Geographical variation in seed and seedling traits of neem (Azadirachta indica A. Juss.) among ten populations studied in growth chamber
1997
Kundu, S.K. | Tigerstedt, P.M.A.
Nineteen biometric characters of seed and seedling of 10 populations of Azadirachta indica from Myanmar, Bangladesh, India, Pakistan and the Sudan were studied under growth chamber conditions. The results obtained by the use of principal component analysis (PCA) and cluster analysis of data revealed three distinct groups of populations. Provenances from the high rainfall areas were separated from lower rainfall areas in PCA. Correlation analyses between biometric traits and geoclimatic factors indicated the existence of ecoclinal variation in seed weight, shoot: root ratio, leaf number, and leaflet ratio. Leaflets of the northern provenances were narrower than those of the southern provenances, with a tendency for a separation between the northern (Pakistan, Myanmar and Bangladesh) and southern occurrences (Sudan and India). Provenances having lower shoot:root ratio and lesser number of leaves were separated with their corresponding mean annual rainfall. The resultssuggest that A. indica employs an adaptive strategy in response to water deficit at the initial phase of seedling growth and establishment.
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