Pollen storage, viability and effect of growth hormones on in vitro pollen germination in two medicinal plants (Clerodendrum colebrookianum Walp. and Clerodendrum infortunatum L.) of the tropical moist forest of North-east India

Clerodendrum colebrookianum Walp. and infortunatum L. are well known for their medicinal uses in treating various human ailments traditionally. Pollen biology study was done both plant species to decipher pollen viability, vitro germination, storage varied temperature conditions. viability tests by 2, 3, 5-triphenyl tetrazolium chloride (TTC test) which grains were collected at the anthesis stage that ascertained high ranged between 71.97%±4.30 % C. 81.63%±3.23 infortunatum. In germination conducted under different hormones (IBA, IAA, GA3, Kinetin) with concentrations of 100 mg L-1, 200 L-1 300 L-1. Highest percentage 52.10±5.30% 61.91±1.76% GA3 (200 L-1) most suitable growth hormone concentration inducing species. Statistically, response all treatments, sucrose, hormones, time on found significantly (p<0.05). contrast, non-significant differences recorded gradient conditions exhibited a similar trend colebrookianum, infortunatum, i.e., remained viable up 28 days -20°C 6°C, respectively. This will be helpful future breeding, hybridization, conservation efforts