【摘要】 香叶天竺葵(Pelargoniumz graveolens L’Her.)离体叶的叶柄中部扦插在石英砂或普通细砂中,在温室中培养约经一星期后,即可见叶柄切口处不规则地发生愈伤组织。到了2星期后,才陆续有不定根的出现。不定芽也在愈伤组织中发生,但是发生时并不与维管组织直接连系。它们的发生可有二种方式:深入愈伤组织中发生(内生的),和在愈伤组织中靠近表面发生(外生的)。它们在发生后不久,在纵切面上前端作钝平形(很多成倒三角形)。后来,前端的中央凹入,现出了第一个叶原基和茎的顶端分生组织。幼芽继续伸展,顶端陆续发生叶原基,并且逐渐趋向正常芽的结构。伸出地面后的茎端结构完全与成长的茎端一样。不定芽上以后发生的腋芽原基的经构,大致也与不定芽原基的一样。更多还原

【Abstract】 Median sized leaves of Pelargonium graveolens L’Her. after being excised from the middle of the petioles were planted in quartz sand or common sand in greenhouse. After one week in culture, calluses were formed aberrantly at the wound surface of the petioles of most of the detached leaves. By the second week, adventitious roots initiated some- where in the callus close to the vascular tissue of the splitted base of the petiole. Adventitious buds also initiated from the callus, but they were not related to the vascular tissue in the origin. There were two different modes of initiation: one from the depth of the callus (endogenous) and the other near its surface (exogenous). Soon after, the distal end of the bud primordium became flattened (most of them became inverted triangular in outline) as was seen in the longitudinal section. Later, the middle part of the distal end became depressed and differentiated into the first leaf primordium and the apical meristem. As the young bud became further elongated, the leaf primordia were consecutively formed. Consequently the structure of the adventitious buds approach- ed normal. The apical portion emerged from the sand was similar to the mature one in structure.更多还原