( ( ( ( ( ( Both ( -LRB- ( potato -RRB- ) ) ) cyst ) - ) and ) ( ( ( ( root-knot nematodes ) ( are ( obligatory ( plant parasites ) ) ) ) and ) ( , ( ( as such ) ( , ( they ( fully ( depend ( on ( this ( self-created foodsource ) ) ) ) ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (DT Both) (-LRB- -LRB-) (NN potato) (-RRB- -RRB-)) (VP (VBP cyst))) (: -) (CC and) (S (S (NP (JJ root-knot) (NNS nematodes)) (VP (VBP are) (NP (JJ obligatory) (NN plant) (NNS parasites)))) (CC and) (S (, ,) (PP (IN as) (NP (JJ such))) (, ,) (NP (PRP they)) (ADVP (RB fully)) (VP (VBP depend) (PP (IN on) (NP (DT this) (JJ self-created) (NN foodsource)))))) (. .)))
Both (potato)cyst- and root-knot nematodes are obligatory plant parasites and, as such, they fully depend on this self-created foodsource.
(ROOT (S (NP (NNS Nematodes)) (VP (MD can) (VP (VB be) (NP (NP (DT a) (NN parasite)) (PP (IN of) (NP (DT both)))))) (. .)))
Nematodes can be a parasite of both.