,籼稻品种多属之.大于上述指标的为“钝型”,粳稻品种多属之.据此提出了水稻“双峰乳突鉴别法”.用谷粒的长/宽比指标和外稃双峰乳突指标对河姆渡·罗家角出土稻谷作了研究.三粒河姆渡出土稻谷具有粒形似籼而双峰乳突为从混沌态到稳定态不同演化状态的“钝型”特征.四粒罗家角出土稻谷中2号稻谷为籼型粒形和混沌态“钝型”双峰乳突,l、5号稻谷则粒形似籼而双峰乳突为分化态和稳定态“钝型”,3号稻谷粒形似粳、双峰乳突为稳定态“钝型”.无论从粒形的长宽分布、双峰距和垭深分布以及峰角度与垭角度分布皆可看到7000年前的出土稻谷均处于与现代籼稻和粳稻不同的区域,表明出土稻谷是一种非典型籼非典型粳的各种中间类型并存的原始混合群体.这种“非籼非粳”是“正在分化的”古栽培稻的重要特征.因此“先有籼或先有粳”的命题,并用现代的籼粳概念去规范古栽培稻的属性,似有不妥,值得商榷.

The bi-peak-tubercle on lemma in the cultivar grains of 8 indica and 8 japonica, 3 grains of Hemudu (6950±130BP) and 5 grains of Luojiajiao(7040±130BP) ancient excavated rice were studied with electric scanning microscope. The significant differences in the bi-peak-tubercle between the indica and japonica varieties have been observed According to the judgement criterion of the peak angle 80°, col angle150° and ratio of bi-peak distance/col depth 10, the bi-peak-tubercles could be classified into two types as 'acute' in indica and 'obtuse'in japonica. Based on the bi-peak-tubercle structure obseved like 'obtuse' type, the 3 grains of Hemudu and 4 Luo jiajiao ancient excavated rice were identified as japonica although the grain shape of the 6 from these 7 grains excavated likes as indica. Therefore, the ancient rice to be considered as a 'dividing'、'non-indica', 'non-japonica' group of rice type were deeply convinced.