The root-knot nematode Meloidogyne graminicola causes significant yield loss and is considered one of the
most important pests affecting rice. After second-stage juveniles hatch from eggs, they invade at the rice root
tips and induce giant cells as food resource throughout their life cycle. These giant cells are embedded as root
galls, which always correlate with susceptibility of plants to nematode. In present research, we used the root
gall index and number of nematodes inside the roots to evaluate resistance/susceptibility to M. graminicola in
different subpopulations of rice. We observed that the number of M. graminicola nematodes inside the roots
correlated very strongly with the nematode gall index. Among the tested varieties, three varieties showed
significantly lower root gall index than others and were highly resistant to M. graminicola under both pot
and field conditions. In addition, nematodes penetrated less often into these highly resistant varieties and
more frequently failed to develop into females. Thereby, the resistant varieties found in the present research
might be useful for the breeding of rice and for further practical nematode management measures in China.
See pages 621–630 by Zhan et al. in details. Photos showed here were different developmental stages of M. graminicola in the root galls and were provided by Prof. Huang Wen-kun from the Institute of Plant
Protection, Chinese Academy of Agricultural Sciences.
