Interpreting Botanical Progress

     Fossil Record and Ecology of Nyssa (Cornaceae)
	Richard Eyde............................................97

     DNA content, chromosome composition and isozyme
	  patterns in the genus Plantago L.
	 Srimanta Pramanik and Sarmistha Sen Raychaudhuri..........124

     The nucellus and chalaza in monocotyledons: 
	  Structure and Systematics
	Paula J. Rudall............................................140

     Review of Studies on the Cadang-Cadang Disease of Coconut
	Jose Velasco...............................................182

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	The New York Botanical Garden
	Issued 30 June 1997


Fossil Record and Ecology of Nyssa (Cornaceae)

RICHARD EYDE

	   I. Abstract     
	  II. Introduction      
	 III. Fruits    
	       A. Stones with Sunken Bundles    
	       B. Stones with Raised Bundles    
	       C. Stones with Little Ribbing    
	       D. Leftovers     
	  IV. Wood      
	   V. Leaves    
	  VI. Ecology and Dispersal     
	 VII. Discussion        
	VIII. Acimowledginents  
	  IX. Literature Cited  



I. Abstract

The fossil record of Nyssa is critically reviewed on the basis of 
reports of fruits, wood, and leaves from numerous localities in the 
Northern Hemisphere.  Commonly overlooked features of fruit stone 
morphology, particularly the placement of vascular bundles relative 
to the surface ribs, are used in grouping the fossil fruits and relating 
them to modem taxa.  Aspects of the ecology of extant species of 
Nyssa are also reviewed to highlight factors important in the 
evolution and dispersal of the genus.  Confirmed fossil occurrences 
document the occurrence of Nyssa already in the Eocene in Europe and 
North America and by at least the Oligocene in Asia. 

--- Richard Eyde died in 1990.  This manuscript was completed by 
     Steven R. Manchester.  Address for reprints: S. R. Manchester, 
     Department of Natural Sciences, Florida Museum of Natural 
     History, University of Florida, Gainesville, FL 3261 1, U.S.A.
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DNA content, chromosome composition and isozyme patterns in the genus Plantago L.

SRIMANTA PRAMANIK and SARMISTHA SEN RAYCHAUDHURI
Plant Molecular Biology Laboratory
Department of Biophysics, Molecular Biology and Genetics
University of Calcutta
92, A.P.C. Road
Calcutta  700 009
INDIA

	   I. Abstract
	  II. Introduction
	 III. Chromosome characteristics in Plantago
	  IV. Nuclear DNA content in relation to chromosome complements 
		 of  Plantago species
	   V. Genetic Distance between species of Plantago
	  VI. In vitro studies on chromosomes and DNA content of the species
		 of Plantago 
	 VII. Isozyme polymorphism in Plantago species in relation to ecology
	VIII. Isozyme polymorphism in different species Plantago of
		 growing in the same locality                          
	  IX. In vitro expression of isozymes during plant regeneration and
		 micropropagation in Plantago ovata
	   X. Conclusion
	  XI. Acknowledgements
	 XII. Literature Cited    


I.  Abstract

Retrospective as well as recent records on DNA content , chromosome
composition and isozyme variation were analyzed criticaly to trace
the evolution of species of the genus Plantago. Both in vivo as well
as in vitro data were taken into consideration. The species with
X = 6 were considered to be ancestral, while X = 5 more advanced.
The cultivated species with X = 4 was thought to be a derivative of
X = 5. The data on isozyme variation supported the findings derived
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The Nucellus and Chalaza in Monocotyledons:  Structure and Systematics


PAULA J. RUDALL
Jodrell Laboratory
Royal Botanic Gardens, Kew
Richmond, Surrey TW9 3AB
UNITED KINGDOM

	   I. Abstract
	  II. Introduction
	 III. Nucellus and Chalaza
	  IV. Distal (Micropylar) Region of Nucellus 
	   V. Proximal (Chalazal) Region of Nucellus
	       A. Hypostase
	       B. Enlarged Dermal Cells and Conducting Passage (Zuleitungsbahn)
	       C. Haustoria and Transfer Cells
	       D. Postaments and Podia
	       E. Perisperm
	       F. Chalazosperm and Pachychalaza
	  VI. Conclusions
	 VII. Acknowledgements
	VIII. Literature Cited


I. Abstract

The majority of monocotyledons are crassinucellate, including some
early-branching taxa (sensu Chase et al., 1995a, b), such as
Tofieldia, although Araceae are predominantly tenuinucellate.
The tenuinucellate condition occurs in a taxonomically wide range
of monocotyledons and there is some congruence between this
character and existing monocot topologies at higher levels. For
example, present evidence indicates a few tenuinucellate asparagoid
clades, including Alliaceae sensu stricto and Hypoxidaceae, possibly
two tenuinucellate lilioid lineages and at least two tenuinucellate
commelinoid lineages.

Proximal nucellar structures arise from a multilayered region of the
ovule and include hypostase, enlarged dermal cells and conducting
passage (Zuleitungsbahn), haustoria, postaments, podia and perisperm.
In some cases they may represent the same tissues at different
developmental stages; in general the last three are seed structures.
For example, a postament may be a resistant conducting passage from
which the surrounding dermal cells have degenerated, or alternatively
a resistant hypostase, although both are nucellar in origin. Such
terminological confusions cause problems in establishing
homologies. Several characters relating to the nucellus are outlined.
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REVIEW OF STUDIES ON THE CADANG-CADANG  DISEASE OF COCONUT

JOSE R.VELASCO
Institute of Biological Sciences
College of Arts and Sciences
University of The Philippines at Los Banos
College, Laguna, PHILIPPINES


		   I. Abstract/Resumen
		  II. Background of the Studies
		 III. Symptoms of Cadang-cadang
			A. Leaf symptoms
			B. Stipules
			C. Leafscar on trunk
			D. Flower  and fruit
			E. The syndrome
			F. Relevance of water-soaked spots
		  IV. Theories about the Cause
		   V. Field Surveys
		  VI. Attempts to Transmit the Virus
		 VII. The Viroid Hypothesis
			A. Mechanical transmission
			B. Experiments to Improving rates of Transmission
			C. Extraction of ccRNA
			D. Fractionation of ccRNA by Polyacrylamide Gel
			     Electrophoresis (PAGE)
			E. Some Misgivings
		VIII. Nutritional Imbalance as Cause
			A. Reasons for the Studies
			   1. Geographic limits
			   2. Rate of dying-off differs per locality
			   3. Rate of dying-off differs by age
			   4. Effects of fertilizer
			   5. Recovery of transplants according to locality
			B. Search for the Putative Soil Constituent
			C. Effect on Plants of Soil Constituent
			   1. Search for an indicator plants
			   2. Effects of rare earths on annual plants
			   3. Effects of rare earths on coconut
		  IX. Acknowledgement
		   X. Literature cited


I.  ABSTRACT
 
The cadang-cadang of coconut is a blight characterized by die-off of
trees until  the patch is laid bare.  The symptoms are: On the leaves --
water-soaked spots are produced on leaflets; the  leaves become small
as the disease grows severe; the crown of leaves is parted into two groups
(a tuft young leaves and a group of old, horizontal or drooping leaves)
the stipules are  profuse and persistent.  On the trunk, the leafscars
are far apart in the mild stage but very close together in the severe stage.
The fruits are big  and profuse in the mild stage; they  are few, small, 
misshapen and scarified in the severe stage of the disease.

To explore the likelihood that the disease is pathogenic, field surveys were
undertaken designed to follow its spread.  The researchers visualized
that the disease originated in San Miguel Island, Tabaco, Albay and fanned
out to outlying areas including the  provinces of Sorsogon, Camarines Sur,
Camarines Norte and  Catanduanes.  This pattern of spread may be mooted.
Complementarily, there were extensive attempts to transmit the  disease
mechanically and biologically using insect vectors.  The rare claims of having
successfully transmitted the virus (gauged by the production of water-soaked
spots on leaflets) have not been verified.

More recently, extensive studies were conducted to prove the viroid nature
of the disease.  The viroid (ccRNA) was characterized biochemically as
regards reaction to solvents, behavior in electrophoretic separation, size
of molecule and its structure.  On the other hand, the search for a soil
constituent as causative factor of the disease became focused on the rare
earth, especially lanthanum,  Given in low concentration, lanthanum was
beneficial to short-lived plants or to young perennials; however, in the
long run, perennials got killed late in life by dilute solution of lanthanum.
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