皱叶酸模种子萌发对光照和温度的响应

Response of Rumex Crispus Seed Germination on Light and Temperature

光照和温度是影响植物种子萌发的两种重要环境信号,且两种信号转导途径间存在交互作用.目前对于光、温信号如何协同调控种子休眠与萌发还知之甚少.以光温双敏性的皱叶酸模种子为材料,通过在选定的两种高低不同的温度下进行光暗交替培养,观测萌发响应,试图一窥光温互作机制.结果表明:皱叶酸模种子属于需光性种子,其萌发被交替光照处理促进,被全黑暗处理抑制,且光照和温度之间存在极显著的交互作用.不管是在较低的15℃还是在较高的25℃条件下,仅交替光照预培养1 d的种子,其萌发在一定程度上受到随后全黑暗培养的抑制;仅在较低的15℃条件下,且全黑暗预培养时间大于等于6 d时,后续的交替光照培养无法完全抵消之前全黑暗预培养对萌发的抑制作用,且全黑暗预培养的时间越长,这种萌发抑制作用越强,越不易被后续交替光照培养所逆转;而在较高的25℃条件下,全黑暗预培养对萌发的抑制均能被后续的交替光照培养所抵消,而使最终累积萌发率达到和交替光照对照组相同的水平.这意味着,相比于光照,温度对皱叶酸模种子的萌发更重要,且光照和黑暗处理的时间也很重要,或者说皱叶酸模种子萌发的需光性依赖于温度和时间.这很可能与光温二受体光敏色素有关,有待进一步研究.

Light and temperature are two important environmental signals affecting plant seed germination,and there is an interaction between the two signal transduction pathways.Very little is known about how light and temperature signals jointly regulate seed dormancy and germination.In this study,Rumex crispus seeds,sensitive to both light and temperature,were used as experimental materials,and the germination response to alternating light and all-dark culture was observed,with an aim to try to explore the interaction mechanism between light and temperature in the way of regulating seed dormancy release and germination.The results showed that:R.crispus seeds were photoblastic,whose germination was promoted by alternating light culture and inhibited by all-dark culture,and there was a very significant interaction between light and temperature;whether at 15℃(lower)or 25℃(higher),for the seeds pre-cultured for 1 d under alternating light,whose germination is inhibited to some extent by the subsequent all-dark culture;only at 15℃(lower),and when the all-dark pre-culture time is greater than or equal to 6 d,subsequent alternating light culture could not completely offset the inhibitory effect of previous all-dark pre-culture on germination,and the longer the all-dark pre-culture time,the stronger the germination inhibition effect,and the more difficult to be reversed by the subsequent alternating light culture.While at 25℃(higher),the germination inhibition by all-dark pre-culture can be offset by subsequent alternating light culture,and the final cumulative germination reached the same level as the alternating light culture control group.These results seem to mean that temperature is more important for the germination of R.crispus seeds than light,and the light/dark treatment time is also very important,or the photodependence of seed germination in R.crispus depends on temperature and time.And these are likely to be associated with the receptor for light and temperature phytochrome and a further study is required.