Isolation barriers and self-compatibility in selected fine fescues1
- R.M. Schmit,
- R.W. Duell and
- C.R. Funk
Fine fescue improvement requires a thorough understanding of isolating factors preventing or restricting crossbreeding, the subject of this investigation. Crossing of distinct fine fescue types appears limited by anthesis date, hour of pollen shed, and/or differences in chromosome number. Strongly rhizomatous Festuca rubra subsp. rubra plants have a chromosome number of 56, thereby isolating them from 42 chromosome, creeping types. However, both shed pollen in late afternoon. Chewings fescues (F. rubra subsp. commutata) and hard fescues (F. longifolia Thuill.) both have 42 chromosomes, but shed pollen in early morning. Typically, anthesis is several days later in the Chewings-types than in hard fescues. Preliminary studies of pollen germination in vitro indicate that pollen viability drops off rapidly after dehiscence. Pollen shed in late afternoon by rhizomatous fescues lost viability by late evening. This effectively isolated Chewings-type fescues from rhizomatous types.
Wide variability in seed set under terylene bags occurred in selected clones of both Chewings and spreading fescues. Practical applications of self-compatibility in hybridization are discussed. Additional index words: Anthesis, Pollination, Polyploids, Rhizomes, Self ing, Speciation.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 1974. . Copyright 1974 by the American Society of Agronomy, Inc. and the Crop Science Society of America, Inc., 5585 Guilford Rd., Madison, WI 53711 USA