|
|
|
|
|
|
|
|
|
|
|
|
资助项目
0.05) between wild (AR = 4.651), semi-cultivated (AR = 5.091) and cultivated (AR = 5.132) populations of C. taliensis, which suggested that the genetic background of long-lived woody plant was not easy to be changed, and there were moderate high gene flow between populations. However, there was a significant difference (P < 0.05) between wild (AR = 5.9) and cultivated (AR = 7.1) populations distributed in the same place in Yun county, Yunnan province, which may result from the hybridization and introgression of species in the tea garden and anthropogenic damages to the wild population. The hypothesis of hybrid origin of C. grandibracteata was tested by morphological and microsatellites analyses. Compared with other species, the locules in ovary of C. grandibracteata are variable, which showed a morphological intermediate and mosaic. Except one private allele, Ninety-nine percent alleles of C. grandibracteata were shared with these of C. taliensis and C. sinensis var. assamica. And C. grandibracteata was nested in the cluster of C. taliensis in the UPGMA tree. Conclusively, our results supported the hypothesis of hybrid origin of C. grandibracteata partly. The speciation of C. grandibracteata was derived from hybridization and asymmetrical introgression potentially. It is possible that C. taliensis was one of its parents, but it still needs more evidences to prove that C. sinensis var. assamica was another parent.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.date.issued.year&advanced=false&query1=Rice%2Bplants&&fq=dc.project.title_filter%3ACamellia%5C+taliensis%5C+%5C%28W.%5C+W.%5C+Smith%5C%29%5C+Melchior%2C%5C+a%5C+member%5C+of%5C+Camellia%5C+sect.%5C+Thea%2C%5C+is%5C+an%5C+indigenous%5C+species%5C+in%5C+local%5C+natural%5C+forest%5C+and%5C+has%5C+a%5C+long%5C+cultivative%5C+history%5C+in%5C+western%5C+Yunnan%5C+and%5C+its%5C+neighborhood%2C%5C+where%5C+the%5C+domestications%5C+of%5C+this%5C+species%5C+in%5C+different%5C+historical%5C+periods%5C+and%5C+in%5C+different%5C+ways%5C+can%5C+be%5C+found.%5C+C.%5C+taliensis%5C+is%5C+an%5C+important%5C+contributor%5C+to%5C+the%5C+formations%5C+of%5C+tea%5C+landraces%5C+by%5C+hybridization%5C+and%5C+introgression.%5C+In%5C+the%5C+present%5C+study%2C%5C+14%5C+microsatellite%5C+loci%5C+screened%5C+from%5C+37%5C+loci%5C+were%5C+used%5C+to%5C+explore%5C+the%5C+genetic%5C+diversity%5C+about%5C+this%5C+species%5C+with%5C+579%5C+samples%5C+from%5C+25%5C+populations%5C+%5C%2816%5C+wild%5C+populations%2C%5C+4%5C+semi%5C-cultivated%5C+populations%5C+and%5C+5%5C+cultivated%5C+populations%5C%29.%5C+At%5C+the%5C+same%5C+time%2C%5C+the%5C+potential%5C+hybrid%5C+speciation%5C+of%5C+C.%5C+grandibracteata%2C%5C+was%5C+investigated%5C+using%5C+39%5C+individuals%5C+from%5C+2%5C+populations%2C%5C+along%5C+with%5C+C.%5C+taliensis%5C+and%5C+C.%5C+sinensis%5C+var.%5C+assamica%5C+%5C%2883%5C+individuals%5C+from%5C+4%5C+populations%5C%29%5C+by%5C+the%5C+same%5C+microsatellite%5C+markers.%5C+C.%5C+taliensis%5C+had%5C+a%5C+moderate%5C+high%5C+level%5C+of%5C+genetic%5C+diversity%5C+%5C%28A%5C+%3D%5C+14.3%2C%5C+Ne%3D%5C+5.7%2C%5C+HE%5C+%3D%5C+0.666%2C%5C+I%5C+%3D%5C+1.753%2C%5C+AR%5C+%3D%5C+7.2%2C%5C+PPB%5C+%3D%5C+100%25%5C%29.%5C+This%5C+may%5C+result%5C+from%5C+several%5C+factors%5C+including%5C+K%5C-strategy%2C%5C+genetic%5C+background%2C%5C+gene%5C+flow%5C+between%5C+populations%2C%5C+hybridization%5C+and%5C+introgression%5C+among%5C+species.%5C+Between%5C+wild%5C+populations%5C+of%5C+C.%5C+taliensis%2C%5C+the%5C+gene%5C+flow%5C+was%5C+moderate%5C+high%5C+%5C%28Nm%5C+%3D%5C+1.197%5C%29%2C%5C+and%5C+genetic%5C+variation%5C+was%5C+less%5C+than%5C+20%25%5C+%5C%28GST%5C+%3D%5C+0.147%2C%5C+FST%5C+%3D%5C+0.173%5C%29%2C%5C+which%5C+was%5C+similar%5C+to%5C+other%5C+research%5C+results%5C+of%5C+long%5C-lived%5C+woody%5C+plants%2C%5C+and%5C+reflected%5C+the%5C+genetic%5C+structure%5C+of%5C+its%5C+ancestry%5C+to%5C+same%5C+extent.%5C+There%5C+was%5C+a%5C+high%5C+significant%5C+correlation%5C+between%5C+geographic%5C+distance%5C+and%5C+Nei%E2%80%99s%5C+genetic%5C+distance%5C+%5C%28r%5C+%3D%5C+0.372%2C%5C+P%5C+%3D%5C+0.001%5C%29%5C+of%5C+populations%2C%5C+which%5C+accorded%5C+with%5C+isolation%5C+by%5C+distance%5C+model.%5C+Inferring%5C+from%5C+Bayesian%5C+clustering%5C+of%5C+genotypes%2C%5C+all%5C+individuals%5C+of%5C+C.%5C+taliensis%5C+were%5C+divided%5C+into%5C+two%5C+groups%2C%5C+conflicting%5C+with%5C+the%5C+result%5C+based%5C+on%5C+Nei%E2%80%99s%5C+genetic%5C+distance%5C+and%5C+real%5C+geographic%5C+distribution%2C%5C+which%5C+suggested%5C+there%5C+were%5C+heavy%5C+and%5C+non%5C-random%5C+influences%5C+by%5C+human%5C+practices.%5C+According%5C+to%5C+allelic%5C+richness%2C%5C+there%5C+were%5C+no%5C+significant%5C+differences%5C+%5C%28P%5C+%3E%5C+0.05%5C%29%5C+between%5C+wild%5C+%5C%28AR%5C+%3D%5C+4.651%5C%29%2C%5C+semi%5C-cultivated%5C+%5C%28AR%5C+%3D%5C+5.091%5C%29%5C+and%5C+cultivated%5C+%5C%28AR%5C+%3D%5C+5.132%5C%29%5C+populations%5C+of%5C+C.%5C+taliensis%2C%5C+which%5C+suggested%5C+that%5C+the%5C+genetic%5C+background%5C+of%5C+long%5C-lived%5C+woody%5C+plant%5C+was%5C+not%5C+easy%5C+to%5C+be%5C+changed%2C%5C+and%5C+there%5C+were%5C+moderate%5C+high%5C+gene%5C+flow%5C+between%5C+populations.%5C+However%2C%5C+there%5C+was%5C+a%5C+significant%5C+difference%5C+%5C%28P%5C+%3C%5C+0.05%5C%29%5C+between%5C+wild%5C+%5C%28AR%5C+%3D%5C+5.9%5C%29%5C+and%5C+cultivated%5C+%5C%28AR%5C+%3D%5C+7.1%5C%29%5C+populations%5C+distributed%5C+in%5C+the%5C+same%5C+place%5C+in%5C+Yun%5C+county%2C%5C+Yunnan%5C+province%2C%5C+which%5C+may%5C+result%5C+from%5C+the%5C+hybridization%5C+and%5C+introgression%5C+of%5C+species%5C+in%5C+the%5C+tea%5C+garden%5C+and%5C+anthropogenic%5C+damages%5C+to%5C+the%5C+wild%5C+population.%5C+The%5C+hypothesis%5C+of%5C+hybrid%5C+origin%5C+of%5C+C.%5C+grandibracteata%5C+was%5C+tested%5C+by%5C+morphological%5C+and%5C+microsatellites%5C+analyses.%5C+Compared%5C+with%5C+other%5C+species%2C%5C+the%5C+locules%5C+in%5C+ovary%5C+of%5C+C.%5C+grandibracteata%5C+are%5C+variable%2C%5C+which%5C+showed%5C+a%5C+morphological%5C+intermediate%5C+and%5C+mosaic.%5C+Except%5C+one%5C+private%5C+allele%2C%5C+Ninety%5C-nine%5C+percent%5C+alleles%5C+of%5C+C.%5C+grandibracteata%5C+were%5C+shared%5C+with%5C+these%5C+of%5C+C.%5C+taliensis%5C+and%5C+C.%5C+sinensis%5C+var.%5C+assamica.%5C+And%5C+C.%5C+grandibracteata%5C+was%5C+nested%5C+in%5C+the%5C+cluster%5C+of%5C+C.%5C+taliensis%5C+in%5C+the%5C+UPGMA%5C+tree.%5C+Conclusively%2C%5C+our%5C+results%5C+supported%5C+the%5C+hypothesis%5C+of%5C+hybrid%5C+origin%5C+of%5C+C.%5C+grandibracteata%5C+partly.%5C+The%5C+speciation%5C+of%5C+C.%5C+grandibracteata%5C+was%5C+derived%5C+from%5C+hybridization%5C+and%5C+asymmetrical%5C+introgression%5C+potentially.%5C+It%5C+is%5C+possible%5C+that%5C+C.%5C+taliensis%5C+was%5C+one%5C+of%5C+its%5C+parents%2C%5C+but%5C+it%5C+still%5C+needs%5C+more%5C+evidences%5C+to%5C+prove%5C+that%5C+C.%5C+sinensis%5C+var.%5C+assamica%5C+was%5C+another%5C+parent."},{"jsname":"Chiang Mai University","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.date.issued.year&advanced=false&query1=Rice%2Bplants&&fq=dc.project.title_filter%3AChiang%5C+Mai%5C+University"},{"jsname":"China Agriculture Research System[CARS-02]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.date.issued.year&advanced=false&query1=Rice%2Bplants&&fq=dc.project.title_filter%3AChina%5C+Agriculture%5C+Research%5C+System%5C%5BCARS%5C-02%5C%5D"},{"jsname":"China Postdoctoral Science Foundation","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.date.issued.year&advanced=false&query1=Rice%2Bplants&&fq=dc.project.title_filter%3AChina%5C+Postdoctoral%5C+Science%5C+Foundation"},{"jsname":"Chinese Academy of Sciences[2013T2S003]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.date.issued.year&advanced=false&query1=Rice%2Bplants&&fq=dc.project.title_filter%3AChinese%5C+Academy%5C+of%5C+Sciences%5C%5B2013T2S003%5C%5D"},{"jsname":"Cluster of Excellence COTE[ANR-10-LABX-45]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.date.issued.year&advanced=false&query1=Rice%2Bplants&&fq=dc.project.title_filter%3ACluster%5C+of%5C+Excellence%5C+COTE%5C%5BANR%5C-10%5C-LABX%5C-45%5C%5D"},{"jsname":"Cold stress is one of the major environmental factors that adversely influence plants growth. Cold stress not only limits plants geographic distribution, but also reduces plants yield by shortening growing season, which brought billions of dollars economic losses for global crop. In nature, responses of overwintering plants to low temperature can be divided into three distinct phases: cold acclimation (CA), freezing, and post-freezing recovery (PFR). Until now, plenty intensive study about molecular mechanism of cold stress mainly focused on the above-zero low temperature phase. However, the studies on the freezing phase below zero and the following PFR phase with temperature going up to above-zero were rare. The previous research form our lab hinted that the responses of plants to freezing and PFR were complex and important. Except for passive reflection, there were also crucial active responses during this process. Several special rules were presented at the different levels including gene expression, signal transduction and membrane lipids changes, and fully understanding these rules would be helpful for us to explore the responses of plants to low temperature and then proceed to improve the freezing resistance of plants. In the present study, the mechanisms of respond to freezing and PFR of model plant Arabidopsis thaliana and its close relative Thellungiella halophlia that with extreme tolerance to abiotic stresses were carried out, including regulation of gene expression, signal transduction pathway and membrane lipids changes three levels which were essential for the freezing resistance of plants. Ground on these work, we obtained results from the following five aspects. First, the complete picture of A. thaliana responding to freezing and PFR at transcriptome level was elaborated and three functional genes closely related to the phases were identified. Second, the cis-elements with high frequent presence in differentially expressed genes were elucidated, and the practical binding of one elements among them was experimental verified during freezing and PFR. Moreover, we predicted the new elements which would respond to freezing and PFR. Third, the regulation of freezing stress by microRNA in A. thaliana was preliminarily investigated and 36 functional genes possibly regulated by miRNA during freezing and PFR were gained. Fourth, the negative effect of phytohormone Auxin on A. thaliana subjected to freezing stress was identified. Fifth, for the freezing-resistant plant T. halophlia, the rules of membrane lipids composition changes under freezing stress were uncovered.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.date.issued.year&advanced=false&query1=Rice%2Bplants&&fq=dc.project.title_filter%3ACold%5C+stress%5C+is%5C+one%5C+of%5C+the%5C+major%5C+environmental%5C+factors%5C+that%5C+adversely%5C+influence%5C+plants%5C+growth.%5C+Cold%5C+stress%5C+not%5C+only%5C+limits%5C+plants%5C+geographic%5C+distribution%2C%5C+but%5C+also%5C+reduces%5C+plants%5C+yield%5C+by%5C+shortening%5C+growing%5C+season%2C%5C+which%5C+brought%5C+billions%5C+of%5C+dollars%5C+economic%5C+losses%5C+for%5C+global%5C+crop.%5C+In%5C+nature%2C%5C+responses%5C+of%5C+overwintering%5C+plants%5C+to%5C+low%5C+temperature%5C+can%5C+be%5C+divided%5C+into%5C+three%5C+distinct%5C+phases%5C%3A%5C+cold%5C+acclimation%5C+%5C%28CA%5C%29%2C%5C+freezing%2C%5C+and%5C+post%5C-freezing%5C+recovery%5C+%5C%28PFR%5C%29.%5C+Until%5C+now%2C%5C+plenty%5C+intensive%5C+study%5C+about%5C+molecular%5C+mechanism%5C+of%5C+cold%5C+stress%5C+mainly%5C+focused%5C+on%5C+the%5C+above%5C-zero%5C+low%5C+temperature%5C+phase.%5C+However%2C%5C+the%5C+studies%5C+on%5C+the%5C+freezing%5C+phase%5C+below%5C+zero%5C+and%5C+the%5C+following%5C+PFR%5C+phase%5C+with%5C+temperature%5C+going%5C+up%5C+to%5C+above%5C-zero%5C+were%5C+rare.%5C+The%5C+previous%5C+research%5C+form%5C+our%5C+lab%5C+hinted%5C+that%5C+the%5C+responses%5C+of%5C+plants%5C+to%5C+freezing%5C+and%5C+PFR%5C+were%5C+complex%5C+and%5C+important.%5C+Except%5C+for%5C+passive%5C+reflection%2C%5C+there%5C+were%5C+also%5C+crucial%5C+active%5C+responses%5C+during%5C+this%5C+process.%5C+Several%5C+special%5C+rules%5C+were%5C+presented%5C+at%5C+the%5C+different%5C+levels%5C+including%5C+gene%5C+expression%2C%5C+signal%5C+transduction%5C+and%5C+membrane%5C+lipids%5C+changes%2C%5C+and%5C+fully%5C+understanding%5C+these%5C+rules%5C+would%5C+be%5C+helpful%5C+for%5C+us%5C+to%5C+explore%5C+the%5C+responses%5C+of%5C+plants%5C+to%5C+low%5C+temperature%5C+and%5C+then%5C+proceed%5C+to%5C+improve%5C+the%5C+freezing%5C+resistance%5C+of%5C+plants.%5C+In%5C+the%5C+present%5C+study%2C%5C+the%5C+mechanisms%5C+of%5C+respond%5C+to%5C+freezing%5C+and%5C+PFR%5C+of%5C+model%5C+plant%5C+Arabidopsis%5C+thaliana%5C+and%5C+its%5C+close%5C+relative%5C+Thellungiella%5C+halophlia%5C+that%5C+with%5C+extreme%5C+tolerance%5C+to%5C+abiotic%5C+stresses%5C+were%5C+carried%5C+out%2C%5C+including%5C+regulation%5C+of%5C+gene%5C+expression%2C%5C+signal%5C+transduction%5C+pathway%5C+and%5C+membrane%5C+lipids%5C+changes%5C+three%5C+levels%5C+which%5C+were%5C+essential%5C+for%5C+the%5C+freezing%5C+resistance%5C+of%5C+plants.%5C+Ground%5C+on%5C+these%5C+work%2C%5C+we%5C+obtained%5C+results%5C+from%5C+the%5C+following%5C+five%5C+aspects.%5C+First%2C%5C+the%5C+complete%5C+picture%5C+of%5C+A.%5C+thaliana%5C+responding%5C+to%5C+freezing%5C+and%5C+PFR%5C+at%5C+transcriptome%5C+level%5C+was%5C+elaborated%5C+and%5C+three%5C+functional%5C+genes%5C+closely%5C+related%5C+to%5C+the%5C+phases%5C+were%5C+identified.%5C+Second%2C%5C+the%5C+cis%5C-elements%5C+with%5C+high%5C+frequent%5C+presence%5C+in%5C+differentially%5C+expressed%5C+genes%5C+were%5C+elucidated%2C%5C+and%5C+the%5C+practical%5C+binding%5C+of%5C+one%5C+elements%5C+among%5C+them%5C+was%5C+experimental%5C+verified%5C+during%5C+freezing%5C+and%5C+PFR.%5C+Moreover%2C%5C+we%5C+predicted%5C+the%5C+new%5C+elements%5C+which%5C+would%5C+respond%5C+to%5C+freezing%5C+and%5C+PFR.%5C+Third%2C%5C+the%5C+regulation%5C+of%5C+freezing%5C+stress%5C+by%5C+microRNA%5C+in%5C+A.%5C+thaliana%5C+was%5C+preliminarily%5C+investigated%5C+and%5C+36%5C+functional%5C+genes%5C+possibly%5C+regulated%5C+by%5C+miRNA%5C+during%5C+freezing%5C+and%5C+PFR%5C+were%5C+gained.%5C+Fourth%2C%5C+the%5C+negative%5C+effect%5C+of%5C+phytohormone%5C+Auxin%5C+on%5C+A.%5C+thaliana%5C+subjected%5C+to%5C+freezing%5C+stress%5C+was%5C+identified.%5C+Fifth%2C%5C+for%5C+the%5C+freezing%5C-resistant%5C+plant%5C+T.%5C+halophlia%2C%5C+the%5C+rules%5C+of%5C+membrane%5C+lipids%5C+composition%5C+changes%5C+under%5C+freezing%5C+stress%5C+were%5C+uncovered."},{"jsname":"Craigia yunnanensis W. W. Smith & W. E. Evans (Tiliaceae) is an endangered deciduous tree species which has high scientific and economic value. C. yunnanensis is seriously threatened and has been pushed to the verge of extinction due to vegetation destruction in China and consequent contraction of its distribution. Hence, it was listed as a nationally rare and endangered plant in 1999 and has also been proposed as a second-ranked plant for national protection in China and included in IUCN red list. As a scientifically important and valued tree species with endangered status, the wild populations of C. yunnanensis therefore represent is a genetic resource that must be conserved. To provide basic information for its conservation, the population dynamics and population size structures, pollination biology and breeding system, eleven fitness-related characters and the genetic variability based on AFLP were comprehensively studied. The main results are summarized as follows: A total of six wild populations of C. yunnanensis were found in two disjunct regions of Yunnan, i.e. WenShan (SE Yunnan) and DeHong (SW Yunnan), from 2005 to 2007. Additionally, in all but one of the populations we detected, mature trees were felled between 2005 and 2007, so destruction of most of these populations is ongoing. Across the six populations of extant C. yunnanensis found during our study, the total number of mature (reproductive) individuals detected was 584 in 2007，plus larger numbers of seedling and resprouts from cut trunks. The result of surveying Population structure showed that there are two regeneration types which are seedlings and sprouts. Seedlings occurred abundantly in gaps or open areas and the size class frequency distributions were often discontinuous, and the same general pattern occurred in all the investigated populations for juveniles and adults. The numbers of seed-origin individuals did however decline sharply with increasing size, indicating a high mortality rate going from seedling to sapling stage may be a problem for this species. Additionally, the cash crop cultivation and logging seriously threaten the survival of the species. We conducted field observations and artificial pollination experiments on the floral biology, pollination process and breeding system of Craigia yunnanensis in Fadou, Xichou county of Yunnan province. The lifespan of a single hermaphrodite flower is approximately 3-4 days. A cyme has 2-9 flowered. The flowering period of an inflorescence is usually 5-14 days. The flowers of C. yunnanensis were protandrous. The stamens were within petal-like staminodes in the opening flowers until the flower withered. Without touchment, the bractlike staminodes can’t open. Self-pollination was partially avoided by temporal and spatial isolation of male and female organs within the same flower. However, autogamous and geitonogamous pollination is unavoidable because of the large number of flowers on a single tree and the action of pollinators. The values of both OCI (≥4) and P/O (1381) and the results of bagging tests indicated there was no apomixes in C. yunnanensis and the breeding system of the species was outcrossing with partial self-compatibility and the pollinators were required during the pollination process. The most frequent effective floral visitor was only beautiful fly (Chrysomyia megacephala). Fruit set and seed set in natural condition were 56.67±3.85％ and 6.26±0.75％, respectively. Therefore, lack of pollinators, low pollination efficiency, unavoidable geitonogamous pollination and partial self-compatibility and inbreeding in small populations may account for the low fruit set, especially seed set.Variations in seed traits, seed germination, and seedling growth characters among six Craigia yunnanensis populations were evaluated. All seed and seedling traits exhibited significant differences among populations (P < 0.05). The fitness of seed as assessed by seed size, seed germination and seedling trait was independent of population size, except for the number of seeds per capsule (r = 0.93，P < 0.01). Correlations between geo-climatic variables of seed origin and seed and seedling related characters were insignificant (P > 0.05). For some populations, germination capacity in 12-h photoperiod was significantly higher than that in completed darkness（W-FD: P < 0.01, W-JD: P < 0.05）.Genetic variation within and among six populations was assessed using AFLP markers. Genetic diversity was higher at species level (PPL = 69.19%, HE = 0.221) than at population level (PPL = 26.22%, HE = 0.095, Is =0.140), and populations in southeast Yunnan were strongly differentiated from those in southwest Yunnan (Nei’s GST = 0.575; FST = 0.655). UPGMA analysis demonstrated a clear genetic division between the two populations from DeHong (SW Yunnan; D-JD and D-HG) and the four from WenShan (SE Yunnan; W-FD, W-LH, W-ML, and W-MG). Within-population genetic variation was significantly correlated with population isolation (r(PPL) = -0.94, P = 0.006; r(HE) = -0.85, P = 0.032; r(Is) = -0.87, P = 0.025), but not with population size (r(PPL) = 0.63, P = 0.178; r(HE) = 0.54, P = 0.268; r(Is) = 0.56, P = 0.249).","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.date.issued.year&advanced=false&query1=Rice%2Bplants&&fq=dc.project.title_filter%3ACraigia%5C+yunnanensis%5C+W.%5C+W.%5C+Smith%5C+%5C%26%5C+W.%5C+E.%5C+Evans%5C+%5C%28Tiliaceae%5C%29%5C+is%5C+an%5C+endangered%5C+deciduous%5C+tree%5C+species%5C+which%5C+has%5C+high%5C+scientific%5C+and%5C+economic%5C+value.%5C+C.%5C+yunnanensis%5C+is%5C+seriously%5C+threatened%5C+and%5C+has%5C+been%5C+pushed%5C+to%5C+the%5C+verge%5C+of%5C+extinction%5C+due%5C+to%5C+vegetation%5C+destruction%5C+in%5C+China%5C+and%5C+consequent%5C+contraction%5C+of%5C+its%5C+distribution.%5C+Hence%2C%5C+it%5C+was%5C+listed%5C+as%5C+a%5C+nationally%5C+rare%5C+and%5C+endangered%5C+plant%5C+in%5C+1999%5C+and%5C+has%5C+also%5C+been%5C+proposed%5C+as%5C+a%5C+second%5C-ranked%5C+plant%5C+for%5C+national%5C+protection%5C+in%5C+China%5C+and%5C+included%5C+in%5C+IUCN%5C+red%5C+list.%5C+As%5C+a%5C+scientifically%5C+important%5C+and%5C+valued%5C+tree%5C+species%5C+with%5C+endangered%5C+status%2C%5C+the%5C+wild%5C+populations%5C+of%5C+C.%5C+yunnanensis%5C+therefore%5C+represent%5C+is%5C+a%5C+genetic%5C+resource%5C+that%5C+must%5C+be%5C+conserved.%5C+To%5C+provide%5C+basic%5C+information%5C+for%5C+its%5C+conservation%2C%5C+the%5C+population%5C+dynamics%5C+and%5C+population%5C+size%5C+structures%2C%5C+pollination%5C+biology%5C+and%5C+breeding%5C+system%2C%5C+eleven%5C+fitness%5C-related%5C+characters%5C+and%5C+the%5C+genetic%5C+variability%5C+based%5C+on%5C+AFLP%5C+were%5C+comprehensively%5C+studied.%5C+The%5C+main%5C+results%5C+are%5C+summarized%5C+as%5C+follows%5C%3A%5C+A%5C+total%5C+of%5C+six%5C+wild%5C+populations%5C+of%5C+C.%5C+yunnanensis%5C+were%5C+found%5C+in%5C+two%5C+disjunct%5C+regions%5C+of%5C+Yunnan%2C%5C+i.e.%5C+WenShan%5C+%5C%28SE%5C+Yunnan%5C%29%5C+and%5C+DeHong%5C+%5C%28SW%5C+Yunnan%5C%29%2C%5C+from%5C+2005%5C+to%5C+2007.%5C+Additionally%2C%5C+in%5C+all%5C+but%5C+one%5C+of%5C+the%5C+populations%5C+we%5C+detected%2C%5C+mature%5C+trees%5C+were%5C+felled%5C+between%5C+2005%5C+and%5C+2007%2C%5C+so%5C+destruction%5C+of%5C+most%5C+of%5C+these%5C+populations%5C+is%5C+ongoing.%5C+Across%5C+the%5C+six%5C+populations%5C+of%5C+extant%5C+C.%5C+yunnanensis%5C+found%5C+during%5C+our%5C+study%2C%5C+the%5C+total%5C+number%5C+of%5C+mature%5C+%5C%28reproductive%5C%29%5C+individuals%5C+detected%5C+was%5C+584%5C+in%5C+2007%EF%BC%8Cplus%5C+larger%5C+numbers%5C+of%5C+seedling%5C+and%5C+resprouts%5C+from%5C+cut%5C+trunks.%5C+The%5C+result%5C+of%5C+surveying%5C+Population%5C+structure%5C+showed%5C+that%5C+there%5C+are%5C+two%5C+regeneration%5C+types%5C+which%5C+are%5C+seedlings%5C+and%5C+sprouts.%5C+Seedlings%5C+occurred%5C+abundantly%5C+in%5C+gaps%5C+or%5C+open%5C+areas%5C+and%5C+the%5C+size%5C+class%5C+frequency%5C+distributions%5C+were%5C+often%5C+discontinuous%2C%5C+and%5C+the%5C+same%5C+general%5C+pattern%5C+occurred%5C+in%5C+all%5C+the%5C+investigated%5C+populations%5C+for%5C+juveniles%5C+and%5C+adults.%5C+The%5C+numbers%5C+of%5C+seed%5C-origin%5C+individuals%5C+did%5C+however%5C+decline%5C+sharply%5C+with%5C+increasing%5C+size%2C%5C+indicating%5C+a%5C+high%5C+mortality%5C+rate%5C+going%5C+from%5C+seedling%5C+to%5C+sapling%5C+stage%5C+may%5C+be%5C+a%5C+problem%5C+for%5C+this%5C+species.%5C+Additionally%2C%5C+the%5C+cash%5C+crop%5C+cultivation%5C+and%5C+logging%5C+seriously%5C+threaten%5C+the%5C+survival%5C+of%5C+the%5C+species.%5C+We%5C+conducted%5C+field%5C+observations%5C+and%5C+artificial%5C+pollination%5C+experiments%5C+on%5C+the%5C+floral%5C+biology%2C%5C+pollination%5C+process%5C+and%5C+breeding%5C+system%5C+of%5C+Craigia%5C+yunnanensis%5C+in%5C+Fadou%2C%5C+Xichou%5C+county%5C+of%5C+Yunnan%5C+province.%5C+The%5C+lifespan%5C+of%5C+a%5C+single%5C+hermaphrodite%5C+flower%5C+is%5C+approximately%5C+3%5C-4%5C+days.%5C+A%5C+cyme%5C+has%5C+2%5C-9%5C+flowered.%5C+The%5C+flowering%5C+period%5C+of%5C+an%5C+inflorescence%5C+is%5C+usually%5C+5%5C-14%5C+days.%5C+The%5C+flowers%5C+of%5C+C.%5C+yunnanensis%5C+were%5C+protandrous.%5C+The%5C+stamens%5C+were%5C+within%5C+petal%5C-like%5C+staminodes%5C+in%5C+the%5C+opening%5C+flowers%5C+until%5C+the%5C+flower%5C+withered.%5C+Without%5C+touchment%2C%5C+the%5C+bractlike%5C+staminodes%5C+can%E2%80%99t%5C+open.%5C+Self%5C-pollination%5C+was%5C+partially%5C+avoided%5C+by%5C+temporal%5C+and%5C+spatial%5C+isolation%5C+of%5C+male%5C+and%5C+female%5C+organs%5C+within%5C+the%5C+same%5C+flower.%5C+However%2C%5C+autogamous%5C+and%5C+geitonogamous%5C+pollination%5C+is%5C+unavoidable%5C+because%5C+of%5C+the%5C+large%5C+number%5C+of%5C+flowers%5C+on%5C+a%5C+single%5C+tree%5C+and%5C+the%5C+action%5C+of%5C+pollinators.%5C+The%5C+values%5C+of%5C+both%5C+OCI%5C+%5C%28%E2%89%A54%5C%29%5C+and%5C+P%5C%2FO%5C+%5C%281381%5C%29%5C+and%5C+the%5C+results%5C+of%5C+bagging%5C+tests%5C+indicated%5C+there%5C+was%5C+no%5C+apomixes%5C+in%5C+C.%5C+yunnanensis%5C+and%5C+the%5C+breeding%5C+system%5C+of%5C+the%5C+species%5C+was%5C+outcrossing%5C+with%5C+partial%5C+self%5C-compatibility%5C+and%5C+the%5C+pollinators%5C+were%5C+required%5C+during%5C+the%5C+pollination%5C+process.%5C+The%5C+most%5C+frequent%5C+effective%5C+floral%5C+visitor%5C+was%5C+only%5C+beautiful%5C+fly%5C+%5C%28Chrysomyia%5C+megacephala%5C%29.%5C+Fruit%5C+set%5C+and%5C+seed%5C+set%5C+in%5C+natural%5C+condition%5C+were%5C+56.67%C2%B13.85%EF%BC%85%5C+and%5C+6.26%C2%B10.75%EF%BC%85%2C%5C+respectively.%5C+Therefore%2C%5C+lack%5C+of%5C+pollinators%2C%5C+low%5C+pollination%5C+efficiency%2C%5C+unavoidable%5C+geitonogamous%5C+pollination%5C+and%5C+partial%5C+self%5C-compatibility%5C+and%5C+inbreeding%5C+in%5C+small%5C+populations%5C+may%5C+account%5C+for%5C+the%5C+low%5C+fruit%5C+set%2C%5C+especially%5C+seed%5C+set.Variations%5C+in%5C+seed%5C+traits%2C%5C+seed%5C+germination%2C%5C+and%5C+seedling%5C+growth%5C+characters%5C+among%5C+six%5C+Craigia%5C+yunnanensis%5C+populations%5C+were%5C+evaluated.%5C+All%5C+seed%5C+and%5C+seedling%5C+traits%5C+exhibited%5C+significant%5C+differences%5C+among%5C+populations%5C+%5C%28P%5C+%3C%5C+0.05%5C%29.%5C+The%5C+fitness%5C+of%5C+seed%5C+as%5C+assessed%5C+by%5C+seed%5C+size%2C%5C+seed%5C+germination%5C+and%5C+seedling%5C+trait%5C+was%5C+independent%5C+of%5C+population%5C+size%2C%5C+except%5C+for%5C+the%5C+number%5C+of%5C+seeds%5C+per%5C+capsule%5C+%5C%28r%5C+%3D%5C+0.93%EF%BC%8CP%5C+%3C%5C+0.01%5C%29.%5C+Correlations%5C+between%5C+geo%5C-climatic%5C+variables%5C+of%5C+seed%5C+origin%5C+and%5C+seed%5C+and%5C+seedling%5C+related%5C+characters%5C+were%5C+insignificant%5C+%5C%28P%5C+%3E%5C+0.05%5C%29.%5C+For%5C+some%5C+populations%2C%5C+germination%5C+capacity%5C+in%5C+12%5C-h%5C+photoperiod%5C+was%5C+significantly%5C+higher%5C+than%5C+that%5C+in%5C+completed%5C+darkness%EF%BC%88W%5C-FD%5C%3A%5C+P%5C+%3C%5C+0.01%2C%5C+W%5C-JD%5C%3A%5C+P%5C+%3C%5C+0.05%EF%BC%89.Genetic%5C+variation%5C+within%5C+and%5C+among%5C+six%5C+populations%5C+was%5C+assessed%5C+using%5C+AFLP%5C+markers.%5C+Genetic%5C+diversity%5C+was%5C+higher%5C+at%5C+species%5C+level%5C+%5C%28PPL%5C+%3D%5C+69.19%25%2C%5C+HE%5C+%3D%5C+0.221%5C%29%5C+than%5C+at%5C+population%5C+level%5C+%5C%28PPL%5C+%3D%5C+26.22%25%2C%5C+HE%5C+%3D%5C+0.095%2C%5C+Is%5C+%3D0.140%5C%29%2C%5C+and%5C+populations%5C+in%5C+southeast%5C+Yunnan%5C+were%5C+strongly%5C+differentiated%5C+from%5C+those%5C+in%5C+southwest%5C+Yunnan%5C+%5C%28Nei%E2%80%99s%5C+GST%5C+%3D%5C+0.575%5C%3B%5C+FST%5C+%3D%5C+0.655%5C%29.%5C+UPGMA%5C+analysis%5C+demonstrated%5C+a%5C+clear%5C+genetic%5C+division%5C+between%5C+the%5C+two%5C+populations%5C+from%5C+DeHong%5C+%5C%28SW%5C+Yunnan%5C%3B%5C+D%5C-JD%5C+and%5C+D%5C-HG%5C%29%5C+and%5C+the%5C+four%5C+from%5C+WenShan%5C+%5C%28SE%5C+Yunnan%5C%3B%5C+W%5C-FD%2C%5C+W%5C-LH%2C%5C+W%5C-ML%2C%5C+and%5C+W%5C-MG%5C%29.%5C+Within%5C-population%5C+genetic%5C+variation%5C+was%5C+significantly%5C+correlated%5C+with%5C+population%5C+isolation%5C+%5C%28r%5C%28PPL%5C%29%5C+%3D%5C+%5C-0.94%2C%5C+P%5C+%3D%5C+0.006%5C%3B%5C+r%5C%28HE%5C%29%5C+%3D%5C+%5C-0.85%2C%5C+P%5C+%3D%5C+0.032%5C%3B%5C+r%5C%28Is%5C%29%5C+%3D%5C+%5C-0.87%2C%5C+P%5C+%3D%5C+0.025%5C%29%2C%5C+but%5C+not%5C+with%5C+population%5C+size%5C+%5C%28r%5C%28PPL%5C%29%5C+%3D%5C+0.63%2C%5C+P%5C+%3D%5C+0.178%5C%3B%5C+r%5C%28HE%5C%29%5C+%3D%5C+0.54%2C%5C+P%5C+%3D%5C+0.268%5C%3B%5C+r%5C%28Is%5C%29%5C+%3D%5C+0.56%2C%5C+P%5C+%3D%5C+0.249%5C%29."},{"jsname":"lastIndexed","jscount":"2024-05-05"}],"资助项目","dc.project.title_filter")'>
|
|
|
|
|
