SELF- AND CROSS-POLLINATIONS IN CICHORIUM 

 INTYBUS WITH REFERENCE TO STERILITY 



A. B. Stout 



New York Botanical Garden 

 (with plate 30) 



Table of contents 



Introduction 334 



Discussion of literature bearing on physiological incompatibility 339 



Methods of study in chicory 361 



Results of the experimental studies 364 



Phenomena of self-compatibility and self-incompatibility 364 



Self-sterility and self-fertility among plants of the Fi generation 368 



Self-sterility and self-fertility in F2 progenies derived from seed of self- 

 fertile Fi plants 371 



Self-fertility and self-sterility among plants of the F3 generation, etc 374 



Summary of the Fi, F2, and F3 generations 378 



Self-sterility and self-fertility in the variety "improved red-leaved 



Treviso " 382 



Self-sterility in hybrids between a wild white-flowered plant and a plant 



of the "improved striped-leaf" variety 383 



Phenomena of physiological inter-incompatibility and compatibility 384 



Results of crosses involving A and various ot its progeny 384 



Results of crosses between (^4 X C) plants and the parents 387 



Results of crossing {A X-Ej) plants and the parents 389 



Results of cross-pollination involving {A 'XE22) hybrids 391 



Results of cross-pollination involving the variety "improved red-leaved 



Treviso " 393 



General summary of all cross-pollinations 395 



General or potential fertility in chicory 396 



Observations on efficiency of open pollinations 397 



Other investigations 401 



Discussion 402 



(General) 402 



Special phases of the phenomena of sterility and fertility 408 



The relation of cross-incompatibility to self-incompatibility 408 



The sporadic and fluctuating nature of sterility resulting from physi- 

 ological incompatibility 409 



The relation of incompatibilities giving sterility to cell organization 412 



Relation of vegetative vigor and fertility to inbreeding and cross-breeding 416 

 Relation of sterility from physiological incompatibility to vegetative 



vigor and production of sex organs 422 



333 



