COMPARATIVE STUDIES ON ISOLATED EMBRYO SACS IN FOUR SPECIES OF CAMPANULACEAE

The present paper deals with the observations on embryo sacs (ES) isolated by enzymatic maceration in four Campannlaceous species, Platycodon grandiflorum, Adenopora axilliflora, A. tetraphylla, Codonopsis lanceolata. Fixed ovules were macerated in a mixture of pecti nase and cellulase. The mature were cleared with lactophenol for mopholgical observation.The mature ESs of all these species had basically similar strueture: an egg cell, tow synergids and a central cell with a secondary nueleus, the antipodal cells degenerated early. Histoehemical reactions such as PAS reaction, Ⅰ₂-KⅠ treatment, Sudan Ⅲ solation and mercuric bromophenol blue staining were carried out. PAS reaction revealed that all the ESs contained plenty of polysaecharide grandules. These species differed from each othe in some aspects, C. lanceolata had broad ES with sparse ytoplasm and large polysaccharide granules. The ES of P. grandiflorum also contained a lot of oil drops.Based on the above mentioned results, it is concluded that the enzymatic technique is a useful means in comparative studies on ESs but to rapid preparation of specimen and stereographic of ESs.