Cytomorphological and biochemical implications of UV-B priming in fennel (Foeniculum vulgare Mill.)

Aim: The aim of this study was to create variability on the morphogenetic make-up, and biochemical attributes of fennel plant which incurred as a result of different exposure of UV-B radiation. Methodology: Seedlings of Foeniculum vulgare Mill. were treated with four different exposure times viz. Set A for Control, Set B for 20 min, Set C for 40 min, Set D for 60 min and Set E for 80 min, respectively. UV-B exposure seedlings with respect to control were transplanted to their respective pots and fields. Three replicates were prepared for each treatment. During the course of growth and development, few morphological, biochemical, and cytological parameters were estimated. Results: The results clearly elucidate that the higher exposure to UV-B radiation substantially affected the growth parameters whereas UV-B radiation (40 min) induced certain beneficial traits viz., increased plant height, intermodal length, etc. Various types of chromosomal aberrations such as stickiness, scattering, precocious, laggard, etc., were also observed. Scattering was the main chromosomal abnormality encountered at longer durations (60-80 min) to UV-B exposure. It was also observed that withincrease in the duration of UV-B exposure (20-80 min), there was a decrease in chlorophyll a (0.98 to 0.82) and chlorophyll b (0.68), and increase in carotenoids (at lower duration of UV-B radiation) was also observed. A maximum increment in carotenoid content was recorded in 40 min treated sets. Interpretation: The present research would be helpful in selecting doses which impart characters of interest in Foeniculum vulgare Mill. The cytological alterations caused by UV-B radiation changes the genetic makeup of fennel, which can be inherited to the subsequent generation to create agronomical superior mutants which will be promising materials for plant breeders in near future.