缺钾对几种作物营养器官组织结构的影响

Effects of potassium deficiency on tissue structure of vegetative organ in some crops.

研究了缺钾对大豆(Glycine max L.Merrill)、棉花(Gossypium HirsutumL.)、甘蓝油菜(Brassica napus L.)和大麦(Hordeum distichum L.)营养器官组织结构的影响.结果表明缺钾时根组织分化不良,常见根冠缺失或发育残缺不全,没有明显的分生区和完整的伸长区.大麦缺钾时茎的表皮细胞变形,基本组织细胞收缩,厚壁机械组织消失,维管束变小;棉花缺钾茎部维管形成层分生能力弱,次生韧皮部和次生木质部不发达,髓体积变小.缺钾使植株叶片表皮细胞破坏,叶肉薄壁细胞常见收缩破裂,叶绿体减少.在大麦叶肉细胞破裂处可见棕褐色物质;大豆下位叶叶绿体外形不规则,叶绿体基粒膨胀或基粒形态模糊不清,基质片层破坏,有许多亲锇小球,叶片表皮细胞角质层发育不良,保卫细胞干瘪.

A study on the effects of potassium deficiency on tissue structure of vegetative organ of soybean (Glycine max L. Merrill), cotton (Gossypium hirsutum L. ) , rape ( Brassica napus L.) and barley (Hordeum distichum L. ) was conducted. The results showed: ( 1 ) Potassium deficiency caused adnormality of structure in the root apex. The root cap was missing or insonplete. ( 2 ) The epidermis and ground tissue clells of barley stem suffering from potassium deficiency changed their normal shape. Sclerench-ymatic ring was not seen. Vascular bundle was small. Secondary phloem and xylem developed poorly because of the reduction of vascular cambium activity in the section of cotton stem with potassium deficiency. ( 3) Parenchyma cells of mesophyll shrunk in the leaves and then collapsed. Brown material appeared around these collapsed cells, and chloroplast diminished. The cuticular layer was poorly developed. Chloroplast of lower leaves of potassium deficient soybean lost normal grana structure. Grana aligned along the inner surface of chloroplast were either swelling or lacking definition. Stroma lamella was destroyed. Starch grains and many osmiophylic globules were present. Chloroplast became irregular in outline. Application of potassium fertilizer to the soil in which available potassium was very low main tained normal tissue structure of vegetative organ of soybean, leading to the increase of the total number of grains per plant, 100 grain weight and field yield.