Table Of Content18
Monographs on
Theoretical and Applied Genetics
Edited by
R. Frankel (Coordinating Editor), Bet-Dagan
M. Grossman, Urbana· H. F. Linskens, Nijmegen
P. Maliga, Piscataway· R. Riley, London
Monographs on Theoretical and Applied Genetics
Volume 1 Meiotic Configurations
A Source of Information for Estimating Genetic Parameters
By 1. Sybenga (1975)
Volume 2 Pollination Mechanisms, Reproduction and Plant Breeding
By R. Frankel and E. Galun (1977)
Volume 3 Incompatibility in Angiosperms
By D. de Nettancourt (1977)
Volume 4 Gene Interactions in Development
By L.1. Korochkin (1981)
Volume 5 The Molecular Theory of Radiation Biology
By K.H. Chadwick and H.P. Leenhouts (1981)
Volume 6 Heterosis
Reappraisal of Theory and Practice
Editor: R. Frankel (1983)
Volume 7 Induced Mutations in Plant Breeding
By W. Gottschalk and G. Wolff (1983)
Volume 8 Protoplast Fusion
Genetic Engineering in Higher Plants
By Y.Y. Gleba and K.M. Sytnik (1984)
Volume 9 Petunia
Editor: K.C. Sink (1984)
Volume 10 Male Sterility in Higher Plants
By M.L.H. Kaul (1988)
Volume 11 Tree Breeding: Principles and Strategies
By G. Namkoong, H.C. Kang, and 1.S. Brouard (1988)
Volume 12 The Wheat Rusts - Breeding for Resistance
By D.R. Knott (1989)
Volume 13 Population Dynamics and the Tribolism Model
Genetics and Demography
By R.F. Costantino and R.A. Desharnais (1991)
Volume 14 Genetic Improvement of Tomato
Editor: G. Kalloo (1991)
Volume 15 Evolution and Function of Heterostyly
Editor: S.C.H. Barrett (1992)
Volume 16 Distant Hybridization of Crop Plants
Editors: G. Kalloo and 1.B. Chowdhury (1992)
Volume 17 Cytogenetics in Plant Breeding
By J. Sybenga (1992)
Volume 18 Cytogenetics of the Festuca-Lolium Complex
By P.P. lauhar (1993)
p. P. lauhar
Cytogenetics
of the Festuca-Lolium
Complex
Relevance to Breeding
With 53 Figures
Springer-Verlag
Berlin Heidelberg New York
London Paris Tokyo
Hong Kong Barcelona
Budapest
Prof. Dr. Prem P. lauhar
USDA-ARS, Red River Valley Agricultural Research Center
Northern Crop Science Laboratory
State University Station
Fargo, North Dakota 58105-5677
U.S.A.
Library of Congress Cataloging-in-Publication Data.
lauhar, Prem P. Cytogenetics of the Festuca-Lolium complex: relevance to breeding/P.P. lauhar.
p. cm.-(Monographs on theoretical and applied genetics: 18) Includes bibliographical
references and index.
ISBN-13: 978-3-642-84088-3 e-ISBN-t3: 978-3-642-84086-9
DO I: to. t 007/ 978-3-642-84086-9
1. Fescue-Breeding. 2. Lolium-Breeding. 3. Fescue-Cytogenetics. 4. Lolium-Cytogenetics.
I. Title. II. Series. SB201.F48J38 1992 633.2'37-dc20 92-15946
This work is subject to copyright. All rights are reserved, whether the whole or part of the material
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© Springer-Verlag Berlin Heidelberg 1993
Softcover reprint of the hardcover lst edition 1993
The use of general descriptive names, registered names, trademarks, etc. in this publication does
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Typesetting: Best-set Typesetter Ltd, Hong Kong
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To the memory of my father, whose life
was a constant struggle for social justice
and rights for all.
Preface
Considering the widespread occurrence and
ecological diversity of grasses, their dominance
over vast regions of our globe, and their
prime importance to humankind, we, the
experts, may congratulate ourselves on having
become authorities on the most important
single family of organisms in the world of life,
rivaled only by the human family itself.
G. Ledyard Stebbins 1987
From times immemorial man has relied heavily on grasses, directly and
indirectly, for most of his basic needs. Grasses have had a profound impact
on the development of human societies and influenced civilization - perhaps
in more ways than any other crop. A paramount factor in the evolution of
civilizations is a steady supply of food. Grasses were indeed essential to the
"evolution" of wild and domestic grazing animals, which, in turn, also
catalyzed the "evolution" of humankind. Thus, grasses and human civiliza
tion were inseparably associated, the association marked by intimate
coevolution of grasses, herbivores, and man.
Even today, on a world-wide basis, acreage under grasslands is es
timated to be twice that of cropland. However, grasslands are still one of
the largest underdeveloped resources in the world. Knowledge acquired
from an array of scientific disciplines should help tap their enormous
potential for increasing agricultural productivity. It should also help preserve
the vast global germplasm resources, the rich reservoirs of desirable genes.
Festuca and Lalium are valuable genera of temperate grasslands. The two
genera are closely related. They contain some very productive, nutritious,
and well-adapted grasses widely used for agricultural and recreational
purposes. They are an important source of feed for the livestock industry
that provides us with wholesome meat, milk, wool, etc. They also play
an important role in conserving and stabilizing soils. These grasses are
widely distributed in temperate and cool climates in Europe, North
Africa, South America, Asia, South and East Africa, Australia, and New
Zealand; and they have been spread by man to several other parts of the
world.
Because of their importance in temperate agriculture, the Festuca
Lalium group of grasses have been extensively studied by agronomists,
animal scientists, plant breeders, taxonomists, and cytogeneticists. However,
no integrated information has been published on them. The results of
various studies remain scattered in numerous journals and periodicals in
different languages, some of which are not easily accessible to a common
researcher. I have attempted, therefore, to compile and synthesize import
ant information on certain aspects of these grasses into this volume. The
ultimate objective would be to use information from different fields of
enquiry to improve the quantity and quality of forage and to stop or reduce
VIII Preface
genetic erosion. This book is, however, not intended to be an encyclopedic
review of different topics.
This book deals mainly with the cytogenetics of agronomically important
grasses of the Festuca-Lolium complex and discusses their basic importance
and breeding relevance. The perennial nature of these grasses makes them
particularly amenable to cytogenetic and breeding manipulation. Modern
biotechnological developments also hold considerable promise for their
improvement. While the current available knowledge on the Festuca-Lolium
group will be synthesized and discussed, what we do not know about them
will also be highlighted.
The book consists of 15 chapters, which deal with various facets of
cytogenetics of the Festuca-Lolium group in relation to breeding. An
appropriate introduction to each chapter and to several sections in different
chapters puts the information in proper perspective to help the reader.
Each chapter can be read independently, an arrangement that has inevitably
led to some duplication between chapters. However, repetition has been
kept to a minimum by giving cross-references. Some speculations have been
made to stir ideas and interest among researchers. After all, science can
and does build on speculates.
Chapter 1 describes the general importance of the Festuca-Lolium
group of grasses, their complementary attributes, and the promise they hold
for agricultural and recreational purposes. Chapter 2 deals with various
taxonomic treatments given to this fascinating group. Certain taxonomic
controversies are highlighted and the multidisciplinary approach to revealing
phylogeny emphasized. Karyotypic features in relation to species evolution
and divergence are discussed in Chapter 3. How species divergence in
diploids is accompanied by massive changes in the amount of nuclear
DNA is described. Discussion of genetic control of diploid-like meiosis in
polyploid species of Festuca forms the main body of Chapter 4, the cyto
genetic basis of reproductive isolation among ecotypes of hexaploid tall
fescue is described in Chapter 5, and the phylogenetic and breeding impli
cations of these phenomena are discussed in Chapter 6, where possibilities
of manipulating the diploidizing mechanism to effect intergeneric gene
transfers are outlined. Chapter 7 deals with B chromosomes and their
controversial role in stabilizing meiosis. Polyploidy and its value in plant
improvement are described in Chapter 8, while Chapter 9 outlines the
natural occurrence and artificial induction of haploidy in species of Lolium
and Festuca, particularly F. arundinacea. Pairing in haploids shows the
haplo-insufficiency of the genetic control of pairing; production of homo
zygous inbred lines is also briefly described. In Chapter 10, aneuploids are
described and their use in elucidating cytogenetic architecture of hexaploid
tall fescue is briefly stated. While Chapters 11 and 12 deal with intra- and
inter-specific, and intergeneric hybridizations, genome relationships, and
the development of superior cultivars, Chapter 13 discusses genomic
balance in relation to hybrid fertility and its bearing on plant improvement.
Preface IX
Chapter 14 highlights some of the biotechnological tools and their potential
use in the genetic enrichment of different grasses. Chapter 15 concludes the
book, discussing the past accomplishments and future outlook.
The book is intended for workers engaged in the genetic improvement
of the Festuca-Lolium group of grasses. Knowledge gained from these
grasses may be relevant or applicable to other cross-pollinated herbage
crops. I hope that this volume will provide useful information to geneticists
and cytogeneticists, taxonomists and biosystematists, and agronomists and
plant breeders. Students of cytogenetics and evolution should find this book
particularly useful. A spectrum of other workers interested in general
biology and agriculture will also find this volume a worthwhile reference.
I am grateful to Professor H.F. Linskens for inviting me to write this
book. Several scientists have read different chapters and given helpful
suggestions. I am thankful to Dr. Elizabeth Kellogg (Harvard University),
Dr. Richard Pohl (Iowa State University), Professor H. James Price (Texas
A&M University), Dr. Craig W. Greene (College of the Atlantic, Bar
Harbor, Maine), Dr. Mary Barkworth (Utah State University, Logan, Utah),
Dr. Leila Shultz (Intermountain Herbarium, Logan, Utah), Professor
Steven Aust (Biotechnology Center, Utah State University, Logan, Utah),
Professor I.K. Vasil (University of Florida, Gainesville) and Professor B.V.
Conger (University of Tennessee, Knoxville) for commenting on different
chapters. Although several scientists have gone through various chapters,
I take full responsibility for any errors, omissions, or misinterpretations.
I am grateful to several scientists who provided photographs for this
book: To Dr. Z. Bulinska-Radomska for Fig. 2.6; to Dr. V. Carnide
for Figs. 3.2 and 3.3; to Dr. Georgia C. Eizenga and Ms. Etta M. Thacker
for Figs. 9.1 and 9.2; to Dr. Robert C. Buckner for Figs. 1l.8b,c; to Mr.
Hu Martin Thomas for Fig. 12.6; and to Ms. Sue Dalton for Figs. 14.3
to 14.6.
My own family members have contributed significantly to this chal
lenging assignment in several ways. I am particularly grateful to my wife,
Raj, who patiently waited for long hours in the night when I was trying to
complete this book assignment. She is a constant source of encouragement.
But for her understanding, I could not have accomplished whatever little I
have done in science. Our daughter, Suneeta, did not see much of me when
she was growing up and I thank her for her sacrifice. Once she commented;
"I wish the day had thirty hours so that my dad could spend a few hours
at home." Our sons, Rajiv and Sandeep, were a constant source of
inspiration and encouragement. Last, but not least, my mother - an
uneducated scientist - never failed to provide moral encouragement from
her room in a nursing home.
Prem P. lauhar
Contents
Chapter 1 The Festuca-Lolium Complex: a Fascinating Group of Grasses
1.1 Agronomic Importance ............................... . 2
1.1.1 Association Between Fungal Infection
and Agronomic Traits ................................ . 3
1.2 Distribution ......................................... . 3
1.3 Genetic Systems and Strategy for Germplasm Collection
and Preservation ..................................... . 5
1.3.1 Level of Hetero- or Homozygosity and Sampling ......... . 6
1.3.2 Preservation of Germplasm ............................ . 6
Chapter 2 Taxonomic Treatments
2.1 General Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Taxonomic Value of Epidermal Patterns
and Leaf Sections .................................... 10
2.3 Limitations Imposed by Natural Introgression . . . . . . . . . . . . . 11
2.4 The Lolium-Festuca-Vulpia Complex .................... 12
2.5 Lolium L. ........................................... 13
2.5.1 Salient Generic Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.5.2 The Outbreeding and Inbreeding Species. . . . . . . . . . . . . . . . . 14
2.5.3 Crosses Between Outbreeders and Inbreeders:
Possible Evolutionary Trends. . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.5.4 Two Important Ryegrasses . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16
2.5.5 Systematic Mutations and Their Taxonomic Implications. . . 17
2.5.6 Vegetative Proliferation in Inflorescences:
a Reproductive and Taxonomic Anomaly. . . . . . . . . . . . . . . .. 17
2.6 Festuca L. ........................................... 19
2.6.1 Salient Generic Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.6.2 Classification into Sections ............................. 20
2.7 Festuca arundinacea, a Compilospecies. . . . . . . . . . . . . . . . . .. 23
2.8 Cytotaxonomic Affinities: Phylogenetic Considerations
in the Festuca-Vulpia-Lolium Complex. . . . . . . . . . . . . . . . . .. 24
XII Contents
Chapter 3 Karyotypes and Species Evolution and Divergence
3.1 Karyotypic Features and Taxonomy ..................... 29
3.2 General Techniques of Studying Somatic Chromosomes . . .. 30
3.2.1 Conventional Staining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 30
3.2.2 General Karyotypic Features of Lolium Species. . . . . . . . . .. 31
3.2.3 General Karyotypic Features of Festuca Species. . . . . . . . . .. 31
3.2.4 Giemsa Staining ...................................... 32
3.2.4.1 Lolium L. ........................................... 32
3.2.4.2 Festuca L. ........................................... 33
3.3 Chromosome Size Variation Among Diploids
and Polyploids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33
3.4 Evolution by Increase in Chromosome Numbers .......... 34
3.5 Evolution by Changes in DNA Content . . . . . . . . . . . . . . . . .. 34
3.5.1 Lolium L. ........................................... 34
3.5.2 Festuca L. ........................................... 36
3.6 DNA Content and Growth Habit. . . . . . . . . . . . . . . . . . . . . . .. 37
3.7 Constitutive Heterochromatin .......................... 38
3.8 Nucleolar Organizer Activity ........................... 38
Chapter 4 Meiosis in Diploid and Polyploid Species
4.1 General Technique of Studying Meiosis . . . . . . . . . . . . . . . . .. 43
4.2 Meiosis in Diploids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 43
4.3 Diploid-Like Meiosis in Polyploids ...................... 43
4.3.1 Genetic Control of Diploid-Like Meiosis
and Disomic Inheritance in Hexaploid Tall Fescue. . . . . . . .. 44
4.3.1.1 Meiotic Analysis of 10 x 10 Dialle\: Chromosome Pairing
in a Critical Monosomic ............................... 46
4.3.1.2 Disomic Inheritance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 48
4.3.1.3 The Haplo-Insufficiency Hypothesis ..................... 48
4.3.2 Occurrence of Haplo-Insufficient Diploidizing Genes
in Other Polyploids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 49
4.3.3 Possible Dosage Effect of Diploidizing Gene(s) ........... 50
4.3.4 Can Tall Fescue Be Considered Autoallohexaploid? ....... 51
4.3.5 Probable Location of the Diploidizing Gene(s)
in Tall Fescue ........................................ 51
4.4 Breakdown of Diploidizing Mechanism
in Haploid Complements in Hybrids. . . . . . . . . . . . . . . . . . . .. 52
4.4.1 Haplo-Insufficiency of Diploidizing Gene(s) .............. 52
4.4.2 Possible Effects of Parental Genotypes. . . . . . . . . . . . . . . . . .. 53
4.5 Chromosome Pairing in Polyhaploids ....... . . . . . . . . . . . .. 54
4.6 B Chromosomes in Relation to Diploidization
of Tall Fescue ........................................ 54
