Cuscuta spp

Allelopathy found hopeful utilization in plant protection against parasite weeds. The main world parasitic species are the witchweeds (Striga spp.), broomrapes (Orobanche spp.), and eventually dodder (Cuscuta spp.). Witchweeds and broom-rapes attack many economically important crops especially throughout the semi-arid regions. Early detection of parasitic weed infestation and protection is difficult because of the growth habit of a root parasite and huge production of dust-like seeds viable up to 20 years (Kebreab and Murdoch 1999). 

Trap crops or so-called false hosts are crops able to stimulate parasite seed germination but are not themselves parasitized. Each trap crop control at least one species but not all genus species. (Abebe et al. 2005). Dodder (Cuscuta spp.) infestation can be effectively reduced by growing cereals or other grass crops (false hosts) continuously for several years (Dawson 1987). Other examples of suitable trap and catch crops are given in the Table 14.3. 

Colletotrlchum nloeosporioides (Penz.) Sacc. f.sp. cuscutae, Alternaria sp. Cuscuta spp. (dodders) 11 118. 119... 

Certain parasitic plants, species of dodders (Cuscuta spp.), synthesize carotenoids, and plant tissue cultures of carrot tissue have been found to contain carotenoids (Goodwin, 1976). 

Fig. 8.1 Glycosidic acids (cuscutic acids), unique acylated trisaccharides without cyclization to a macrolactone structurally closely related to resin glycosides (cus-1, cus-2), and a real resin glycoside (cuscutic resinoside A) from the seeds of Cuscuta spp. (clearing up of the abbreviations concerning sugar units and acyl residues see Table 8.2)...

Carotinoid Carotenes P-Carotene From Cuscuta spp. Waller (1995c) ... 

Certain flavonoids are used by plants to protect them from invasion by parasites. For example, poplar (Populus spp.) cultivars produce a chemical barrier to parasitization by mistletoe (Viscum album).Resistant poplar cultivars were significantly higher in flavonols and flavones compared to susceptible cultivars. Likewise, in Streblus asper the bark and wood of trees that are resistant to the parasite Cuscuta reflexa hold higher levels of flavonoids, as well as steroids and alkaloids. 

Constit. of Astilbe, Rodgersia, Peltoboyki-nia and Bergenia spp. Also Corylopsis, Mallotus, Caesalpinia, Shorea, Ardisia, Cuscuta, Connarus and others. Antitussive agent. Prisms + IH2O (H2O). 

However, to date reports on structural elucidations of resin glycosides are confined to 34 species belonging to six genera, altogether listed in Table 8.2 together with the respective authorities for the species and the phytochemical references Ipomoea (23 spp.), Merremia (3), Convolvulus (3), Operculina (2) Cuscuta (2), Calystegia (1). The vast majority of these plants are of tropical origin. 

Cuscuttt spp. C. tinctoria Mart. C. americana Linn. C. odontolepis Engelmann Daemonorops spp.D. draco-, D. propinquus Convolvulaceae (Cuscutaceae) Palmae Cuscuta Dragon s blood p- and 7-Carotenes Dracoflavan A, Dracooxepine, Dracombin, Nordracorubin plus various methoxyflavan compounds Waller (1995c) ... 

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