2006 Vol. 24 No. 2
Abstract:
RNA editing exists extensively in the higher plant mitochondria,and is a required step for forming functional proteins.The editing of mitochondrial gene atp6,coxⅡ and orf H79 was studied with(using) the tetrad anthers,uninucleate and dinucleate pollens of gametophytice male sterility line YueTai A,maintainer line YueTai B,and the F1 hybrid HongLian You6 of HL-type cytoplasmic male sterility(CMS) rice.The results indicated the editing capability of atp6 gene was influenced markedly by nuclear restorer gene.The atp6 transcript was not edited or partially edited in male sterility line,but the higher editing capability was found in the F1 hybrid containing restorer gene.There was no difference in the editing level of coxⅡ gene among three lines,and the chimeric gene,orf H79 was not edited in all materials.So it is guessed that there is a close association between HL-CS and the loss of editing capability of atp6 gene.
RNA editing exists extensively in the higher plant mitochondria,and is a required step for forming functional proteins.The editing of mitochondrial gene atp6,coxⅡ and orf H79 was studied with(using) the tetrad anthers,uninucleate and dinucleate pollens of gametophytice male sterility line YueTai A,maintainer line YueTai B,and the F1 hybrid HongLian You6 of HL-type cytoplasmic male sterility(CMS) rice.The results indicated the editing capability of atp6 gene was influenced markedly by nuclear restorer gene.The atp6 transcript was not edited or partially edited in male sterility line,but the higher editing capability was found in the F1 hybrid containing restorer gene.There was no difference in the editing level of coxⅡ gene among three lines,and the chimeric gene,orf H79 was not edited in all materials.So it is guessed that there is a close association between HL-CS and the loss of editing capability of atp6 gene.
2006, 24(2): 100-105.
Abstract:
Calnexin,an important lectin-like chaperone in endoplasm reticulum,can assist in protein fol-(ding) and modulate Ca2+ homeostasis in cell.A cDNA of 1964 bp encoding a full-length calnexin was cloned from Lycopersicon esculentum,and designated as(Lecnx61.0).A single copy of(Lecnx61.0) was found in tomato genomic DNA by Southern-blot analysis.The levels of mRNA and protein of(Lecnx61.0) were increased when plants were treated by heat shock,chilling shock,salinity stress and endoplasm reticulum stress,but(Lecnx61.0) had no obvious response to drought stress.The protein of(LeCNX61.0) only in speci-(fic) tissues made response to Ca2+ depletion.Howerver,the expression of(LeCNX61.0) was not induced by high concentration of Ca2+.These results suggested that(LeCNX61.0) might play an important role in stress tolerance.
Calnexin,an important lectin-like chaperone in endoplasm reticulum,can assist in protein fol-(ding) and modulate Ca2+ homeostasis in cell.A cDNA of 1964 bp encoding a full-length calnexin was cloned from Lycopersicon esculentum,and designated as(Lecnx61.0).A single copy of(Lecnx61.0) was found in tomato genomic DNA by Southern-blot analysis.The levels of mRNA and protein of(Lecnx61.0) were increased when plants were treated by heat shock,chilling shock,salinity stress and endoplasm reticulum stress,but(Lecnx61.0) had no obvious response to drought stress.The protein of(LeCNX61.0) only in speci-(fic) tissues made response to Ca2+ depletion.Howerver,the expression of(LeCNX61.0) was not induced by high concentration of Ca2+.These results suggested that(LeCNX61.0) might play an important role in stress tolerance.
Abstract:
The megasporogenesis and development of female gametophyte were studied by paraffin sections in line M14,a chromosome 9 monosomic addition line of Beta corolliflora Zoss.in sugar beet,in which revealed that the egg cell could been produced through diplospory or sexuality.The results are as follows:sexuality is of Polygonum-type,and diplospory is of two types,Allium odorum-type and Antennatia-type in M14.The megasporocyte of Allium odorum-type and Antennatia-type turn into a mature diplosporous female gametophyte.The Megasporocyte Polygonum-type turns into a mature monoplontic female gametophyte.Compared with the sexual female gametophyte,bradygenesis and abortion can be frequently observed during the development of diplosporous female gametophyte.Only 25% of them are normal.The characteristic of diplosporous reproduction is discussed.
The megasporogenesis and development of female gametophyte were studied by paraffin sections in line M14,a chromosome 9 monosomic addition line of Beta corolliflora Zoss.in sugar beet,in which revealed that the egg cell could been produced through diplospory or sexuality.The results are as follows:sexuality is of Polygonum-type,and diplospory is of two types,Allium odorum-type and Antennatia-type in M14.The megasporocyte of Allium odorum-type and Antennatia-type turn into a mature diplosporous female gametophyte.The Megasporocyte Polygonum-type turns into a mature monoplontic female gametophyte.Compared with the sexual female gametophyte,bradygenesis and abortion can be frequently observed during the development of diplosporous female gametophyte.Only 25% of them are normal.The characteristic of diplosporous reproduction is discussed.
2006, 24(2): 113-118.
Abstract:
The spores of 11 species(including 1 variety) of Polypodiodes Ching were examined under LM and SEM,and most of the species were studied for the first time.The spores of Polypodiodes are monolete,bilaterally symmetric,elliptic in polar view and kidney shaped or semirounded in equator view.Based on the spore morphology,the relationships between P.wattii and P.niponica,P.microrhizoma and Metapoly-(podium) manmeiense were also discussed,providing the palynological to the systematics of Polypodiodes.According to the study at the palynology of this genus,we concluded that Polypodiodes is a natural taxon and agreed with Ching’s point in 1978.
The spores of 11 species(including 1 variety) of Polypodiodes Ching were examined under LM and SEM,and most of the species were studied for the first time.The spores of Polypodiodes are monolete,bilaterally symmetric,elliptic in polar view and kidney shaped or semirounded in equator view.Based on the spore morphology,the relationships between P.wattii and P.niponica,P.microrhizoma and Metapoly-(podium) manmeiense were also discussed,providing the palynological to the systematics of Polypodiodes.According to the study at the palynology of this genus,we concluded that Polypodiodes is a natural taxon and agreed with Ching’s point in 1978.
2006, 24(2): 119-129.
Abstract:
Dapeng Peninsula is located in southeast of Shenzhen Special Economic Zone,Guangdong,at 22°26’ to 22°34’N and 114°28’ to 114°37’E,with a total area of 106.7 km2.The highest mountain in Dapeng Peninsula is Qiniang Mountain range,with the highest peak at 867 m.Surveys on plant resources and floristic composition have been conducted since 1998,and more than 3000 specimens were collected.Up to 990 species(including intraspecific taxa) of spermatophytic plants,belonging to 158 families and 575 genera,were recorded in Dapeng Peninsula,of which 6 species,belonging to 5 families and 5 genera,are gymnosperms;984 species,belonging to 153 families and 570 genera,are angiosperms.The major vegetation types in Dapeng Peninsula are evergreen monsoon forest,south subtropical evergreen broad-leaf forest,shrub forest,shrub-grassland,grassland and beach vegetation.The charateristic families are Cyperaceae,Theaceae,Moraceae,Orchidaceae,Urticaceae,Rutaceae,Myrsinaceae,Fagaceae.The species-rich tree genera with more than 8 species are Ficus,Fimbristylis,Hedyotis,Camellia and Syzygium,and most of them are of tropical and wide distribution.According to the geographical distribution,the spermatophyte genera may be divided into 13 types and 10 subtypes,of which Pantropic and Tropical Asia are the main ones in the flora and the temperate compositions(15.63%) are relatively poor.At specific level,the Tropical Asia-compositions(28.99%) are dominant.Comparing the composition of the flora with those of 4 neighbouring regions,the flora of Dapeng Peninsula is much more closely allied to Heishiding than to the others with the indices of genera similarity and species similarity 63.57% and 41.49% respectively.As a part of Guangdong flora,the flora of Dapeng Peninsula shares the same origin with South China.
Dapeng Peninsula is located in southeast of Shenzhen Special Economic Zone,Guangdong,at 22°26’ to 22°34’N and 114°28’ to 114°37’E,with a total area of 106.7 km2.The highest mountain in Dapeng Peninsula is Qiniang Mountain range,with the highest peak at 867 m.Surveys on plant resources and floristic composition have been conducted since 1998,and more than 3000 specimens were collected.Up to 990 species(including intraspecific taxa) of spermatophytic plants,belonging to 158 families and 575 genera,were recorded in Dapeng Peninsula,of which 6 species,belonging to 5 families and 5 genera,are gymnosperms;984 species,belonging to 153 families and 570 genera,are angiosperms.The major vegetation types in Dapeng Peninsula are evergreen monsoon forest,south subtropical evergreen broad-leaf forest,shrub forest,shrub-grassland,grassland and beach vegetation.The charateristic families are Cyperaceae,Theaceae,Moraceae,Orchidaceae,Urticaceae,Rutaceae,Myrsinaceae,Fagaceae.The species-rich tree genera with more than 8 species are Ficus,Fimbristylis,Hedyotis,Camellia and Syzygium,and most of them are of tropical and wide distribution.According to the geographical distribution,the spermatophyte genera may be divided into 13 types and 10 subtypes,of which Pantropic and Tropical Asia are the main ones in the flora and the temperate compositions(15.63%) are relatively poor.At specific level,the Tropical Asia-compositions(28.99%) are dominant.Comparing the composition of the flora with those of 4 neighbouring regions,the flora of Dapeng Peninsula is much more closely allied to Heishiding than to the others with the indices of genera similarity and species similarity 63.57% and 41.49% respectively.As a part of Guangdong flora,the flora of Dapeng Peninsula shares the same origin with South China.
2006, 24(2): 130-134.
Abstract:
18 gap patches and the controlled quadrates near gap patches of understory were sampled in subalpine dark coniferous forest in Wolong Nature Reserve.For each gap patch and controlled quadrate,the quantity characteristics of the major tree species and shrubs were measured,as well.According to different importance value of the major trees between gap and understory and their ecological characters,the major tree species in the whole community were classified into two ecological groups of species(pioneer group and shadetolerant group).The composition of ecological groups of species was distinctly different in gaps and understory,and the recruitment of the seedlings for the two ecological groups of species in gap patches differed from that in understory condition,which is due to their different ecological characters and gap conditions.As a dominant species of the shrubs layer,the growth of dwarf bamboo had affected the regeneration patters of the species.
18 gap patches and the controlled quadrates near gap patches of understory were sampled in subalpine dark coniferous forest in Wolong Nature Reserve.For each gap patch and controlled quadrate,the quantity characteristics of the major tree species and shrubs were measured,as well.According to different importance value of the major trees between gap and understory and their ecological characters,the major tree species in the whole community were classified into two ecological groups of species(pioneer group and shadetolerant group).The composition of ecological groups of species was distinctly different in gaps and understory,and the recruitment of the seedlings for the two ecological groups of species in gap patches differed from that in understory condition,which is due to their different ecological characters and gap conditions.As a dominant species of the shrubs layer,the growth of dwarf bamboo had affected the regeneration patters of the species.
2006, 24(2): 135-139.
Abstract:
In this paper,by periodical measuring the growth indices of Phalaris arundinacea in whole growing process in Beigu Mountain wetland,including plant length,sheath height,leaves age and biomass,the seasonal growing dynamic of P.arundinacea were studied and provided the theoretical and technical data for the resources exploitation of P.arundinacea.The results showed that the seasonal growing dynamics of above four growing indices were similar,and all appeared "S" curves.Further analysised,the cubic fitting curve was best.The change trend of absolute growth rate and relative growth rate were almost synchrony,and both exhibited monopeaks curve,but there was little difference in time when negative growth rate appeared.The seasonal dynamic of accumulation absolute growth rate and accumulation relative growth rate of growing indices were both "S" curve shaped,and the cubic fitting curves were best also.
In this paper,by periodical measuring the growth indices of Phalaris arundinacea in whole growing process in Beigu Mountain wetland,including plant length,sheath height,leaves age and biomass,the seasonal growing dynamic of P.arundinacea were studied and provided the theoretical and technical data for the resources exploitation of P.arundinacea.The results showed that the seasonal growing dynamics of above four growing indices were similar,and all appeared "S" curves.Further analysised,the cubic fitting curve was best.The change trend of absolute growth rate and relative growth rate were almost synchrony,and both exhibited monopeaks curve,but there was little difference in time when negative growth rate appeared.The seasonal dynamic of accumulation absolute growth rate and accumulation relative growth rate of growing indices were both "S" curve shaped,and the cubic fitting curves were best also.
2006, 24(2): 140-143.
Abstract:
The photosynthetic characteristics of a shrub,Mahonia fortunei in the limestone area of Chongqing was studied by CI-310 portable photosynthesis system.The results showed as follows: The diurnal variation of Pn and Gs of M.fortunei was "twin-peaked" curves and appeared "photosynthetic depressed" in the noon that related to non-stomatal restriction factor.The diurnal variation of E was "singled-peaked" curve and that of WUE looked like an "L".The seasonal changes of Pn,E and Gs were all "twin-peaked" curves,but WUE appeared a "W" curve.In order to grow well in limestone area M.fortunei took a way of "low photosynthesis,low transpiration and high water use efficiency".The experiment of response of Pn to CO2 indicated that Pn increased with the rise of CO2 and CO2 compensation point was 90 μmol·mol-1 and CE was 0.0125,which caused that M.fortunei had slow grow speed.
The photosynthetic characteristics of a shrub,Mahonia fortunei in the limestone area of Chongqing was studied by CI-310 portable photosynthesis system.The results showed as follows: The diurnal variation of Pn and Gs of M.fortunei was "twin-peaked" curves and appeared "photosynthetic depressed" in the noon that related to non-stomatal restriction factor.The diurnal variation of E was "singled-peaked" curve and that of WUE looked like an "L".The seasonal changes of Pn,E and Gs were all "twin-peaked" curves,but WUE appeared a "W" curve.In order to grow well in limestone area M.fortunei took a way of "low photosynthesis,low transpiration and high water use efficiency".The experiment of response of Pn to CO2 indicated that Pn increased with the rise of CO2 and CO2 compensation point was 90 μmol·mol-1 and CE was 0.0125,which caused that M.fortunei had slow grow speed.
2006, 24(2): 144-148.
Abstract:
The restoration of limestone-degraded ecosystem may improve soil substrate.Heavenly bamboo was planted to pots in three different soil types(black limestone soil,yellow soil,purple soil) in order to do research on the soil enzyme activities.The results show the activities of amylase,alkaline phosphatase,and asparaginases in black limestone soil are higher than the other two soil types.But the activities of urease,peroxidase and polyphenol oxidase in purple soil are higher than that in the other two soil types.All the differences among them are significant(p<0.05).The correlation among soil enzyme(acti-)(vities),soil phosphorus and pH are not significant,while the correlation among some soil enzyme(acti-)(vities),soil nitrogen and moisture content in different soil types are significant(p<0.05).Different soil types show different correlation.Different soil enzymes show different correlation,too.The results can give some advices on the restoration of limestone-degraded ecosystem.
The restoration of limestone-degraded ecosystem may improve soil substrate.Heavenly bamboo was planted to pots in three different soil types(black limestone soil,yellow soil,purple soil) in order to do research on the soil enzyme activities.The results show the activities of amylase,alkaline phosphatase,and asparaginases in black limestone soil are higher than the other two soil types.But the activities of urease,peroxidase and polyphenol oxidase in purple soil are higher than that in the other two soil types.All the differences among them are significant(p<0.05).The correlation among soil enzyme(acti-)(vities),soil phosphorus and pH are not significant,while the correlation among some soil enzyme(acti-)(vities),soil nitrogen and moisture content in different soil types are significant(p<0.05).Different soil types show different correlation.Different soil enzymes show different correlation,too.The results can give some advices on the restoration of limestone-degraded ecosystem.
2006, 24(2): 149-153.
Abstract:
Effects of nutrient concentrations on the growth and accumulation of exopolysacchrides of spaceflight and non-spaceflight Dunaliella salina were studied.It showed that the optimal combination in concentration of nutrients for their growth was different,because of the complex effects of several space environmental factors.The optimal combinations for the growth of non-spaceflight and spaceflight D.salina were CaCl2 200 mg/L,MgCl2 500 mg/L,KNO3 1000 mg/L,KH2PO4 55 mg/L and CaCl2 250 mg/L,MgCl2 500 mg/L,KNO3 1000 mg/L,KH2PO4 15 mg/L,respectively.The optimal combination for(accumulation) of exopolysacchrides of spaceflight and non-spaceflight D.salina was similar.It was CaCl2 250 mg/L,MgCl2 2000 mg/L,KNO3 500 mg/L,KH2PO4 15 mg/L.The yield of exopolysacchrides of spaceflight D.salina was higher than that of non-spaceflight D.salina.
Effects of nutrient concentrations on the growth and accumulation of exopolysacchrides of spaceflight and non-spaceflight Dunaliella salina were studied.It showed that the optimal combination in concentration of nutrients for their growth was different,because of the complex effects of several space environmental factors.The optimal combinations for the growth of non-spaceflight and spaceflight D.salina were CaCl2 200 mg/L,MgCl2 500 mg/L,KNO3 1000 mg/L,KH2PO4 55 mg/L and CaCl2 250 mg/L,MgCl2 500 mg/L,KNO3 1000 mg/L,KH2PO4 15 mg/L,respectively.The optimal combination for(accumulation) of exopolysacchrides of spaceflight and non-spaceflight D.salina was similar.It was CaCl2 250 mg/L,MgCl2 2000 mg/L,KNO3 500 mg/L,KH2PO4 15 mg/L.The yield of exopolysacchrides of spaceflight D.salina was higher than that of non-spaceflight D.salina.
2006, 24(2): 154-158.
Abstract:
In order to clarify the physiological and biochemical basis of Nostoc commune lived in different environmental light levels,their daily changes of Fv/Fm,photosynthetic characteristics and content of carotenoids and chlorophyll were studied.Compared with shade-acclimated N.commune,sun-acclimated N.commune had higher light saturation point,higher content of carotenoids and higher ratios of carotnenoids to chlorophyll as while as lower ascending slope of light-limited part of P-I curve,lower dark respiration,lower Fv/Fm and lower content of chl a and MAAs on the basis of dry weight or surface areas.And their maximum photosynthetic rate and light compensation point were insignificantly different.Both of them had no obvious photorespiration.Shade-acclimated N.commune was more sensitive to high light than sun-acclimated ones.If the sunlight was high enough after rain,they both were photoinhibited,but they could recover immediately at lower light levels or at night.Results showed that photosynthetic characteristics and pigmentation for sun-acclimated and shade-acclimated N.commune were significantly different and these might be responsible for their adaptations to different light levels.
In order to clarify the physiological and biochemical basis of Nostoc commune lived in different environmental light levels,their daily changes of Fv/Fm,photosynthetic characteristics and content of carotenoids and chlorophyll were studied.Compared with shade-acclimated N.commune,sun-acclimated N.commune had higher light saturation point,higher content of carotenoids and higher ratios of carotnenoids to chlorophyll as while as lower ascending slope of light-limited part of P-I curve,lower dark respiration,lower Fv/Fm and lower content of chl a and MAAs on the basis of dry weight or surface areas.And their maximum photosynthetic rate and light compensation point were insignificantly different.Both of them had no obvious photorespiration.Shade-acclimated N.commune was more sensitive to high light than sun-acclimated ones.If the sunlight was high enough after rain,they both were photoinhibited,but they could recover immediately at lower light levels or at night.Results showed that photosynthetic characteristics and pigmentation for sun-acclimated and shade-acclimated N.commune were significantly different and these might be responsible for their adaptations to different light levels.
2006, 24(2): 159-162.
Abstract:
Diploid plants of non-heading Chinese cabbage(Brassica campestris ssp.chinensis Makino)were induced by treating the apical portion of seedlings with different solution of colchicine.Autotetraploid plants were selected and identified based on morphological,anatomic,agronomic and cytological characters and nutritional traits.The results indicated that the treatment with 0.1 mol/L colchicine for(6 times)yielded the highest doubled chromosome at highest rates.Compared with the diploid plant,the autotetraploid plants possessed gigantism in plant,stomata,flowering organs.The density of stomata and fecundity were recede remarkably.The contents of protein,solubility sugar and vitamin C of the autotetraploid plants were increased by 15.69%,71.25% and 22.18% than that of diploid,respectively.The autotetraploid plants performed high-fertility and heat-tolerance under high temperature in summer.
Diploid plants of non-heading Chinese cabbage(Brassica campestris ssp.chinensis Makino)were induced by treating the apical portion of seedlings with different solution of colchicine.Autotetraploid plants were selected and identified based on morphological,anatomic,agronomic and cytological characters and nutritional traits.The results indicated that the treatment with 0.1 mol/L colchicine for(6 times)yielded the highest doubled chromosome at highest rates.Compared with the diploid plant,the autotetraploid plants possessed gigantism in plant,stomata,flowering organs.The density of stomata and fecundity were recede remarkably.The contents of protein,solubility sugar and vitamin C of the autotetraploid plants were increased by 15.69%,71.25% and 22.18% than that of diploid,respectively.The autotetraploid plants performed high-fertility and heat-tolerance under high temperature in summer.
2006, 24(2): 163-166.
Abstract:
The micro-morphology of leaf lower epidermis for 9 species(beloging to 5 genera) of the tribe Triticeae from Shandong were examined under light microscope(LM).It is considered that the micro-morphological characters of leaf lower epidermis could be used as evidence to distinguish genera because they are obviously different among the genera in this tribe.In addition,5 species of Roegneria may be divided into two types based on the micro-morphological characters of leaf lower epidermis,and it is in agreement with the classification into sect.Roegneria and sect.Cynopoa by its external characteristics.
The micro-morphology of leaf lower epidermis for 9 species(beloging to 5 genera) of the tribe Triticeae from Shandong were examined under light microscope(LM).It is considered that the micro-morphological characters of leaf lower epidermis could be used as evidence to distinguish genera because they are obviously different among the genera in this tribe.In addition,5 species of Roegneria may be divided into two types based on the micro-morphological characters of leaf lower epidermis,and it is in agreement with the classification into sect.Roegneria and sect.Cynopoa by its external characteristics.
2006, 24(2): 167-170.
Abstract:
Outcrossing rate in an open-pollinated breeding population(Huli population,Chaling,Hunan Province) of Caldesia parnassifolia was estimated by the dominant RAPD makers using 10 open-pollinated progeny arrays of 24 individuals.The multilocus outcrossing rate(tm) was 1.008 and the single-locus outcrossing rate(ts) was 1.028.The multilocus outcrossing rate did not significantly differ from the single-locus outcrossing rate(tm-ts =-0.021).The fixation index(F) was-0.200.The estimates of (tm),(ts) and F utilizing windows version of MLTR program clearly indicate that outcrossing is predominant in the C.parnassifolia open-pollinated breeding population.This is possibly influenced by factors such as plant density,the adaptability of pollinator and so on.
Outcrossing rate in an open-pollinated breeding population(Huli population,Chaling,Hunan Province) of Caldesia parnassifolia was estimated by the dominant RAPD makers using 10 open-pollinated progeny arrays of 24 individuals.The multilocus outcrossing rate(tm) was 1.008 and the single-locus outcrossing rate(ts) was 1.028.The multilocus outcrossing rate did not significantly differ from the single-locus outcrossing rate(tm-ts =-0.021).The fixation index(F) was-0.200.The estimates of (tm),(ts) and F utilizing windows version of MLTR program clearly indicate that outcrossing is predominant in the C.parnassifolia open-pollinated breeding population.This is possibly influenced by factors such as plant density,the adaptability of pollinator and so on.
2006, 24(2): 171-172.
Abstract:
The article is mainly to describe flowering and bearing habit of Chinese flowering quince[Chaenomeles speciosa(Sweet) Nakai] in Changyang, Hubei. The author points out:Chinese floweringquince flowers first, then unfolds its leaves; the inflorescence is a cyme;bearing branch is a specializeddwarf and cluster twig;the development can be divided into two phases:young fruit development and laterfruit growth.
The article is mainly to describe flowering and bearing habit of Chinese flowering quince[Chaenomeles speciosa(Sweet) Nakai] in Changyang, Hubei. The author points out:Chinese floweringquince flowers first, then unfolds its leaves; the inflorescence is a cyme;bearing branch is a specializeddwarf and cluster twig;the development can be divided into two phases:young fruit development and laterfruit growth.
2006, 24(2): 173-182.
Abstract:
Morphological studies indicate that the family Nymphaeaceae,also called paleoherbs,possess many primitive characters.Recent phylogenetic analyses indicate that this family are some of the basalmost taxa among the extant angiosperms,which implies their important value for study of the origin and early evolution of angiosperms(flowering plants).The circumscription and systematic position of Nymphaeaceae have been disputed for a long time.The origin and radiation of angiosperms have long been hot issues attracting botanists.This paper reviews the research history and recent advances related to this family.
Morphological studies indicate that the family Nymphaeaceae,also called paleoherbs,possess many primitive characters.Recent phylogenetic analyses indicate that this family are some of the basalmost taxa among the extant angiosperms,which implies their important value for study of the origin and early evolution of angiosperms(flowering plants).The circumscription and systematic position of Nymphaeaceae have been disputed for a long time.The origin and radiation of angiosperms have long been hot issues attracting botanists.This paper reviews the research history and recent advances related to this family.
2006, 24(2): 183-190.
Abstract:
It’s urgent to search new renewable energy resources for supplement as fossil fuel facing with shortage.In this article some hydrocarbon-produced fuel plants are introduced.By comparison the components between the plants and petroleum,large quantity of suitable plants(including families,genera and species) are reported,especially those of which developed and used in domestic and foreign.Prospect of development and problems in fuel plants are also put forward.
It’s urgent to search new renewable energy resources for supplement as fossil fuel facing with shortage.In this article some hydrocarbon-produced fuel plants are introduced.By comparison the components between the plants and petroleum,large quantity of suitable plants(including families,genera and species) are reported,especially those of which developed and used in domestic and foreign.Prospect of development and problems in fuel plants are also put forward.