Study of meiotic behavior and fertility of pollen seed in Cumin (Cuminum cyminum) under drought stress and titanium dioxide nanoparticles

Cumin (Cuminum cyminum) from Apiaceae family is one of the important plants in traditional medicine because of its pharmaceutical properties. For the first time, we studied the meiotic behavior and seed pollen fertility under late-season drought stress condition (reproductive stage) and TiO2 nanoparticle treatment. To examine the different meiosis phases and determine meiotic aberration, premature flowers were collected from plants grown under drought stress and different levels of nanoparticles. Different aberration types, including stickiness, clumping, disorganized chromosome, anaphase bridge, delayed chromosome, leader chromosome, laggard chromosome, micronucleus, tripolar, syncyte and the nondisjunction of chromosomes were examined at all levels and different frequencies identified. Pollen fertility was evaluated with regard to its size. Pollen grains with natural size were considered as normal and potentially fertile. The highest reduction rate in fertility (13.33%) was observed in 0.03% nanoparticles with drought stress. The lowest fertility rate (0.69%) was observed in 0.015% nanoparticle with drought stress condition.