Resistance of Hybrid Citrus Rootstocks to a Mediterranean Biotype of Tylenchulus semipenetrans Cobb
in HortScienceThe response of 52 citrus hybrid rootstocks to a Mediterranean biotype of Tylenchulus semipenetrans Cobb was determined in greenhouse tests. Seven selections of the cross `Cleopatra' mandarin [Citrus reshni Hort. × Poncirus trifoliata (L.) Raf], and one of Citrus volkameriana Pasq. × P. trifoliata did not support nematode reproduction and were considered as highly resistant to the citrus nematode. The nematode showed very low infectivity and reproductive potential on seven additional selections of `Cleopatra' mandarin × P. trifoliata, one of `King' mandarin × P. trifoliata, and two C. volkameriana × P. trifoliata. These selections were considered as nematode resistant. All the selections with `Troyer' citrange [Citrus sinensis (L). Osbeck × P. trifoliata (L.) Raf] in their parentage supported nematode reproduction but showed different levels of susceptibility.
