PLANT REPRODUCTIVE-BIOLOGY - TRENDS

During the course of the past several years considerable progress has been made in understanding the reproductive biology of angiosperms in a number of separate areas. This chapter reviews the advances in compatibility and male–female interactions in pollen. Genetic selection could operate on pollen tubes during growth within the transmitting tissue (sporophytic tissue). Competitive selection of pollen is considered to be a crucial evolutionary factor that leads to the domination of the angiosperms among the other plant groups. The complex and resistant wall of the pollen grain is of considerable importance because of its unique external sculpturing and biochemistry. The characteristics of the pollen wall are often species-specific and are used in various systematic treatments of specific groups, serving as a character in some taxonomic keys. A common problem of pollen assessment is judging the fertility of the pollen. Three classical methods are widely used to estimate pollen quality: seed set, pollen tube culture, and cytochemical staining tests. The chapter also discusses the pistil receptivity and embryo sac isolation. Within the ovule the embryo sac represents female gametophytic generation and is generally composed of seven cells and eight nuclei (Polygonum type). © 1992, Academic Press Inc.