硫代硫酸银对二倍体马铃薯试管苗生长和生理特性的影响

植物组织培养中由于气体交换的限制, 培养器皿中常伴有乙烯积累, 影响植株形态建成和器官生长发育。以马铃薯二倍体品系HS66、ED13和DH401为试材, 研究不同浓度(0、1、2、4、8 mg L^-1)硫代硫酸银(STS)对试管苗生长和相关生理指标的影响。结果发现, 与培养基中不加STS相比, 附加1 mg L^-1 STS可增加试管苗叶面积和叶绿素含量, 抑制气生根的产生; 附加4 mg L^-1以上STS试管苗出现紫色色素沉积、叶片背面生成愈伤组织等畸形现象。试管苗可溶性蛋白、脯氨酸和丙二醛含量随STS浓度的增加呈先降后升的趋势, 在培养基中附加1 mg L^-1 STS时, 3个品系试管苗的可溶性蛋白、脯氨酸和丙二醛含量均下降; 附加2 mg L^-1 STS时, DH401可溶性蛋白和脯氨酸含量及HS66丙二醛含量反弹升高; 附加4 mg L^-1以上STS时, 3个品系试管苗的可溶性蛋白、脯氨酸和丙二醛含量均随STS浓度的增加而增加。上述结果说明, 低浓度STS可以缓解乙烯胁迫, 促进试管苗正常生长, 高浓度STS则造成试管苗生理及形态上的明显毒害。

Effects of Silver Thiosulfate (STS) on Growth and Physiological Characteristics of Potato Plantlets in vitro

Ethylene accumulation often occurs in plant tissue culture owing to limited gas exchange. The effect of silver thiosulfate (STS), an inhibitor of ethylene activity, on reducing ethylene-induced plant abnormalities was investigated in three diploid potato (Solanum tuberosum L.) genotypes (HS66, ED13, and DH401) with different concentrations (0, 1, 2, 4, and 8 mg L^-1) of STS in culture medium. The results showed that the leaf areas and total chlorophyll contents in three genotypes increased and aerial root could be eliminated by addition of 1 mg L^-1 STS into culture medium as compared with control (0 mg L^-1). Toxic symptoms like black purple pigment accumulation and callus occurring on leaf abaxial surface were observed on plantlets when the STS concentration was over 4 mg L^-1. The soluble protein, proline, and malondialdehyde (MDA) contents in three genotypes decreased first and increased then with the STS concentration increase. They declined in the medium containing 1 mg L^-1 STS compared with control. Addition of 2 mg L^-1 STS resulted in the ascending of soluble protein and proline contents in DH401 and MDA content in HS66. The soluble protein, proline, and MDA contents of three genotypes increased with STS concentration increasing in the medium containing 4–8 mg L^-1 STS. These results indicated that supplement of 1 mg L^-1 STS in medium could alleviate ethylene stress and improve plantlet growth. No morphological abnormality was observed in plantlets, but some physiological parameters showed STS toxicity to plantlets of HS66 and DH401 in the medium containing 2 mg L^-1 STS. Both morphological and physiological parameters indicated that higher concentration (4–8 mg L^-1) of STS in the medium was toxic to three genotypes in vitro.