Asparagus ploidy distribution related to climates adaptation in Iran

Asparagus basic chromosome number is 2n = 2x = 20. The high rate of polyploidy in wild asparagus has been found in natural surroundings of Iran. It is not entirely clear how asparagus polyploidy occurs in relation to ecological areas. To investigate, climatic parameters were used to determine the effect of climate on the geographical distribution of diploid and polyploid asparagus. Wild asparagus (96 individual) were collected from natural regions of Iran, belong to the asparagus subgenus that includes A. officinalis, A. persicus, A. verticillatus and A. breslerianus. The variation patterns in ploidy levels across different zones were recognized by principal components analysis (PCA) and canonical correlation analysis (CCA). Associated with humidity (47%), average minimum (4.9–5.3 °C) and maximum (17.26–16.5 °C) temperatures were lower, while soil salinity (2.2–3.2 dsm−1) was higher in 8X and 10X asparagus growth conditions than those of 2X and 4X populations. The PCA demonstrated that 2X of A. officinalis, A. persicus and A. verticillatus species habit a similar climatic niche, which varies from that of 8X and 10X. According to CCA and stepwise regression, 4X populations were highly correlated with total precipitation, while 8X and 10X take place at higher altitude than 2X and 4X. Asparagus capability to inhabit in a wide range of climate situations by development polyploidy confirmed by the extracted results. As well as, the results revealed that 8X and 10X asparagus could be adapted to dry and salinity land.