[Objective] The aim was to study the conditions of tissue culture regeneration seedling by using the stem segments of Euphorbia tirucalli and determine the optimum culture condition of each culture stage,so as to prov...[Objective] The aim was to study the conditions of tissue culture regeneration seedling by using the stem segments of Euphorbia tirucalli and determine the optimum culture condition of each culture stage,so as to provide references for the factory production and relative study of tissue culture seedling of E. tirucalli. [Method] Taking the stem segments of E. tirucalli as explants,the effects of various mediums on germination rate,multiplication coefficient and rooting rate were studied. [Result] The optimum induction medium of germination culture was 1/2MS+NAA 0.02 mg/L+6-BA 1.0 mg/L,with differentiation rate of 89.7%; the best subculture medium was 1/2MS+NAA 0.02 mg/L+6-BA 0.60 mg/L+AD 3.0 mg/L,with multiplication coefficient of 5.70; the optimum rooting culture medium was 1/2MS+NAA 0.40 mg/L+IBA 0.4 mg/L,with rooting rate of 100% and transplanting survival rate of 80%. [Conclusion] The tissue culture conditions of stem segments of E. tirucalli were determined primarily.展开更多
Maize chlorotic dwarf virus (MCDV) is a quarantine pest as approved by Chinese government. A rapid, sensitive and specific MCDV detection method using reverse transcription-loop-mediated isothermal amplification (R...Maize chlorotic dwarf virus (MCDV) is a quarantine pest as approved by Chinese government. A rapid, sensitive and specific MCDV detection method using reverse transcription-loop-mediated isothermal amplification (RT-LAMP) was estab- lished in this study. Based on the sequence of MCDV coat protein coding gene, specific primers were designed and similar sensitivities were observed between RT- LAMP and RT-PCR, except that RT-LAMP was quicker, and the reaction could be finished within 1 h. In addition, the presence or absence of the fluorescent display in daylight allows naked easy detection of the amplification of MCDV genomic RNA using calcein. The RT-LAMP assay was applied successfully to detect MCDV in maize seeds, and the result by the addition of calcein was consistent with the result detected by the real time turbidimeter.展开更多
Evidence that nitrogen (N) fertilization tends to accelerate maturation as well as increase rates of growth has received little attention when diagnosing N deficiencies in corn (Zea mays L.).Such a tendency could be a...Evidence that nitrogen (N) fertilization tends to accelerate maturation as well as increase rates of growth has received little attention when diagnosing N deficiencies in corn (Zea mays L.).Such a tendency could be a potential source of errors when the diagnosis is solely based on comparing plants with different rates of growth.Whether N fertilization could accelerate rates of growth and maturation was tested in a field study with 12 paired plots representing relatively large variability in soil properties and landscape positions.The plots were located under conditions where preplant N fertilization reduced or avoided temporary N shortages for some plants but did not reduce for other plants early in the season.We measured corn heights to the youngest leaf collar,stages of growth and chlorophyll meter readings (CMRs). The added N advanced growth stages as well as increased corn heights and CMRs at any given time.Fertilization effects on corn heights,growth stages and ear weights were statistically significant (P<0.05) despite substantial variability associated with landscape.Reductions in growth due to a temporary shortage of N within a growth stage might be partially offset by longer periods of growth within that stage to physiological maturity.Temporary shortages of N,therefore,may produce symptoms of N deficiency in situations where subsequent additions of N should not be expected to increase yields.Recognition of these two somewhat different effects (i.e.,increase growth rates and advance growth stages) on corn growth could help to define N deficiency more precisely and to improve the accuracy of diagnosing N status in production agriculture.展开更多
[Objective] This study aimed to investigate the influence of illumination intensity, 5-aminolevulinic acid (ALA) concentration and their interaction on chlorophyll fluorescence parameters and yield of summer maize. ...[Objective] This study aimed to investigate the influence of illumination intensity, 5-aminolevulinic acid (ALA) concentration and their interaction on chlorophyll fluorescence parameters and yield of summer maize. [Method] Two illumination intensity levels and five ALA concentrations were applied in the experiment using 2x5 completely balanced program. The two illumination intensity levels were natural light (So) and 60% shade (SO, and five ALA concentrations were 0, 1, 10, 25 and 50 mg/L. [Result] The relative chlorophyll content of leaf (SPAD), the optimal/maximal quantum yield of PS II (Fv/Fm), the photochemical quenching coefficient (qP), electron transport rate (ETR), grain number per cob and grain weight per cob in $1 treatment were significantly reduced compared with that in So. However, the non- photochemical quenching coefficient (qN) was significantly increased. The responses of these parameters to ALA were different under So and $1 treatments. The SPAD, Fv/Fm, qP, ETR, grain number and grain weight per cob were firstly increased, but then decreased following the raise of ALA concentration, ranging from 0 to 50 mg/L, whereas qN showed opposite trend. The effect of the interaction of illumination in- tensity and ALA concentration on these parameters was significant (P〈0.05). Under natural light, summer maize could obtain higher SPAD, Fv/Fm, qP and ETR and lower qN combined with low concentration of ALA. However, high concentration of ALA was needed under shading to get the same results. [Conclusion] Soaking seed in suitable concentration of ALA can reduce the yield loss of summer maize caused by short-term shading in seedling stage.展开更多
Maize chlorotic mottle virus (MCMV) is a quarantine pest as approved by Chinese government: A rapid, sensitive and specific MCMV detection method using reverse transcription-loop-mediated isothermal amplification ...Maize chlorotic mottle virus (MCMV) is a quarantine pest as approved by Chinese government: A rapid, sensitive and specific MCMV detection method using reverse transcription-loop-mediated isothermal amplification (RT-LAMP) was established in this study. Based on the sequence of MCMV coat protein coding gene, 3 sets of primers were designed and specificity test showed that the second set of primers was specific to MCMV, Similar sensitivities were observed on RT-LAMP and RT-PCR, except that RT-LAMP was quicker, and the reaction could be finished within 1 h. In addition, the presence or absence of the fluorescence under daylight allows naked easy detection of the amplification of MCMV genomic RNA using calcein. The RT-LAMP assay was applied successfully to detect MCMV in maize seeds, and the result by the addition of calcein was consistent with the result detected by the real time turbidimeter. The method is rapid, specific, sensitive without the need for complicated equipment, and is suitable for rapid field detection of MCMV.展开更多
The western Iratsu mass, the largest tectonic body in the Sambagawa metamorphic belt, central Shikoku, is mainly composed of epidote amphibolite with minor amounts of eclogite. Systematically, a majority of garnets sh...The western Iratsu mass, the largest tectonic body in the Sambagawa metamorphic belt, central Shikoku, is mainly composed of epidote amphibolite with minor amounts of eclogite. Systematically, a majority of garnets show bell-shaped chemical zoning of pyrope contents and Mg/(Mg+Fe2+) monotonously increasing outward. The grossular component in zonal garnet increases outwards, maximizes at an intermediate part, and then decreases towards the outermost rim, reflecting a process from increasing to decreasing pressure conditions during the prograde metamorphism. Jadeite contents of omphacite range from 25~20mole% within the cores to 15~10 mole% at the rims, implying a pressure-decreasing process (from 11 × 105 Pa to 8 × 105 Pa). The peak pressure-temperature (P-T) condition of 630~680 ℃ and ca. 15× 105 Pa in the western Iratsu mass is much higher than that of (610±25) ℃ and (10± 1)× 105 Pa of the Sambagawa oligoclase-biotite zone schists. The authors suggest a clockwise P-T-t path for the western Iratsu mass.展开更多
Many studies have shown that chlorophyll meter readings (CMRs) can be used to diagnose deficiencies of nitrogen (N) during the growth of corn (Zea mays L.) in small-plot trials, but there is need to address addi...Many studies have shown that chlorophyll meter readings (CMRs) can be used to diagnose deficiencies of nitrogen (N) during the growth of corn (Zea mays L.) in small-plot trials, but there is need to address additional problems encountered when diagnoses are made in fields of the size managed in production agriculture. A noteworthy difference between smallplot trials and production agriculture is the extent to which the effects of N are confounded with the effects of other factors such as tillage, landscape, soil organic matter and moisture content. We illustrate how some of these factors can cause differences in the physiological age of plants and introduce errors in the diagnoses of N deficiencies. We suggest methods (measuring the height to the youngest leaf collar and assigning leaf numbers by using the first leaf with pubescence and the ear leaf as references to identify growth stages) for minimizing these errors. The simplified method of growth stage identification can be used to select appropriate plants and leaves for making diagnoses in fields and to distinguish the effects of N from the effects of other factors that influence plant growth.展开更多
In order to find the best intercropping pattern of fresh maize and mung bean, five planting patterns, namely fresh maize monocropping, mung bean monocropping, fresh maize and mung bean intercropping at row ratios of 2...In order to find the best intercropping pattern of fresh maize and mung bean, five planting patterns, namely fresh maize monocropping, mung bean monocropping, fresh maize and mung bean intercropping at row ratios of 2∶4, 3∶3 and 4∶2 were set up, and the yields and economic benefits of these planting patterns were analyzed. The results showed that the LERs of the three intercropping patterns were all above 1, and the economic benefits of 2∶4, 3∶3 and 4∶2 fresh maize and mung bean intercropping patterns were seen an increase of 2.85%, 17.64% and 14.26% respectively compared with fresh maize monocropping and an increase of 52.06%, 73.92% and 68.93% respectively compared with mung bean monocropping.Among the three intercropping patterns, the intercropping pattern with row ratio 3∶3showed the best effect, which also derived the highest LER with greatest economic benefit.展开更多
Effect of fertilizer source (mineral fertilizer or organic manure) on photosynthetic pigments leaves content of four brassica vegetables (Pak choi, Kohlrabi, Cauliflower and Cabbage) was tested. Among treatments, ...Effect of fertilizer source (mineral fertilizer or organic manure) on photosynthetic pigments leaves content of four brassica vegetables (Pak choi, Kohlrabi, Cauliflower and Cabbage) was tested. Among treatments, cauliflower fertilized with chicken manure had the highest content of chlorophyll a and b (10.08 and 9.37 μm·g^-1), while, pak choi had the lowest values (2.00 and 2.44 μm·g^-1) in non-fertilized plants. These differences in chlorophyll a and b content may have a great impact on photosynthetic rate and activity. Total carotenoids and total xanthophylls (lutein, zeaxanthin, antheraxanthin and violaxanthin) were the highest in cauliflower while the lowest was in pakchoi, β-carotene, on the other hand, was the highest percentage of total carotenoids (65.7%) in pak choi while Kohlrabi had the lowest percent (57.4%). This high percentage offl-carotene of total carotenoids may compensate for lower content of chlorophylls and assist for efficient light harvesting process. Lutein showed to be the major components of xanthophyll pigments brassica vegetables and ranged from 0.462μm·g^-1 in cabbage to 0.626μm·g^-1 in kohlrabi but not differed significantly which may refer to genetically controlled. However, lutein, antheraxanthin and zeaxanthin content were increased significantly by the application of chicken manure regardless ofbrassica vegetable type. Violaxanthin was only detected in pak choi and not affected by fertilizer source. It can be concluding from the increasing contents of total xanthophylls pigments that may increase photosynthetic efficiency through non-photochemical quenching process.展开更多
In a long term study photosynthetically active radiation was monitored for three rainy seasons to measure the effects of hedgerow intercropping in rotation with maize and cowpea in a senna/siamea and panicum/grass str...In a long term study photosynthetically active radiation was monitored for three rainy seasons to measure the effects of hedgerow intercropping in rotation with maize and cowpea in a senna/siamea and panicum/grass strip on biomass yield and light use efficiency. Maize/cowpea intercropped with senna siamea or grass stripped were compared with sole maize and cowpea. A ceptometer was applied to measure PAR interception by sole maize or cowpea or crop/tree and grass/crop interfaces and separation of PAR used by each plant or tree/grass component. Hedgerow intercropping increased PAR interception and biomass formation. C4 plants had higher LUE than C3 plants while combining C4 and C3 in the agroforestry system lowered LUE. The tree/crop interfaces increased PAR interception than at 1 m and 2 m away from the hedgerow. The row of maize or cowpea at lm intercepted more PAR than the row at 2 m from hedgerow while the cowpea row next to the hedgerow was depressed compared to the rows in the middle rows which had higher yields. The maize or cowpea row next to the grass strip was more stressed than the rows in the middle of the alley.展开更多
Magnolia grandiflora is an important medicinal, ornamental and horticultural plant species. The chloroplast (cp) genome of M. grandiflora was sequenced using a 454 sequencing platform and the genome structure was co...Magnolia grandiflora is an important medicinal, ornamental and horticultural plant species. The chloroplast (cp) genome of M. grandiflora was sequenced using a 454 sequencing platform and the genome structure was compared with other related species. The complete cp genome ofM. grandiflora was 159623 bp in length and contained a pair of inverted repeats (IR) of 26563 bp separated by large and small single copy (LSC, SSC) regions of 87757 and 18740 bp, respectively. A total of 129 genes were successfully annotated, 18 of which included introns. The identity, number and GC content of M. grandiflora cp genes were similar to those of other Magnoliaceae species genomes. Analysis revealed 218 simple sequence repeat (SSR) loci, most composed of A or T, contributing to a bias in base composition. The types and abundances of repeat units in Magnoliaceae species were relatively conserved and these loci will be useful for developing M. grandiflora cp genome vectors. In addition, results indicated that the cp genome size in Magnoliaceae species and the position of the IR border were closely related to the length of the ycfl gene. Phylogenetic analyses based on 66 shared genes from 30 species using maximum parsimony (MP) and max- imum likelihood (ML) methods provided strong support for the phylogenetic position of Magnolia. The availability of the complete cp genome sequence of M. grandiflora provides valuable information for breeding of desirable varieties, cp genetic engineering, developing useful molecular markers and phylogenetic analyses in Magnoliaceae.展开更多
基金Supported by Key Technologies R &D Program of Guangdong Province (2009B0203030092006B20201007)~~
文摘[Objective] The aim was to study the conditions of tissue culture regeneration seedling by using the stem segments of Euphorbia tirucalli and determine the optimum culture condition of each culture stage,so as to provide references for the factory production and relative study of tissue culture seedling of E. tirucalli. [Method] Taking the stem segments of E. tirucalli as explants,the effects of various mediums on germination rate,multiplication coefficient and rooting rate were studied. [Result] The optimum induction medium of germination culture was 1/2MS+NAA 0.02 mg/L+6-BA 1.0 mg/L,with differentiation rate of 89.7%; the best subculture medium was 1/2MS+NAA 0.02 mg/L+6-BA 0.60 mg/L+AD 3.0 mg/L,with multiplication coefficient of 5.70; the optimum rooting culture medium was 1/2MS+NAA 0.40 mg/L+IBA 0.4 mg/L,with rooting rate of 100% and transplanting survival rate of 80%. [Conclusion] The tissue culture conditions of stem segments of E. tirucalli were determined primarily.
文摘Maize chlorotic dwarf virus (MCDV) is a quarantine pest as approved by Chinese government. A rapid, sensitive and specific MCDV detection method using reverse transcription-loop-mediated isothermal amplification (RT-LAMP) was estab- lished in this study. Based on the sequence of MCDV coat protein coding gene, specific primers were designed and similar sensitivities were observed between RT- LAMP and RT-PCR, except that RT-LAMP was quicker, and the reaction could be finished within 1 h. In addition, the presence or absence of the fluorescent display in daylight allows naked easy detection of the amplification of MCDV genomic RNA using calcein. The RT-LAMP assay was applied successfully to detect MCDV in maize seeds, and the result by the addition of calcein was consistent with the result detected by the real time turbidimeter.
基金Project supported by the Iowa Soybean Association,USA through the ISA On-Farm Network~(TM)
文摘Evidence that nitrogen (N) fertilization tends to accelerate maturation as well as increase rates of growth has received little attention when diagnosing N deficiencies in corn (Zea mays L.).Such a tendency could be a potential source of errors when the diagnosis is solely based on comparing plants with different rates of growth.Whether N fertilization could accelerate rates of growth and maturation was tested in a field study with 12 paired plots representing relatively large variability in soil properties and landscape positions.The plots were located under conditions where preplant N fertilization reduced or avoided temporary N shortages for some plants but did not reduce for other plants early in the season.We measured corn heights to the youngest leaf collar,stages of growth and chlorophyll meter readings (CMRs). The added N advanced growth stages as well as increased corn heights and CMRs at any given time.Fertilization effects on corn heights,growth stages and ear weights were statistically significant (P<0.05) despite substantial variability associated with landscape.Reductions in growth due to a temporary shortage of N within a growth stage might be partially offset by longer periods of growth within that stage to physiological maturity.Temporary shortages of N,therefore,may produce symptoms of N deficiency in situations where subsequent additions of N should not be expected to increase yields.Recognition of these two somewhat different effects (i.e.,increase growth rates and advance growth stages) on corn growth could help to define N deficiency more precisely and to improve the accuracy of diagnosing N status in production agriculture.
基金Supported by National Key Technology Research and Development Program(2011BAD10B07)~~
文摘[Objective] This study aimed to investigate the influence of illumination intensity, 5-aminolevulinic acid (ALA) concentration and their interaction on chlorophyll fluorescence parameters and yield of summer maize. [Method] Two illumination intensity levels and five ALA concentrations were applied in the experiment using 2x5 completely balanced program. The two illumination intensity levels were natural light (So) and 60% shade (SO, and five ALA concentrations were 0, 1, 10, 25 and 50 mg/L. [Result] The relative chlorophyll content of leaf (SPAD), the optimal/maximal quantum yield of PS II (Fv/Fm), the photochemical quenching coefficient (qP), electron transport rate (ETR), grain number per cob and grain weight per cob in $1 treatment were significantly reduced compared with that in So. However, the non- photochemical quenching coefficient (qN) was significantly increased. The responses of these parameters to ALA were different under So and $1 treatments. The SPAD, Fv/Fm, qP, ETR, grain number and grain weight per cob were firstly increased, but then decreased following the raise of ALA concentration, ranging from 0 to 50 mg/L, whereas qN showed opposite trend. The effect of the interaction of illumination in- tensity and ALA concentration on these parameters was significant (P〈0.05). Under natural light, summer maize could obtain higher SPAD, Fv/Fm, qP and ETR and lower qN combined with low concentration of ALA. However, high concentration of ALA was needed under shading to get the same results. [Conclusion] Soaking seed in suitable concentration of ALA can reduce the yield loss of summer maize caused by short-term shading in seedling stage.
文摘Maize chlorotic mottle virus (MCMV) is a quarantine pest as approved by Chinese government: A rapid, sensitive and specific MCMV detection method using reverse transcription-loop-mediated isothermal amplification (RT-LAMP) was established in this study. Based on the sequence of MCMV coat protein coding gene, 3 sets of primers were designed and specificity test showed that the second set of primers was specific to MCMV, Similar sensitivities were observed on RT-LAMP and RT-PCR, except that RT-LAMP was quicker, and the reaction could be finished within 1 h. In addition, the presence or absence of the fluorescence under daylight allows naked easy detection of the amplification of MCMV genomic RNA using calcein. The RT-LAMP assay was applied successfully to detect MCMV in maize seeds, and the result by the addition of calcein was consistent with the result detected by the real time turbidimeter. The method is rapid, specific, sensitive without the need for complicated equipment, and is suitable for rapid field detection of MCMV.
基金Project supported by the National Natural Science Foundation of China (No. 40472040) and Starting Fund of Education Ministry, China
文摘The western Iratsu mass, the largest tectonic body in the Sambagawa metamorphic belt, central Shikoku, is mainly composed of epidote amphibolite with minor amounts of eclogite. Systematically, a majority of garnets show bell-shaped chemical zoning of pyrope contents and Mg/(Mg+Fe2+) monotonously increasing outward. The grossular component in zonal garnet increases outwards, maximizes at an intermediate part, and then decreases towards the outermost rim, reflecting a process from increasing to decreasing pressure conditions during the prograde metamorphism. Jadeite contents of omphacite range from 25~20mole% within the cores to 15~10 mole% at the rims, implying a pressure-decreasing process (from 11 × 105 Pa to 8 × 105 Pa). The peak pressure-temperature (P-T) condition of 630~680 ℃ and ca. 15× 105 Pa in the western Iratsu mass is much higher than that of (610±25) ℃ and (10± 1)× 105 Pa of the Sambagawa oligoclase-biotite zone schists. The authors suggest a clockwise P-T-t path for the western Iratsu mass.
基金the Iowa Soybean Association, USA through the ISA On-Farm NetworkTM and Watershed Programming.
文摘Many studies have shown that chlorophyll meter readings (CMRs) can be used to diagnose deficiencies of nitrogen (N) during the growth of corn (Zea mays L.) in small-plot trials, but there is need to address additional problems encountered when diagnoses are made in fields of the size managed in production agriculture. A noteworthy difference between smallplot trials and production agriculture is the extent to which the effects of N are confounded with the effects of other factors such as tillage, landscape, soil organic matter and moisture content. We illustrate how some of these factors can cause differences in the physiological age of plants and introduce errors in the diagnoses of N deficiencies. We suggest methods (measuring the height to the youngest leaf collar and assigning leaf numbers by using the first leaf with pubescence and the ear leaf as references to identify growth stages) for minimizing these errors. The simplified method of growth stage identification can be used to select appropriate plants and leaves for making diagnoses in fields and to distinguish the effects of N from the effects of other factors that influence plant growth.
基金Supported by Hunan Dry Grain Industry Technology System Project (Xiangnongfa [2019]105)Hunan Agricultural Science and Technology Innovation Fund Project (2021CX22)。
文摘In order to find the best intercropping pattern of fresh maize and mung bean, five planting patterns, namely fresh maize monocropping, mung bean monocropping, fresh maize and mung bean intercropping at row ratios of 2∶4, 3∶3 and 4∶2 were set up, and the yields and economic benefits of these planting patterns were analyzed. The results showed that the LERs of the three intercropping patterns were all above 1, and the economic benefits of 2∶4, 3∶3 and 4∶2 fresh maize and mung bean intercropping patterns were seen an increase of 2.85%, 17.64% and 14.26% respectively compared with fresh maize monocropping and an increase of 52.06%, 73.92% and 68.93% respectively compared with mung bean monocropping.Among the three intercropping patterns, the intercropping pattern with row ratio 3∶3showed the best effect, which also derived the highest LER with greatest economic benefit.
文摘Effect of fertilizer source (mineral fertilizer or organic manure) on photosynthetic pigments leaves content of four brassica vegetables (Pak choi, Kohlrabi, Cauliflower and Cabbage) was tested. Among treatments, cauliflower fertilized with chicken manure had the highest content of chlorophyll a and b (10.08 and 9.37 μm·g^-1), while, pak choi had the lowest values (2.00 and 2.44 μm·g^-1) in non-fertilized plants. These differences in chlorophyll a and b content may have a great impact on photosynthetic rate and activity. Total carotenoids and total xanthophylls (lutein, zeaxanthin, antheraxanthin and violaxanthin) were the highest in cauliflower while the lowest was in pakchoi, β-carotene, on the other hand, was the highest percentage of total carotenoids (65.7%) in pak choi while Kohlrabi had the lowest percent (57.4%). This high percentage offl-carotene of total carotenoids may compensate for lower content of chlorophylls and assist for efficient light harvesting process. Lutein showed to be the major components of xanthophyll pigments brassica vegetables and ranged from 0.462μm·g^-1 in cabbage to 0.626μm·g^-1 in kohlrabi but not differed significantly which may refer to genetically controlled. However, lutein, antheraxanthin and zeaxanthin content were increased significantly by the application of chicken manure regardless ofbrassica vegetable type. Violaxanthin was only detected in pak choi and not affected by fertilizer source. It can be concluding from the increasing contents of total xanthophylls pigments that may increase photosynthetic efficiency through non-photochemical quenching process.
文摘In a long term study photosynthetically active radiation was monitored for three rainy seasons to measure the effects of hedgerow intercropping in rotation with maize and cowpea in a senna/siamea and panicum/grass strip on biomass yield and light use efficiency. Maize/cowpea intercropped with senna siamea or grass stripped were compared with sole maize and cowpea. A ceptometer was applied to measure PAR interception by sole maize or cowpea or crop/tree and grass/crop interfaces and separation of PAR used by each plant or tree/grass component. Hedgerow intercropping increased PAR interception and biomass formation. C4 plants had higher LUE than C3 plants while combining C4 and C3 in the agroforestry system lowered LUE. The tree/crop interfaces increased PAR interception than at 1 m and 2 m away from the hedgerow. The row of maize or cowpea at lm intercepted more PAR than the row at 2 m from hedgerow while the cowpea row next to the hedgerow was depressed compared to the rows in the middle rows which had higher yields. The maize or cowpea row next to the grass strip was more stressed than the rows in the middle of the alley.
基金supported by the National Natural Science Foundation of China (30970307, 81130069)the Innovation Research Team of the University of Ministry of Education of China (IRT1150)
文摘Magnolia grandiflora is an important medicinal, ornamental and horticultural plant species. The chloroplast (cp) genome of M. grandiflora was sequenced using a 454 sequencing platform and the genome structure was compared with other related species. The complete cp genome ofM. grandiflora was 159623 bp in length and contained a pair of inverted repeats (IR) of 26563 bp separated by large and small single copy (LSC, SSC) regions of 87757 and 18740 bp, respectively. A total of 129 genes were successfully annotated, 18 of which included introns. The identity, number and GC content of M. grandiflora cp genes were similar to those of other Magnoliaceae species genomes. Analysis revealed 218 simple sequence repeat (SSR) loci, most composed of A or T, contributing to a bias in base composition. The types and abundances of repeat units in Magnoliaceae species were relatively conserved and these loci will be useful for developing M. grandiflora cp genome vectors. In addition, results indicated that the cp genome size in Magnoliaceae species and the position of the IR border were closely related to the length of the ycfl gene. Phylogenetic analyses based on 66 shared genes from 30 species using maximum parsimony (MP) and max- imum likelihood (ML) methods provided strong support for the phylogenetic position of Magnolia. The availability of the complete cp genome sequence of M. grandiflora provides valuable information for breeding of desirable varieties, cp genetic engineering, developing useful molecular markers and phylogenetic analyses in Magnoliaceae.