Physicochemical Properties and Bioactivity of a New Guar Gum-Based Film Incorporated with Citral to Brown Planthopper, <i>Nilaparvata lugens</i> (Stål) (Hemiptera: Delphacidae)
The brown planthopper (BPH), Nilaparvata lugens (Stål), is the most notorious rice insect pest. In order to repel BPH effectively while being environmentally friendly, a new film based on guar gum incorporated with citral (GC film) was formulated. A toxicity bioassay of citral and guar gum at differ...
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-04-01
|
| Series: | Molecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1420-3049/25/9/2044 |
| _version_ | 1827717905663393792 |
|---|---|
| author | Xiubing Gao Can Guo Ming Li Rongyu Li Xiaomao Wu Anlong Hu Xianfeng Hu Feixu Mo Shuai Wu |
| author_facet | Xiubing Gao Can Guo Ming Li Rongyu Li Xiaomao Wu Anlong Hu Xianfeng Hu Feixu Mo Shuai Wu |
| author_sort | Xiubing Gao |
| collection | DOAJ |
| description | The brown planthopper (BPH), Nilaparvata lugens (Stål), is the most notorious rice insect pest. In order to repel BPH effectively while being environmentally friendly, a new film based on guar gum incorporated with citral (GC film) was formulated. A toxicity bioassay of citral and guar gum at different proportions (ratios of 3:1, 2:1, 1:1, 1:2, and 1:3 in <i>w</i>/<i>w</i>) of GC film-forming emulsion to BPH was performed with the rice stem dipping method. Results showed that the most effective ratio of citral to guar gum was 1:1 with the median lethal concentration (LC<sub>50</sub>) of 4.30 mg/mL, far below the LC<sub>50</sub> of guar gum (GG)/citral individual (141.51 and 44.38 mg/mL, respectively). The mortality of BPH adults and nymphs in the third instar treated with different dilution multiples of GC film-forming emulsion ranged from 46.67% to 82.22% and from 37.78% to 71.11%, respectively. These indicated that GC film-forming emulsion had a direct toxicity on BPH, and the mixture of citral and GG had synergistic interactions. Subsequently, Fourier-transform infrared spectroscopy showed that the incorporation of guar gum with citral was successful and did not result in the formation of new chemical bonds. The GC film exhibited a darker color and rougher surface topography with larger apertures and deeper gullies (Ra = 1.42 nm, Rq = 2.05 nm, and Rmax = 25.40 nm) compared to the guar gum film (GG film) (Ra = 1.00 nm, Rq = 1.33 nm, and Rmax = 16.40 nm), as determined by transmission electron microscopy and atomic force microscopy. The GC film exhibited a 50.4% lower solubility in water (30.30% vs. 15.00%) and 71.3% oxygen permeability (8.26 × 10<sup>−9</sup> vs. 2.37 × 10<sup>−9</sup> cm<sup>3</sup>/m<sup>2</sup>·d·Pa) (<i>p <</i> 0.05) but did not demonstrate any significant difference in mechanical properties, such as thickness (39.10 vs. 41.70 mm), tensile strength (41.89 vs. 38.30 N/mm<sup>2</sup>), and elongation at break (1.82% vs. 2.03%) (<i>p <</i> 0.05) compared to the GG film. Our findings established a link between physicochemical properties and bioactivity, which can provide useful information on developing and improving GC films and may offer an alternative approach for the control of BPH in the near future. |
| first_indexed | 2024-03-10T20:11:55Z |
| format | Article |
| id | doaj.art-e9b948a19ed1499199777396dfc58711 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-10T20:11:55Z |
| publishDate | 2020-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-e9b948a19ed1499199777396dfc587112023-11-19T22:54:06ZengMDPI AGMolecules1420-30492020-04-01259204410.3390/molecules25092044Physicochemical Properties and Bioactivity of a New Guar Gum-Based Film Incorporated with Citral to Brown Planthopper, <i>Nilaparvata lugens</i> (Stål) (Hemiptera: Delphacidae)Xiubing Gao0Can Guo1Ming Li2Rongyu Li3Xiaomao Wu4Anlong Hu5Xianfeng Hu6Feixu Mo7Shuai Wu8Institute of Plant Protection, College of Agriculture, Guizhou University, Guiyang 550025, Guizhou, ChinaGuizhou Tea Research Institute, Guizhou Province Academy of Agricultural Science, Xiaohe District, Guiyang 550006, Guizhou, ChinaInstitute of Plant Protection, College of Agriculture, Guizhou University, Guiyang 550025, Guizhou, ChinaInstitute of Plant Protection, College of Agriculture, Guizhou University, Guiyang 550025, Guizhou, ChinaInstitute of Plant Protection, College of Agriculture, Guizhou University, Guiyang 550025, Guizhou, ChinaInstitute of Plant Protection, College of Agriculture, Guizhou University, Guiyang 550025, Guizhou, ChinaInstitute of Plant Protection, College of Agriculture, Guizhou University, Guiyang 550025, Guizhou, ChinaInstitute of Plant Protection, College of Agriculture, Guizhou University, Guiyang 550025, Guizhou, ChinaInstitute of Plant Protection, College of Agriculture, Guizhou University, Guiyang 550025, Guizhou, ChinaThe brown planthopper (BPH), Nilaparvata lugens (Stål), is the most notorious rice insect pest. In order to repel BPH effectively while being environmentally friendly, a new film based on guar gum incorporated with citral (GC film) was formulated. A toxicity bioassay of citral and guar gum at different proportions (ratios of 3:1, 2:1, 1:1, 1:2, and 1:3 in <i>w</i>/<i>w</i>) of GC film-forming emulsion to BPH was performed with the rice stem dipping method. Results showed that the most effective ratio of citral to guar gum was 1:1 with the median lethal concentration (LC<sub>50</sub>) of 4.30 mg/mL, far below the LC<sub>50</sub> of guar gum (GG)/citral individual (141.51 and 44.38 mg/mL, respectively). The mortality of BPH adults and nymphs in the third instar treated with different dilution multiples of GC film-forming emulsion ranged from 46.67% to 82.22% and from 37.78% to 71.11%, respectively. These indicated that GC film-forming emulsion had a direct toxicity on BPH, and the mixture of citral and GG had synergistic interactions. Subsequently, Fourier-transform infrared spectroscopy showed that the incorporation of guar gum with citral was successful and did not result in the formation of new chemical bonds. The GC film exhibited a darker color and rougher surface topography with larger apertures and deeper gullies (Ra = 1.42 nm, Rq = 2.05 nm, and Rmax = 25.40 nm) compared to the guar gum film (GG film) (Ra = 1.00 nm, Rq = 1.33 nm, and Rmax = 16.40 nm), as determined by transmission electron microscopy and atomic force microscopy. The GC film exhibited a 50.4% lower solubility in water (30.30% vs. 15.00%) and 71.3% oxygen permeability (8.26 × 10<sup>−9</sup> vs. 2.37 × 10<sup>−9</sup> cm<sup>3</sup>/m<sup>2</sup>·d·Pa) (<i>p <</i> 0.05) but did not demonstrate any significant difference in mechanical properties, such as thickness (39.10 vs. 41.70 mm), tensile strength (41.89 vs. 38.30 N/mm<sup>2</sup>), and elongation at break (1.82% vs. 2.03%) (<i>p <</i> 0.05) compared to the GG film. Our findings established a link between physicochemical properties and bioactivity, which can provide useful information on developing and improving GC films and may offer an alternative approach for the control of BPH in the near future.https://www.mdpi.com/1420-3049/25/9/2044<i>Nilaparvata lugens</i>filmcitralguar gumphysicochemical propertiesbioactivity |
| spellingShingle | Xiubing Gao Can Guo Ming Li Rongyu Li Xiaomao Wu Anlong Hu Xianfeng Hu Feixu Mo Shuai Wu Physicochemical Properties and Bioactivity of a New Guar Gum-Based Film Incorporated with Citral to Brown Planthopper, <i>Nilaparvata lugens</i> (Stål) (Hemiptera: Delphacidae) Molecules <i>Nilaparvata lugens</i> film citral guar gum physicochemical properties bioactivity |
| title | Physicochemical Properties and Bioactivity of a New Guar Gum-Based Film Incorporated with Citral to Brown Planthopper, <i>Nilaparvata lugens</i> (Stål) (Hemiptera: Delphacidae) |
| title_full | Physicochemical Properties and Bioactivity of a New Guar Gum-Based Film Incorporated with Citral to Brown Planthopper, <i>Nilaparvata lugens</i> (Stål) (Hemiptera: Delphacidae) |
| title_fullStr | Physicochemical Properties and Bioactivity of a New Guar Gum-Based Film Incorporated with Citral to Brown Planthopper, <i>Nilaparvata lugens</i> (Stål) (Hemiptera: Delphacidae) |
| title_full_unstemmed | Physicochemical Properties and Bioactivity of a New Guar Gum-Based Film Incorporated with Citral to Brown Planthopper, <i>Nilaparvata lugens</i> (Stål) (Hemiptera: Delphacidae) |
| title_short | Physicochemical Properties and Bioactivity of a New Guar Gum-Based Film Incorporated with Citral to Brown Planthopper, <i>Nilaparvata lugens</i> (Stål) (Hemiptera: Delphacidae) |
| title_sort | physicochemical properties and bioactivity of a new guar gum based film incorporated with citral to brown planthopper i nilaparvata lugens i stal hemiptera delphacidae |
| topic | <i>Nilaparvata lugens</i> film citral guar gum physicochemical properties bioactivity |
| url | https://www.mdpi.com/1420-3049/25/9/2044 |
| work_keys_str_mv | AT xiubinggao physicochemicalpropertiesandbioactivityofanewguargumbasedfilmincorporatedwithcitraltobrownplanthopperinilaparvatalugensistalhemipteradelphacidae AT canguo physicochemicalpropertiesandbioactivityofanewguargumbasedfilmincorporatedwithcitraltobrownplanthopperinilaparvatalugensistalhemipteradelphacidae AT mingli physicochemicalpropertiesandbioactivityofanewguargumbasedfilmincorporatedwithcitraltobrownplanthopperinilaparvatalugensistalhemipteradelphacidae AT rongyuli physicochemicalpropertiesandbioactivityofanewguargumbasedfilmincorporatedwithcitraltobrownplanthopperinilaparvatalugensistalhemipteradelphacidae AT xiaomaowu physicochemicalpropertiesandbioactivityofanewguargumbasedfilmincorporatedwithcitraltobrownplanthopperinilaparvatalugensistalhemipteradelphacidae AT anlonghu physicochemicalpropertiesandbioactivityofanewguargumbasedfilmincorporatedwithcitraltobrownplanthopperinilaparvatalugensistalhemipteradelphacidae AT xianfenghu physicochemicalpropertiesandbioactivityofanewguargumbasedfilmincorporatedwithcitraltobrownplanthopperinilaparvatalugensistalhemipteradelphacidae AT feixumo physicochemicalpropertiesandbioactivityofanewguargumbasedfilmincorporatedwithcitraltobrownplanthopperinilaparvatalugensistalhemipteradelphacidae AT shuaiwu physicochemicalpropertiesandbioactivityofanewguargumbasedfilmincorporatedwithcitraltobrownplanthopperinilaparvatalugensistalhemipteradelphacidae |