Chapter XV 



EMBRYOGENESIS IN FLOWERING PLANTS: 

 ANALYTICAL AND EXPERIMENTAL INVESTIGATIONS 



E 



XPERIMENTAL studics of angiospemi embryology have been mainly 



- concerned with the compatibilities of the male and female gametes, 



the inhibition and, not infrequently, destruction of the embryo due to 

 genetical factors, induced parthenogenesis, and factors affecting the 

 embryonic development as ascertained by the methods of aseptic embryo 

 cuhure. Maheshwari (1951) states that experimental embryology 'is 

 concerned with an imitation and a modification of the course of 

 Nature, with a view to understanding the physics and chemistry of the 

 various processes underlying the development and differentiation of 

 the embryo, so as to bring them under human control to the furthest 

 extent possible.' This definition comes close to the heart of the matter, 

 provided the complexity of organismal phenomena is constantly borne 

 in mind. The experimental embryologist may rightly be concerned 

 with the events leading to the fertilisation of the ovum as well as with 

 its subsequent development. Some of these have been considered by 

 Maheshwari (1950). As our primary interest here lies in the actual 

 embryonic development, our study begins with the activated ovum, or 

 other embryo-yielding cells in or near the embryo sac. 



Experimental investigations do not stand alone: they usually have 

 their inception in morphological and anatomical observations, or in 

 the data of growth and metabolic studies. Observational, analytical, 

 and experimental studies should, indeed, go together if an adequate 

 account of the phenomena of development is to be given. In the 

 two preceding Chapters a selection of the descriptive morphological 

 observations has been given: in the present Chapter the data of 

 analytical and experimental investigations are considered. 



HORMONES AND SEED DEVELOPMENT 



Marre and Murneek (1953) have shown that one effect of fertilisation 

 in maize is that hormones are produced and that these have a regulating 

 action on the movement of carbohydrates and nitrogen-containing 

 metabolites into the ovule; also, if growth-regulating substances are 

 applied externally, they stimulate the accumulation of sugars and the 

 formation of starch in the young tissues of the flowers and fruits. Ears 

 of an inbred line of sweet corn were treated with water-lanoline 



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