Analysis and identification of SCAR molecular markers associated with birch fiber length trait

The fiber length trait （FLT） of 538 individuals from nature birch population in Maorshan region, Heilongjang, China were measured, of which 100 individuals were selected as representative variety of correlated fragments screening with random amplified polymorphism DNA （RAPD） technique. In total of 20 RAPD primers were tested through multiple regression analysis between amplified strip and the character behaviors, and a correlative segment BFLR-16 was obtained. The correlation coefficient between BFLI-16 and FLT was 0.6144, with the significant level of 1%. BFLI-16 was then cloned, sequenced and transformed into SCAR marker. The percentage of identifying long fiber birches by this SCAR was more than 92. The result indicates that the SCAR markers has high specificity for the long fiber individuals and is highly linked with the gene controlling the character of fiber length, and its existence is significantly correlative with the increase in the fiber length.

Quantitative Estimates of Outcrossing Rates in a Natural Population of Caldesia grandis (Alismataceae)

Outcrossing rate in a natural population of Caldesia grandis was estimated by the dominant random amplified polymorphism DNA （RAPD） marker using 10 open-pollinated progeny arrays of 24 individuals. The multilocus outcrossing rate estimated based on all 25 RAPD loci was 0.872 ±0.033 and the single-locus outcrossing rate was 0.795 ±0.032. Multilocus esti- mates did not differ significantly from the single-locus estimates. The fixation index, F, in the progeny estimated from RAPD data was -0.142 ±0.000. The estimates of multilocus outcrossing rates （tm） and single-locus outcrossing rates （ts） obtained from MLDT clearly indicate that outcrossing is predominant in the open-pollinated C. grandis population. An empirical analysis suggests that 15 should be the minimum number of dominant marker loci necessary to achieve robust estimates of tm.

Combination of ARDRA and RAPD genotyping techniques in identification of Acinetobacter spp. genomic species

A total of 10 non-repetitive multi-drug-resistant Acinetobacter strains were collected.With reference to A.calcoaceticus(ATCC23055),A.baumannii(ATCC19606),A.lwoffii(ATCC17986),and A.junii(NCTC5866),DNA fingerprint technique,amplified ribosomal DNA restriction analysis(ARDRA),and random amplified polymorphism DNA(RAPD)were carried out to identify the genomic species of Acinetobacter spp.The distances between them were calculated by the unweighted pair group method with arithmetic(UPGMA).Genotypes of Acinetobacter spp.were effectively classified and an A.junii together with nine A.baumannii isolates was genomically identified.The combination of ARDRA and RAPD DNA-fingerprint technique shows high complementarity,and could be a useful tool in Acinetobacter genomic species identification.