Optimizing pollen viability and in vitro pollen germination potential in foxtail millet genotypes

Foxtail millet is a C4 model crop with very small florets. To improve the yield of any crop, pollen germination and development are important to know, which is still not well-known in foxtail millet. The present investigation was conducted in the Department of Seed Science and Technology, Hemvati Nandan Bahuguna Garhwal University (HNBGU), Srinagar, Garhwal, Uttarakhand, during the Kharif seasons of 2023 and 2024 to study flowering phenology and achieve synchronous flowering for the development of a hybrid seed production programme. The study involved 14 genotypes, including 12 landraces and 2 varieties as checks. The timing of pollination in foxtail millet germplasm was observed to be approximately 1-2 hrs. Further to understand the pollen viability, in vitro pollen germination and development of pollen tube under the influence of different media and time durations at a temperature of 25 °C with 85 % relative humidity. Significant variation in pollen viability and pollen germination was recorded across the different media tested. The maximum pollen viability, lasting up to 5 hr, was observed in the genotype FMC-1, indicating its potential for crop improvement. A combination of sucrose, boric acid and potassium nitrate (KNO3) was found to be the best media compared to others, such as 2,3,5-triphenyl tetrazolium chloride (TTC), acetocarmine, boric acid + sucrose, as pollen grains began germinating within 30 min in most genotypes. This study provides valuable insights for designing a crossbreeding programme in foxtail millet.