8个野生稻种的叶片硅体研究

用强酸溶液分离8个野生稻种叶片中的硅体并用光学显微镜和电子扫描显微镜进行观测研究.结果显示,(1)叶片含有3种类型的硅体,即不规则硅体、哑铃形硅体和扇形硅体,前2种硅体不能作为属内分类的依据,但短药野生稻哑铃形硅体的表面纹饰独特,可作为识别该物种的特征.(2)同一个物种的扇形硅体变异很大,统计学表明它总以其中的某一种类型占有优势,紧穗野生稻和短舌野生稻中小型硅体占优势,药用野生稻和普通野生稻中约有一半为中型硅体,另一半为小型硅体,其余4种野生稻包括斑点野生稻、澳洲野生稻、展颖野生稻和短药野生稻中绝大多数为中型硅体,即野生稻的扇形硅体以中、小型为主.(3)根据扇面长/扇柄长的比值,将扇形硅体划分为长柄型、中间形和短柄型3种形态,依此对8个稻种的硅体分类.结果表明,斑点野生稻、药用野生稻、紧穗野生稻和澳洲野生稻以长柄型为优势;普通野生稻、短舌野生稻、展颖野生稻和短药野生稻则以中间型为主,且扇形硅体的扇面长/扇柄长的比值的大小与野生稻染色体组型或原产地有关.

Silicas in Leaves of Eight Wild Rice Species

Concentrated acid solution by mixing nitrate and sulfuric acids was used to isolate silicas from leaves of 8 wild rice species and silica was observed with optical microscope and scanning electron microscope.Three types of silica were obtained as irregular silica,dumb bell silica and fan shape silica.The irregular and dumb bell silicas cannot be applied in classification in Oryza,but a special ornament on the surface of O.brachyantha was found to be a significant character to identify the species.Although fan shape silica in one species vary greatly,statistics revealed that it is the dominant shape.In O.eichingeri and O.barthii,the tiny fan shape silica was dominant,and in O.officinalis and O.rufipogon half was medium and half was tiny and in the other wild rice species including O.punctata,O.australiensis,O.glumaepatula and O.brachyantha,the most was medium.This results showed that wild rice has more medium fan shape silica.Based on the ratio of b/a,the fan shape silica was classified as long handle,short handle and intermediate types.Accordingly,the different types of the silica in the 8 species were accounted.In O.punctata,O.officinalis,O.eichingeri and O.australiensis,the dominant was long handle type,and in O.rufipogon,O.barthii,O.glumaepatula and O.brachyantha,the intermediate type was the major type.The ratio of b/a of the fan shape silica is relevant to the chromosome type or the distribution of the wild rice.