VARIATION IN RESIN DUCTS AND YIELD IN CHIR PINE POPULATION

Pinus roxburghii (F-Pinaceae) is one of the most common chir-pine found in the mid-Himalayan region. The crown of this species displays two different needle colour morphotypes (Dark- Green, Light- Green). It is a well known timber and resin yielding tree. Wood exudes oleoresin which yields rosin and turpentine oil having important role in commercial industry. So, the present study was focused on the identification of superior phenotypes possessing higher quality resin yield from two morphotypes of P. roxburghii of Himachal Pradesh. Trees were selected from different areas of Himachal Pradesh with varying latitude and altitude and were tapped for one month. Needle from the same trees were collected, washed and used for section cutting to determine resin ducts. The needle colour, altitude and latitude had significant influence on these parameter. Results showed that the Dharamshala latitudinal cline -32^o to 33^o N (L₃) has recorded maximum resin yield (544.439g) whereas Kullu – Mandi latitudinal cline -31^o to 32^o N (L₂) observed minimum resin yield (312.795g) and the highly significant resin ducts (4.622) was found in Dharamshala latitudinal cline -32^o to 33^o N (L₃) whereas minimum resin ducts (2.317) was observed in Solan latitudinal cline -30 ^o to 31^o N (L₁).