大麦浆片控制开花的机理研究

 开颖开花型和闭颖开花型大麦均由表皮、基本组织和脉状维管束3部分组成。浆片表皮不具气孔。细胞外壁角质化、不透水气。浆片脉状维管束为有限外韧型，呈散生状分布。脉状维管束数与其所含导管数为六棱大麦多于二棱大麦，可育系多于不育系。一个发育良好的脉状维管束由数个导管、筛管及伴胞和维管薄壁细胞组成。其维管薄壁细胞壁厚、核大、质浓、线粒体丰富，可能有利于浆片的吸胀和物质的撤离而萎缩。浆片中含有淀粉酶。开花时浆片的鲜重、干重和可溶性糖含量均增加。小花的开放由浆片内细胞的渗透压变化来调节，而小花的关闭则由于浆片内细胞的自溶，降解物通过质外体途径撤离，浆片萎缩。闭花过程与小花轴有关。

On Machanism of Barley Lodicule Controlling Opening-lemma

Lodicule consists of epidermis, ground tissue and vernal vascular bundles. There is a cuticular layer, but no stoma on the epidermis. The closed collateral bundles scatter in a lodicule. The number of the vascular bundles and their trachea of the hexagonus barley is more than that of the diplogonus barley, and so is the fertile line than the male infertile line. A typical veinal vascular bundle is composed of trachea, sieve tubes and companion cells, and the vascular parenchyma cells with large nucleus,thick cell wall and cytoplasm, and many organelles, especially mitochondria. All these are beneficial for a lodicule imbibing and wilting. Amylases are found in the lodicule and it is also found that there is an increase in dry weight, fresh weight and the content of the soluble sugars of the lodicules at the beginning of the opening-lemma. It is therefore suggested that the change of the osmotic pressure in the lodicules regulates the opening-lemma of the floret, and that the vascular bundle network system in a floret is related to the closing-lemma of a floret.