After flower induction, some longan trees can successfully blossom and bear fruit, while others with similar tree body status can only sprout leaf buds. In order to investigate the main reason for these differences, i...After flower induction, some longan trees can successfully blossom and bear fruit, while others with similar tree body status can only sprout leaf buds. In order to investigate the main reason for these differences, in this study, off-season flowering and non-flowering longan trees were used as experimental materials to analyze the changes of carbon content in mature leaves, tender leaves, mature shoots, tender shoots and terminal buds of longan trees after flower induction by potassium chlorate. The result showed that carbon content played an important role in flowering process. Off-season longan trees with carbon content in mature leaves reached 50.93 mg/g could successfully blossom, but those with carbon content in mature leaves lower than 37.40 mg/g were usually difficult to blossom. In addition, the maturity of tender leaves posed great influence on flowering. Specifically, tender leaves with a higher maturity contained higher carbon content and could easily blossom, which could be used as a new indicator to evaluate flower induction in off-season longan trees.展开更多
Flower-bud differentiation is the most critical stage of fruit yield formation, as well as a complicated carbon transfer process. To understand the changes of carbon during the flower bud differentiation process of lo...Flower-bud differentiation is the most critical stage of fruit yield formation, as well as a complicated carbon transfer process. To understand the changes of carbon during the flower bud differentiation process of longan, it is very important to adopt suitable planting measures and control flowering time. This study fo- cused on the changes of sugar and starch content of on-season and off-season longan during the flowering process. The results showed that the accumulation and transformation of carben differed between on-season and off-season longan during flower-bud differentiation process ; to be specific, sugar and starch content in tissues differentiated from apical buds of on-season longan were reduced at the late flower-bud physiological differentiation stage except in leaf buds ; on the contrary, sugar and starch content in off-season longan increased at the late flower-bud physiological differentiation stage： specifically, total sugar content increased from 15.43 （ - 7 d） to 31.38 mg/g （7 d） ; starch content increased from 5.42 to 8.31 mg/g during this time, which may be relevant to the external environment or tree original metabolism damaged by potassium chlorate.展开更多
[Objectives] This study was conducted to analyze the internal causes of flower reversal in Longan （ Dimocarpus longan Lour.） trees. [Methods] With flowering trees and flower reversal trees as experimental materials,...[Objectives] This study was conducted to analyze the internal causes of flower reversal in Longan （ Dimocarpus longan Lour.） trees. [Methods] With flowering trees and flower reversal trees as experimental materials, the variations in sugar and starch in mature leaves, tender leaves, mature branches, twigs and terminal buds after flower forcing were analyzed. [Results] During flowering process, sugar content showed the greatest difference between flowering and flower reversal trees, and the difference was the greatest in mature leaves. Trees with mature leaves having a sugar content above 44.71 mg/g were found to be more prone to flowering, while those with leaf sugar content lower than 27.80 mg/g were susceptible to flower reversal. In addition, longan trees with a higher sugar content in tender leaves were not prone to flower reversal. [Conclusions] In future, whether off-season flower forcing can be performed on longan trees could be judged through the detection of tree leaves, which is of great significance to prevention of flower reversal in off-season longan production.展开更多
[Objective] This study aimed to investigate the effects of H2O2 and NO on flower development and 4P1 gene expression of off-season longan. [Meth-od ]Nine-year-old off-season Chuliang longan was sprayed wit...[Objective] This study aimed to investigate the effects of H2O2 and NO on flower development and 4P1 gene expression of off-season longan. [Meth-od ]Nine-year-old off-season Chuliang longan was sprayed with enhancers and blockers of H2O2 and NO to analyze dynamic changes of flower development and API expression. [ Result] The expression level of API gene in off-season longan was improved during flower development. SNP and MV treatments up-regulated the expression level of API gene in leaves and terminal buds to varying degrees during lateral primordium formation. Especially, SNP treatment exhibited the most remark-able effect. DMTU treatment significantly inhibited the expression of AP1 gene in leaves and terminal buds during lateral primordium formation. L-NNA treatment slightly inhibited the expression of API gene in leaves and exerted no significant effect on expression of AP1 gene in terminal buds. [ Conclusion] It can be specu-lated that the enhancement of NO and H2O2 signals is conducive to flower development of off-season longan, while blocking H2O2 signals may inhibit flower develop-ment of off-season longan.展开更多
Litchi anthracnose caused by Colletotrictum gloeosporioides （Penz） Saec. is an extremely destructive and widely distributed disease, which results in poor market value. Borate, an essential plant micronutrient that ...Litchi anthracnose caused by Colletotrictum gloeosporioides （Penz） Saec. is an extremely destructive and widely distributed disease, which results in poor market value. Borate, an essential plant micronutrient that helps plant growth and has been used extensively in industry and agriculture as a safe method for control of fungi, was effective in the form of potassium tetraborate for control of C. gloeosporioides （Penz）. In this study, boron strongly inhibited spore germina- tion, germ tube elongation, and mycelial spread of C. gloeosporioides （Penz） in the culture medium. Application of boron at 1% caused the appearance of abnor- mal spores （disrupted） in some cases. On the basis of propidium iodide fluorescent staining, the loss of membrane integrity in C. gloeosporioides （Penz） was ob- served after boron treatment. Furthermore, Boron led to the leakage of cellular constituents （soluble proteins and carbohydrates） from hyphae of C. gloeosporioides （Penz）. These data suggest that the mechanisms may be directly related with the disruption effect of boron on cell membrane of the fungal pathogen, resulting in the breakdown of cell membrane structure and loss of cytoplasmic materials from the hyphae.展开更多
In the canonical version of evolution by gene duplication, one copy is kept unaltered while the other is free to evolve. This process of evolutionary experimentation can persist for millions of years. Since it is so s...In the canonical version of evolution by gene duplication, one copy is kept unaltered while the other is free to evolve. This process of evolutionary experimentation can persist for millions of years. Since it is so short lived in comparison to the lifetime of the core genes that make up the majority of most genomes, a substantial fraction of the genome and the transcriptome may—in principle—be attributable to what we will refer to as ＂evolutionary transients＂, referring here to both the process and the genes that have gone or are undergoing this process. Using the rice gene set as a test case, we argue that this phenomenon goes a long way towards explaining why there are so many more rice genes than Arabidopsis genes, and why most excess rice genes show low similarity to eudicots.展开更多
基金Supported by National Nonprofit Institute Research Grant of CATAS-TCGRI(1630032014017)Special Fund for Agro-scientific Research in the PublicInterest(201003021)China Agriculture Research System(CARS-33-25)
文摘After flower induction, some longan trees can successfully blossom and bear fruit, while others with similar tree body status can only sprout leaf buds. In order to investigate the main reason for these differences, in this study, off-season flowering and non-flowering longan trees were used as experimental materials to analyze the changes of carbon content in mature leaves, tender leaves, mature shoots, tender shoots and terminal buds of longan trees after flower induction by potassium chlorate. The result showed that carbon content played an important role in flowering process. Off-season longan trees with carbon content in mature leaves reached 50.93 mg/g could successfully blossom, but those with carbon content in mature leaves lower than 37.40 mg/g were usually difficult to blossom. In addition, the maturity of tender leaves posed great influence on flowering. Specifically, tender leaves with a higher maturity contained higher carbon content and could easily blossom, which could be used as a new indicator to evaluate flower induction in off-season longan trees.
基金Supported by National Nonprofit Institute Research Grant of CATAS-TCGRI(1630032012016,1630032014017)Special Fund for Agro-scientific Research in the Public Interest(201003021)China Agriculture Research System(CARS-33-25)
文摘Flower-bud differentiation is the most critical stage of fruit yield formation, as well as a complicated carbon transfer process. To understand the changes of carbon during the flower bud differentiation process of longan, it is very important to adopt suitable planting measures and control flowering time. This study fo- cused on the changes of sugar and starch content of on-season and off-season longan during the flowering process. The results showed that the accumulation and transformation of carben differed between on-season and off-season longan during flower-bud differentiation process ; to be specific, sugar and starch content in tissues differentiated from apical buds of on-season longan were reduced at the late flower-bud physiological differentiation stage except in leaf buds ; on the contrary, sugar and starch content in off-season longan increased at the late flower-bud physiological differentiation stage： specifically, total sugar content increased from 15.43 （ - 7 d） to 31.38 mg/g （7 d） ; starch content increased from 5.42 to 8.31 mg/g during this time, which may be relevant to the external environment or tree original metabolism damaged by potassium chlorate.
基金Supported by State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources(SKLCUSA-b201601)Non-profit Research Institution Reform Start-up Fund for Tropical Crop Germplasm Research Institute,Chinese Academy of Tropical Agricultural Sciences(pzsfyl-201804)China Agriculture Research System(CARS-33-27)
文摘[Objectives] This study was conducted to analyze the internal causes of flower reversal in Longan （ Dimocarpus longan Lour.） trees. [Methods] With flowering trees and flower reversal trees as experimental materials, the variations in sugar and starch in mature leaves, tender leaves, mature branches, twigs and terminal buds after flower forcing were analyzed. [Results] During flowering process, sugar content showed the greatest difference between flowering and flower reversal trees, and the difference was the greatest in mature leaves. Trees with mature leaves having a sugar content above 44.71 mg/g were found to be more prone to flowering, while those with leaf sugar content lower than 27.80 mg/g were susceptible to flower reversal. In addition, longan trees with a higher sugar content in tender leaves were not prone to flower reversal. [Conclusions] In future, whether off-season flower forcing can be performed on longan trees could be judged through the detection of tree leaves, which is of great significance to prevention of flower reversal in off-season longan production.
基金Supported by China Agriculture Research System(CARS-33-25)
文摘[Objective] This study aimed to investigate the effects of H2O2 and NO on flower development and 4P1 gene expression of off-season longan. [Meth-od ]Nine-year-old off-season Chuliang longan was sprayed with enhancers and blockers of H2O2 and NO to analyze dynamic changes of flower development and API expression. [ Result] The expression level of API gene in off-season longan was improved during flower development. SNP and MV treatments up-regulated the expression level of API gene in leaves and terminal buds to varying degrees during lateral primordium formation. Especially, SNP treatment exhibited the most remark-able effect. DMTU treatment significantly inhibited the expression of AP1 gene in leaves and terminal buds during lateral primordium formation. L-NNA treatment slightly inhibited the expression of API gene in leaves and exerted no significant effect on expression of AP1 gene in terminal buds. [ Conclusion] It can be specu-lated that the enhancement of NO and H2O2 signals is conducive to flower development of off-season longan, while blocking H2O2 signals may inhibit flower develop-ment of off-season longan.
基金Supported by China Agriculture Research System(CARS-33-25)
文摘Litchi anthracnose caused by Colletotrictum gloeosporioides （Penz） Saec. is an extremely destructive and widely distributed disease, which results in poor market value. Borate, an essential plant micronutrient that helps plant growth and has been used extensively in industry and agriculture as a safe method for control of fungi, was effective in the form of potassium tetraborate for control of C. gloeosporioides （Penz）. In this study, boron strongly inhibited spore germina- tion, germ tube elongation, and mycelial spread of C. gloeosporioides （Penz） in the culture medium. Application of boron at 1% caused the appearance of abnor- mal spores （disrupted） in some cases. On the basis of propidium iodide fluorescent staining, the loss of membrane integrity in C. gloeosporioides （Penz） was ob- served after boron treatment. Furthermore, Boron led to the leakage of cellular constituents （soluble proteins and carbohydrates） from hyphae of C. gloeosporioides （Penz）. These data suggest that the mechanisms may be directly related with the disruption effect of boron on cell membrane of the fungal pathogen, resulting in the breakdown of cell membrane structure and loss of cytoplasmic materials from the hyphae.
基金supported by Chinese Academy of Sciences (Grants No. GJHZ0701-6 and KSCX2-YWN-023)National Natural Science Foundation of China (Grants No. 30725008, 90403130, 90608010, 30221004, 90612019, and 30392130)+4 种基金the "973" Program (Grants No. 2006CB910400, 2007CB815701, 2007CB815703, and 2007CB815705)the "863" Program (Grants No. 2006AA02Z334, 2006AA10A121, and 2006AA02Z177)Beijing Municipal Science and Technology Commission (Grant No. D07030200740000)Danish Platform for Integrative Biology, Danish Natural Science Research Council, Danish Research Council, the Solexa Project (Grant No. 272-07-0196)National Science Foundation of USA (Grant No. DBI 0217241)
文摘In the canonical version of evolution by gene duplication, one copy is kept unaltered while the other is free to evolve. This process of evolutionary experimentation can persist for millions of years. Since it is so short lived in comparison to the lifetime of the core genes that make up the majority of most genomes, a substantial fraction of the genome and the transcriptome may—in principle—be attributable to what we will refer to as ＂evolutionary transients＂, referring here to both the process and the genes that have gone or are undergoing this process. Using the rice gene set as a test case, we argue that this phenomenon goes a long way towards explaining why there are so many more rice genes than Arabidopsis genes, and why most excess rice genes show low similarity to eudicots.
