朱顶红幼嫩花梗胚性愈伤组织诱导和高效植株再生

为建立高效的朱顶红植株再生和种苗繁育技术体系，以幼嫩花梗为外植体开展胚性愈伤组织诱导和植株再生研究。对2,4-D和噻苯隆（TDZ）浓度、外植体发育时期及大小进行了筛选，结果表明：将切片厚度为1 mm的幼嫩花梗外植体置于添加0.5 mg ? L-1 TDZ 和2.0 mg ? L-1 2,4-D的MS固体培养基上培养8周，胚性愈伤组织诱导率最高，达85.3%。将胚性愈伤组织转移至相同的培养基上，每月继代1次，平均每月增殖10.6倍。在不含任何生长调节剂的MS培养基上，胚性愈伤组织的植株再生率达98.0%，平均每块愈伤组织可再生出12.3个小植株。经过36次（3年）继代培养后，胚性愈伤组织的增殖和植株再生效率没有显著变化。幼苗移栽至温室驯化，成活率达97.5%。再生植株移栽到田间，没有发现明显的表型变异。对随机选择的再生植株和母株进行简单序列重复区间（ISSR）扩增分析，证实再生植株没有发生DNA水平变异。

Induction of Embryogenic Calli from Immature Pedicels and Efficient Plant Regeneration of Hippeastrum

The aim of this study was to establish an efficient system of plantlet regeneration and seedling production for Hippeastrum. We focused on embryogenic calli induction from immature pedicel explants and plantlet regeneration. The effects of plant growth regulator concentration，the developmental period of the explant，and explant size were evaluated. The highest induction rate of embryogenic calli（85.3%）was achieved by culturing 1 mm thick slices of immature pedicel explants on Murashige and Skoog（MS）medium supplemented with 0.5 mg ? L-1 N-phenyl-N’-1,2,3-thiadiazol-5-ylurea（TDZ）and 2.0 mg ? L-1 2,4-dichlorophenoxyacetic acid（2,4-D）for 8 weeks. Embryogenic calli were subcultured on the same medium and were subcultured once a month. Under these conditions，the proliferation rate of embryogenic calli was 10.6-fold per month. The plant regeneration rate of embryogenic calli reached 98.0%，and an average of 12.3 plantlets formed from each embryonic callus on MS medium without any growth regulators. After subculturing 36 times（3 years），there were no significant changes in embryogenic calli proliferation and plant regeneration efficiency. The survival percentage of these seedlings hardened in the greenhouse was 97.5%. After transplanting into the field，no obvious phenotypic variations were observed among the regenerated plants. Inter-simple sequence repeat（ISSR）marker analysis supported the absence of DNA-level variations among the regenerated plants.