The Research On Population Characters And Evaluated The Genetic Diversity Of Chinese Wild Pyrus Ussuriensis Maxim.

Application of Crops and cultivars is attributable to Domestication Cultivation of Wild Species in Modern Agriculture For giving too much emphasis toeconomical character, much precious genetic resources was washed out. Application of Crops and cultivars is attributable to Domestication Cultivation of Wild Species in Modern Agriculture For giving too much emphasis toeconomical character, much precious genetic resources was washed out. In addition, while human developing rapidlyothe economy the nature give to wildlife resources progressively to decrease. wildlife resources of Pyrus ussuriensis Maxim is noted for freezing resistance, Flavor, higher sugar and acid contents, characteristic and rich flavor. Population Characters of Chinese wild Pyrus ussuriensis Maxim was studied in the main distribution area. On these bases, the research evaluated the genetic diversity of Chinese wild P. ussuriensis by using specifical cpDNA as a marker. The results were obtained as follows.1. Distribution of Wild P. ussuriensis mainly in altitudes from 1000to 1200 m above the sea level in Inner Mongolia, is High Altitude Area. But, Distribution of Wild P. ussuriensis mainly in altitudes from 300 to 600m above the sea level in Heillingjiang and Jilin,is low Altitude Area.Hight of Wild P. ussuriensis population in Inner Mongolia, Heilongjiang and Jilin is mainly 3-4m, they are 40%,48%,36% in population quantity separately.The chest measurement of Wild P. ussuriensis population in Inner Mongolia is mainly 40-70cm,they are 50% in the group. The chest measurement of Wild P. ussuriensis population in Heilongjiang is mainly 20-50cm, they are 55% in the group. The chest measurement of Wild P. ussuriensis population in Jilin is mainly 20-30cm, they are 60% in the group. Wild P. ussuriensis distribute fleetfully and centrally in Inner Mongol of 4 area,. But Wild P. ussuriensis distribute ispersolly in Jilin and Heilongjiang. Wild P. ussuriensis is bigger effect of natural disasters in Inner Mongol and human disturbance in Jilin and Heilongjiangwe speculate that the age of Wild P. ussuriensis is main 20-50 years old aspen in in Inner Mongol,40-50 years old aspen in Heilongjiang and 20-30 years old aspen in Jilin.2. Using Katayama two hypervariable regions(Type A accD-psaI genes and rps16-trnQ genes) in cpDNA of Pyrus established the model of A,B,C. the model distinguishes Wild Pyrus(the two hypervariable regions don't delete), oriental pear cultivars(Type B delete 228bp in length betweet accD-psaI genes), and Pyrus communis.L(Type C deletes 141bp in length betweet rpsl6-trnQgenes). According to above model, Chines wild P. ussuriensis genetic diversity was evaluated. As a result, Type A percentage of wild P. ussuriensis in Inner Mongol, Heilongjiang and Jilin are 100%,96%,94% separately. These illustrate that genetic background of Chinese P. ussuriensis is relatively pure including that wild P. ussuriensis in Inner Mongo is the most pure,but happened in the natural hybrid of 4% P. ussuriensis in Heilongjiang and Pyrus communis.L,7% P. ussuriensis in Jilin and oriental pear cultivars.3. The study used DNA sequencing and sequences alignment from 107 accessions in 8 wild Pyrus ussuriensis Maxim population, and 49 pear cultivars. Theresult was found 31 mutations in the two hypervariable regions.These included 16 Gaps(Insertion/deletion) and 15 base changes but excluded 8 chlorophlastDNA simple sequences repeats (cpSSR). Chinese wild P. ussuriensis were found 2 specia Gaps and 7 special base changes. Pear cultivars were found 5 specia Gaps.We also found in the intergenic region between accD—psaI that BC4(434#A/C) was the special position of Wild P. ussuriensis in Jilin and Heilongjiang., G7(656#+26) was the special position of Chinesw wild P. ussuriensis, BC2(379#T/C)andBC3(424#G/T) were the special positions of Pcommunis.L. Refer to Gaps and base changes in two intergenic regions between accD—psal and between rps16—trnQ, Haplotype analysis was studied. As follows, Thirty haplotypes(H1-H30) were identified in Chinese wild P. ussuriensis and controlled Pear cultivars. Ten haplotypes(H1-H10) were identified in Chinese wild P. ussuriensis H1 consisted of mostly of wild P. ussuriensis in Inner Mongol, was 96%. H3 consisted of mostly of P. ussuriensis in Heilongjiang and Jilin, was 88% and 66% separately. H2,H11-H30 consisted of Chinese pear cultivars in four spieces, H11was 50%-60%. Pcommunis.L.was abundant in mution. The genetic diversity of Chinese wild P. ussuriensis was lower. The genetic diversity of wild P. ussuriensis was lower in Heilongjiang and Neimenggu than in Jilin. Wild Pyrus ussuriensis Maxim in Jilin mighty be in hybridization area.4.Phylogenetic relationships between the 30 haplotypes in two intergenic regions between accD—psaI and between rps16—trnQ, were generated by haplotype network analysis. As a result, three groups (A-C) were identified in 107 accessions in 8 wild P. ussuriensis population, and 49 Cultivar Pear. Phylogenetic relationships represented that wild P. ussuriensis in Helongjiang was the most primitive relatively, Cultivar Pear was the most evolutionary, wild P. ussuriensis in Jilin and Inner Mongolia were the farthest between the former and the latter. This is the first systematic study about Population Characters of Chinese wild P. ussuriensis in the main distribution area and the analysis of genetic diversity.This research will provide a theoretical basis for the protection and utilization of Chinese wild Pyrus ussuriensis Maxim.