尾穗苋茎的异常加厚  

ANOMALOUS THICKENING IN THE STEM OF AMARANTHUS CRAUDATUS

作　　者：杨培君[1] 赵桦[1] 胡正海 

机构地区：[1]汉中师范学院生物系,西北大学植物研究所

出　　处：《西北植物学报》1994年第5期7-11,162,共6页Acta Botanica Boreali-Occidentalia Sinica

摘　　要：尾穗苋茎中多轮散生维管束的产生是由起源于原形成层的异常形成层连续活动的结果。异常形成层由１─２层细胞组成，在早期的活动中，通常以单向方式向内交替产生维管束原束和薄壁结合组织；而后期则以双向活动方式向内产生木质部和其间的厚壁结合组织，韧皮部较晚在异常形成层的外缘发生。原形成层束分化为具束中形成层的外韧维管束，但无束间形成层分化。中央维管束和各轮异常维管束中的束中形成层能产生一些次生维管组织。Anomalous thickening occurs in the stem of Amaranthus craudatus as a result of successive activity of anomalous cambium originated from procambium, which gives rise to many rings of scattered anomalous bundles. Anomalous cambium composed of one to two cell layers,in the early stage of the stem growth, is usually in uni-directional action to produce alternatively prodemogen strands and conjunctive ground tissue on the inner side;but in the later period of the stem growth, it is approximately in bi-directional action. Xylem and thick-walled conjunctive tissue are produced to the inside, and phloem strands occur later on the periphery of anomalous cambium. The procambium strands differentiate into collateral bundles with intrafascicular cambium, but no interfascicular cambium. Thus, a continuous stelar cambium does not occur in stem. However, anomalous bundles are also with intrafascicular cambium. They continue to producesome secondary tissues.

关 键 词：尾穗苋 茎 异常加厚 

分 类 号：Q959.745.2[生物学—动物学]