Male reproduction stability assessed through meiotic and post-meiotic cycles in bushy matgrass (Lippia alba) genotypes for use in breeding

The aim of the present study is to analyze the meiotic and post-meiotic cycles of bushy matgrass genotypes (citral chemotype) in order to better understand their respective male reproduction stability. It is essential estimating such a stability when a non-domesticated species is selected. Therefore, the number of chromosomes of pollen-mother cells, and their ploidy were assessed; possible meiosis anomalies were assessed. Recombination index (RI) was estimated. The number of normal and abnormal post-meiotic products (PM’s) was counted. Meiotic index (MI) and pollen grain viability (VIA) were estimated. These estimates were carried out per genotype and they were subjected to ANOVA and to average tests. All genotypes were diploid (2n = 30 chromosomes). Pairing was quite regular (RI = 44.33%). Meiotic cycle anomalies recorded very low frequency rates. Assumingly, chromosomal breaks resulted from micronuclei formation in PM’s. Estimated MI was 94.48%, and estimated VIA was 94.32%. MI and Via did not statistically differ between genotypes. These outcomes point towards genotypes’ high male reproduction stability and to the significant influence of genetic effects on MI and VIA.