Chromosome Count, Male Meiotic Behavior and Pollen Analysis of Eight Populations of Trachyspermum ammi (L.) Sprague (Apiaceae) from Iran

Trachyspermum ammi (L.) Sprague (Ajwan) is one of the most important industrial and medicinal plants which belongs to the family Apiaceae. A meiotic study of eight populations from Iran was performed. All populations were diploid n=9 (2n=2x= 18) forming mainly bivalents with some amount of quadrivalent and hexavalent possibly due to the occurrence of heterozygote translocations. The ANOVA test of meiotic characters showed a significant difference (p<0.05) in chiasma frequency as well as chromosome associations in Ajwan populations. Chromosome migration or cytomixis and syncyte formation and tripolar structure in telophase II were also reported for the first time in natural populations in Iran and led to diploid gamete formation or 2n pollen grains in almost all populations were studied. Cluster analysis of meiotic data showed the distinctness of the populations in their meiotic behavior.

Automated summary

This study conducted a meiotic analysis of Ajwan populations in Iran and found significant differences in the characteristics of bivalent formation and chromosome associations. Additionally, chromosome migration and tripolar structure were observed in the populations, resulting in the formation of diploid gametes or 2n pollen grains in most populations.