Subjects: Biology >> Botany >> Applied botany submitted time 2023-12-24 Cooperative journals: 《广西植物》
Abstract： Effects of different nitrogen fertilizer application rates on fruit quality of pitaya under the condition of calcareous soil in karst area were discussed in order to promote the growth, development and quality improvement of pitaya. The ‘Taiwan Dahong’ pitaya in 3-year-old were used as the experiment material. Based on 0.216 kg of phosphorus (P) and 0.324kg of potassium (K), four nitrogen application levels (CK, T1, T2, T3) were setted. 21 fruit quality indexes were determined, and the quality differences of pitaya with different nitrogen application levels (CK,T1,T2,T3) were compared. At the same time, 11 appearance quality indexes were comprehensicely analyzed by principal component analysis. The results were as follows: (1) Compared with the control, nitrogen application could increase the soluble sugar content and soluble solids of fruit content, reduce the protein content and dietary fiber content, and the high nitrogen treatment (T3) was significantly different from other treatments. With the increase of nitrogen application rate, the titratable acid content and vitamin C content of fruit increased first and then decreased, while the solid-acid ratio decreased first and then increased with the increase of nitrogen application rate, and the high nitrogen treatment(T3) was significantly higher than other treatments. High nitrogen level significantly increased the fruit vertical and horizontal diameter, fruit shape index and single fruit weight. (2) Compared with the control, nitrogen application treatment reduced the N content of pitaya fruit and increased the P content, and the N and P contents of each treatment were significantly different. The K content of fruit increased with the increase of nitrogen application rate, and T3 treatment was significantly higher than other treatments. Nitrogen application increased fruit B content and decreased fruit Cu content. The contents of Mn, Fe, Ca and Mg in different treatments were ranked as T3 > T1 > CK > T2. The content of Zn decreased first and then increased with the increase of nitrogen application rate. (3) The principal component comprehensive evaluation score of the high nitrogen level treatment was the highest, indicating that when selecting brown calcareous soil in Guilin karst area to grow pitaya, supplemented by a certain amount of P and K fertilizer, high nitrogen treatment was more conducive to improving the quality of pitaya. In actual production, it is necessary to make appropriate adjustments according to the soil fertility status of the plantation.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-08-05 Cooperative journals: 《广西植物》
Abstract： Excentrodendron tonkinensis is a constructive species of karst seasonal rainforest and an obligate karst plant, which is also one of the national secondary key protected wild plant and an IUCN endangered plant, with high economic and ecological value. However, there is still a lack of understanding of how the potential suitable areas of Excentrodendron tonkinensis change in the context of global change and its key driving factors, which affect the scientific protection and utilization of Excentrodendron tonkinensis.To assess the impacts of climate change on the extents of the habitat of Excentrodendron tonkinensis, we used the Maximum-entropy model to analyze the potential changes in the geographical distribution in China of future climate scenarios SSP1-2.6 and SSP5-8.5), and tested the influence of the karst geological background distribution on predicting the suitable areas of karst obligate plants. The results show that: (1) in the case of adding karst geological background data, the average AUC of the prediction model for the suitable area is 0.997, which has a good prediction effect. And the model prediction results are strictly limited to the karst region, consistent with the characteristics of Excentrodendron tonkinensis which is karst obligate plant; (2) According to the fitting results of the model, the karst geological background, precipitation of warmest quarter(800-950 mm), and the min temperature of coldest month(7-11 ℃) are the key factors limiting the distribution of Excentrodendron tonkinensis; (3) with the increase of temperature in the future, the area of potential suitable areas for Excentrodendron tonkinensis would expand to higher latitudes karst areas. Large numbers of areas of stable habitats exist in parts of southwest Guangxi and southeastern Yunnan. These results suggest that the karst geological distribution is essential as predicting the potential geographic distribution of karst obligate plants such as Excentrodendron tonkinensis; if the temperature continues to rise in the future, its potential suitable areas will expand to high latitudes, and the degree of endangerment may be affected by climate, which means it is not obvious under the influence of climate changes; parts of southwestern Guangxi and southeastern Yunnan are suitable areas for the conservation and utilization of Excentrodendron tonkinensis under the climate changes in the future.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-06-29 Cooperative journals: 《广西植物》
Abstract： In order to study the adaptive strategy of dominant tree species in a karst seasonal rain forest to heterogeneous habitat conditions, seven dominant tree species in a virgin forest in Nonggang, China, were taken as the research objects. The leaf micromorphological indexes of adult individuals of each tree species and the photosynthetic indexes of leaves in the growing season of these trees were measured. The ecological adaptability of these leaf structural and functional indexes to the habitat gradient in the karst peak cluster depression landform was tested. The results were as follows: (1) Along the karst habitat gradient from depression to peak, nine leaf micro-morphological indexes, such as leaf compactness, palisade tissue thickness, cuticle thickness, and upper epidermis thickness, showed a significant upward trend, while leaf looseness showed a significant downward trend. (2) Along the karst habitat gradient from depression to peak, the light compensation point, dark respiration efficiency, and maximum transpiration rate of these leaves all showed a significant upward trend. However, the maximum water use efficiency, the maximum intercellular CO2 concentration, and the apparent quantum efficiency showed a significant downward trend. (3) Leaf compactness was positively correlated with photosynthetic and transpiration ability indexes. Leaf looseness was negatively correlated with these two types of indexes. The above results show that there is a trade-off relationship between photosynthetic efficiency and drought tolerance in leaf functional traits of dominant tree species in the karst seasonal rain forest. Trees distributed in the depressions have obvious adaptive characteristics to weak light. Trees distributed on the middle slopes show extensive habitat adaptability. Due to the limitation of strong light, high temperature and exposed rock, the trees distributed on the mountain peaks show strong drought adaptability and conservative ecological adaptive strategies.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-12-19 Cooperative journals: 《广西植物》
Abstract： Different varieties have different resistances. In order to further explore the resistance differences in different varieties of pitaya fruit and provide a reference for further study on breeding of pitaya fruit resistance. Our study using Illumina HiSeq 2000 sequencing platform to sequencing the transcriptome of ‘Putongbairou’ （BR） and ‘Ecuador Yellow’ （EY）. Functional classification and enrichment analysis of differentially expressed genes （DEGs） were performed by reference to GO Ontology, KEGG and others databases. The results were as follows: (1) There were 14 248 DEGs between BR and EY, of which 5 446 genes were up-regulated and 8 802 genes were down-regulated. (2) GO functional analysis showed that these DEGs are mainly involved in enzyme catalytic activity, cell components, metabolic processes, etc. Among them, there were 349 differential genes involved in oxidoreductase activity. (3) KEGG pathway analysis showed that most of the DEGs were enriched in metabolism, biosynthesis, etc. , and 12 key genes such as CYP86 and CER1 involving in Cutin, suberine and wax biosynthesis. We found the expression of DEGs involved in oxidoreductase activity were higher in BR than that in EY, which significantly enriched, indicating that may be differences in growth and cell metabolism between BR and EY. DEGs involved in the biosynthesis of Cutin, suberine and wax biosynthesis were up-regulated in BR. Such genes have higher expression in BR, and significantly enriched, suggesting that BR may be superior drought and disease resistance than EY.
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