Influence of Meloidogyne javanica parasitism on soybean development and chemical composition

Abstract

Background Soybean is a major economic crop worldwide, but its yield and quality are greatly affected by root-knot nematode infection. This study aimed to assess the effects of Meloidogyne javanica parasitism on soybean growth, yield, and quality. Soybean plants were inoculated with 0, 1000, 2000, or 4000 eggs + second-stage juveniles (J2) of M. javanica and evaluated for vegetative and nematode parameters. Grains from each treatment were analyzed for yield, proximate composition, total phenolic content, total flavonoid content, isoflavone profile, and antioxidant capacity. Results Plants free of nematodes had lower vegetative growth and higher yield than nematode-infected plants. The maximum estimated reproduction factor was 34.85, achieved by inoculation of 2433 eggs + J2. Moisture, fiber, and protein contents decreased with increasing inoculum levels. Lipid content increased with inoculum level until reaching 22.59 g 100 g−1 of sample. Total phenolic and flavonoid contents decreased with increasing inoculum level up to about 2000 eggs + J2 and then increased until reaching 219.20 mg gallic acid equivalents 100 g−1 of sample and 121.67 mg quercetin equivalent 100 g−1 of sample, respectively, at 4000 eggs + J2. A similar behavior was observed for antioxidant capacity determined by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging, superoxide radical scavenging, and ferric reducing antioxidant power assays. The highest contents of malonylgenistin (539 mmol g−1), acetylglycitin (106 mmol g−1), and genistin (87 mmol g−1) were found in grains from plants inoculated with 4000 eggs + J2. Conclusions M. javanica inoculum level affected soybean development, grain production, yield, composition, and antioxidant capacity.

Plant parasitic nematodes on soybean (Glycine max (L) Merr.) in the Metekel zone (Ethiopia) and varietal resistance evaluation to Meloidogyne javanica

“…Castanheira et al. (2021) reported a significant soybean growth reduction in shoot height and root length caused by M. javanica , which is consistent with the present study. The nine soybean varieties tested exhibited a severe reduction in shoot growth attributed to inadequate water and nutrient supply to the areal plant part that resulted from the damage caused to the root system (Escobar et al., 2015).…”

“…In this study, the length of the roots decreased as the number of galls and final population increased. Similar findings were reported by Nora et al (2020) and Balardin et al (2022), which found a significant decrease in the yield of soybean cultivars with an increase in the number of galls and final population of M. javanica that can negatively affect pod number and grain weight of soybean (Castanheira et al, 2021).…”

“…In a few varieties, higher relative minimum biomass was observed, attributed to an increase in the host's tolerance against the nematode, suggesting that each soybean variety responds differently to nematode parasitism. Vegetative growth of nematode infected soybean could be a compensatory response to the nematode infection as an acquired defence (Castanheira et al., 2021).…”

Response of soybean and tomato plants under dual inoculation with Glomus sp. and root-knot nematode Meloidogyne incognita

“…Plant height was measured three times: 2, 4 and 5 weeks after sowing (WAS) of soybean seeds and 2, 4 and 5 weeks after transplanting (WAT) of tomato seedlings. The plant height data were used to calculate the area under plant height progress curve (AUHPC) using the formula analogue to that of area under disease progress curve or AUDPC [19] as in equation (1).…”

“…Soybean and tomato are globally important and major economic crops worldwide due to their high nutritive value. Because of its high oil content and high-quality proteins, soybean is used in a variety of ways in both human and animal diets [1]. Tomato, on the other hand, is a rich source of vitamins and minerals, which are important micronutrients in the diet of humans [2].…”