Meloidogyne graminicola’s Effect on Growth Performance of Rice under Low Population Density

Abstract

Meloidogyne graminicola is a destructive soil-borne pathogen that causes rice yield losses (Oryza sativa L.) in tropical and subtropical areas. This study investigated the effect of M. graminicola population densities on plant height, heading, and the photosynthetic parameters of rice in a greenhouse. Two-week-old rice plants were inoculated with different M. graminicola densities (250, 500, 750, 1000, 1500, and 2000 J2s/plant) and observations were recorded at 30, 60, and 90 days after inoculation (DAI). Reductions in growth and photosynthetic parameters caused by M. graminicola densities were calculated in relation to a control (non-inoculated rice). Results revealed that M. graminicola infection with low population densities (0–500 J2s/plant) did not influence the rice plant height during 30–60 DAI, but significantly lowered the plant height, panicle growth rate, and panicle length of rice at 90 DAI. The chlorophyll content of rice inoculated with 500–2000 J2s was significantly lower than that of the control. Furthermore, M. graminicola infection with 500 J2s/plant significantly lowered the transpiration rate and net photosynthetic rate by 21.21% and 21.81%, respectively, compared with the control (p < 0.05). M. graminicola with a low population density significantly reduced the net photosynthetic rate of rice, which affected organic matter accumulation, resulting in growth retardation and lower yields (p < 0.05).

Growth, Physiological, and Biochemical Variations in Tomatoes after Infection with Different Density Levels of Meloidogyne enterolobii

“…In a previous study, the nematode infections in tomato plants reduced or altered photosynthetic pigments in tomato plants [ 58 ]. Chen et al [ 59 ] also determined that the leaf chlorophyll content of rice plants decreased after infection with M. graminicola , with an inoculum density ranging from 500 to 2000 J2s per plant. Further demonstrated that the tomato plant inoculation with the highest inoculum (2000 J2s/plant) resulted in a considerable reduction in chlorophyll a (80.19%), chlorophyll b (55.12%), carotenoids (67.21%), and total chlorophyll content (74.32%) as compared to the control or non-inoculated plants.…”

“…The outcomes of the current investigation demonstrate that the inoculation of nematodes resulted in a noteworthy decrease in various leaf gas exchange characteristics. The previous research investigation was conducted with rice plant inoculation with RKN juveniles (100, 500, 1000, and 2000 J2s/plant), which resulted in a significant decrease in the photosynthetic process [ 59 ]. Therefore, the density of the nematode population was adversely associated with the photosynthesis rate.…”

A Seinhorst Model Determined the Host-Parasite Relationships of Meloidogyne javanica Infecting Fenugreek cv. UM202

“…These changes harm plant health, resulting in inadequate development ( Gullino et al, 2019 ). In addition, RKNs alter physiological and metabolic functions, such as photosynthesis in plants, along with their physical attributes ( Chen et al, 2022 ). RKNs have complex interactions with their hosts and the plant genes that are induced during a compatible plant–nematode interaction.…”