01. Purpose
In order to test the various stress tolerance effects of Dora Sailor (chitosan oligosaccharide powder).
In order to test the various stress tolerance effects of Dora Sailor (chitosan oligosaccharide powder).
2. Materials and methods
2.1 Test materials
The lettuce is ‘ Italy’, and the biostimulant is chitosan oligosaccharide powder, a chitosan oligosaccharide product, which was provided by Suzhou Dora Agritech Co., Ltd.
2.2 Test method
The experiment was conducted in the greenhouse, National Agriculture Park Changshu(CSNAP). A total of 6 treatment groups were set up in the experiment. 5 plants were set in each group.
Group A1: Control group with water in drought
Group A2: Control group with water in waterlogging
Group A3: Control group with water in salinization
Group B1: 150ppm SailorTM powder in drought
Group B2: 150ppm SailorTM powder in waterlogging
Group B3: 150ppm SailorTM powder in salinization
Lettuce seeds were sterilized with 75% (v/v) alcohol for 15 min, washed with distilled water for 3 times, and then sown in seedling trays. One pot one plant, watered with clear water and 150 ppm SailorTM solution on the 1st and 10th day after transplanting, respectively. Stress simulation treatment was started 14 days after seedling transplanting:
1. Drought: Maintain low soil moisture levels from day 14 to day 22 after transplant.
2. Waterlogging: On the 14th day of transplanting, the waterlogging layer was kept at 2cm, maintain this state for 4 days. After applying clear water and 150ppm SailorTM solution, respectively, the waterlogging state continued for 4 days.
3. Salt stress: From the 14th day of transplanting, each pot of root irrigation contains 150 mL of NaCl solution, and the NaCl concentration is 4% (w/v)), and maintains the state of salt stress for 4 days. Continue to maintain the salinity state for 4 days.
After the treatment, the plants were harvested, and the relative water content, plant height, stem diameter and plant weight of the plants were determined.
Weigh the lettuce with a balance, measure the plant height with a ruler, measure the stem thickness with a vernier caliper.
The relative water content of the plant = (X1-X2)/(X3-X2), X1 is the fresh mass except for the roots, X2 is the mass after the greening at 105 °C for 15 minutes, and then dried at 80 °C, X3 is immersed in distilled water at 4 °C 24 h to obtain the mass when saturated with water.
Photographs were taken to record the growth process of lettuce and the comparison of each group.
2.3 Statistical analysis
Excel & Spass were used for data statistical analysis.
3. Test Data Collection
3.1 Production & Fertilizer Record
Date | Application Records |
4.7 | Seed sowing |
5.7 | Transplanting |
5.8 | Treat with Dora Chitosan Oligosaccharide |
5.17 | Treat with Dora Chitosan Oligosaccharide |
5.24 | Treat with Dora Chitosan Oligosaccharide |
5.30 | Harvest |
6.1 | Dry |
3.2 Lettuce Plant Growth Record
4. Data Analysis
4.1 Effects of chitosan oligosaccharide on lettuce growth in drought stress
Table.1：Data in drought stress | ||||
Treatment | P.H（cm） | S.W (mm) | P.W (g) | R.W (%) |
A1 | 17.04 | 6.08 | 30.98a | 65.10%a |
B1 | 17.12 | 5.56 | 40.42b | 71.32%b |
4.2 Effects of chitosan oligosaccharide on lettuce growth in waterlogging stress
Table.2：Data in waterlogging stress | ||||
Treatment | P.H（cm） | S.W (mm) | P.W (g) | R.W (%) |
A2 | 14.62 | 7.55 | 16.48a | 39.30a |
B2 | 14.20 | 8.17 | 23.08b | 70.19b |
It can be seen from Table 2 that:
(1) Plant height: There are less differences between group A and group B.
(2) Stem diameter: Although the main stem of group B was wider than that of group A, the overall difference isn’t very large in early time.
(3) Plant weight: the lettuce plant weight in the treatment group was greater than that in the control group, with a more weight of 6.66g.
(4) Relative water content of plants: The relative water content of the plants in the control group was 39.30%, and the relative water content of the plants in the B group was 70.19%, which was 330.89% higher, the difference is very obvious.
4.3 Effects of chitosan oligosaccharide on lettuce growth in salinization stress
Table.3：Data in salinization stress | ||||
Treatment | P.H（cm） | S.W (mm) | P.W (g) | R.W (%) |
A3 | 17.40 | 5.48 | 28.40 | 69.23a |
B3 | 18.06 | 5.41 | 33.08 | 79.92b |
(1) Plant height: the plant height of seedlings under the treatment of Sailor powder (150ppm) in group B is higher than that of the CK group.
(2) Stem diameter: There are less differences between group A and group B.
(3) Plant weight: Sailor powder (150ppm) in group B was 33.08g, which had more 4.68g growth advantages over the control group.
(4) Relative water content of plants: The relative water content of the plants in the control group was the lowest, only 69.23%, and the relative water content of the group B treated with Sailor powder (150ppm) was the highest at 79.92%.
5. Trial Results
1. In terms of drought stress, Dora Sailor powder (150ppm) has a certain promoting effect on relative water content, so the plant weight also shows this result.
2. Under the condition of waterlogging, Dora Sailor powder (150ppm) can help plants maintain their water content, and plant weight, although it does not grow taller in appearance.
3. Sailor powder (150ppm) has a good anti-salinization effect, reflecting in plant weight and relative water content.
In summary, Dora chitosan oligosaccharide is evident in helping lettuce plants defend stress like drought, waterlogging and salinization. In the two dimensions of plant weight and relative water content, Dora’s chitosan oligosaccharide has a high level of performance. so we recommend to apply Dora SailorTM in promoting plants’ abilities to resist abiotic stress, the final dosage is 150ppm.