2012 Vol. 3, No. 3
2012, 3(3): 197-203.
doi: 10.15886/j.cnki.rdswxb.2012.03.017
Abstract
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Abstract:
Larvae of Nile tilapia （Oreochromis niloticus） were observed morphologically, histologically and microstructurally under the natural condition with the temperature ranging from 26℃ to 28℃ in terms of ontogenetic development and gonadal differentiation and development. Observations showed that the development of larvae Nile tilapia can be divided into two stages: early larval stage from hatching to the complete yolk-sac absorption, and late larval stage from the complete yolk-sac absorption to the appearance of odd fin fold. The sex differentiation occurs at around 28 days post hatching （DPH）. The genital ridge, incomplete velum and enteron start to appear at 5 DPH. The primordial germ cells （PGCs） appear at 10 DPH although few, and form primordial gonad. The oocytes can be easily distinguished at 28 DPH and show clear histological characteristics of gonadal differentiation. The spermatogonia can be distinguished at 42 DPH.
Larvae of Nile tilapia （Oreochromis niloticus） were observed morphologically, histologically and microstructurally under the natural condition with the temperature ranging from 26℃ to 28℃ in terms of ontogenetic development and gonadal differentiation and development. Observations showed that the development of larvae Nile tilapia can be divided into two stages: early larval stage from hatching to the complete yolk-sac absorption, and late larval stage from the complete yolk-sac absorption to the appearance of odd fin fold. The sex differentiation occurs at around 28 days post hatching （DPH）. The genital ridge, incomplete velum and enteron start to appear at 5 DPH. The primordial germ cells （PGCs） appear at 10 DPH although few, and form primordial gonad. The oocytes can be easily distinguished at 28 DPH and show clear histological characteristics of gonadal differentiation. The spermatogonia can be distinguished at 42 DPH.
2012, 3(3): 204-207.
doi: 10.15886/j.cnki.rdswxb.2012.03.018
Abstract:
Agar Eucheuma （Betaphycus gelatinum）, rich in carrageenan, polysaccharide and various pigments, is an important economic tropical alga. However, production of Eucheuma, both wild and farmed, has become less and less due to the influence of deterioration of seawater environment. Eucheuma growing in different relative densities of seawater were observed and determined in growth rate and content of carrageenan and pigment. Results show that Eucheuma survived at a seawater relative density range of 1.014 to 1.030 and grew well at the relative density from 1.018 to 1.024. Eucheuma grew at a daily rate of upto 4.6% at the relative density of seawater of 1.022, contained 64.2% of carrageenan （the highest among all the treatments） at the seawater relative density of 1.024, and had maximum contents of chlorophyll a, PC, PE and APC at the respective seawater relative densities of 1.026, 1.024,1.022 and 1.020. These results give us more insight into the growth characteristics of Eucheuma to revitalize farming and development of Eucheuma in the future.
Agar Eucheuma （Betaphycus gelatinum）, rich in carrageenan, polysaccharide and various pigments, is an important economic tropical alga. However, production of Eucheuma, both wild and farmed, has become less and less due to the influence of deterioration of seawater environment. Eucheuma growing in different relative densities of seawater were observed and determined in growth rate and content of carrageenan and pigment. Results show that Eucheuma survived at a seawater relative density range of 1.014 to 1.030 and grew well at the relative density from 1.018 to 1.024. Eucheuma grew at a daily rate of upto 4.6% at the relative density of seawater of 1.022, contained 64.2% of carrageenan （the highest among all the treatments） at the seawater relative density of 1.024, and had maximum contents of chlorophyll a, PC, PE and APC at the respective seawater relative densities of 1.026, 1.024,1.022 and 1.020. These results give us more insight into the growth characteristics of Eucheuma to revitalize farming and development of Eucheuma in the future.
2012, 3(3): 208-215.
doi: 10.15886/j.cnki.rdswxb.2012.03.008
Abstract:
An orthogonal design was made to optimize RAPD-PCR amplification system of Ilex kudingcha in 5 factors （DNA template, Mg2+, primer, dNTPs, Taq polymerase） at 4 levels, respectively. Through comprehensive analysis, an optimized RAPD-PCR reaction system, was established: 10×buffer 2.5 μL, 20 ng DNA template, 2.5 mmol·L-1 Mg2+, 0.3 μmol·L-1 primers, 2.0 U Taq polymerase, and 200 μmol·L-1 dNTPs in the 25 μL reaction system, and the optimized RAPD-PCR amplification program: predenaturing at 94 ℃ for 5 min, then denaturing at 94 ℃ for 30 s, elongation at 36 ℃ for 30 s and extension at 72 ℃ for 120 s, running for 40 cycles, and final extension at 72 ℃ for 10 min. The products were stored at 4 ℃. Furthermore, a total number of 91 random primers were screened in the RAPD-PCR. Polymorphic fragments were detected with 24 primers in female and male DNA samples pools. Two male-associated fragments （S164-900 and S191-800） were respectively generated with S164 primer and S191 primer. Repeated experiments indicated that these RAPD markers appeared stably in male individuals. So these RAPD markers can be applied to identify the sex of the young plantlets of Ilex kudingcha C. J. Tseng at the early stage.
An orthogonal design was made to optimize RAPD-PCR amplification system of Ilex kudingcha in 5 factors （DNA template, Mg2+, primer, dNTPs, Taq polymerase） at 4 levels, respectively. Through comprehensive analysis, an optimized RAPD-PCR reaction system, was established: 10×buffer 2.5 μL, 20 ng DNA template, 2.5 mmol·L-1 Mg2+, 0.3 μmol·L-1 primers, 2.0 U Taq polymerase, and 200 μmol·L-1 dNTPs in the 25 μL reaction system, and the optimized RAPD-PCR amplification program: predenaturing at 94 ℃ for 5 min, then denaturing at 94 ℃ for 30 s, elongation at 36 ℃ for 30 s and extension at 72 ℃ for 120 s, running for 40 cycles, and final extension at 72 ℃ for 10 min. The products were stored at 4 ℃. Furthermore, a total number of 91 random primers were screened in the RAPD-PCR. Polymorphic fragments were detected with 24 primers in female and male DNA samples pools. Two male-associated fragments （S164-900 and S191-800） were respectively generated with S164 primer and S191 primer. Repeated experiments indicated that these RAPD markers appeared stably in male individuals. So these RAPD markers can be applied to identify the sex of the young plantlets of Ilex kudingcha C. J. Tseng at the early stage.
2012, 3(3): 216-221.
doi: 10.15886/j.cnki.rdswxb.2012.03.001
Abstract:
Energy crisis and environmental pollution have become increasingly prominent with the extensive use of fossil fuels, which is widely considered to be unsustainable. Biodiesel is a potential alternative to fossil fuels. Microalgae have been considered the most promising biodiesel sources. Microalgae were collected from tropical freshwater water sampled around Haikou, and 185 strains of pure algae were obtained by flat-panel separation. Of the strains four were preliminarily identified as chlorella strains, CE1, CE14, CE18 and CE31, and were cultured on 4 different high salt minimal （HSM） media, HSM, HSM-N （N-deficient）, HSM-S, and HSM-P. Their biomass and lipid content were determined. The cultural media deficient of N and S gave notable impact on biomass production of all the four chlorella strains, and significantly increased their lipid contents as compared with the control. The cultural medium deficient of P had less influence on biomass production of the four chlorella strains, but increased notably lipid contents of strains CE1 and CE18. The strain CE14 grew very fast and contained high liquid, and its lipid content was the highest when cultured under the medium HSM-S as against other three media and accounted for 86.55% of the cell dry weight. This strain was identified based on 18S rDNA sequencing and designated as the genus Chlorella, family Chlorellaceae, order Chlorocaccales, class Chlorophyceae, division Chlorophyta, and its gene shared 99% similarity with the 18S rDNA gene of Chlorella vulgaris. CE14 is a promising potential alga source for production of biodiesel fuel.
Energy crisis and environmental pollution have become increasingly prominent with the extensive use of fossil fuels, which is widely considered to be unsustainable. Biodiesel is a potential alternative to fossil fuels. Microalgae have been considered the most promising biodiesel sources. Microalgae were collected from tropical freshwater water sampled around Haikou, and 185 strains of pure algae were obtained by flat-panel separation. Of the strains four were preliminarily identified as chlorella strains, CE1, CE14, CE18 and CE31, and were cultured on 4 different high salt minimal （HSM） media, HSM, HSM-N （N-deficient）, HSM-S, and HSM-P. Their biomass and lipid content were determined. The cultural media deficient of N and S gave notable impact on biomass production of all the four chlorella strains, and significantly increased their lipid contents as compared with the control. The cultural medium deficient of P had less influence on biomass production of the four chlorella strains, but increased notably lipid contents of strains CE1 and CE18. The strain CE14 grew very fast and contained high liquid, and its lipid content was the highest when cultured under the medium HSM-S as against other three media and accounted for 86.55% of the cell dry weight. This strain was identified based on 18S rDNA sequencing and designated as the genus Chlorella, family Chlorellaceae, order Chlorocaccales, class Chlorophyceae, division Chlorophyta, and its gene shared 99% similarity with the 18S rDNA gene of Chlorella vulgaris. CE14 is a promising potential alga source for production of biodiesel fuel.
2012, 3(3): 222-227.
doi: 10.15886/j.cnki.rdswxb.2012.03.013
Abstract:
MicroRNAs （miRNAs） are small RNAs （sRNA） that regulate post-transcriptional gene expression by cleaving or inhibiting the translation of target gene transcripts. Based on the conservation of miRNAs in many plant species and the currently available genome sequence, 10 individual conserved miRNAs have been predicted in Musa acuminata, and these miRNAs were found to belong to 8 families. Online psRNATagret software was run and 24 pairs of miRNAs were predicted to interact with their targets in Musa acuminata, and these target genes are involved in metabolism, development, response to biotic and abiotic stresses, and other cellular processes. This study has provided information on Musa acuminata miRNAs and their targets for future studies.
MicroRNAs （miRNAs） are small RNAs （sRNA） that regulate post-transcriptional gene expression by cleaving or inhibiting the translation of target gene transcripts. Based on the conservation of miRNAs in many plant species and the currently available genome sequence, 10 individual conserved miRNAs have been predicted in Musa acuminata, and these miRNAs were found to belong to 8 families. Online psRNATagret software was run and 24 pairs of miRNAs were predicted to interact with their targets in Musa acuminata, and these target genes are involved in metabolism, development, response to biotic and abiotic stresses, and other cellular processes. This study has provided information on Musa acuminata miRNAs and their targets for future studies.
2012, 3(3): 228-231.
doi: 10.15886/j.cnki.rdswxb.2012.03.006
Abstract:
Litchi anthracnose caused by Colletotrichum gloesporioides （Penz） Saec is an important disease in Litchi production. The mycelium growth rate method was used to measure and compare the toxicities of 4 fungicides against strains 4-1-1and 4-1 of C. gloesporioides Penz. These fungicides included 10% difenoconazole, 400g·L-1 flusilazole, 40% myclobutanil and 45% prochloraz. The results showed that 10% difenoconazole was most effective in inhibiting the radial mycelial growth of the strains 4-1-1 and 1-1 with the respective EC50 values of 1.607 7 mg·L-1 and 1.614 0 mg·L-1. The 40% myclobutanil showed the lowest toxicity against the mycelial growth of the strains 4-1-1 and 1-1 with the EC50 values being 9.405 9 mg·L-1 and 10.595 0 mg·L-1, respectively. The 10% difenoconazole gave a 5.9 and 6.6 times higher inhibition rate against these two strains than the 40% myclobutanil.
Litchi anthracnose caused by Colletotrichum gloesporioides （Penz） Saec is an important disease in Litchi production. The mycelium growth rate method was used to measure and compare the toxicities of 4 fungicides against strains 4-1-1and 4-1 of C. gloesporioides Penz. These fungicides included 10% difenoconazole, 400g·L-1 flusilazole, 40% myclobutanil and 45% prochloraz. The results showed that 10% difenoconazole was most effective in inhibiting the radial mycelial growth of the strains 4-1-1 and 1-1 with the respective EC50 values of 1.607 7 mg·L-1 and 1.614 0 mg·L-1. The 40% myclobutanil showed the lowest toxicity against the mycelial growth of the strains 4-1-1 and 1-1 with the EC50 values being 9.405 9 mg·L-1 and 10.595 0 mg·L-1, respectively. The 10% difenoconazole gave a 5.9 and 6.6 times higher inhibition rate against these two strains than the 40% myclobutanil.
2012, 3(3): 232-235.
doi: 10.15886/j.cnki.rdswxb.2012.03.009
Abstract:
Five strains of nitrogen fixing bacteria, Rhizobium, were inoculated onto Stylosanthes guianensis Reyan 2 water cultured under different acidity levels to observe their impact on the yield and nitrogen contents of S.guianensis Reyan 2. S.guianensis Reyan 2 showed higher dry weight and nitrogen contents under 3 acidic levels after inoculated with the rhizobium bacteria. Strain B4 inoculation treatment gave the highest yield at pH 3.5, while other strains inoculation treatments produced the highest yield and nitrogen content at pH 4.5, which were the same as the CK. Strain B4 was adapted to more acid environment, followed by Strains B1 and B2. All the strains of the rhizobium had great improvement on the growth of S.guianensis Reyan 2 water cultured under acidic conditions, and reduced the dry weight and nitrogen content of S.guianensis Reyan 2 with the increase of the acidity of the cultural solution.
Five strains of nitrogen fixing bacteria, Rhizobium, were inoculated onto Stylosanthes guianensis Reyan 2 water cultured under different acidity levels to observe their impact on the yield and nitrogen contents of S.guianensis Reyan 2. S.guianensis Reyan 2 showed higher dry weight and nitrogen contents under 3 acidic levels after inoculated with the rhizobium bacteria. Strain B4 inoculation treatment gave the highest yield at pH 3.5, while other strains inoculation treatments produced the highest yield and nitrogen content at pH 4.5, which were the same as the CK. Strain B4 was adapted to more acid environment, followed by Strains B1 and B2. All the strains of the rhizobium had great improvement on the growth of S.guianensis Reyan 2 water cultured under acidic conditions, and reduced the dry weight and nitrogen content of S.guianensis Reyan 2 with the increase of the acidity of the cultural solution.
2012, 3(3): 236-242.
doi: 10.15886/j.cnki.rdswxb.2012.03.003
Abstract:
Homoharringtonine （HHRT） was produced from Alternaria tenuissima CH1307, an endophytical fungus of Cephalotaxus mannii Hook.f through fermentation. Four factors such as the concentrations of glucose, magnesium sulfate and vitamin B compound and the rotating speed were analyzed by using response surface methodology to determine their effect on fermentation of the fungus CH1370. The best operating conditions resulted to be 32.022 6 g·L-1 for glucose , 0.096 6 g·L-1 for magnesium sulfate and 0.123 9 g·L-1 for vitamin B compound as well as 146.474 2 r·min-1 for the rotating speed, and 190.637 0 μg·L-1 of HHRT were produced from this fungus when the values of the four factors were entered into a formula established.
Homoharringtonine （HHRT） was produced from Alternaria tenuissima CH1307, an endophytical fungus of Cephalotaxus mannii Hook.f through fermentation. Four factors such as the concentrations of glucose, magnesium sulfate and vitamin B compound and the rotating speed were analyzed by using response surface methodology to determine their effect on fermentation of the fungus CH1370. The best operating conditions resulted to be 32.022 6 g·L-1 for glucose , 0.096 6 g·L-1 for magnesium sulfate and 0.123 9 g·L-1 for vitamin B compound as well as 146.474 2 r·min-1 for the rotating speed, and 190.637 0 μg·L-1 of HHRT were produced from this fungus when the values of the four factors were entered into a formula established.
2012, 3(3): 243-246.
doi: 10.15886/j.cnki.rdswxb.2012.03.004
Abstract:
Star anise （Illicium verum Hook. f.）, an important source of natural anti-oxidants, was extracted with solvents of water, ethanol, actone and n- butanol, respectively. The extracts were determined in free radical scavenging activity by using 2,2-diphenyL-1-picrylhydrazyl （DPPH） assay. The volatile oil and the ethyl acetate extract from these extracts were used as antioxidants and added into the lard quantitatively, and the peroxide value （POV） of the lard stored for a given time was measured to compare the influence of different rates of the volatile oil and the ethyl acetate extract on oxidation resistance of the lard. The results showed that the extracts varied in free radical scavenging activity which was the highest in the ethanol extract with the order of ethanol＞n- butanol＞actone＞water under the same concentration. The volatile oil was low in anti-oxidative activity while the ethyl acetate extract had very high anti-oxidative activity. The ethyl acetate extract was higher in oxidation resistance when added into the lard at a rate of 0.10% （w） than the butylated hydroxytoluene （BHT） at a rate of 0.02% （w）, and had higher anti-oxidative activity when added at a higher rate.
Star anise （Illicium verum Hook. f.）, an important source of natural anti-oxidants, was extracted with solvents of water, ethanol, actone and n- butanol, respectively. The extracts were determined in free radical scavenging activity by using 2,2-diphenyL-1-picrylhydrazyl （DPPH） assay. The volatile oil and the ethyl acetate extract from these extracts were used as antioxidants and added into the lard quantitatively, and the peroxide value （POV） of the lard stored for a given time was measured to compare the influence of different rates of the volatile oil and the ethyl acetate extract on oxidation resistance of the lard. The results showed that the extracts varied in free radical scavenging activity which was the highest in the ethanol extract with the order of ethanol＞n- butanol＞actone＞water under the same concentration. The volatile oil was low in anti-oxidative activity while the ethyl acetate extract had very high anti-oxidative activity. The ethyl acetate extract was higher in oxidation resistance when added into the lard at a rate of 0.10% （w） than the butylated hydroxytoluene （BHT） at a rate of 0.02% （w）, and had higher anti-oxidative activity when added at a higher rate.
2012, 3(3): 247-251.
doi: 10.15886/j.cnki.rdswxb.2012.03.012
Abstract:
Problems arising from successive cropping of black pepper（Piper nigrum） were analyzed, such as weak growth vigor, low yield, deteriorated soil physic-chemical properties, serious attack of diseases and pests, etc. and some cultural practices for successive cropping of black pepper were put forward as technical reference for sustainable cultivation of black pepper.
Problems arising from successive cropping of black pepper（Piper nigrum） were analyzed, such as weak growth vigor, low yield, deteriorated soil physic-chemical properties, serious attack of diseases and pests, etc. and some cultural practices for successive cropping of black pepper were put forward as technical reference for sustainable cultivation of black pepper.
2012, 3(3): 252-257.
doi: 10.15886/j.cnki.rdswxb.2012.03.014
Abstract:
Tissues of most tropical fruit trees contain polysaccharide and polyphenolics that restrict the extraction of high-quality genomic DNA for further molecular biology analysis. This experiment was conducted to develop a simple, universal and effective modified CTAB method for genomic DNA extraction from tissues of tropical fruit trees for southern blot analysis. This optimized procedure includes two steps. First, before the DNA was extracted, the polysaccharide and polyphenolics were pre-removed through the STE lysis buffer by centrifugation. In addition, possible contamination by secondary metaboliates could be avoided by picking up the cotton-shaped genomic DNA floccules resuspended in liquid at the DNA precipitation step with ethanol. With the modified CTAB method, high-quality DNAs were extracted from young leaves of the three representative tropical fruit trees, banana （Musa spp.）, papaya （Carica papaya L.） and longan （Dimocarpus longan Lour.）. After digested with different restriction enzymes, fragments of banana ethylene receptor gene （GenBank accession No. AF113748）, papaya phytoene desaturase gene （DQ779922） and longan flowering-related LEAFY homologous gene （DQ160214） were used as probes for further Southern blot analysis, respectively. The hybridization bands were clear with high background. The results indicate that the modified CTAB method, with pre-treated conjugation by DNA pick-up, is a simple and effective protocol for genomic DNA isolation from tropical fruit trees, which produces high-quality genomic DNA available for further Southern blot analysis and other tests in molecular biology.
Tissues of most tropical fruit trees contain polysaccharide and polyphenolics that restrict the extraction of high-quality genomic DNA for further molecular biology analysis. This experiment was conducted to develop a simple, universal and effective modified CTAB method for genomic DNA extraction from tissues of tropical fruit trees for southern blot analysis. This optimized procedure includes two steps. First, before the DNA was extracted, the polysaccharide and polyphenolics were pre-removed through the STE lysis buffer by centrifugation. In addition, possible contamination by secondary metaboliates could be avoided by picking up the cotton-shaped genomic DNA floccules resuspended in liquid at the DNA precipitation step with ethanol. With the modified CTAB method, high-quality DNAs were extracted from young leaves of the three representative tropical fruit trees, banana （Musa spp.）, papaya （Carica papaya L.） and longan （Dimocarpus longan Lour.）. After digested with different restriction enzymes, fragments of banana ethylene receptor gene （GenBank accession No. AF113748）, papaya phytoene desaturase gene （DQ779922） and longan flowering-related LEAFY homologous gene （DQ160214） were used as probes for further Southern blot analysis, respectively. The hybridization bands were clear with high background. The results indicate that the modified CTAB method, with pre-treated conjugation by DNA pick-up, is a simple and effective protocol for genomic DNA isolation from tropical fruit trees, which produces high-quality genomic DNA available for further Southern blot analysis and other tests in molecular biology.
2012, 3(3): 258-260,270.
doi: 10.15886/j.cnki.rdswxb.2012.03.005
Abstract:
Ursolic acid was extracted supercritically from Ilex kudingcha C.J.Tseng with fluid CO2. The extract liquid was purified with acid and alkali and detected with high performance liquid chromatography （HPLC）. Optimal extracting conditions resulted to be absolute ethanol as entrainer, CO2 flow rate at 20 L·h-1, extracting temperature at 45 ℃, extracting pressure at 30 MPa and extracting time for 3 h, and the extraction rate was upto 0.453%. Moreover, crude products of ursolic acid with a purity of 21.44% were produced finally. This extraction technology is superior to the traditional solvent extraction of ursolic acid, and suitable for industrial production.
Ursolic acid was extracted supercritically from Ilex kudingcha C.J.Tseng with fluid CO2. The extract liquid was purified with acid and alkali and detected with high performance liquid chromatography （HPLC）. Optimal extracting conditions resulted to be absolute ethanol as entrainer, CO2 flow rate at 20 L·h-1, extracting temperature at 45 ℃, extracting pressure at 30 MPa and extracting time for 3 h, and the extraction rate was upto 0.453%. Moreover, crude products of ursolic acid with a purity of 21.44% were produced finally. This extraction technology is superior to the traditional solvent extraction of ursolic acid, and suitable for industrial production.
2012, 3(3): 261-266.
doi: 10.15886/j.cnki.rdswxb.2012.03.015
Abstract:
Lateral buds of Cymbidium were used as explants to induce to form clustered shoots or multiple shoot clumps for rapid propagation of Cymbidium. The multiple shoot clumps were proliferated much faster when cultured on 1/2MS+ 6-BA 3.5 mg·L-1+NAA 0.2 mg·L-1+10% coconut water （CW） （or 10% banana homogenate） medium, and proliferation could be done at least 9 times a year when a subculture cycle took 40 days to complete, or a lateral bud can produce 3.69（about 100 thousand） plants a year. Browning occurred occasionally in multiple shoot clumps during the subculture but did not give negative impact on the proliferation of the multiple shoot clumps. Addition of 10% coconut water （CW） （or 10% banana homogenate） into the bud proliferation medium gave a higher proliferation rate of multiple shoot clumps and improved their growth vigor. The test tube plantlets were rooted well with the rooting rate of 86.1% when cultured on the rooting medium of 1/2MS+NAA1.0 mg·L-1+1.0 g·L-1 AC+10% CW. The rooted plantlets had a survival rate of upto 92.5% when transferred and cultured on the sphagnum.
Lateral buds of Cymbidium were used as explants to induce to form clustered shoots or multiple shoot clumps for rapid propagation of Cymbidium. The multiple shoot clumps were proliferated much faster when cultured on 1/2MS+ 6-BA 3.5 mg·L-1+NAA 0.2 mg·L-1+10% coconut water （CW） （or 10% banana homogenate） medium, and proliferation could be done at least 9 times a year when a subculture cycle took 40 days to complete, or a lateral bud can produce 3.69（about 100 thousand） plants a year. Browning occurred occasionally in multiple shoot clumps during the subculture but did not give negative impact on the proliferation of the multiple shoot clumps. Addition of 10% coconut water （CW） （or 10% banana homogenate） into the bud proliferation medium gave a higher proliferation rate of multiple shoot clumps and improved their growth vigor. The test tube plantlets were rooted well with the rooting rate of 86.1% when cultured on the rooting medium of 1/2MS+NAA1.0 mg·L-1+1.0 g·L-1 AC+10% CW. The rooted plantlets had a survival rate of upto 92.5% when transferred and cultured on the sphagnum.
2012, 3(3): 267-270.
doi: 10.15886/j.cnki.rdswxb.2012.03.010
Abstract:
Shoot tips were used as explants to mass propagate Alpinia zerumbet cv. vaniegata. The shoot tips were cultured on the MS medium at the presence of BA 3.0 mg·L-1+NAA 0.2 mg·L-1+ sugar 30 mg·L-1 for 30 days and produced adventitious shoots continuously. These shoots were transferred onto the MS medium supplemented with 6-BA 2.0—2.5 mg·L-1+NAA 0.2 mg·L-1 + sugar 30 mg·L-1 for further culture and were well proliferated with a proliferation coefficient of 4.0. The multiplied shoots grew normal with dark green color and were rooted well with stout roots on the 1/2MS medium supplemented with NAA 1.0—1.5 mg·L-1 with a rooting rate of 93.0%. The rooted plantlets of A.zerumbet cv. vaniegata were transplanted in the mixed substrate （river sand: perlite: surface soil =1:1:1）, and survived upto 70.1%.
Shoot tips were used as explants to mass propagate Alpinia zerumbet cv. vaniegata. The shoot tips were cultured on the MS medium at the presence of BA 3.0 mg·L-1+NAA 0.2 mg·L-1+ sugar 30 mg·L-1 for 30 days and produced adventitious shoots continuously. These shoots were transferred onto the MS medium supplemented with 6-BA 2.0—2.5 mg·L-1+NAA 0.2 mg·L-1 + sugar 30 mg·L-1 for further culture and were well proliferated with a proliferation coefficient of 4.0. The multiplied shoots grew normal with dark green color and were rooted well with stout roots on the 1/2MS medium supplemented with NAA 1.0—1.5 mg·L-1 with a rooting rate of 93.0%. The rooted plantlets of A.zerumbet cv. vaniegata were transplanted in the mixed substrate （river sand: perlite: surface soil =1:1:1）, and survived upto 70.1%.
2012, 3(3): 271-275.
doi: 10.15886/j.cnki.rdswxb.2012.03.011
Abstract:
Dioscorea alata L. were mass propagated through tissue culture on different MS media with the nodal stem segments as explants. The explants were induced to form axillary buds at an initiation rate of 100% when cultured on the MS medium without any auxins. The initiated nodal shoots were rapidly multiplied in the subculture basic medium supplemented with 80 mg·L-1 AD （adenine sulfate） and 4 times of nodal shoots could be produced at day 50 of subculture. Adventitious buds were induced from the nodal segments subcultured in the basic medium supplemented with 6-BA 1.0 mg·L-1,NAA0.1 mg·L-1 and 80 mg·L-1 AD, and produced robust shoots when cultured on the medium supplemented with 80 mg·L-1 AD. The adventitious shoots were rooted on the MS medium containing NAA0.1 mg·L-1 to form complete plants, and the rooting rate was 100%. The rooted plantlets were transplanted onto a mixed substrate of garden soil, sand and plant ash（V:V:V=2:2:1） and resulted in 88.3% survival.
Dioscorea alata L. were mass propagated through tissue culture on different MS media with the nodal stem segments as explants. The explants were induced to form axillary buds at an initiation rate of 100% when cultured on the MS medium without any auxins. The initiated nodal shoots were rapidly multiplied in the subculture basic medium supplemented with 80 mg·L-1 AD （adenine sulfate） and 4 times of nodal shoots could be produced at day 50 of subculture. Adventitious buds were induced from the nodal segments subcultured in the basic medium supplemented with 6-BA 1.0 mg·L-1,NAA0.1 mg·L-1 and 80 mg·L-1 AD, and produced robust shoots when cultured on the medium supplemented with 80 mg·L-1 AD. The adventitious shoots were rooted on the MS medium containing NAA0.1 mg·L-1 to form complete plants, and the rooting rate was 100%. The rooted plantlets were transplanted onto a mixed substrate of garden soil, sand and plant ash（V:V:V=2:2:1） and resulted in 88.3% survival.
2012, 3(3): 276-280.
doi: 10.15886/j.cnki.rdswxb.2012.03.002
Abstract:
An investigation of harmful algal blooms of Noctiluca scintillans was conducted in the waters around the Naozhou Island, Zhanjiang, China. The investigation showed that the harmful algal blooms appeared in the waters around the Island when the sea temperature was 19 ℃, the salinity 27-32, the pH 6.87-8.33, the dissolved oxygen 2.81-8.11 mg·L-1, the chemical oxygen demand 0.97-492.28 mg·L-1, the ammonia nitrogen 0.002-0.258 mg·L-1, the nitrate 0.04-0.262 mg·L-1, the nitrite 0.005-0.175 mg·L-1, the inorganic nitrogen 0.047-0.529 mg·L-1, and the reactive phosphate 0.048-1.682 mg·L-. This was due to the fact that large amounts of eutrophic waste water were discharged into the sea waters directly from the local prawn ponds due to pond cleaning. This mass of eutrophic waste water was the major factor that caused the harmful algal blooms of N. scintillans covering the waters 2 km long and 50 m wide, or a sea area of 10 hectares in the waters around the Island.
An investigation of harmful algal blooms of Noctiluca scintillans was conducted in the waters around the Naozhou Island, Zhanjiang, China. The investigation showed that the harmful algal blooms appeared in the waters around the Island when the sea temperature was 19 ℃, the salinity 27-32, the pH 6.87-8.33, the dissolved oxygen 2.81-8.11 mg·L-1, the chemical oxygen demand 0.97-492.28 mg·L-1, the ammonia nitrogen 0.002-0.258 mg·L-1, the nitrate 0.04-0.262 mg·L-1, the nitrite 0.005-0.175 mg·L-1, the inorganic nitrogen 0.047-0.529 mg·L-1, and the reactive phosphate 0.048-1.682 mg·L-. This was due to the fact that large amounts of eutrophic waste water were discharged into the sea waters directly from the local prawn ponds due to pond cleaning. This mass of eutrophic waste water was the major factor that caused the harmful algal blooms of N. scintillans covering the waters 2 km long and 50 m wide, or a sea area of 10 hectares in the waters around the Island.
2012, 3(3): 281-286.
doi: 10.15886/j.cnki.rdswxb.2012.03.016
Abstract:
Originated in the Central America, pitaya have been spread for cultivation in 20 countries or regions. Pitaya flower has many medical benefits such as lowering blood pressure, lung-nourishing, beauty care, etc. Pitaya have a long period of flowering and produce a huge number of pitaya flower each year. The recent research and developments of pitaya are reviewed in terms of planting area and cultivars as well as the biological characteristics and functional constituents of pitaya flower and pilot trial of pitaya flower products. Essential amino acids and medical amino acids were evaluated nutritionally based on the available data. The evaluation showed that pitaya flower contained limited amount of Met+Cys amino acids and large amount of Leu and Try amino acids and similar amount of Ile, Phe+Tyr and Thr amino acids to the pattern spectrum which FAO/WHO revised in 1973. A good prospect for development of pitaya flower is also described.
Originated in the Central America, pitaya have been spread for cultivation in 20 countries or regions. Pitaya flower has many medical benefits such as lowering blood pressure, lung-nourishing, beauty care, etc. Pitaya have a long period of flowering and produce a huge number of pitaya flower each year. The recent research and developments of pitaya are reviewed in terms of planting area and cultivars as well as the biological characteristics and functional constituents of pitaya flower and pilot trial of pitaya flower products. Essential amino acids and medical amino acids were evaluated nutritionally based on the available data. The evaluation showed that pitaya flower contained limited amount of Met+Cys amino acids and large amount of Leu and Try amino acids and similar amount of Ile, Phe+Tyr and Thr amino acids to the pattern spectrum which FAO/WHO revised in 1973. A good prospect for development of pitaya flower is also described.
2012, 3(3): 287-292.
doi: 10.15886/j.cnki.rdswxb.2012.03.007
Abstract:
This paper reviews briefly the advances on biological control strategies of sugarcane borers in recent years and put forward a new strategy of controling sugarcane borers by using RNA interference technique to regulate molt-regulating transcription factor genes in sugarcane borers. This review provides a reference for the development of borer-resistant sugarcane germplasm by transgenic technology.
This paper reviews briefly the advances on biological control strategies of sugarcane borers in recent years and put forward a new strategy of controling sugarcane borers by using RNA interference technique to regulate molt-regulating transcription factor genes in sugarcane borers. This review provides a reference for the development of borer-resistant sugarcane germplasm by transgenic technology.
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