肉苁蓉寄生生长形态发育

肉苁蓉(Cistanche deserticola)是一种沙生根寄生濒危药用植物。利用光镜和电镜手段, 采用人工培养和诱导等方法详细观察并研究了肉苁蓉寄生生长过程中种子萌发、吸器产生以及植物体形态发育的过程。结果表明: (1)人工可以诱导肉苁蓉的种子萌发。肉苁蓉种胚具有明显的极性, 珠孔端细胞小于合点端, 珠孔端细胞分化、生长并产生白色的类胚根状结构。(2)有些化学物质可以诱导初生吸器的产生。用2, 6二甲氧基-对苯醌培养肉苁蓉24-26小时后, 其先端膨大并产生突起, 形成类似根毛状的结构, 即初生吸器。(3) 肉苁蓉属于主动寄生植物, 其在初生吸器与寄主幼根黏连后产生次生吸器。肉苁蓉与寄主梭梭(Haloxylon ammodendron)共培养, 其初生吸器主动与寄主幼根(0.1 mm左右)黏连, 穿过寄主根表皮和皮层后与维管束连通形成次生吸器, 肉苁蓉植物体分化、发育的基本组织形成。被寄生后的寄主根横向发育加快, 同时肉苁蓉植物体开始分化和发育。(4)肉苁蓉可以寄生在寄主幼根(0.1 mm左右)的任意部位。

Morphological Development of Parasitic Growth in Cistanche deserticola

Cistanche deserticola, a kind of root parasitic psammophyte, is an endangered rare Chinese traditional medicine plant. We performed artificial culture and induction of C. deserticola to study seed germination, haustorium generation and morphologic development by optical microscopy and scanning electronmic roscopy. The results showed the following: (1) Artificial culture could produce seed germination, and embryo of C. deserticola showed polarity, with the micropyle cells being smaller than the chalazal ends and differentiated into white radicle-like organs.(2) The primary haustorium can be induced by some chemicals. After culture in 2,6-dimethoxyl pbenzoquinone for 24-26 h, the anterior part extended, formed the protuberance, then transformed into a root hair-like structure called primary haustorium.(3) C. deserticola is an active parasitic plant, and secondary haustorium or iginated after adhesion between the primary haustorium and young roots of the host. Co-culture with Haloxylon ammodendron, the primary haustorium conglutinate with young roots of the host (0.1 mm), pass through the host's epidermis and cortex , then connect with the vascular bundle and transform into secondary haustorium, shaped by fundamental tissues of differentiation and development. The development of horizontal growth of the parasitized host was quickened, and the same time, C. deserticola began to differentiate and develop. (4) C. deserticola can be a parasite anywhere in young roots (0.1 mm) of a host.