Studies on relationship between Stomatal density and oleoresin yield in Chirpine (Pinus roxburghii Sargent)

The production of oleoresin has suffered from past and has come down from 75 thousand tones in 1975 to 25-30 thousand tones in 1995 (Coppan and Hone, 1995). In many parts of the world, considerable work has been done on pine species other than chirpine. So there is a need of hour to increase the oleoresin production potential from chirpine trees to narrow down the gap between the requirement and supply. This can be achieved either through horizontal spread of chirpine or vertical improvement of the species through selection of high resin yielding progenies for advanced generation development. As there is very less scope of horizontal improvement due to population pressure, so the only method is the genetic improvement which can be conventionally achieved through selection of high resin yielders among the progenies of plus trees. The present Studies on relationship between Stomatal density and oleoresin yield in Chirpine is a step forward in this direction. Dibkon-P3 and Leda-P5 progenies recorded with maximum number of stomatal rows on round surface. Whereas, maximum number of stomata per mm of a row was obtained in Bagthan-PT-Black Top. Correlation studies between oleoresin yield and number of stomata per mm of a row of progenies projected significant and positive correlation. Genetic advance (320.28) and Genetic gain (35.51%) were found to be highest for oleoresin yield. Number of stomata per mm of a row and Average number of stomatal rows on needle surface had significant effect on the resin yield; hence oleoresin yield can be predicted on the basis of these characters.