Current Issue
2024 Vol.15 NO.3
2024,
15(3):
259-267.
doi: 10.15886/j.cnki.rdswxb.20230031
Abstract
FullText HTML
PDF 1989KB
Abstract:
Ash content and moisture content are important indexes for cassava quality evaluation. It is of great significance to establish a method for rapid detection of ash and moisture contents in cassava by using near infrared spectroscopy combined with multivariate mathematical analysis. Tubers of 137 accessions of cassava were harvested at the cassava growing site and their ash and water contents were determined by using the methods described in the standards GB5009.3—2016 and GB/T5009.4—2016 and at the same time the near-infrared spectroscopy. The NIR spectral data collected were analyzed by using the software TQ Analyst 9.0. The NIR calibration models for ash and water contents of cassava were constructed by using the partial least squares (PLS) method. The results showed that correlation coefficients (R) of the ash and water content models were 0.94 and 0.93, respectively. Root mean square error of correction (RMSEC) was 0.22 and 0.48, respectively. Root mean square error of prediction (RMSEP) was 0.21 and 1.46, respectively. Root mean square error of cross-validation (RMSECV) was 0.40 and 1.54, respectively. Twenty accessions of cassava germplasm that were not involved in the modelling were selected for external validation of the model. The results showed that there is no significant difference between the predicted value and the actual value, with the p-values (P>0.05) being 0.464 and 0.459, respectively, indicating that the model could be applied to the detection of cassava ash and water contents. The near-infrared quantitative detection models of ash and moisture established can be used for rapid detection.
Ash content and moisture content are important indexes for cassava quality evaluation. It is of great significance to establish a method for rapid detection of ash and moisture contents in cassava by using near infrared spectroscopy combined with multivariate mathematical analysis. Tubers of 137 accessions of cassava were harvested at the cassava growing site and their ash and water contents were determined by using the methods described in the standards GB5009.3—2016 and GB/T5009.4—2016 and at the same time the near-infrared spectroscopy. The NIR spectral data collected were analyzed by using the software TQ Analyst 9.0. The NIR calibration models for ash and water contents of cassava were constructed by using the partial least squares (PLS) method. The results showed that correlation coefficients (R) of the ash and water content models were 0.94 and 0.93, respectively. Root mean square error of correction (RMSEC) was 0.22 and 0.48, respectively. Root mean square error of prediction (RMSEP) was 0.21 and 1.46, respectively. Root mean square error of cross-validation (RMSECV) was 0.40 and 1.54, respectively. Twenty accessions of cassava germplasm that were not involved in the modelling were selected for external validation of the model. The results showed that there is no significant difference between the predicted value and the actual value, with the p-values (P>0.05) being 0.464 and 0.459, respectively, indicating that the model could be applied to the detection of cassava ash and water contents. The near-infrared quantitative detection models of ash and moisture established can be used for rapid detection.
2024,
15(3):
268-271.
doi: 10.15886/j.cnki.rdswxb.20230064
Abstract:
Limnophila sessiliflora var. jiulianshanensis G.L.Xu, a new variety of L. sessiliflora (Vahl) Blume from Jiangxi Jiulianshan National Nature Reserve in China was recorded based on its morphological evidence. This variety is morphologically very similar to L. sessiliflora (Vahl) Blume var. sessiliflora but its aerial stems and calyxes are glabrous, with a pair of 1-3 mm bracteoles each flower, and five raised purplish-red stripes on calyxes in flowering and fruiting periods, distinguished from the latter.
Limnophila sessiliflora var. jiulianshanensis G.L.Xu, a new variety of L. sessiliflora (Vahl) Blume from Jiangxi Jiulianshan National Nature Reserve in China was recorded based on its morphological evidence. This variety is morphologically very similar to L. sessiliflora (Vahl) Blume var. sessiliflora but its aerial stems and calyxes are glabrous, with a pair of 1-3 mm bracteoles each flower, and five raised purplish-red stripes on calyxes in flowering and fruiting periods, distinguished from the latter.
2024,
15(3):
272-280.
doi: 10.15886/j.cnki.rdswxb.20230096
Abstract:
In order to investigate the effects of short-term precipitation reduction on the changes of organic carbon mineralization rate and its carbon fractions in different soil layers, parameters such as soil organic carbon mineralization rate and organic carbon fractions under different precipitation conditions were determined by building a field isolated penetrating rain control platform and combining with indoor constant temperature incubation experiments using a typical plantation type of rubber forest soils in Hainan as the research object. The results showed that the short-term precipitation decreased the cumulative mineralization of SOC, the mineralization rate and the microbial metabolic entropy (qCO2) in the soil layer from 0 to 10 cm, and the contents of easily oxidizable organic carbon (EOC), microbial biomass carbon (MBC) and inert organic carbon (NEOC) decreased with the decrease of the soil water content, but the effect was only significant on the EOC in the soil layer from 0 to 10 cm. Correlation analysis showed that the cumulative mineralization of soil SOC and the mineralization rate of SOC were both significantly and positively correlated with soil carbon and nitrogen contents (SOC, TN), the contents of each carbon fraction (EOC, MBC, NEOC), and qCO2. In conclusion, short-term precipitation reduction inhibited the mineralization of SOC in rubber forest soils, and this change may be closely related to the effectiveness of soil substrate supply and changes in microbial metabolism under different moisture conditions.
In order to investigate the effects of short-term precipitation reduction on the changes of organic carbon mineralization rate and its carbon fractions in different soil layers, parameters such as soil organic carbon mineralization rate and organic carbon fractions under different precipitation conditions were determined by building a field isolated penetrating rain control platform and combining with indoor constant temperature incubation experiments using a typical plantation type of rubber forest soils in Hainan as the research object. The results showed that the short-term precipitation decreased the cumulative mineralization of SOC, the mineralization rate and the microbial metabolic entropy (qCO2) in the soil layer from 0 to 10 cm, and the contents of easily oxidizable organic carbon (EOC), microbial biomass carbon (MBC) and inert organic carbon (NEOC) decreased with the decrease of the soil water content, but the effect was only significant on the EOC in the soil layer from 0 to 10 cm. Correlation analysis showed that the cumulative mineralization of soil SOC and the mineralization rate of SOC were both significantly and positively correlated with soil carbon and nitrogen contents (SOC, TN), the contents of each carbon fraction (EOC, MBC, NEOC), and qCO2. In conclusion, short-term precipitation reduction inhibited the mineralization of SOC in rubber forest soils, and this change may be closely related to the effectiveness of soil substrate supply and changes in microbial metabolism under different moisture conditions.
2024,
15(3):
281-289.
doi: 10.15886/j.cnki.rdswxb.20230073
Abstract:
In recent years the rapid proliferation of Derris trifoliata populations in mangrove areas has resulted in extensive mortality of mangrove plants in certain regions, posing a serious threat to the mangrove wetland ecosystem. During field investigations it was observed that the impact of D. trifoliata on mangrove plants was more pronounced in areas with shorter flooding durations and lower salinity levels compared to those with longer flooding durations and higher salinity levels. To investigate the underlying causes of this phenomenon, an attempt was made to simulate 25 different tidal environments through controlled artificial experiments, under which D. trifoliata seedlings were raised to observe variations in antioxidant enzyme activity, osmotic regulation mechanisms, and membrane system damage levels in their leaves. The results demonstrated that under the individual influence of salinity and flood, the activities of superoxide dismutase (SOD) and catalase (CAT) in the leaves of D. trifoliata seedlings initially increased and then decreased at a salinity level of 0—40‰. The peak value was observed at a salinity level of 20‰. In D. trifoliata seedlings SOD and CAT activities in the leaves did not show significant changes during the 0 h/d-8 h/d flooding period. However, free proline (FPRO) and malondialdehyde (MDA) contents in the seedling leaves exhibited an increasing trend with salinity levels and flooding duration, and their maximum values were reached under treatment conditions of 40‰ salinity and 8 h/d flooding. When both salinity levels and flooding duration were put together, the SOD activity, CAT activity, FPRO content, and MDA content in the seedling leaves came to peak under the treatment of 20‰ salt for 6 h/d, 20‰ salt for 8 h/d, and 40‰ salt for 8 h/d, respectively. In summary, in an environment with short flooding durations and low salinity levels, D. trifoliata seedlings exhibited a heightened capacity for antioxidant enzymes to combat stress-induced damage, resulting in normal growth and consequently a relatively significant impact on mangrove plants. Conversely, in an environment with prolonged flooding duration and high salinity levels, the efficacy of antioxidant enzymes in mitigating stress damage was diminished, leading to inhibited growth and consequently a relatively less influence on the mangrove plants.
In recent years the rapid proliferation of Derris trifoliata populations in mangrove areas has resulted in extensive mortality of mangrove plants in certain regions, posing a serious threat to the mangrove wetland ecosystem. During field investigations it was observed that the impact of D. trifoliata on mangrove plants was more pronounced in areas with shorter flooding durations and lower salinity levels compared to those with longer flooding durations and higher salinity levels. To investigate the underlying causes of this phenomenon, an attempt was made to simulate 25 different tidal environments through controlled artificial experiments, under which D. trifoliata seedlings were raised to observe variations in antioxidant enzyme activity, osmotic regulation mechanisms, and membrane system damage levels in their leaves. The results demonstrated that under the individual influence of salinity and flood, the activities of superoxide dismutase (SOD) and catalase (CAT) in the leaves of D. trifoliata seedlings initially increased and then decreased at a salinity level of 0—40‰. The peak value was observed at a salinity level of 20‰. In D. trifoliata seedlings SOD and CAT activities in the leaves did not show significant changes during the 0 h/d-8 h/d flooding period. However, free proline (FPRO) and malondialdehyde (MDA) contents in the seedling leaves exhibited an increasing trend with salinity levels and flooding duration, and their maximum values were reached under treatment conditions of 40‰ salinity and 8 h/d flooding. When both salinity levels and flooding duration were put together, the SOD activity, CAT activity, FPRO content, and MDA content in the seedling leaves came to peak under the treatment of 20‰ salt for 6 h/d, 20‰ salt for 8 h/d, and 40‰ salt for 8 h/d, respectively. In summary, in an environment with short flooding durations and low salinity levels, D. trifoliata seedlings exhibited a heightened capacity for antioxidant enzymes to combat stress-induced damage, resulting in normal growth and consequently a relatively significant impact on mangrove plants. Conversely, in an environment with prolonged flooding duration and high salinity levels, the efficacy of antioxidant enzymes in mitigating stress damage was diminished, leading to inhibited growth and consequently a relatively less influence on the mangrove plants.
2024,
15(3):
290-298.
doi: 10.15886/j.cnki.rdswxb.20220110
Abstract:
Essential oil was extracted from floral buds and leaves of Michelia shiluensis (M. shiluensis) by steam distillation. After treatment, the components of the essential oil were determined by gas chromatography-mass spectrometry (GC-MS). The GC-MS analysis showed that the main components of the two essential oils were sesquiterpenes. A total of 39 chemical components were identified from the essential oil of floral buds, of which three, β-bisabolene, α-curcumene and β-elemene, were the highest in relative content. A total of 31 chemical constituents were identified from the essential oil of leaves, including guaiacol, isoguaiacol, (Z, Z, Z) -1,8,11,14-heptadecatetraene, and so on. The relative content of alc cohols and olefins is an important index to distinguish between the essential oils of the floral buds and the leaves. The components of M. shiluensis essential oil were analyzed for the first time, and the inhibitory activity of M. shiluensis essential oil on α-glucosidase was determined. When the mass concentration was 3 g·L-1, the essential oils of the leaves and floral buds had an inhibition rate of 87.13% and 72.27% against α-glucosidase activity, and their IC50 was 0.73 ± 0.04 g·L-1 and 1.77 ± 0.07 g·L-1, respectively. M. shiluensis essential oil has a strong inhibitory effect on α-glucosidase activity, and can be developed and used as a hypoglycemic efficacy factor, which provides a theoretical basis for value-added utilization of M. shiluensis resources.
Essential oil was extracted from floral buds and leaves of Michelia shiluensis (M. shiluensis) by steam distillation. After treatment, the components of the essential oil were determined by gas chromatography-mass spectrometry (GC-MS). The GC-MS analysis showed that the main components of the two essential oils were sesquiterpenes. A total of 39 chemical components were identified from the essential oil of floral buds, of which three, β-bisabolene, α-curcumene and β-elemene, were the highest in relative content. A total of 31 chemical constituents were identified from the essential oil of leaves, including guaiacol, isoguaiacol, (Z, Z, Z) -1,8,11,14-heptadecatetraene, and so on. The relative content of alc cohols and olefins is an important index to distinguish between the essential oils of the floral buds and the leaves. The components of M. shiluensis essential oil were analyzed for the first time, and the inhibitory activity of M. shiluensis essential oil on α-glucosidase was determined. When the mass concentration was 3 g·L-1, the essential oils of the leaves and floral buds had an inhibition rate of 87.13% and 72.27% against α-glucosidase activity, and their IC50 was 0.73 ± 0.04 g·L-1 and 1.77 ± 0.07 g·L-1, respectively. M. shiluensis essential oil has a strong inhibitory effect on α-glucosidase activity, and can be developed and used as a hypoglycemic efficacy factor, which provides a theoretical basis for value-added utilization of M. shiluensis resources.
2024,
15(3):
299-305.
doi: 10.15886/j.cnki.rdswxb.20230042
Abstract:
An attempt was made to analyze the effect of rhizobia on seedling growth of Falcataria falcata, which could provide scientific basis for the application of rhizobia in seedling cultivation of F. falcata. A rhizobium strain ZS530-8 isolated and purified was used as an inoculant, and an inoculation and nutrient application comparative trial was made in different culture substrates. Seedling height and ground diameter were regularly measured to analyze the differences in seedling growth dynamics and growth effects in different treatments. From planting to 30 d, the seedlings of F. falcata grew normally in different treatments, and the difference in seedling height was only observed in the different culture substrates. The growth rate of seedling height and ground diameter of the inoculated seedlings gradually increased from 30 d to 60 d, and the growth peak occurred from 60 d to 90 d, showing a trend of steady and then accelerated growth. The seedlings treated with nutrients maintained a trend of continuous growth at a certain rate, while the control failed to grow normally after 60 d. At 90 d, the height and ground diameter of inoculated seedlings were 8.18-10.10 cm and 1.67-2.14 mm, which were 3.2%-9.4% and 16.0%-33.8% higher than those of the nutrient treated seedlings in the corresponding substrates, respectively. The ground diameter of the quartz sand + rhizobia treatment was consistently better than that of the vermiculite + rhizobia treatment, and the difference reached a highly significant level (P<0.001). Rhizobia provide nitrogen-based essential nutrient elements for the growth of the seedlings of F. falcata, and have a significant effect on the growth of the seedlings, especially the growth of seedling ground diameter, and their growth-promoting effect is enhanced with the growth of the seedlings. The culture substrates with stable, loose and well-aerated texture and pH neutral acid are more conducive to growth-promoting of rhizobia.
An attempt was made to analyze the effect of rhizobia on seedling growth of Falcataria falcata, which could provide scientific basis for the application of rhizobia in seedling cultivation of F. falcata. A rhizobium strain ZS530-8 isolated and purified was used as an inoculant, and an inoculation and nutrient application comparative trial was made in different culture substrates. Seedling height and ground diameter were regularly measured to analyze the differences in seedling growth dynamics and growth effects in different treatments. From planting to 30 d, the seedlings of F. falcata grew normally in different treatments, and the difference in seedling height was only observed in the different culture substrates. The growth rate of seedling height and ground diameter of the inoculated seedlings gradually increased from 30 d to 60 d, and the growth peak occurred from 60 d to 90 d, showing a trend of steady and then accelerated growth. The seedlings treated with nutrients maintained a trend of continuous growth at a certain rate, while the control failed to grow normally after 60 d. At 90 d, the height and ground diameter of inoculated seedlings were 8.18-10.10 cm and 1.67-2.14 mm, which were 3.2%-9.4% and 16.0%-33.8% higher than those of the nutrient treated seedlings in the corresponding substrates, respectively. The ground diameter of the quartz sand + rhizobia treatment was consistently better than that of the vermiculite + rhizobia treatment, and the difference reached a highly significant level (P<0.001). Rhizobia provide nitrogen-based essential nutrient elements for the growth of the seedlings of F. falcata, and have a significant effect on the growth of the seedlings, especially the growth of seedling ground diameter, and their growth-promoting effect is enhanced with the growth of the seedlings. The culture substrates with stable, loose and well-aerated texture and pH neutral acid are more conducive to growth-promoting of rhizobia.
2024,
15(3):
306-314.
doi: 10.15886/j.cnki.rdswxb.20230118
Abstract:
In order to meet the needs of development of pitaya industry, it is necessary to develop numerous commercial varieties of pitaya with high yield and high quality through breeding and selection. The main way for pitaya breeding is to collect and evaluate pitaya germplasm resources for cross-breeding. Pitaya germplasm is diverse, and its genetic ploidy is unknown. The ploidy identification is indispensable to breeding innovation. Forty two accessions of pitaya germplasm were collected and their ploidy was identified by stem tip chromosome preparation technique and flow cytometry. When the current hypotonic time is 2 h, the dissociation time is 1.5 h, the enzymatic hydrolysis time is 1 h, and the post-hypotonic time is 30 min, the cells prepared are intact with good chromosome dispersion and clear background and without overlapping. The ploidy of the pitaya stem tip is stable, and the stem tip is the most reliable material for chromosome determination. The mature stems contain a large number of tetraploid and octaploid cells, and are hence not suitable for ploidy identification. Among the 42 accessions of pitaya germplasm there are 41 accessions diploid, 1 tetraploid and no triploid. The genome size was estimated with accession ‘Jindu No.1’ as a reference. It was found that 15 accessions of pitaya germplasm were very small in genome size with the 1C-value (1C) being ≤1.34 Gb while 27 accessions of pitaya germplasm were small in genome size with the 1C being in the range of 1.35 Gb~3.34 Gb. The identification of the ploidy of 42 accessions of pitaya germplasm might provide some reference for parent selection in pitaya cross breeding.
In order to meet the needs of development of pitaya industry, it is necessary to develop numerous commercial varieties of pitaya with high yield and high quality through breeding and selection. The main way for pitaya breeding is to collect and evaluate pitaya germplasm resources for cross-breeding. Pitaya germplasm is diverse, and its genetic ploidy is unknown. The ploidy identification is indispensable to breeding innovation. Forty two accessions of pitaya germplasm were collected and their ploidy was identified by stem tip chromosome preparation technique and flow cytometry. When the current hypotonic time is 2 h, the dissociation time is 1.5 h, the enzymatic hydrolysis time is 1 h, and the post-hypotonic time is 30 min, the cells prepared are intact with good chromosome dispersion and clear background and without overlapping. The ploidy of the pitaya stem tip is stable, and the stem tip is the most reliable material for chromosome determination. The mature stems contain a large number of tetraploid and octaploid cells, and are hence not suitable for ploidy identification. Among the 42 accessions of pitaya germplasm there are 41 accessions diploid, 1 tetraploid and no triploid. The genome size was estimated with accession ‘Jindu No.1’ as a reference. It was found that 15 accessions of pitaya germplasm were very small in genome size with the 1C-value (1C) being ≤1.34 Gb while 27 accessions of pitaya germplasm were small in genome size with the 1C being in the range of 1.35 Gb~3.34 Gb. The identification of the ploidy of 42 accessions of pitaya germplasm might provide some reference for parent selection in pitaya cross breeding.
Effects of different flower forcing methods on flowering and fruit quality of pineapple 'Tainong 16'
2024,
15(3):
315-322.
doi: 10.15886/j.cnki.rdswxb.20230091
Abstract:
Flower forcing is one of the key practices for large-scale and standardized pineapple production. In order to understand the effects of different flower forcing methods on the growth and fruit quality of pineapple, pineapple cultivar 'Tainong 16' was forced to flower by using eight flower forcing methods, and its flowering rate, morphology and fruit quality were determined and analyzed by using correlation analysis. The results showed that the pineapple treated with ethephon at different concentrations was forced to flower at a rate of more than 97%. Under the ethephon treatment in combination of uniconazole or paclobutrazol the plant height decreased, the leaf length and the number of slips increased. Under the ethephon treatment the fruit weight was higher, and the crown was longer, but the peduncle was smaller and easy to break. Fruit quality test showed that the pineapple in the ethephon treatment had higher contents of soluble sugar, soluble solid and vitamin C, and a lower content of total acid. Correlation analysis of 17 characteristics showed the sucker length and the peduncle thickness were highly correlated with yield index, such as fruit weight and longitudinal diameter, whereas the number of slips and the high water content of fruit affected the accumulation of fruit weight and soluble solid. On the whole, ethephon treatment increased the flowering rate, and improved the fruit shape and quality, and can hence be used to promote the production of pineapple 'Tainong 16' in the Pearl River Delta region.
Flower forcing is one of the key practices for large-scale and standardized pineapple production. In order to understand the effects of different flower forcing methods on the growth and fruit quality of pineapple, pineapple cultivar 'Tainong 16' was forced to flower by using eight flower forcing methods, and its flowering rate, morphology and fruit quality were determined and analyzed by using correlation analysis. The results showed that the pineapple treated with ethephon at different concentrations was forced to flower at a rate of more than 97%. Under the ethephon treatment in combination of uniconazole or paclobutrazol the plant height decreased, the leaf length and the number of slips increased. Under the ethephon treatment the fruit weight was higher, and the crown was longer, but the peduncle was smaller and easy to break. Fruit quality test showed that the pineapple in the ethephon treatment had higher contents of soluble sugar, soluble solid and vitamin C, and a lower content of total acid. Correlation analysis of 17 characteristics showed the sucker length and the peduncle thickness were highly correlated with yield index, such as fruit weight and longitudinal diameter, whereas the number of slips and the high water content of fruit affected the accumulation of fruit weight and soluble solid. On the whole, ethephon treatment increased the flowering rate, and improved the fruit shape and quality, and can hence be used to promote the production of pineapple 'Tainong 16' in the Pearl River Delta region.
Effects of flower-forcing treatment at different time on the fruit quality of pineapple ‘Tainong 17’
2024,
15(3):
323-331.
doi: 10.15886/j.cnki.rdswxb.20230124
Abstract:
In order to clarify the effects of flower-forcing treatment at different time on the yield, quality and key endogenous hormones of fruits of pineapple ‘Tainong 17’, flower-forcing treatment was carried out at different time in August and mid-September 2022. Pineapple plants were treated with 2.0% calcium carbide solution at night for 3-5 s at an interval of 1 day in the field. The normal fruit rate, plant dry matter, yield quality and endogenous hormone content of pineapple after forced flowering were determined and their differences were statistically analyzed. The results showed that the maturing time of pineapple fruits in mid-September was about 30 days longer than that in mid-August, and that the proportion of deformed fruits without crowns and multiple crowns in mid-September was 31.33% less than in mid-August. The dry matter accumulation, yield, sugar-acid ratio and soluble protein content of the fruits in the mid-September flower-forcing treatment increased by 6.63%, 25.75%, 23.73% and 50.36%, respectively, and the titratable acid decreased by 14.71%. Compared with the flower-forcing treatment in mid-August, the contents of gibberellin, abscisic acid and trans-zeatin in the fruit of the mid-September treatment were significantly reduced, and the contents of jasmonic acid in the deformed fruit without crowns were significantly increased by 120.93%, and the abscisic acid content in the normal fruits was significantly reduced. In the normal fruits the content of salicylic acid was decreased by 18.18% and 54.81%, respectively, and the content of trans-zeatin was significantly increased by 27.91%. Comprehensive analysis showed that the pineapple ‘Tainong 17’ was higher in fruit quality and yield when forced to flower in mid-September.
In order to clarify the effects of flower-forcing treatment at different time on the yield, quality and key endogenous hormones of fruits of pineapple ‘Tainong 17’, flower-forcing treatment was carried out at different time in August and mid-September 2022. Pineapple plants were treated with 2.0% calcium carbide solution at night for 3-5 s at an interval of 1 day in the field. The normal fruit rate, plant dry matter, yield quality and endogenous hormone content of pineapple after forced flowering were determined and their differences were statistically analyzed. The results showed that the maturing time of pineapple fruits in mid-September was about 30 days longer than that in mid-August, and that the proportion of deformed fruits without crowns and multiple crowns in mid-September was 31.33% less than in mid-August. The dry matter accumulation, yield, sugar-acid ratio and soluble protein content of the fruits in the mid-September flower-forcing treatment increased by 6.63%, 25.75%, 23.73% and 50.36%, respectively, and the titratable acid decreased by 14.71%. Compared with the flower-forcing treatment in mid-August, the contents of gibberellin, abscisic acid and trans-zeatin in the fruit of the mid-September treatment were significantly reduced, and the contents of jasmonic acid in the deformed fruit without crowns were significantly increased by 120.93%, and the abscisic acid content in the normal fruits was significantly reduced. In the normal fruits the content of salicylic acid was decreased by 18.18% and 54.81%, respectively, and the content of trans-zeatin was significantly increased by 27.91%. Comprehensive analysis showed that the pineapple ‘Tainong 17’ was higher in fruit quality and yield when forced to flower in mid-September.
2024,
15(3):
332-336.
doi: 10.15886/j.cnki.rdswxb.20230115
Abstract:
Pissodes castaneus is an important invasive forest pest and a phytosanitary pest in China. The insect pest is native to European countries and has been introduced into Africa and South America. There is no record of the distribution of the insect pest in China, and it was first intercepted at Yangpu Port in Hainan, China in August 2017. P. castaneus mainly infests the cambium and phloem of Pinaceae plants and form pupa chambers under the bark, and it can be spread over long distances through imported timber trade. The adults, larva and pupa of an insect were collected at Yangput Port in August 2017, and their mitochondrial COI genes were amplified by using DNA barcoding and compared with those in GenBank database and BOLD database. The phylogenetic tree of this insect was constructed by using the neighbor-joining algorithm. The results showed that the insect sample and P. castaneus were clustered into the same family and had more than 99% homology. This DNA barcoding method provides a scientific basis for rapid quarantine clearance and detection of invasive forest pests.
Pissodes castaneus is an important invasive forest pest and a phytosanitary pest in China. The insect pest is native to European countries and has been introduced into Africa and South America. There is no record of the distribution of the insect pest in China, and it was first intercepted at Yangpu Port in Hainan, China in August 2017. P. castaneus mainly infests the cambium and phloem of Pinaceae plants and form pupa chambers under the bark, and it can be spread over long distances through imported timber trade. The adults, larva and pupa of an insect were collected at Yangput Port in August 2017, and their mitochondrial COI genes were amplified by using DNA barcoding and compared with those in GenBank database and BOLD database. The phylogenetic tree of this insect was constructed by using the neighbor-joining algorithm. The results showed that the insect sample and P. castaneus were clustered into the same family and had more than 99% homology. This DNA barcoding method provides a scientific basis for rapid quarantine clearance and detection of invasive forest pests.
2024,
15(3):
337-342.
doi: 10.15886/j.cnki.rdswxb.20230053
Abstract:
In order to clarify the harmful symptoms and annual dynamics of coffee leaf rust in dry-hot regions, as well as the impact of altitude gradients on coffee leaf rust and mycoparasitic fungi, the symptoms of coffee leaf rust were observed in the field and its annual dynamics were monitored. An investigation was conducted on the occurrence of coffee leaf rust and mycoparasitic fungi in Arabica coffee plantations at 9 gradients of altitude from 700 to 1 500 m in the dry-hot region of Baoshan, Yunnan. The results show that the coffee leaf rust occurs throughout the year, with the peaks being in December, February and April, and most severe in December in the dry-hot region. The infection of coffee leaf rust is significantly correlated with altitude. The infection of coffee leaf rust at an altitude of 1 500 meters is significantly higher than that at the other eight altitude gradients from 700 m to 1 400 m. Coffee leaf rust occurs all the year round at an altitude of 1 400 m to 1 500 m, and does not occur for more than 2 months at an altitude of 700 m to 1 300 m. The mycoparasitism of coffee leaf rust was found from November to June, and had two peaks, in January with a mycoparasitization rate of (20.19±5.44)% and in March (25.70±5.72)%, respectively. The mycoparasitization increased with the altitude, and the mycoparasitization rates at 1 400 m and 1 500 m were significantly higher than those at the other seven altitude gradients ranging from 800 m to 1 300 m. All these results indicate that altitude has a significant impact on coffee leaf rust, and that the occurrence of mycoparasites and coffee leaf rust is significantly delayed in the dry-hot region. In the areas of high altitude, the mycoparasitization rate of coffee leaf rust exceeds 20%, and the mycoparasitic fungi shows promise as a biocontrol agent of the coffee leaf rust.
In order to clarify the harmful symptoms and annual dynamics of coffee leaf rust in dry-hot regions, as well as the impact of altitude gradients on coffee leaf rust and mycoparasitic fungi, the symptoms of coffee leaf rust were observed in the field and its annual dynamics were monitored. An investigation was conducted on the occurrence of coffee leaf rust and mycoparasitic fungi in Arabica coffee plantations at 9 gradients of altitude from 700 to 1 500 m in the dry-hot region of Baoshan, Yunnan. The results show that the coffee leaf rust occurs throughout the year, with the peaks being in December, February and April, and most severe in December in the dry-hot region. The infection of coffee leaf rust is significantly correlated with altitude. The infection of coffee leaf rust at an altitude of 1 500 meters is significantly higher than that at the other eight altitude gradients from 700 m to 1 400 m. Coffee leaf rust occurs all the year round at an altitude of 1 400 m to 1 500 m, and does not occur for more than 2 months at an altitude of 700 m to 1 300 m. The mycoparasitism of coffee leaf rust was found from November to June, and had two peaks, in January with a mycoparasitization rate of (20.19±5.44)% and in March (25.70±5.72)%, respectively. The mycoparasitization increased with the altitude, and the mycoparasitization rates at 1 400 m and 1 500 m were significantly higher than those at the other seven altitude gradients ranging from 800 m to 1 300 m. All these results indicate that altitude has a significant impact on coffee leaf rust, and that the occurrence of mycoparasites and coffee leaf rust is significantly delayed in the dry-hot region. In the areas of high altitude, the mycoparasitization rate of coffee leaf rust exceeds 20%, and the mycoparasitic fungi shows promise as a biocontrol agent of the coffee leaf rust.
2024,
15(3):
343-348.
doi: 10.15886/j.cnki.rdswxb.20230085
Abstract:
Natural enemy insects are important biological factors in pest control, which can not only decrease population of pests through direct predation, but also change the growth, development and reproduction of pests through non-consumptive effects, indirectly affecting the fitness of pests. Winter melons and vegetables are important crops for high-efficient development of tropical agriculture in Hainan, and an aphid, Aphis gossypii, was considered as an important pest causing great damage to cucumbers and other melons crops. For comprehensive assessment of the impact of natural enemies on aphid populations, the life table method was utilized to investigate the non-consumptive effects of a local predatory natural enemy, Cheilomenes sexmaculata, on aphids, A. gossypii. The results revealed that the non-consumptive effect of C. sexmaculata on A. gossypii varied depending on the duration of treatment. After a 24-hour treatment, the aphid offspring showed a significant decrease in the longevity, reproduction duration, total reproduction, and R0. The research findings indicate that the non-consumptive effects of C. sexmaculata significantly altered the growth, development, reproduction, and other population life table parameters of the aphids. The findings will contribute to a more thorough assessment of ladybeetles' capacity to regulate aphid populations, thus offering novel approaches for ecologically-friendly aphid management (especially resistant aphids).
Natural enemy insects are important biological factors in pest control, which can not only decrease population of pests through direct predation, but also change the growth, development and reproduction of pests through non-consumptive effects, indirectly affecting the fitness of pests. Winter melons and vegetables are important crops for high-efficient development of tropical agriculture in Hainan, and an aphid, Aphis gossypii, was considered as an important pest causing great damage to cucumbers and other melons crops. For comprehensive assessment of the impact of natural enemies on aphid populations, the life table method was utilized to investigate the non-consumptive effects of a local predatory natural enemy, Cheilomenes sexmaculata, on aphids, A. gossypii. The results revealed that the non-consumptive effect of C. sexmaculata on A. gossypii varied depending on the duration of treatment. After a 24-hour treatment, the aphid offspring showed a significant decrease in the longevity, reproduction duration, total reproduction, and R0. The research findings indicate that the non-consumptive effects of C. sexmaculata significantly altered the growth, development, reproduction, and other population life table parameters of the aphids. The findings will contribute to a more thorough assessment of ladybeetles' capacity to regulate aphid populations, thus offering novel approaches for ecologically-friendly aphid management (especially resistant aphids).
2024,
15(3):
349-353.
doi: 10.15886/j.cnki.rdswxb.20230014
Abstract:
The species diversity of the Conidae is extremely high, and has been getting extensive attention for the research of conotoxin (CTx). In China waters, conids are distributed mainly in Taiwan and the South China Sea, and there are more than 160 species so far, accounting for almost 17% of the global conids species. The common Conidae species in the South China Sea, Conus marmoreus Linnaeus, 1758 is similar to Conus bandanus Hwass in Bruguière, 1792 in shape and there is some overlap in their distribution range in China seas, so they are easy to be confused. Our comparative study between the two species is conducted on the Conus specimens deposited in Marine Biodiversity Collections of South China Sea (SCSMBC, Guangzhou). The taxonomic confusion of the two species is clarified on shell morphology and habitat: C. marmoreus has week shoulder tubercles or even absent, and both the size and the pattern of the nearly triangular white spots on the body-whorl surface are relatively uniform, without dark brown spiral bands; while C. bandanus has more pronounced spire tubercles and a less regular pattern with two distinct dark color bands. Ecological differences also favour separation at the species level: C. bandanus usually lives in deeper water. In China, C. bandanus has been found in Taiwan before; the speciesmens examinated in this work were collected from Hainan, Xisha Islands and Nansha Islands, which further improves the geographical distribution information of C. bandanus in China Seas and can also provide a reliable basis for the accurate identification of CTx-derived organisms.
The species diversity of the Conidae is extremely high, and has been getting extensive attention for the research of conotoxin (CTx). In China waters, conids are distributed mainly in Taiwan and the South China Sea, and there are more than 160 species so far, accounting for almost 17% of the global conids species. The common Conidae species in the South China Sea, Conus marmoreus Linnaeus, 1758 is similar to Conus bandanus Hwass in Bruguière, 1792 in shape and there is some overlap in their distribution range in China seas, so they are easy to be confused. Our comparative study between the two species is conducted on the Conus specimens deposited in Marine Biodiversity Collections of South China Sea (SCSMBC, Guangzhou). The taxonomic confusion of the two species is clarified on shell morphology and habitat: C. marmoreus has week shoulder tubercles or even absent, and both the size and the pattern of the nearly triangular white spots on the body-whorl surface are relatively uniform, without dark brown spiral bands; while C. bandanus has more pronounced spire tubercles and a less regular pattern with two distinct dark color bands. Ecological differences also favour separation at the species level: C. bandanus usually lives in deeper water. In China, C. bandanus has been found in Taiwan before; the speciesmens examinated in this work were collected from Hainan, Xisha Islands and Nansha Islands, which further improves the geographical distribution information of C. bandanus in China Seas and can also provide a reliable basis for the accurate identification of CTx-derived organisms.
2024,
15(3):
354-360.
doi: 10.15886/j.cnki.rdswxb.20230086
Abstract:
As one of the key techniques in fry fish rearing, feeding management affects survival, growth and development of the fry. An attempt was made to analyze the effect of the feeding management on the growth and body color change of the fry of white angelfish. The fry of white angelfish (Pterophyllum scalare) were fed with three combinations of foods, including commercial microcapsule feed (M group), microcapsule feed with Artemia sp. nauplii (MA group) and fishmeal feed with Artemia sp. nauplii (AF group). The survival, growth and body color of the white angelfish fry fed with different food combinations were analyzed and compared. The results showed that the survival rates in all the groups were more than 82%, where the MA group was significantly higher than the M and AF groups (P < 0.05). The body weight, length, weight gain rate and specific growth rate were significantly higher in the MA group than in the AF group (P < 0.05). The regularity was observed in the body color of different body position in each group with the lightness(L*) being in the order of “abdomen > operculum > lower back”, the red tonality (a*) being in the order of “operculum > abdomen > lower back” and the yellow hue (b*) in the order of “lower back > abdomen > operculum”. Feeding Artemia sp. nauplii could affect the yellow hue (b*) of P. scalare fry during rearing. The proper use of Artemia sp. nauplii to feed the white angelfish at the right stage of fish rearing helps to improve the growth performance and enhance the ornamental character of the fish body color.
As one of the key techniques in fry fish rearing, feeding management affects survival, growth and development of the fry. An attempt was made to analyze the effect of the feeding management on the growth and body color change of the fry of white angelfish. The fry of white angelfish (Pterophyllum scalare) were fed with three combinations of foods, including commercial microcapsule feed (M group), microcapsule feed with Artemia sp. nauplii (MA group) and fishmeal feed with Artemia sp. nauplii (AF group). The survival, growth and body color of the white angelfish fry fed with different food combinations were analyzed and compared. The results showed that the survival rates in all the groups were more than 82%, where the MA group was significantly higher than the M and AF groups (P < 0.05). The body weight, length, weight gain rate and specific growth rate were significantly higher in the MA group than in the AF group (P < 0.05). The regularity was observed in the body color of different body position in each group with the lightness(L*) being in the order of “abdomen > operculum > lower back”, the red tonality (a*) being in the order of “operculum > abdomen > lower back” and the yellow hue (b*) in the order of “lower back > abdomen > operculum”. Feeding Artemia sp. nauplii could affect the yellow hue (b*) of P. scalare fry during rearing. The proper use of Artemia sp. nauplii to feed the white angelfish at the right stage of fish rearing helps to improve the growth performance and enhance the ornamental character of the fish body color.
2024,
15(3):
361-367.
doi: 10.15886/j.cnki.rdswxb.20230102
Abstract:
Betaphycus gelatinae was cut into sections of different lengths from different explants and cultured at different temperatures to explore the suitable conditions for its tissue culture to determine the effects of different explants (stem tip, main branch and trunk), section lengths (5 mm, 10 mm and 15 mm) and culture temperatures (21 ℃, 24 ℃, 27 ℃, 30 ℃ and 33 ℃) on bud emergence and growth of the explants of B. gelatinae. The results showed that the survival rate and bud emergence rate of different explants and section lengths were all up to 100%. The number of buds in different explants was in the order of the trunk > the main branch > the stem tip. The stem tip mainly grew elongate, while the main branch and trunk were mainly expanded and formed buds. The buds were formed on the upper cut, not on the lower cut, showing obvious polarity. The number of the buds in the sections of different lengths was in the order of the sections 15 mm long > the sections 10 mm long > the sections 5 mm long. The number of individual buds in the sections 15 mm long was 5.90 ± 0.67 in the stem tip, 10.16 ± 1.14 in the main branch and 11.90 ± 0.88 in the trunk. The highest budding density was in the sections 5 mm long. The suitable growth temperature for tissue culture of B. gelatinae ranged from 21℃ to 27 ℃, under which the survival rate and bud emergence rate were both 100%, and the number of buds increased with the temperature. The survival rate and bud emergenc rate of the sections were decreased when the temperature was above 27 ℃. For optimal tissue culture B. gelatinae was cultured at 27 ℃ with the trunk sections 15 mm long as explants.
Betaphycus gelatinae was cut into sections of different lengths from different explants and cultured at different temperatures to explore the suitable conditions for its tissue culture to determine the effects of different explants (stem tip, main branch and trunk), section lengths (5 mm, 10 mm and 15 mm) and culture temperatures (21 ℃, 24 ℃, 27 ℃, 30 ℃ and 33 ℃) on bud emergence and growth of the explants of B. gelatinae. The results showed that the survival rate and bud emergence rate of different explants and section lengths were all up to 100%. The number of buds in different explants was in the order of the trunk > the main branch > the stem tip. The stem tip mainly grew elongate, while the main branch and trunk were mainly expanded and formed buds. The buds were formed on the upper cut, not on the lower cut, showing obvious polarity. The number of the buds in the sections of different lengths was in the order of the sections 15 mm long > the sections 10 mm long > the sections 5 mm long. The number of individual buds in the sections 15 mm long was 5.90 ± 0.67 in the stem tip, 10.16 ± 1.14 in the main branch and 11.90 ± 0.88 in the trunk. The highest budding density was in the sections 5 mm long. The suitable growth temperature for tissue culture of B. gelatinae ranged from 21℃ to 27 ℃, under which the survival rate and bud emergence rate were both 100%, and the number of buds increased with the temperature. The survival rate and bud emergenc rate of the sections were decreased when the temperature was above 27 ℃. For optimal tissue culture B. gelatinae was cultured at 27 ℃ with the trunk sections 15 mm long as explants.
2024,
15(3):
368-372.
doi: 10.15886/j.cnki.rdswxb.20230016
Abstract:
Onchidium verruculatum, a characteristic resource in the South China Sea, was extracted and isolated by using a variety of separation and purification methods, including silica gel, Sephadex LH-20, thin layer chromatography and semi-prepared HPLC. The structures of the compounds were identified by combining their biochemical characteristics, NMR data analysis and reference comparison. Twelve compounds were isolated from Onchidium verruculatum, and their structures were identified as Cyclo-(L-Pro-L-Val) ( 1 ), Cyclo-(Pro-Ile) ( 2 ), Cyclo-(L-Pro-D-Leu) ( 3 ), Tyramine ( 4 ), Cyclo-(L-Pro-L-Phe) ( 5 ), 2-Piperidone ( 6 ), Cyclo-(L-Ala-L-Pro) ( 7 ), uracil ribonucleoside ( 8 ), uracil ( 9 ), thymine ( 10 ), 2'-methoxyuracil nucleoside ( 11 ), thymidine ( 12 ). Compounds ( 1-6, 11 ) were isolated for the first time from Onchidium verruculatum.
Onchidium verruculatum, a characteristic resource in the South China Sea, was extracted and isolated by using a variety of separation and purification methods, including silica gel, Sephadex LH-20, thin layer chromatography and semi-prepared HPLC. The structures of the compounds were identified by combining their biochemical characteristics, NMR data analysis and reference comparison. Twelve compounds were isolated from Onchidium verruculatum, and their structures were identified as Cyclo-(L-Pro-L-Val) ( 1 ), Cyclo-(Pro-Ile) ( 2 ), Cyclo-(L-Pro-D-Leu) ( 3 ), Tyramine ( 4 ), Cyclo-(L-Pro-L-Phe) ( 5 ), 2-Piperidone ( 6 ), Cyclo-(L-Ala-L-Pro) ( 7 ), uracil ribonucleoside ( 8 ), uracil ( 9 ), thymine ( 10 ), 2'-methoxyuracil nucleoside ( 11 ), thymidine ( 12 ). Compounds ( 1-6, 11 ) were isolated for the first time from Onchidium verruculatum.
Email alert
RSS