【摘要】 怀山药脱毒试管苗经诱导可形成脱毒微型块茎,其作为繁殖体比试管苗具有优势。以继代培养的脱毒试管苗带芽茎段为外植体,接种于含60 g·L-1蔗糖的MS液体培养基中,采用黑暗震荡的培养方式进行微型块茎诱导,分别在外植体时期、出芽期、芽伸长期、微型块茎形成期、膨大期和成熟期取材进行相关生理生化指标的测定。结果表明,微型块茎形成过程中可溶性总糖、葡萄糖和果糖含量变化趋势基本一致,均在微型块茎形成期达最大值;蔗糖和淀粉逐渐积累,含量逐步升高;蔗糖合成酶(SS)合成方向活性与蔗糖磷酸合成酶(SPS)活性分别在微型块茎成熟期和膨大期达最大值,共同促进微型块茎内蔗糖的积累;腺苷二磷酸葡萄糖焦磷酸化酶(AGPase)和淀粉合成酶(SSS)分别在酶活性最高时与淀粉合成积累量呈极显著相关;IAA、ABA和ZR含量均与微型块茎形成正相关,JA与微型块茎形成无明显相关。更多还原

【Abstract】 Microtubers may provide a feasible alternative to in-vitro-grown plantlets as a means of micropropagation. In this study, changes in physiological and biochemical parameters were followed during the process of microtuber formation in Dioscorea opposita. Microtubers were produced from single nodal segments incubated in MS basal medium supplemented with 60 g·L-1 sucrose in a rotary shaking condition. During the process of microtuber formation, the contents of soluble sugar, glucose and fructose showed similar changes and simultaneously reached the highest levels. The microtuber formation was associated with gradual accumulation of sugar and starch. The activities of sucrose synthase in direction of sucrose synthesis and sucrose phosphate synthase reached the maximum levels in the microtuber mature stage and the microtuber enlargement stage, respectively, indicating that they work in concert to promote the accumulation of glucose in microtuber. The levels of adenosine diphosphoglucose pyrophosphprylase and starch synthase were significantly correlated with the accumulation of starch synthesis. The levels of 3-indoleacetic acid, abscisic acid and zeatin riboside but not jasmonic acid showed a positive association with the process of microtuber formation.更多还原