Stunted growth of fall-sown sugar beets (Beta vulgaris) associated with high incidence of crownroot infections and large soil infestations by Ditylenchus dipsaci were observed at the end of the crop growing season in southern Spain. The largest proportion (75%) of the nematode life-stages in plant and soil was the fourth-stage juvenile. The large number (up to 3,750 nematodes per gram of fresh tissue) of D. dipsaci individuals and severe anatomical alterations observed in storage sugar beet roots suggest that the stem and bulb nematode is the causal agent of the impaired growth of sugar beets observed in commercial fields. Observed morphological traits of nematode specimens and results of specific polymerase chain reaction (PCR) and phylogenetic analyses confirmed that the population of D. dipsaci infecting sugar beet belongs to the normal (nongiant) biological type of the nematode. Results of host-range bioassays indicated that the population of D. dipsaci infecting sugar beet in southern Spain reproduces on pea (including seeds and pods), onion, potato, spinach, and tomato, but not on bean, cotton, maize, and tobacco.
Host-parasite relationships in fall-sown sugar beets infected by the stem and bulb nematode, Ditylenchus dipsaci.
Vovlas N;
2007
Abstract
Stunted growth of fall-sown sugar beets (Beta vulgaris) associated with high incidence of crownroot infections and large soil infestations by Ditylenchus dipsaci were observed at the end of the crop growing season in southern Spain. The largest proportion (75%) of the nematode life-stages in plant and soil was the fourth-stage juvenile. The large number (up to 3,750 nematodes per gram of fresh tissue) of D. dipsaci individuals and severe anatomical alterations observed in storage sugar beet roots suggest that the stem and bulb nematode is the causal agent of the impaired growth of sugar beets observed in commercial fields. Observed morphological traits of nematode specimens and results of specific polymerase chain reaction (PCR) and phylogenetic analyses confirmed that the population of D. dipsaci infecting sugar beet belongs to the normal (nongiant) biological type of the nematode. Results of host-range bioassays indicated that the population of D. dipsaci infecting sugar beet in southern Spain reproduces on pea (including seeds and pods), onion, potato, spinach, and tomato, but not on bean, cotton, maize, and tobacco.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
