Hydroponics mediated seedling dehydration stress revealed variable tolerance in pearl millet (Pennisetum glaucum L.) minicore collection

In drier zones pearl millet faces moderate to severe drought stress at seedling stage leading to mortality and poor plant stand. An effective and rapid drought screening protocol as well as tolerant genotypes are required to address the issue. Hydroponics provide an uniform stress environment which we utilized in the study to create dehydration stress in pearl millet seedlings through root dehydration. Stress duration for 7 days @ 6 h/day differentiated the tolerant and susceptible genotypes. Pearl millet minicore collection of 207 genotypes were divided in to four groups based on seedlings traits measured under stress. Phenotypic response of seedlings to dehydration stress measured through drought score showed moderate correlation with quantum yield and fresh shoot weight. In all, 32 genotypes showed tolerant reaction to seedling drought stress. Both tolerant and susceptible genotypes identified under hydroponics performed at par under soil-pot conditions. Genotypes IP 3642, IP 20995, IP 10665, IP 1556, IP 2322, IP 8562, IP 18579, IP 8472, IP 5711, IP 277, IP 11268 showed better seedling growth parameters under rapid dehydration through hydroponics as well in progressive soil drying under pot conditions.