| Iris halophila is a kind of perennial herbaceous plant of Iris L. It has a lot of characteristics such as fighting a drought, a cold, and insect pests, strongly adaptability and so on. So it is going to take an important part in virescence. At present, Iris halophila is still in a state of undeveloped. With the influences of environment changing and human activity, their genetic diversities have risk of comedown. In this article, the genetic diversity and genetic relationship of Iris halophila populations in Xinjiang were studied by ISSR and RAPD markers.1. Uniform design was applied to establish optimized PCR reactions for ISSR and RAPD in a 25μL reaction mixture. The ISSR system was consisted of 2.5μL PCRBuffer, 2.0mmol/L Mg2+, 250μmol/L dNTP, 0.1μmol/L primer, 0.5U TaqDNA polymerase and 40ng template DNA. The suitable ISSR-PCR procedure was 1 cycle of denaturing for 3 min at 94℃, 40 cycles of denaturing for 45 s at 94℃, annealing for 30 s at 50-56℃, extending for 1.5 min at 72℃and the last cycle of extending for 5 min at 72℃. The RAPD system was consisted of 2.5μL PCRBuffer (with Mg2+), 200μmol/L dNTP, 0.4μmol/L primer, 0.75U TaqDNA polymerase and 16ng template DNA. The suitable RAPD-PCR procedure was 1 cycle of denaturing for 3 min at 94℃, 40 cycles of denaturing for 1 min at 94℃, annealing for 1 min at 35-38℃, extending for 2 min at 72℃and the last cycle of extending for 10 min at 72℃. All the producetions of PCR were holded in 4℃.2. 10 ISSR primers and 8 RAPD primers were used in the study. The percentage of polymorphic were 100℅ and 99% for each other, the Shannon index were 0.5224 and 0.4995, the Nei's index were 0.3479 and 0.3331, the genetic diversity based on Nei's method, among Iris halophila populations were 0.2141 and 0.1871, the coefficient of gene differentiation were 0.5333 and 0.5282 and the gene flow were 0.4376 and 0.4466.3. Based on the results of ISSR and RAPD markers, UPGMA trees were built. The nine populations were divided into three groups. The genetic distance had relativity with geographical distance. The correlation between the two sets of similarity parameters calculated with ISSR and RAPD data respectively ( r = 0.968, P=0.001 ), indicating that the two methods were consistant and able for detecting genetic diversity of Iris halophila populations in Xinjiang. |
