Assessment of Seed Viability and Vigour in Neem (Azadirachta indica A. Juss.)

Abstract

Rapid loss in viability of neem (Azadirachta indica A. Juss.) seed is a major problem. Present effort was undertaken for developing a set pattern for assessing of viability and vigour in seed of various mother tree age of neem (Age I-06 years, Age II-15 years, Age III-25 years and Age IV-＞30 years old). Various viability test viz. triphenyle tetrazolium chloride test, electrical conductivity, excised embryo test, and germination test have been performed on seeds obtained from mother tree age classes. Inconsistency was observed with the TTC and EC test in germination of seed in laboratory as well as nursery. While various vigour tests viz. cold test, chemical stress test (methanol stress test), and accelerated ageing test alongwith ageing index, germination test (G%, MGT and GV) and various seedling growth parameters like seedling length (cm), number of leaves, collar diameter (cm), total biomass (g) alongwith mathematical indices i.e. vigour index, sturdiness quotient, volume index, quality index, root shoot ratio in nursery as well have been taken for study and showed better consistency. On the basis present study results of various viability and vigour test indicated that mother tree age class II performed better in comparison to others and it can be recommended for seed collection. Further it is also recommended that viability of neem seed may be assessed using various laboratory tests like excise embryo test and germination test (G%, MGT and GV) and vigour test may be taken preferably by cold germination test, chemical (methanol) stress test, accelerated ageing test in laboratory and germination alongwith various seedling growth parameters seedling length (cm), number of leaves, collar diameter (cm), total biomass (g) alongwith mathematical indices like Vigour Index, Sturdiness quotient, Volume Index, Quality index, root shoot ratio in nursery as discussed in this study.