From Chromosomes to Seeds: Meiotic Behavior and Its Effect on the Reproductive Outcomes in Phytolacca acinosa Roxb., a Multipurpose Medicinal Herb From the Himalaya.

Understanding meiotic behavior and pollen biology is crucial for effective conservation of plant species. This study presents the first detailed analysis of meiotic behavior and its correlation with pollen fertility and seed set in Phytolacca acinosa Roxb., a multipurpose medicinal herb native to the Himalaya. The flower buds were collected from two selected sites in the Kashmir Himalaya, India. In this study, we used the squash technique, in which anthers were squashed in 2% acetocarmine, and the slides were observed under a microscope to assess chromosome number and meiotic behavior. The species exhibited a chromosome count of 2n = 8x = 72. Most pollen mother cells (PMCs) (74%-79%) underwent normal meiosis; however, 21%-26% PMCs exhibited abnormalities, including chromosome stickiness, chromosomal bridges, laggards, un-oriented bivalents, and micronuclei. Chromosome stickiness was the most prominent meiotic abnormality, followed by laggard and bridge formation. These meiotic irregularities significantly reduced pollen fertility (75.45%-77.57%), fruit set (73.22%-75.67%), and seed set (71.1%-72.14%) across both selected sites. The findings highlight meiotic irregularities as a potential reproductive constraint, emphasizing the need for conservation measures to ensure the sustainable utilization of this medicinally important plant species. Future studies should investigate the genetic and environmental factors underlying these meiotic disturbances.