Phylogeography Of Tamarindus Indica L.

Tamarindus indica L.is a member of Tamarindus L.in Caesalpiniaceae family,it is a single species genus plant and a high and evergreen tropical fruit tree.The fruit is characteristic of tropical fruits,rich in nutrition,and can extract tamarind gum from seeds.Because its characteristics of nice looking tree form,evergreen,leanness-resistant,tolerance of dry and fast-growing,T.indica L.was often used as landscaping species and greening trees in the tropics,especially in the area of dry-hot valley,it can give attention to social benefit,economic benefit and ecological benefit.It is generally believed that the origin of T.indica L.is tropical Africa,and now it is widespread on world's tropical and south subtropical regions.Because of scattered distribution and destruction of habitats,though T.indica L.is widely dispersed,the germplasm resources is decreased rapidly,and some excellent germplasm resources even become extinct.The germplasm resources of T.indica L.is rich and it's distribution is extensive,but it's distributing situation has not been know enough especially genetic diversity and genetic differentiation,which affected not only effective protection,but the efficient use of pomelo resource.Based on comprehensive sampling,the patterns variation and the main chemical compositions of morphology variation,the level of genetic diversity and genetic structure were systematically studied,in order to find out the distributed condition and regularity of T.indica L.,reveal the differentiation and distribution of the single species genus plant,and provide a basis for effective protection and use of resources.The main results are as follows:Only a separation of individual fruit phenotypic of T.indica L.has significant variation,but the group of each fruit phenotypic diversity of were higher.The protein content(12.75%)and the iron content(17.35mg/100g)of JH populations,the total sugar content(46.78%)of YS populations,the total acid content(20.25%)and the manganese content(0.90 mg/100g)of YY populations have significant differences from the other 7 populations,and there was no significantly different between the 7 populations.the home group flesh protein content changes from 1.42% to 12.75%,the range is 11.33%.Analysis of atpF-atpH fragment and ITS2 fragment suggested that,T.indica L.has a high genetic diversity present,genetic variation distributed mainly in the same populations,and the genetic differentiation among populations is not significantly;All haplotypes was divided into two groups by clustering analyse: Asia and Africa.22 hapolotypes(atpF-atpH)and 13 hapolotypes(ITS2)were detected on the two fragments,respectively.Genetic diversity at the level of species was shown as follows: atpF-atpH: HT = 0.882,HS = 0.787,? = 0.373 × 10-2;ITS2: HT = 0.563,HS = 0.660,? = 0.551 × 10-2.The coefficient of gene differentiation at the level of populations was shown as folows: atpF-atpH: GST = 0.107,NST = 0.397;ITS2: GST = 0.148,NST = 0.216.The results of variance analysis indicated that the genetic variation resided within populations(atpF-atpH: 59.70%,ITS2: 78.40%).The 12 populations of the T.indica L.were divided into two pedigrees which were Asia and Africa by using network analysis,and there was a significantly positive correlation between genetic and distance geographical distance(atpF-atpH: r = 0.779,P = 0.03;ITS2: r = 0.546,P = 0.03;P < 0.05).The analysis of SSR showed that a relatively high genetic diversity existed in T.indica L.,a low level of genetic differentiation among populations,but a higher genetic variation within populations.Cluster analysis indicated two distinct lineages of T.indica L.which was corresponded with the atpF-atpH results.Genetic diversity was HO = 0.316,HE = 0.356,HS = 0.386,HT = 0.457 at the level of species,and gene differentiation(GST)was 0.156 among populations.AMOVA analysis suggested 24% of variations come from among populations,76% of variations come from within populations.NJ analysis also indicated T.indica L.could be divided into two major groups,the first one group was from Africa populations,the second group was from Asia populations.Meanwhile geographic distance was significantly positive associated with genetic distance(r = 0.606,P = 0.04,P < 0.05).Based on the above research results,T.indica L.from Africa maybe introduced to Asia,thus gradually forming Asia populations.T.indica L.were introduced to different countries and areas with high economic value,which greatly enhanced the exchange of genes of populations(Nm = 1.138),could impair the influence of geographic isolation from Himalayas and Hengduan Mountains.A low genetic differentiation existed among populations but a higher level within populations may be the result of human activities.The exchange of gene could be restricted by geographic isolation between Africa and Asia,which introduced two distinct lineages of T.indica L..There was a high genetic diversity at the level of species,but a low genetic diversity and fruit characters variation among populations.That had provided plentiful material for selection and reoriented the directions ofresource protection.To protect abundant gerplasm resource,deforestation of T.indica L.should be prohibited,which is hugely significant for economic development.The results above show that T.indica L.the area with higher genetic variation(such as YX)should be as natural reserve area of T.indica L.resources.On the other hand,the old T.indica L.should be on the list of protected ancient and famous trees to avoid further destruction of human activities.