1National Research Centre on DNA Fingerprinting, National Bureau of Plant Genetic Resources, New Delhi-110 012.
2Division of Agricultural Chemicals, Indian Agricultural Research Institute, New Delhi-110 012.
3CCS Haryana Agricultural University, Hisar-125 004 (Haryana).
4Indian Agricultural Statistics Research Institute, New Delhi-110 012.
Fifty-eight accessions of neem collected from two agro-ecological regions of North-western plains of India covering the states of Punjab, Haryana and Rajasthan were characterized at morphological, chemical and molecular level to ascertain the variability. For statistical treatment, the regions were sub-divided into sub-zones (categories) with the sub-zone 5 further sub-divided into two. Seed characters for morphological, oil, azadirachtin, salannin and nimbin for chemical and six AFLP primer combinations for molecular evaluation were considered. Variability was observed for all the morphological and chemical characters amongst the samples. Among the categories, significant chemical variability existed for azadirachtin-A but the morphological variability was non-significant. At molecular level the genetic similarity (Jaccard's coefficient) varied from 0.07 to 0.759. UPGMA cluster analysis grouped the accessions into five, four and three clusters, respectively based on genetic, morphological and chemical analyses. The dendrograms based on these three parameters revealed no uniformity in their grouping pattern. A high correlation between the cophenetic and dissimilarity matrices has been observed, the correlation being the highest for genetic (r = 0.969) followed by morphological (r = 0.835) and chemical (r = 0.727) matrices. Mantel's test revealed a low correlation among the three parameters.
Azadirachta indica, Chemical Components, Genetic Markers, Morphological Characters, Neem
