论文部分内容阅读
在生长素诱导下,大白菜(Brassicaampestris.spp.pekinensis)的下胚轴切段显示了一定的发根能力,其中,0.4—1.0mg/L IAA显著地促进大白菜不定根的发生。在生长素诱导24h后,可借助显微切片观察到下胚轴切面明显的解剖学变化:首先是中柱鞘内靠近韧皮部的薄壁细胞的细胞质与细胞核变浓,染色加深,部分细胞分裂;随后是分裂的细胞团增大,逐渐形成根原基并分化出根冠。当下胚轴切段培养5天后,大量不定根穿破皮层,达到肉眼可见的程度。同一外植体中不定根的发育是不同步的,下胚轴不同部位的切段具有不同的发根能力;当下胚轴切段在培养基上反插时,提高外源IAA可修饰根发生的极性,提高蔗糖浓度能增强IAA的修饰作用;在模拟微重力效应条件下,不定根发生的极性没有明显变化,但是,增加了外植体对IAA诱导发根的敏感性。本结果为进一步研究不定根发生的分子机制建立了试验系统。
Hypocotyl segments of Chinese cabbage (Brassica campestris spp. Pekinensis) showed some hairy ability under auxin induction. IAA 0.4-1.0 mg / L significantly promoted the adventitious root formation of Chinese cabbage. After 24 hours of auxin induction, obvious anatomical changes in the hypocotyls of the hypocotyls can be observed by means of microsection. The first is that the cytoplasm and nucleus of the parenchyma near the phloem in the mid-column sheath are thickened, the staining deepens and some cells divide. Then split the cell mass increases, and gradually form the root primordia and differentiation of the root crown. When the hypocotyl cuttings were cultured for 5 days, a large number of adventitious roots penetrated the cortex to the extent visible to the naked eye. The development of adventitious roots in the same explant is asynchronous. The cuttings of different parts of hypocotyls have different hair root abilities. When hypocotyl cuttings are inserted into the medium, the exogenous IAA modifiable roots are increased Polarity and sucrose concentration increased the modification of IAA. Under simulated microgravity effect, the polarity of adventitious root did not change significantly, but increased the sensitivity of explants to IAA-induced hairy roots. This result establishes a test system for further research on the molecular mechanism of adventitious root formation.