Comparative Study Of The Morphological Phenotype, Pollen Morphology And ISSR Molecular Markers Between The White And Pink Weigela Florida

Weigela florida is the precious genetic resources which is mainly distributed in the Wuling mountain in Hebei province with pink and white colors. In this study, the wild Weigela florida in the Wuling mountain was taken as the experiments materials. The comparative research had been conducted from the morphological phenotype including branches, leaves, flowers, the pollen morphology and DNA molecular markers between the two groups of wild Weigela florida species. The results showed as follows:1. The 1/4 leaf width, the 3/4 leaf width, the distance from the leaf width to stem base, sharp leaf angle, basic leaf angle and corolla long between different color flowers were significantly different.2. The white flowers pollen grains were three protuberant irregular circle and three germinal apertures distributed in three symmetrical parts. Pink flower pollen grains were rules circle and it had one pollen germination hole cover with irregular shape. The pollen grain size differences were also significant. The diameter of the white pollen grains was 80.9±2.9μm and pink is 77.7±1.2μm. Besides there were many cone protrusions in the pollen grain surface which were distributed more intensively in the pink flower compared with white population.3. At the same time, the impacting factors of ISSR-PCR reaction system were optimized to establish the best reaction system for Weigela florida. That was in 20.μL reaction system, DNA template with 20.00 ng/μL, 0.20mmol/L dNTP, 10×Pfu PCR Buffer(Mg2+)3.00μl, 1.00μmol/L primer and 1.25U Taq enzyme.The optimal PCR amplification process was:5 minutes at 94℃for predenaturation, then followed by 45 cycles, each with 30 seconds at 94℃for denaturation, 45 seconds at 52℃for annealing, 90 seconds at 72℃for extension, finally extension at 72℃for 5 minutes and holding the samples at 4℃.4. DNA sequences between different color groups were amplified by 12 primers which were candidate ISSR marker, and 2 to 7 bands could be amplified by each primer,an average of 4.5 per primer, product size were 200 bp to 2000 bp.The number of polymorphic loci was 12, polymorphic loci percentage for 100.00% . Using POPGENE 32 software, fragments of H allele frequency in white and pink between populations were quite different, white group was less. White flowers in different genetic loci group on A value had great variability.Shannon’s information indexes of pink group were higher than white group, which was higher of the genetic diversity in pink group. Unbiased genetic similarity (I) of two color groups was 0.6709, which means that two color groups had higher genetic variation. Unbiased genetic distance between two groups was 0.3991. According to the result mentioned above, there was a distance between two populations. Two kinds of color populations existed the gene flow,1.5767 Nm between groups.