Thermal requirements for the embryonic development and life cycle of Meloidogyne hispanica

Abstract

The life cycle of a Portuguese Meloidogyne hispanica isolate on susceptible cv. Easypeel and resistant (Mi-1.2 gene) cv. Rossol tomato plants was studied in growth chambers at constant temperatures (10-35°C). The development within the egg and hatching were compared to those of a Portuguese M. arenaria isolate. The base temperature was 10AE11 and 8AE31°C with 179AE5 and 235AE3 thermal units for M. hispanica and M. arenaria, respectively, suggesting better potential adaptation to low temperatures by M. arenaria than M. hispanica. No egg development occurred at 10 or 35°C. An increase in invasion of tomato roots by M. hispanica second-stage juveniles (J2s) was correlated with an increase in temperature on both tomato cultivars. Tomato cv. Rossol limited M. hispanica development at 20, 25 and 30°C, but not at 35°C, indicating that these high temperatures blocked the resistance mechanism provided by the Mi-1.2 gene. At 15°C, J2s penetrated tomato cv. Rossol roots, but failed to develop and establish feeding sites. On tomato cv. Easypeel, nematode development and reproduction occurred at 20, 25 and 30°C, but at 20°C the life cycle was 1AE5 and 2AE0 times longer than at 25 and 30°C, respectively. No egg production was observed at 15°C. The results of this study showed that M. hispanica is most suited to soil temperatures around 25°C. Predicted climate change might favour the spread of this nematode species into southern Europe and northwards. The thermal requirements for M. hispanica development are analysed and compared with those of M. arenaria, M. hapla, M. incognita and M. javanica.

Thermal time requirements of root-knot nematodes on zucchini-squash and population dynamics with associated yield losses on spring and autumn cropping cycles

“…Our results support the suggestion that any factor delaying nematode development, such as host status, may affect thermal requirements (Tb and S) (Madulu and Trudgill 1994;Trudgill 1995). This hypothesis is further supported by the fact that development of M. konaensis on coffee was slower than on tomato (Zhang and Schmitt 1995), or that of M. hispanica on resistant than susceptible tomato (Maleita et al 2012).…”

Thermal requirements and population dynamics of root‐knot nematodes on cucumber and yield losses under protected cultivation

“…Differences in thermal requirements to complete specific biological stages of the life cycle have been demonstrated for several RKN species, e.g. embryonic development and hatching for M. hispanica and M. arenaria (Maleita et al ., ), M. javanica and M. incognita (Tzortzakakis & Trudgill, ) and M. chitwoodi and M. hapla (Charchar & Santo, ). In this study, the thermal requirements of M. incognita and M. javanica on cucumber were similar for the biological stages considered.…”

“…A constant number of accumulated degree‐days ( S ) over a base temperature ( T b : temperature below which no development occurs) is required for a crop to develop (Elnesr et al ., ), as well as for RKN to complete the life cycle on a given plant or to change from one developmental stage to the next. Phenology models have been developed for life cycle completion of several RKN species, and for embryogenesis and emergence of second‐stage juveniles (J2) (Ferris et al ., ; Lahtinen et al ., ; Madulu & Trudgill, ; Ploeg & Maris, ; Tzortzakakis & Trudgill, ; Maleita et al ., ). However, from an epidemiological point of view, knowledge of thermal requirements for specific processes such as infection, development, and production and emergence of new inoculum (J2) can help with making decisions to reduce RKN population growth and crop yield losses; for example, the use of trap crops, changes of planting date to escape infection, or to reduce the number of generations and population densities for the following crop.…”

Host status of cultivated plants to Meloidogyne hispanica

“…Five plants of each pepper cultivar were inoculated with 2,500 or 5,000 eggs (Pi) and maintained in growth chambers at 25± 2.7°C, 29.3±1.8°C or 33.6±1.2°C, or exposed outdoors during summer (July and August, 24.4±8.2°C), in a completely randomized design. The nematode had a shorter life cycle at 30°C than at 25°C and at 35°C the completion of the life cycle was inhibited (Maleita et al 2011a). The tomato cv.…”