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6.6. Conclusions
The phylogenetic relationship among species in the genus Diplazium was very difficult to explain due to the lack of or weak support Bootstrap value.
Therefore the monophyletic species groups in this genus could not be identified confidently. Consequently, sister-group relationships among these species also
could not be established. The high homoplastic on morphological characters in Diplazium distort the
inference of phylogenetic relationship among species. Moreover parallel evolution seems occurring.
Lack of or weak support for a phylogenetic tree does not strictly indicate that the pattern observed is incorrect but it does limit the amount of confidence
that can be placed in the relationships between taxa.and the conclusions can be drawn from them. This study showed that some terminal clades formed are
consisting of species that presumed to be closely related by formerly authors and congruence with the some terminal clades of gene rbcL tree, such as the affinity
of D. porphyrorachis group and ‘imparipinnate frond group’ {D. subintegrum D. bantamense, D. lobbianum D. fraxinifolium, D. xiphophyllum D. hottae
D. crameri D. riparium, D. wahauense} This study also revealed that the
classification of van Alderwereld van Rosenburgh 1908 in dividing Diplazium into two sections Eudiplazium and Anisogonium is not natural. Moreover, this
study gave indication that Kato’s classification 1977 could not be applied on West Malesian Diplazium. The lack of phylogenetic signal in morphological
datasets shows the need for other more informative data, such as molecular data, for inferring phylogentic relationships.
Cytological data in the Chapter 5 showed that Diplazium is very complicated. It indicates that cytological information is very important in
detecting the evolution and speciation in the Diplazium. Therefore in the future cytological data, including both somatic and gametic chromosome, the
chromosomal behavior in meiosis, and chromosomal karyotype, should be incorporated in the phylogenetic analysis of Diplazium.
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CHAPTER 7 SPECIFIC DELIMITATION AND RELATIONSHIP AMONG SPECIES
OF DIPLAZIUM BASED ON SPORE MORPHOLOGY 7.1. Introduction
Ferns spores display remarkable variation and have been extremely heplful in systematic studies. In many cases particular spore morphology are distinctive
for families or genera, or in some instance individual species Taylor Mickel 1974. Extensive studies on the spore of Pteridophyta showed that spore
morphology can be used as one of the taxonomic evidence for delimiting taxa. Ferrarini et al. 1986 reported the illustration, by scanning electron microscope,
of the spores of the Pteridophyta native in Italy amount to 124 specific and intraspecific taxa. They showed that spore morphology provide supporting
taxonomic evidence for delimiting both generic and species level in the Pteridophyta. Even they recognized some infraspecific of Asplenium, such. A.
trichomanes , A. ruta-muraria, A. seelosii and A. officinarum, based on its spore
morphological characters. Harris 1955 described spores from 170 taxa of New Zealand fern based on samples taken from herbarium specimens. Forty six years
after Large Braggins 1991 revised this work and provided full spores description of 211 species from New Zealand based on samples taken from fresh
material. These works also reveled that spore morphology among the genera in a family are diversified so that a tentative general key to the genera of pteridophytes
from New Zealand is given. However they did not discuss dealing the correlation between palynological characters and its taxomical treatments. Ohta Takamiya
1999 used spore morphology characters that observed by using SEM to distinguish Diplazium griffithii from other species in the Diplazium mettenianum
complex. Palynological characters may also provide evidence to illustrate the pattern
of relationship. Blackmore 2000 showed the the use of pollen morphology, in isolation, as a means of explicitly illutrating the relationship pattern of species
included in subtribe Scorzonerinae Asteraceae. The direction of the transformation was determined by method of outgroup comparison, because it is
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