大麦浆片结构及其在开花过程中的变化

浆片由表皮、基本组织和维管束三部分组成。表皮上不具气孔，细胞外壁角质化。维管束为有限外韧型，呈散生状分布。浆片中管束数与其所含导管数因品种（系）而异，可育系多于不育系。大维管束由数个导管、筛管及伴胞和维管束薄壁细胞组成，且其维管束薄壁细胞壁厚、核大、质浓，线粒体丰富，中、小维管束一般不含导管。

CHANGES OF STRUCTURE AND SUBSTANCES IN THE LODICULE DURING THE OPENING AND CLOSING LEMMA OF BARLEY

Lodicule consisted of epidermis,ground tissue cells and some veinal vascular bundles.There was a cuticular layer,but no stoma on the epidermis.The number of the closed collateral vascular bundles and their vessels of the hexagonus barley is more than that of the diplogonus,and so the fertile lines more than the male sterile lines.A typical veinal vascular bundle was composed of a few vessels,sieve tubes and companion cells,and the vascular parenchyma cells with large nucleus,thick cell wall and cytoplasm,and many organelles,especially mitochondria,in a vascular bundle.All these are beneficial for a lodicule to imbibe and to wilt. Analysis were found in the lodicule and it was also found that there was an increase in dry weight,fresh weight and the content of the soluble sugars in the lodicule as the opening lemma. It was therefore suggested that the change of the osmotic pressure in the lodicule regulated the opening lemma of the floret,and that the vascular bundle network system in a floret axis was possibly relative on the closing lemma of a floret.