The Population Genetic Diversity And Programmed Cell Death Induced By Vegetative Incompatibility In Cryphonectria Parasitica

We studied the population genetic diversity of Cryphonectria parasitica, which was from China, Japan, Italy and the USA, with the inter simple sequence repeat (ISSR); besides, the partial morphologic investigation had been done, what was about of programmed cell death (PCD) induced by vegetative incompatibility comong isolates.Genetic diversity and genetic differentiation of Cryphonectria parasitica, which were from China, Japan, Italy and the USA, were analyzed using inter simple sequence repeat (ISSR). By using 11 primers filtrated from total 53 primers, ISSR amplification was conducted in 220 individuals from eleven Cryphonectria parasitica subpopulations which were from four countries, and 174 polymorphic loci were detected from total 177 loci. The percentage of polymorphic loci (P) of the total populations was 98.31%, while that at a subpopulation level averaged 20.43 %. Shannon's Information index (I) and Nei's gene diversity (h) of the fungus at the total populations level was 0.1769 and 0.7386, respectively. The mean of I and h at a subpopulation level was 0.0943 and 0.0614, respectively. It indicated that the genetic diversity of C. parasitica between the populations was relatively high. The genetic differentiation coefficient (Gst) among populations was 0.7386. The gene flow (Nm) among populations was low down to 0.1769. The mean of pair-wise genetic distance between eleven C. parasitica subpopulations was 0.2289. These eleven subpopulations could be clustered into three groups using unweighted pair group method with arithmetic mean (UPGMA).The DAPI was used to dye the isolates which were cultivated within partnership, and with the help of the fluorescence microscope the cell nucleolus, cytoplasm and hyphal shape were observed, which had occurred a series of diversification progress after the vegetative compatible / vegetative incompatible hyphae fusion. The result of experimentation is that: (1) During a series of diversification progress of hyphae fusion between the vegetative compatible isolates, the nucleolus took place the inosculate and then got right, moreover there was any other distinct variety in the hyphae. (2) During a series of diversification progress of hyphae fusion between the vegetative incompatible isolates, there was out of obvious variety in the early nucleolus, and that the phenomenons of vacuolization, cytoplasmic shrinkage were all appeared in these hyphae; there had integrant nucleus which had been appeared clearing up, came forth nebulous cell remnant nucleus in medium-term nucleolus, and the hypha appeared vacuolization, cytoplasmic shrinkage, also had the portion of collapsed cell contents; the nucleolus had been completely cleared up ,or remain part nebulous cell remnant nucleus in the termination, and the hypha may occur fearful abnormality, part or overall clearing up.We exert scan electron microscope to observe the hyphae fusion progress which were cultivated by partnership. The result of experimentation is that: when the vegetative compatibility hyphal fusion, there was nothing changed in the joint of mycelium, and which were still growth in gear, when the vegetative incompatibility hyphal fusion, the joint of mycelium might take place rimple or death and so on.