Population Structure and Sexual Fertility of Colletotrichum gloeosporioides sensu lato from Citrus in Northern Iran

Anthracnose caused by Colletotrichum gloeosporioides s. l. is one of the most important diseases of citrus in northern Iran. To study the genetic structure of C. gloeosporioides s. l. from citrus spp., infected samples were collected from three citrus cultivating regions of northern Iran, during the summer of 2009. Fifty one monoconidial isolates were used as the objective of REP- and BOX-PCR fingerprintings. Eight fingerprinting groups were observed in the constructed phenogram. The largest proportion (94.37%) of total genetic diversity (Ht) was attributed to diversity within populations (Hs). Estimates of Nei’s genetic similarity and distances exhibited the high level of similarity among three populations. The value of gene flow, NM= 8.4, indicates that there is low limitation to gene flow among these geographically distant populations, which make these groups genetically homogenous. The results indicate that the three geographic populations are not developing independently and can be part of a Mega-population. Forty three isolates were divided into 19 groups in the phenogram constructed by combination of morphological characteristics data. Estimation of correlation between morphologic and rep-PCR matrixes indicated a weak and non-significant correlation between morphology and repPCR haplotypes (r= 0.2, P= 0.992). Fifty one isolates were examined to clarify their sexual behavior. Eight isolates were identified as homothallic and 14 successful outcrosses were observed among self-sterile isolates.