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草石蚕(Stachys sieboldii Miq.)在秋季一般由地下茎上形成大量的块茎;这种形成的方式基本上与马铃薯的一样。但是如果在夏末秋初截取不同长短的地下茎末端,在人工培养条件下,则可以促使继续生长,原来匍匐茎的性状消失,而完全转变成为直立的地上茎状。同时在基部发生出大量不定根,建立超完整的根系。不过不定根是否容易发生,则尚需视存留的节数多少而有很大的不同。普通在保留有5—6节长短的离体茎端最易生长;基部的不定根发生率也最高。如只截取3节长短时,则多难以继续伸长。这些离体的茎端,经过培养3、4星期,就可长成一完整的小植株;全株密生表皮毛,茎成方形;每节上着生较细小的对生营养叶呈深绿色,而基部即有由不定根所形成的旺盛根系。但是培养到8星期以后,这种已转变成直立地上茎的顶端上却可再形成念珠状的块茎。这种特殊形成的方式与自然界中多在地下发生的情况很不相同。并且也很难完全用当前块茎形成机制的各种理论来解释说明。
Stachys sieboldii Miq. Forms a large number of tubers on underground stems in autumn; this is done in much the same way as potatoes. However, if the ends of underground stems of different lengths were taken in late summer and early autumn, under artificial cultivation conditions, they could be encouraged to continue growing. The original stoloniferous traits disappeared and completely transformed into upright stems above ground. At the same time, a large number of adventitious roots occur at the base and an ultra-complete root system is established. However, adventitious root is easy to occur, you still need depending on the number of surviving section there is a big difference. Common in the preservation of 5-6 length of the ex vivo stems most likely to grow; the highest incidence of adventitious roots. If only interception of the length of 3, then more difficult to continue to stretch. These ex vivo stem ends, after 3, 4 weeks of culture, grow into a complete plantlet; the whole plant has epidermal hairs and stems in a square shape; each section has a dark green counterpart to vegetative leaves, Roots formed by adventitious roots. However, after 8 weeks of cultivation, this has transformed into a rosary on the top of the upright stem. This particular pattern of formation is quite different from what happens in nature in many places underground. It is also difficult to explain completely the various theories of current tuber formation mechanisms.