Gall counts observed in the lateral roots of sweetpotato genotypes inoculated with Meloidogyne enterolobii at 14 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by the Kruskal-Wallis test followed by the Dunn test (α = 0.05). Presented data include results from trial A (top) and trial B (bottom).
Gall counts observed in the lateral roots of sweetpotato genotypes inoculated with Meloidogyne enterolobii at 21 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by the Kruskal-Wallis test followed by the Dunn test (α = 0.05). Presented data include results from trial A (top) and trial B (bottom).
Measured root architecture attributes of sweetpotato genotypes inoculated with Meloidogyne enterolobii at 14 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by a two-way analysis of variance (ANOVA) followed by Fisher’s least significant difference (LSD) test (α = 0.05). (A) Variations in lateral root length (cm). (B) Variations in lateral root surface area (cm2). (C) Variations in lateral root volume (cm3) at 14 DPI. Presented data include results from trial A (top) and trial B (bottom).
Measured root architecture attributes of sweetpotato genotypes inoculated with Meloidogyne enterolobii at 21 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by a two-way analysis of variance (ANOVA) followed by Fisher’s least significant difference (LSD) test (α = 0.05). (A) Variations in lateral root length (cm). (B) Variations in lateral root surface area (cm2). (C) Variations in lateral root volume (cm3) at 21 DPI. Presented data include results from trial A (top) and trial B (bottom).
Gall counts observed in the lateral roots of sweetpotato genotypes inoculated with Meloidogyne incognita at 14 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by the Kruskal-Wallis test followed by the Dunn test (α = 0.05). Presented data include results from trial A (top) and trial B (bottom).
Gall counts observed in the lateral roots of sweetpotato genotypes inoculated with Meloidogyne incognita at 21 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by the Kruskal-Wallis test followed by the Dunn test (α = 0.05). Presented data include results from trial A (top) and trial B (bottom).
Measured root architecture attributes of sweetpotato genotypes inoculated with Meloidogyne incognita at 14 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by a two-way analysis of variance (ANOVA) followed by Fisher’s least significant difference (LSD) test (α = 0.05). (A) Variations in lateral root length (cm). (B) Variations in lateral root surface area (cm2). (C) Variations in lateral root volume (cm3) at 14 DPI. Presented data include results from trial A (top) and trial B (bottom).
Measured root architecture attributes of sweetpotato genotypes inoculated with Meloidogyne incognita at 21 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by a two-way analysis of variance (ANOVA) followed by Fisher’s least significant difference (LSD) test (α = 0.05). (A) Variations in lateral root length (cm). (B) Variations in lateral root surface area (cm2). (C) Variations in lateral root volume (cm3) at 21 DPI. Presented data include results from trial A (top) and trial B (bottom).
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In sweetpotato (Ipomoea batatas), the emergence and development of lateral roots (LRs) is crucial for determining the root system architecture (RSA), which impacts plant establishment, storage root formation, and yield potential. This study evaluated RSA responses of five sweetpotato genotypes to Meloidogyne enterolobii or Meloidogyne incognita infection. The genotypes included ‘Beauregard’ (susceptible to both nematodes), ‘Jewel’ (resistant to M. enterolobii and moderately resistant to M. incognita), and Louisiana State University Agricultural Center genotypes LA14-31 (resistant to M. enterolobii and moderately resistant to M. incognita), LA18-100 (susceptible to M. enterolobii and resistant to M. incognita), and LA19-65 (resistant to M. enterolobii and susceptible to M. incognita). Sweetpotato vine cuttings were inoculated at planting with approximately 3000, 500, or no eggs of either nematode species. Entire root systems were collected at 14 and 21 days postinoculation (DPI) and scanned. Images were analyzed using RhizoVision Explorer software. Gall counts per root system and RSA attributes such as lateral root length, surface area, and volume were evaluated. Variations in gall formation and RSA attributes among genotypes were observed as early as 14 DPI and continued at 21 DPI, with LA18-100 (released as ‘Avoyelles’) showing consistently greater lateral root length, surface area, and volume compared with those of the other genotypes. The RSA response to varying nematode inoculum densities was genotype-specific and not linked to the resistance response to M. enterolobii or M. incognita. The incorporation of RSA attributes into sweetpotato breeding programs has potential for identifying genotypes with favorable rooting characteristics.
Sweetpotato [Ipomoea batatas (L.) Lam] is one of the most important cultivated crops worldwide and plays a key role in the global food system (FAO 2020). Widespread cultivation of sweetpotato is attributed to its adaptability to tropical and semitropical growing conditions, short production cycle, high yield potential, and high nutritional content (Hijmans et al. 2001; Truong et al. 2018). However, sweetpotato production faces severe economic losses because of damage caused by insects and plant pathogens (Clark et al. 2013; Overstreet 2009). The importance of lateral root (LR) development to determining the capacity of adventitious roots (ARs) to undergo storage root formation in sweetpotato has been previously documented (Villordon et al. 2012). The LRs also play a crucial role in water use efficiency and nutrient uptake (Dubrovsky and Forde 2012; Pardales and Yamauchi 2003). However, plant parasitic fungi, nematodes, and viruses can alter the development of ARs and LRs (Villordon and Clark 2014, 2018; Villordon et al. 2024), which can negatively affect both the quality and quantity of sweetpotato yield (Clark et al. 2013).
Root-knot nematodes (RKNs), Meloidogyne spp., are among the most damaging plant parasitic nematodes that cause yield reduction and esthetic damage of sweetpotato storage roots (Cervantes-Flores et al. 2002; Overstreet 2009). A prior study has presented evidence that the RKN-resistant cultivar Evangeline exhibits compensatory root growth (i.e., enhanced root growth in response to stress) with increasing levels of Meloidogyne incognita inoculum relative to the susceptible cultivar Beauregard (Villordon and Clark 2018). This suggests that further investigation is required to clarify the association between compensatory root growth and RKN resistance.
Because sweetpotato ARs typically begin developing at approximately 5 to 7 d after planting (Villordon et al. 2009; Villordon and Clark 2014), nematode penetration often targets emerging lateral roots (Abad et al. 2003; Curtis et al. 2009). Nematode infection, especially during the establishment and storage root formation stages, can modify root system architecture (RSA) and impair sweetpotato development (Villordon and Clark 2018), potentially leading to reduced yields. Hence, it is necessary to understand the relationship between RSA attributes and sweetpotato responses to both M. incognita and Meloidogyne enterolobii. The primary objective of this study was to evaluate the RSA response of sweetpotato genotypes that exhibit varying levels of resistance to M. enterolobii and M. incognita infection with varying inoculation densities of M. incognita or M. enterolobii. By evaluating the RSA attributes such as root length, surface area, and volume of lateral roots, we aimed to provide a better understanding of how different sweetpotato genotypes respond to parasitism by each Meloidogyne species.
Five sweetpotato genotypes were evaluated to identify the potential differences in root architecture attributes when inoculated with either M. enterolobii or M. incognita at different inoculum levels. Sweetpotato genotypes evaluated during this study (Table 1) were selected based on their response to M. enterolobii and M. incognita infections (Galo et al. 2024). Sweetpotato vine cuttings (length, 20–25 cm) with four to five developed leaves were transplanted to polyvinyl chloride (PVC) pots (diameter, 10 cm; height, 30 cm) filled with pasteurized construction sand. Plants were watered every other day, alternating between 150 mL deionized water and 0.5× Hoagland solution.
This study used a population of M. enterolobii isolated from a sweetpotato storage root intercepted from a shipment that originated from North Carolina (Santos Rezende et al. 2022) along with a population of M. incognita (race 3) isolated from a sweetpotato field in Louisiana. The nematode populations were maintained under greenhouse conditions on ‘Rutgers’ tomato (Solanum lycopersicum) plants. Inoculum was harvested at 60 d after inoculation by shaking roots in 0.522% sodium hypochlorite (NaOCl) for 4 min and passing the suspension through an 80 mesh (177-µm opening) sieve to remove debris and retain eggs on a 500 mesh (25-µm opening) sieve. The NaOCl solution was washed away with tap water, and the nematode egg suspension was transferred in water to a glass beaker prior to use.
Experiments were conducted at the Louisiana State University Agricultural Center’s Plant Material Center greenhouses located in the Central Research Station, Baton Rouge, LA, USA. Egg suspensions containing approximately 0 (control), 500, and 3000 eggs (diluted in 10 mL of water) of either M. enterolobii or M. incognita were added to each pot. The suspension was dispersed in four holes spaced at 2.5 to 3 cm around the planted stem (depth, 2 cm) on the planting day. Light-emitting diode growth lights (SolarSystem® 500; California Light Works, Canoga Park, CA, USA) were used to extend to 14 h·d−1 at a spectrum of 50:50:50 RGB, respectively. Plants were arranged in a randomized complete block design separately for each nematode species. Data were collected at 14 d postinoculation (DPI) and 21 DPI. One pot was treated as a replication, and there were four replicates per genotype in each experiment. This experiment was conducted twice; trial A was planted on 24 Apr 2022, and trial B was planted on 20 Jun 2022. The greenhouse temperatures recorded for trial A were 27 ± 1.5 °C during the day and 25 ± 2.1 °C at night, with an average relative humidity of 84%. For trial B, temperatures were 29 ± 1.1 °C during the day and 28 ± 1.0 °C at night, with an average relative humidity of 98%.
Entire root systems were washed free of sand at 14 and 21 DPI according to Villordon et al. (2012), and root systems were saved in 70% ethanol until further use. For scanning, roots were placed on transparent waterproof trays floated with water and scanned using a specialized Epson Perfection V850 (Epson America, Inc., Long Beach, CA, USA) using its built-in software. Program settings were as follows: professional mode; document type film (with film area guide); positive film type; image type with 24-bit color; resolution of 400 dpi (dots per inch); width of 8 inches; and height of 10 inches. The unsharp mask and dust removal options were activated. For each plant, root architecture attributes such as length, surface area, and volume of the LRs were measured using the RhizoVision Explorer (Seethepalli and York 2020). Segmentation settings were adjusted as needed based on the age and diameter of each root system. Measurements were classified based on the diameter range of the specific type of root (main or lateral root). Galls on LRs were quantified using the scanned images. The sum of data from all root images obtained from a single pot (one plant per pot) was treated as an experimental unit.
Data were analyzed separately for each trial to assess the effects of inoculation density (main factor) and genotype (main factor) at each sampling time using RStudio 2024.04.2+ Build 764 statistical analysis software. Data collected from both trials were evaluated for normality using the Shapiro-Wilk test. For data that fulfilled the criteria for the parametric test, a two-way analysis of variance (ANOVA) followed by Fisher’s least significant difference (LSD) test were conducted. Because root gall data did not follow a normal distribution, it was analyzed using the Kruskal-Wallis nonparametric test, followed by the Dunn test for mean separation. P value adjustments were conducted using the Benjamini-Hochberg method to determine significant differences (P < 0.05). The data are presented as means from nontransformed values. For both nematode species, there was a significant genotype × inoculation level × trial effect for all root attributes; therefore, data were analyzed separately for each trial.
At 14 DPI, a significant genotype effect was associated with the number of galls (P < 0.0001). The genotypes LA18-100 and ‘Beauregard’ had a greater number of galls in LR compared to that of ‘Jewel’, LA14-31, and LA19-65 (Fig. 1). Gall counts of LA18-100 and ‘Beauregard’ increased as the inoculum level increased (P < 0.0001). No galls were observed in ‘Jewel’, LA14-31, or LA19-65 at any inoculation level (genotype × inoculation level interaction; P < 0.0001). Although higher gall counts were observed in LA18-100 and ‘Beauregard’ in trial B at 14 DPI, the effects of genotype and inoculation levels were consistent across both trials.
Citation: HortScience 60, 5; 10.21273/HORTSCI18398-24
At 21 DPI (Fig. 2), galls were observed only in ‘Beauregard’ and LA18-100 (genotype main factor effect, P < 0.0001), and gall counts increased as the inoculum level increased (inoculum level main factor effect, P < 0.0001). No galls were observed in ‘Jewel’, LA14-31, or LA19-65. Gall counts at 21 DPI were similar to those at 14 DPI; genotypes susceptible to M. enterolobii exhibited more galls with higher inoculation levels. These findings are consistent with those of a previous study that reported that susceptible genotypes have higher gall counts as RKN inoculum density increases (Villordon and Clark 2018), whereas resistant genotypes like ‘Jewel’, LA14-31, and LA19-65 did not exhibit gall formation with M. enterolobii (Galo et al. 2024).
Citation: HortScience 60, 5; 10.21273/HORTSCI18398-24
The response of sweetpotato genotypes to different inoculation levels of M. enterolobii varied across trials (Table 2). At 14 DPI, inherent genotype effects were evident among noninoculated plants, with LA18-100 showing greater LR length, surface area, and volume than those of LA19-65, LA14-31, and ‘Beauregard’ (P < 0.0001). ‘Jewel’ displayed RA measurements similar to those of LA18-100 only in trial B. In trial A, ‘Jewel’ plants treated with 3000 eggs showed increased LR length, surface area, and volume compared with those of the untreated control (Fig. 3). Conversely, LA18-100 plants showed an increase in LR volume when treated with 500 eggs, but plants treated with 3000 eggs had an LR volume similar to that of the noninoculated control. In trial B, significant differences in LR surface area (P = 0.0334) and volume (P = 0.0322) were observed with increasing inoculum levels (Table 2). Notable within-genotype differences were evident in LA14-31; the RSA attributes increased as inoculum levels increased. No interaction effects among genotype × inoculation level were detected in RA attributes at 14 DPI in either trial.
Citation: HortScience 60, 5; 10.21273/HORTSCI18398-24
At 21 DPI, RSA variability was consistently attributed to genotype effects in both trials (Table 2). The genotype LA18-100 consistently showed increased RSA attributes relative to other genotypes, except for ‘Jewel’, in trial B. In trial A, LA18-100 plants treated with 3000 eggs of M. enterolobii showed significantly reduced RSA attributes compared with those of plants treated with 500 eggs (Fig. 4). Conversely, ‘Jewel’ plants showed increased RSA attributes when treated with both 500 and 3000 eggs. Additionally, an interaction effect between genotype × inoculation level was observed in trial A, demonstrating varying responses in LR length among sweetpotato genotypes (P = 0.0394). In trial B at 21 DPI, ‘Jewel’ plants treated with 500 eggs had reduced RSA attributes compared with those of plants treated with 3000 eggs or not inoculated. Additionally, a significant interaction effect between genotype × inoculation level on LR volume was observed (P = 0.0118), suggesting that sweetpotato genotypes responded differently to each inoculum level.
Citation: HortScience 60, 5; 10.21273/HORTSCI18398-24
At 14 DPI (Fig. 5), sweetpotato genotypes showed varied responses to M. incognita infection (genotype main factor effect, P < 0.0001). Gall counts increased with higher inoculum levels (P < 0.0001). In trial A, galls were observed on ‘Beauregard’, ‘Jewel’, LA18-100, and LA19-65; only LA19-65 plants inoculated with 3000 eggs showed a significant increase in gall counts compared with the noninoculated control. No galls were observed on LA14-31 across inoculation levels (genotype × inoculation level interaction effect, P = 0.0002). In trial B, all plants treated with M. incognita eggs exhibited galls, with LA19-65 and ‘Beauregard’ showing the highest gall counts when inoculated with 3000 eggs, whereas LA18-100 plants showed the lowest gall counts at this inoculum level (P < 0.0001).
Citation: HortScience 60, 5; 10.21273/HORTSCI18398-24
At 21 DPI (Fig. 6), a consistent genotype main factor effect that influenced the gall count responses to M. incognita infection was observed across trials (P < 0.0001). Except for LA18-100 plants, gall counts increased with higher inoculum levels (P < 0.0001). The responses observed at 21 DPI were similar to those observed at 14 DPI, with the genotypes LA19-65 and ‘Beauregard’ showing more galls at similar inoculum levels, followed by ‘Jewel’ and LA14-31. Notably, the LA18-100 genotype consistently showed minimal gall formation, as reported by Galo et al. (2024) and La Bonte et al. (2024), who identified LA18-100 as resistant to M. incognita. Additionally, these results align with those of Villordon and Clark (2018), who reported that susceptible sweetpotato genotypes, such as ‘Beauregard’ and LA19-65, exhibit higher gall counts with increasing M. incognita inoculum levels, whereas resistant and moderately resistant genotypes like LA18-100, ‘Jewel’, and LA14-31 showed fewer galls.
Citation: HortScience 60, 5; 10.21273/HORTSCI18398-24
At 14 DPI, the sweetpotato genotypes showed variations in the RSA response to different inoculation levels of M. incognita across trials (Table 2). A pronounced genotype effect was evident among noninoculated controls, with the LA18-100 genotype showing increased RSA measurements compared with those of ‘Beauregard’, ‘Jewel’, LA14-31, and LA19-65 (P < 0.0001). In trial A, ‘Jewel’ plants treated with 3000 eggs had reduced LR length compared with that of plants treated with 500 eggs (Fig. 7). Furthermore, LA18-100 plants treated with 500 eggs showed a significant decrease in LR surface area and volume relative to the noninoculated control (P = 0.0474). In trial B, ‘Beauregard’ plants treated with 500 and 3000 eggs exhibited decreased RSA measurements compared with those of the noninoculated control, whereas ‘Jewel’ plants inoculated with 500 eggs showed an increase in LR surface area and volume. This variation in response between ‘Beauregard’ and ‘Jewel’ regarding LR volume resulted in a significant interaction between genotype × inoculation level (P = 0.0375).
Citation: HortScience 60, 5; 10.21273/HORTSCI18398-24
At 21 DPI, RSA attribute variation caused by genotype effects was consistently observed across trials, as shown by the noninoculated controls of each genotype (Table 2). The genotype LA18-100 consistently showed greater RSA attributes than most genotypes in both trials, whereas ‘Jewel’ showed RSA attributes comparable to LA18-100 only in trial B (Fig. 8). Significant effects caused by inoculation levels on RSA attributes were only observed in trial B, with ‘Beauregard’ and LA18-100 plants showing a reduced LR length when treated with 3000 eggs of M. incognita relative to plants treated with 500 eggs (P = 0.0079). In contrast, the genotype LA19-65 showed an increase in LR length when plants were treated with either 500 or 3000 eggs, relative to the untreated control. The variation in response among sweetpotato genotypes to different levels of M. incognita resulted in a significant interaction between genotype × inoculum level that affected the RSA attributes measured in trial B (Table 2). Specifically, ‘Beauregard’ and LA18-100 plants inoculated with 3000 eggs showed decreased RSA attributes compared with those of the noninoculated control, whereas LA19-65 plants exhibited increased RSA attributes at the same inoculum level.
Citation: HortScience 60, 5; 10.21273/HORTSCI18398-24
Cumulative evidence shows that biotic and abiotic factors influence RSA development during the sweetpotato storage root formation stage, but these effects are modulated by genotype (Pardales and Yamauchi 2003; Villordon and Clark 2018). Our study corroborated these findings and showed that genotype significantly influences RSA, with differences observable as early as 14 DPI and remaining consistent at 21 DPI. Specifically, compared with other sweetpotato genotypes, including ‘Beauregard’, LA18-100 consistently showed increased RSA attributes. Evidence also indicated that LA18-100 has a higher marketable yield than ‘Beauregard’, thus underscoring the genotypic effects (La Bonte et al. 2024). Because enhanced RSA attributes are associated with early plant establishment and consistent storage root formation (Duque et al. 2024; Pardales and Yamauchi 2003), early RSA measurements may serve as indicators of yield potential.
Prior studies have shown that high parasitism levels reduce root growth and modify plant biomass allocation (Brinkman et al. 2015; Franco et al. 2020). In contrast, low nematode infection levels can enhance plant performance by stimulating root growth (Bardgett et al. 1999; Wurst et al. 2006). Tu et al. (2003) reported that infection by M. incognita elicits compensatory root growth in various hosts such as barley, cotton, tobacco, and white clover (Haase et al. 2007; Johnson and Nusbaum 1970; Ma et al. 2013; Treonis et al. 2005). However, this response was not consistently observed in the current study, in which the effects of nematode inoculum on RSA attributes varied across trials and genotypes. In sweetpotato, the mechanism behind compensatory root growth in response to nematode infection remains unclear, genotype-dependent, and not directly associated with host resistance (Villordon and Clark 2018).
Despite significant efforts to minimize variability (including conducting trials within the same year within a 2-month interval using virus-tested sweetpotato slips from the same source and standardizing watering, fertilization, and light exposure), the RSA response to nematode inoculation remained variable across trials and genotypes in this study. The significant trial × genotype interaction aligned with previous findings in terms of the role of environmental effects on RSA variability in sweetpotato (Pardales and Yamauchi 2003; Villordon and Clark 2018).
This study showed that differences in RSA attributes among genotypes can be detected as early as 14 d after planting. Although Pang et al. (2011) proposed a water displacement method for measuring root volume, root scanning and computer-based image analysis methods provide more detailed and effective insights when studying RSA traits (Bouma et al. 2000; Villordon and Clark 2018). The evidence suggested that RSA traits could be useful for selecting sweetpotato genotypes with high yield potential (Duque et al. 2024). However, incorporating RSA traits into breeding programs presents challenges, such as the lack of practical tools for analyzing and screening these traits, particularly under various stress conditions (Pardales and Yamauchi 2003; Villordon and Clark 2014).
We confirmed variations in RSA attributes among sweetpotato genotypes, suggesting that these traits could be integrated in a breeding program to potentially predict and enhance sweetpotato yield. We also validated that RKN infection induces genotype-specific changes in RSA attributes, thus extending these findings to new sweetpotato genotypes and two RKN species, M. enterolobii and M. incognita. Notably, the compensatory root growth observed in some genotypes was not directly associated with host resistance to the nematode species, suggesting that breeding for RKN resistance and RSA attributes in sweetpotato are two different traits. Consistent with prior research, environmental variability significantly influenced RSA attributes.
Gall counts observed in the lateral roots of sweetpotato genotypes inoculated with Meloidogyne enterolobii at 14 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by the Kruskal-Wallis test followed by the Dunn test (α = 0.05). Presented data include results from trial A (top) and trial B (bottom).
Gall counts observed in the lateral roots of sweetpotato genotypes inoculated with Meloidogyne enterolobii at 21 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by the Kruskal-Wallis test followed by the Dunn test (α = 0.05). Presented data include results from trial A (top) and trial B (bottom).
Measured root architecture attributes of sweetpotato genotypes inoculated with Meloidogyne enterolobii at 14 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by a two-way analysis of variance (ANOVA) followed by Fisher’s least significant difference (LSD) test (α = 0.05). (A) Variations in lateral root length (cm). (B) Variations in lateral root surface area (cm2). (C) Variations in lateral root volume (cm3) at 14 DPI. Presented data include results from trial A (top) and trial B (bottom).
Measured root architecture attributes of sweetpotato genotypes inoculated with Meloidogyne enterolobii at 21 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by a two-way analysis of variance (ANOVA) followed by Fisher’s least significant difference (LSD) test (α = 0.05). (A) Variations in lateral root length (cm). (B) Variations in lateral root surface area (cm2). (C) Variations in lateral root volume (cm3) at 21 DPI. Presented data include results from trial A (top) and trial B (bottom).
Gall counts observed in the lateral roots of sweetpotato genotypes inoculated with Meloidogyne incognita at 14 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by the Kruskal-Wallis test followed by the Dunn test (α = 0.05). Presented data include results from trial A (top) and trial B (bottom).
Gall counts observed in the lateral roots of sweetpotato genotypes inoculated with Meloidogyne incognita at 21 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by the Kruskal-Wallis test followed by the Dunn test (α = 0.05). Presented data include results from trial A (top) and trial B (bottom).
Measured root architecture attributes of sweetpotato genotypes inoculated with Meloidogyne incognita at 14 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by a two-way analysis of variance (ANOVA) followed by Fisher’s least significant difference (LSD) test (α = 0.05). (A) Variations in lateral root length (cm). (B) Variations in lateral root surface area (cm2). (C) Variations in lateral root volume (cm3) at 14 DPI. Presented data include results from trial A (top) and trial B (bottom).
Measured root architecture attributes of sweetpotato genotypes inoculated with Meloidogyne incognita at 21 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by a two-way analysis of variance (ANOVA) followed by Fisher’s least significant difference (LSD) test (α = 0.05). (A) Variations in lateral root length (cm). (B) Variations in lateral root surface area (cm2). (C) Variations in lateral root volume (cm3) at 21 DPI. Presented data include results from trial A (top) and trial B (bottom).
Contributor Notes
Gall counts observed in the lateral roots of sweetpotato genotypes inoculated with Meloidogyne enterolobii at 14 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by the Kruskal-Wallis test followed by the Dunn test (α = 0.05). Presented data include results from trial A (top) and trial B (bottom).
Gall counts observed in the lateral roots of sweetpotato genotypes inoculated with Meloidogyne enterolobii at 21 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by the Kruskal-Wallis test followed by the Dunn test (α = 0.05). Presented data include results from trial A (top) and trial B (bottom).
Measured root architecture attributes of sweetpotato genotypes inoculated with Meloidogyne enterolobii at 14 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by a two-way analysis of variance (ANOVA) followed by Fisher’s least significant difference (LSD) test (α = 0.05). (A) Variations in lateral root length (cm). (B) Variations in lateral root surface area (cm2). (C) Variations in lateral root volume (cm3) at 14 DPI. Presented data include results from trial A (top) and trial B (bottom).
Measured root architecture attributes of sweetpotato genotypes inoculated with Meloidogyne enterolobii at 21 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by a two-way analysis of variance (ANOVA) followed by Fisher’s least significant difference (LSD) test (α = 0.05). (A) Variations in lateral root length (cm). (B) Variations in lateral root surface area (cm2). (C) Variations in lateral root volume (cm3) at 21 DPI. Presented data include results from trial A (top) and trial B (bottom).
Gall counts observed in the lateral roots of sweetpotato genotypes inoculated with Meloidogyne incognita at 14 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by the Kruskal-Wallis test followed by the Dunn test (α = 0.05). Presented data include results from trial A (top) and trial B (bottom).
Gall counts observed in the lateral roots of sweetpotato genotypes inoculated with Meloidogyne incognita at 21 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by the Kruskal-Wallis test followed by the Dunn test (α = 0.05). Presented data include results from trial A (top) and trial B (bottom).
Measured root architecture attributes of sweetpotato genotypes inoculated with Meloidogyne incognita at 14 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by a two-way analysis of variance (ANOVA) followed by Fisher’s least significant difference (LSD) test (α = 0.05). (A) Variations in lateral root length (cm). (B) Variations in lateral root surface area (cm2). (C) Variations in lateral root volume (cm3) at 14 DPI. Presented data include results from trial A (top) and trial B (bottom).
Measured root architecture attributes of sweetpotato genotypes inoculated with Meloidogyne incognita at 21 d postinoculation (DPI). Different letters over bars indicate significant differences as determined by a two-way analysis of variance (ANOVA) followed by Fisher’s least significant difference (LSD) test (α = 0.05). (A) Variations in lateral root length (cm). (B) Variations in lateral root surface area (cm2). (C) Variations in lateral root volume (cm3) at 21 DPI. Presented data include results from trial A (top) and trial B (bottom).
