INSTYTUT DENDROLOGII

Abstract: Cupressus Linn., commonly known as ‘cypress', belongs to the family Cupressaceae. It consists of 20 species with a wide and discontinuous distribution in the Northern Hemisphere. In the present study, three species, namely C. torulosa Don., C. arizonica Greene and C. glabra Sudw., growing in the western Himalayan region of India at an altitude of 1760 m. have been studied. This is a preliminary attempt where embryology is used in estimating seed quality and in seed testing. Seed quality was analysed according to five (0-IV) seed classes based on the presence of the embryo and endosperm and their nature of development in the seed-cutting test. Seeds having neither  embryo nor endosperm belong to class ‘0'. In class ‘I' seeds contain the endosperm but a shrivelled embryo or sometimes no embryo. Class ‘II' contains seeds with an embryo of half-length of the embryo cavity and class ‘III' seeds containing an embryo of at least three-quarter length of the embryo cavity. Seeds with completely developed full embryo were assigned to class ‘IV'. However a high percentage of seeds of classes 0-III present in seed lots from particular trees of a species decrease the quality of seeds. Similarly a high percentage of seeds of class ‘IV' improves the seed quality of a given tree selected as plus tree for germplasm collection.

Additional Keywords: embryo, endosperm, sterility, germplasm