For. Stud. China, 2011, 13(4): 270–273 DOI 10.1007/s11632-013-0404-6 RESEARCH ARTICLE * Author for correspondence. E-mail: altamashwani@rediffmail.com Characterization and identification of leaf morphology of Populus deltoides Bartr. clones Ajaz LONE 1 , Altamah BASHIR 2* , Salil K. TEWARI 3 , Mumtaz MAJEED 2 1 Faculty of Plant Breeding and Genetics, Sher-e-e-Kashmir University of Agricultural Sciences & Technology of Kashmir, Srinagar 191121, India 2 Faculty of Forestry, Sher-e-e-Kashmir University of Agricultural Sciences & Technology of Kashmir, Srinagar 191121, India 3 Department of Silviculture, G.B. Pant University of Agriculture and Technology, Pantnagar 263145, India © Beijing Forestry University and Springer-Verlag Berlin Heidelberg 2011 Abstract Leaves are of fundamental importance to plants, representing their facility to generate power and are the sensing units of plants towards the environment. An attempt was made to characterize and compare the variations of leaf morphology of various Populus deltoides Bartr. clones by studying the winter buds and other leaf parameters of fully developed leaves. To achieve these ob- jectives, forty-three exotic and indigenous clones of P. deltoides Bartr. were evaluated for different parameters. On the basis of vari- ous morphological characteristics the results reveal that each clone has a distinct color pattern of leaves. Different colors observed in these clones varied from light green through green to dark green. Two distinct lengths of the leaf apex were found, i.e., short and long; as well both acuminate and acute apex types were found. Erratic distribution of serration of leaves was also found. In this study, the morphological traits of leaves provided discriminatory grounds for separating various populations of P. deltoides Bartr. clones. Winter bud studies indicate that different clones vary considerably with regard to shape, color, shape of leaf scars and exudation. Key words Populus deltoides Bartr., leaves, morphology, winter buds 1 Introduction Leaves are of fundamental importance to plants, rep- resenting their facility to generate power and are the sensing units of plants towards the environment and, by extension, ultimately provide the energy for sus- taining most terrestrial species on earth (Max et al., 2008). The relevance of the use of leaf traits as de- terminants of biomass production as well as for taxo- nomic applications is therefore strongly dependent on the growth conditions of the plant material under con- sideration. For instance, it has been shown that incre- ments in leaf area and the number of leaves are robust indicators of productivity under various environmental conditions, while the links between productivity and specific leaf area vary according to growth irradiance and temperature as well as with the age of the plants (Marron et al., 2003; Monclus et al., 2005; Marron and Ceulemans, 2006). Thus, the finding of stable de- terminants remains an open question and only a few studies have, for this purpose, examined the relevance of leaf anatomy and stomatal characteristics. It is recognized that biomass productivity in pop- lars is closely related to total leaf area (Larson and Isebrands 1972; Zavitkovski et al., 1974; Isebrands and Nelson, 1982). Physiological components known to determine leaf area include rate of individual leaf growth, rate of leaf production and duration of growth. A more detailed knowledge of the relationship be- tween the components of leaf growth and tree produc- tivity would assist efforts to increase productivity of poplar plantations (Heilman and Stettler, 1985; Weber et al., 1985). A number of studies have demonstrated that leaf variation is of adaptive significance for growth and competitive survival in a wide range of plants (Ra- schke, 1960; Parkhurst and Loucks, 1972; Givnish, 1979; Hinckley et al., 1989; Gurevitch, 1992). Cal- laham (1964) worked on provenances with the aim to define the genetic and environmental components of phenotypic variability between trees from different geographic origins. Several studies suggest that the