Endogenous hormone concentrations and embryogenic callus development in wheat
Endogenous hormone concentrations and embryogenic callus development in wheat
复制标题
DOI：
10.1023/a:1011671310451
复制
发表时间：
2001-10-01
影响因子：
3
通讯作者：
Bangerth, F
中科院分区：
文献类型：
--
作者：
Jiménez, VM;Bangerth, F
以两种小麦（Triticum aestivum L.）基因型的未成熟合子胚为初始外植体，建立愈伤组织培养。从胜任基因型（Combi）中获得胚性和非胚性愈伤组织，而从无能基因型（Devon）中只产生非胚性愈伤组织。将部分愈伤组织转移到再生条件下，评价了各类型愈伤组织的形态发生能力。内源激素浓度(游离吲哚-3-乙酸[IAA]、脱落酸[ABA]、赤霉素(1)、（3)和（20）[GAs]、玉米素/玉米素核苷[Z/ZR]和N-6[δ(2)-异戊烯基]腺嘌呤/ N-6[δ 2-异戊烯基]腺苷）；[iP/iPA])通过放射免疫法测定，结果表明，最适基因型胚中ABA含量较高；其胚胎的早熟率较低。通过对各基因型愈伤组织中内源激素浓度的分析，发现只有游离IAA浓度的差异与愈伤组织形态发生特性的变化有关。较高浓度的内源游离IAA是胚性愈伤组织培养的典型特征。还观察到，由于培养时间的延长，愈伤组织的胚胎发育能力下降，与游离IAA浓度的降低同时发生，几乎与未发生胚胎发育的愈伤组织的浓度相当。
Immature zygotic embryos of two wheat (Triticum aestivum L.) genotypes, known for their different ability to generate embryogenic callus, were used as initial explants to establish callus cultures. Embryogenic and non-embryogenic calluses were obtained from the competent genotype (`Combi'), while only non-embryogenic callus was produced by the incompetent one (`Devon'). The morphogenetic competence of each callus type was evaluated by transferring some segments to regeneration conditions. The endogenous hormone concentrations (free indole-3-acetic acid [IAA], abscisic acid [ABA], gibberellins (1), (3) and (20) [GAs], zeatin/zeatin riboside [Z/ZR] and N-6[Delta (2)-isopentenyl] adenine/ N-6[Delta 2-isopentenyl] adenosine; [iP/iPA]) of the initial explants were determined by means of radio-immunoassay and showed that the only difference was the higher concentration of ABA found in the embryos of the most competent genotype; whose embryos showed a reduced rate of precocious germination. When analysing the endogenous hormone concentrations in the various callus types generated in each genotype, it was found that only differences in the free IAA concentrations were associated with variations in the morphogenic properties of the calluses. Higher concentrations of endogenous free IAA were typical of embryogenic callus cultures. It was also observed that a loss in the embryogenic competence of the calluses, due to a prolonged time of culture, occurred concomitantly with a reduction in free IAA concentrations, practically to the concentrations found in the non-embryogenic calluses.