A CYTOLOGICAL CONSPECTUS OF THE GENUS CALYCADENIA (ASTERACEAE): AN EXAMPLE OF CONTRASTING MODES OF EVOLUTION

The chromosome numbers of 12 taxa of Calycadenia are documented by determinations in 77 widespread populations of the genus. Results of biosystematic studies indicate that hybrids among C. multiglandulosa, C. ciliosa, C. pauciflora, C. hispida, C. spicata, and C. oppositifolia characteristically have multiple associations of chromosomes producing complex meiotic configurations, whereas hybrids among C. villosa, C. mollis, C. truncata, and C. tenella generally yield few or no bivalents and a predominance of univalents during meiosis. Hybrids between C. multiglandulosa and C. hispida exhibit strict bivalent pairing and high pollen stainability. It is demonstrated that C. pauciflora and C. ciliosa comprise several sibling taxa that are morphologically cryptic, yet highly differentiated cytologically. Conversely, it is concluded that C. multiglandulosa and C. hispida comprise at least five morphologically distinct taxa that so far as known are highly interfertile (as judged by pollen stainability of hybrids) and cytologically uniform. Reproductive biology, chromosome mutation rates, habitats, flowering time, and genetic recombination mechanisms of the C. pauciflora-C. ciliosa and C. multiglandulosa-C. hispida complexes are compared in an attempt to account for the different modes of evolution observed in these closely related groups of Calycadenia. Lacking other plausible explanations, it is suggested that differential methods for limiting recombination of critical adaptive gene complexes might account for the divergent evolutionary patterns encountered in Calycadenia.     

NEW EVIDENCE OF THE SPECIFIC AFFINITY OF CUCULUS LEPIDUS MÜLLER

Scanning electron microscopy of eggshells of Cuculus lepidus of Java and Cuculus p. poliocephalus of the Asian continent revealed differences in ultra-structure incompatible with conspecific grouping. Eggshell ultra-structure, egg-type and colouration, and host selection of C. lepidus are to a high degree similar to C. saturatus, as are morphological characteristics and vocalizations (discussed elsewhere). It is therefore concluded that C. lepidus is a small tropical form of C. saturatus. The hosts of C. lepidus are Phylloscopus trivirgatus and Seicercus grammiceps in Java, and S. castaniceps in Malaya. In Java there are two breeding seasons of C. lepidus, April-June and September—October, whereas in Malaya breeding is centred in February-May. During the second breeding season of C. lepidus on Java conspecific migratory races of C. saturatus occur sympatrically. Of the two migratory races of C. saturatus occurring on Java, the C. s. saturatus appears to be twice as common as the northern race horsfieldi. Collection dates indicate that the former race is more abundant in January and February and C. s. horsfieldi in September—November. Between the three races on Java there is no evidence of genetic exchange; residents are largely isolated by habitat, and wintering migrants are non-vocal.     

SEED PROTEIN PROFILES IN THE NARROW-LEAVED SPECIES OF CHENOPODIUM OF THE WESTERN UNITED STATES: TAXONOMIC VALUE AND COMPARISON WITH DISTRIBUTION OF FLAVONOID COMPOUNDS

Water soluble seed proteins from 69 populations representing seven species of Chenopodium were separated electrophoretically. Very little or no intraspecific variation was detected. The use of seed proteins as taxonomic characters was evaluated and compared to data from flavonoid chemistry. Seed proteins are of value in distinguishing C. atrovirens and C. leptophyllum, something which could not be done with flavonoids. Proteins and flavonoid data demonstrated that C. hians and C. leptophyllum are distinct. An analysis of storage proteins failed to differentiate C. desiccatum from C. atrovirens and C. pratericola even though the species are distinct in flavonoids and other characters. Chenopodium atrovirens and C. pratericola produce similar or identical seed proteins, just as they are identical in flavonoids. Seed proteins indicated that plants referable to C. incognitum represent two biological entities, one apparently a minor morphological variant of C. atrovirens and the other conspecific with C. hians. The same interpretation had been given on the basis of flavonoid chemistry. The protein data suggest a close relationship between C. subglabrum on the one hand and C. atrovirens and/or C. desiccatum on the other.     

CYTOGENETICS OF HYBRIDS OF CARTHAMUS SPECIES (COMPOSITAE) WITH TEN PAIRS OF CHROMOSOMES

Plants thought to be typical of 7 species were chosen to represent the various taxa of Carthamus species with 10 pairs of chromosomes. These entities were crossed in all possible combinations and 20 of the possible 21 interspecific hybrids were obtained after 3 seasons of crosses. Analyses of the hybrids included studies of microsporocytes, pollen stainability, achene fertility, rudimentary ovaries, and other morphological characteristics. Pairing of chromosomes at metaphase I indicated no translocations were present in hybrids between C. tenuis from Israel, C. alexandrinus from Egypt, C. glaucus from northern Israel, and C. syriacus from Jordan. Members of this group are assigned the standard arrangement. Hybrids of C. glaucus from Iran, C. glaucus from Syria, and C. dentatus from Turkey always showed a translocation or chromosomal interchange when crossed with any member having the “standard” arrangement. The last 3 species are considered to have the “non-standard” chromosomal arrangement. The parental species used in this study can be regarded as a set of testers which will allow identification of chromosomal differentiation in additional Carthamus materials as they are collected.     

ALLOZYME VARIATION IN SEVERAL CLOSELY RELATED DIPLOID SPECIES OF CHENOPODIUM OF THE WESTERN UNITED STATES

Twelve allozyme loci were examined in a complex of closely related diploid (2n = 18) members of the genus Chenopodium occurring in the western United States. These plants are generally treated taxonomically as belonging to C. atrovirens, C. desiccatum, C. hians, C. leptophyllum, and C. pratericola. Also included were populations referable to C. incognitum. The enzymes examined and the allelic designations are given as follows: leucine aminopeptidase, Lap; phosphoglucoisomerase, Pgi-1, Pgi-2; glutamate-oxaloacetate transaminase, Got-1, Got-2, Got-3; glutamate dehydrogenase, Gdh; phosphoglucomutase, Pgm-1, Pgm-2; malate dehydrogenase, Mdh-1, Mdh-2; and malic enzyme, Me. All populations were fixed for the same allele at Gdh, Pgi-2, and Mdh-1. Chenopodium hians was fixed for a unique allele at Got-3 and contained two alleles at the Lap locus and two at Pgi-1 which were not detected elsewhere. Chenopodium leptophyllum likewise has unique alleles at Lap and Pgi-1. The other three taxa, C. atrovirens, C. desiccatum and C. pratericola, have alleles at Lap and Pgi-1 which were not found in C. hians or C. leptophyllum. The former three species have the same alleles in highest frequency at all polymorphic loci except Me, where C. desiccatum is consistently separable from C. atrovirens and C. pratericola. Allozyme data are concordant with information from morphology, flavonoid chemistry and seed protein profiles in suggesting that: (1) Chenopodium hians and C. leptophyllum are best regarded as distinct species; (2) C. atrovirens and C. pratericola are very similar and perhaps should not be recognized at the specific level; (3) C. desiccatum appears most closely allied to C. pratericola; (4) plants referable to C. incognitum represent two biological entities, one the same as C. atrovirens, and the other conspecific with C. hians; (5) little genetic variation is detectable in any taxon of these weedy annuals; (6) interspecific hybridization is not a cause of taxonomic difficulties in these plants.     

ELECTROPHORETIC ANALYSIS OF ENZYMES FROM THREE SPECIES OF CHLAMYDOMONAS

Isoenzyme patterns of acetone-extracted proteins revealed a close similarity between Chlamydomonas eugametos and C. moewusii but a distant relationship between the two and C. reinhardtii. Chlamydomonas eugametos and C. moewusii had identical banding patterns of malate dehydrogenase (MDH) and leucine aminopeptidase (LAP) in starch gels. These two species exhibited the same MDH distribution spectrum in analytical disc polyacrylamide gels but neither species showed definitive LAP or glutamate dehydrogenase (GDH) activity. There were differences in the starch gel alpha esterase (α-EST) patterns of C. eugametos and C. moewusii due to an additional weak band at Rf 0.75 in the latter species and a slight variation in the position of another band at Rf 0.80–0.82. Some variations between the two species also occurred in the α-EST banding in disc gels at Rf 0.70–0.85 and at Rf 0.06–0.14 with C. moewusii exhibiting the greatest number of bands. Chlamydomonas reinhardtii displayed patterns of all four enzymes but the band characteristics were distinctively different from those of C. eugametos and C. moewusii. There appeared to be no obvious isoenzyme difference between mating types of either species. It is concluded that C. eugametos and C. moewusii are not identical species but are closely related in regard to the enzymes assayed. Isoenzyme analysis is considered to be a useful approach to algal systematics.     

OBSERVATIONS OF CHROMOSOMES IN CIRCAEA (ONAGRACEAE)

Observations of meiotic and/or mitotic chromosomes for 16 specific, infraspecific, and hybrid taxa from 56 populations are presented; chromosome numbers for 11 taxa are reported for the first time. All samples reported have 2n = 22, with the exception that 3 of 12 collections of C. × intermedia have at least some individuals that are triploid. North American diploid collections of this hybrid are heterozygous for one reciprocal translocation; only 1 of 5 European diploid collections also exhibited a translocation. Meiosis in four naturally occurring Asian hybrids is also analyzed: C. × ovata (C. cordata × C. mollis), C. × decipiens (C. erubescens × C. lutetiana) and C. x× dubia (C. cordata × C. eurbescens) possess a single translocation; C. × mentiens (C. alpina × C. eurbescens) is structurally homozygous. With the exception of the translocation, chromosome pairing in these hybrids is normal. Early diakinesis chromosomes possess densely staining centric regions and diffusely staining arms that are subequal in length.     

A CHEMOSYSTEMATIC STUDY OF SELECTED TAXA OF CAPSICUM

Six taxa of Capsicum were chosen for a comparative chemosystematic study. A “key” individual from each taxon was selected for intensive chemical investigation. Thirteen flavonoids were isolated from leaf material and characterized by paper chromatography and absorption spectroscopy. The C-glycosylflavones vitexin and isovitexin, and orientin and iso-orientin, as well as O-glycosides of the flavones apigenin, luteolin, and chrysoeriol, were isolated from the key individuals. Chromatographic analysis of collections from various regions of South America, Central America, and Mexico showed in general that flavonoid variability is more common in cultivated taxa than in wild. Three groups of Capsicum were recognized and the main systematic conclusions were: (1) The white-flowered taxa in Group I, C. baccatum var. baccatum and C. baccatum var. pendulum, have identical flavonoids, corroborating previous conclusions that they are one species. The absence of chrysoeriol in this group separates it from Groups II and III. (2) The purple-to-white-flowered C. eximium var. eximium and C. eximium var. lomenlosum, Group II, have a complex flavonoid chemistry which appears to link Groups I and III. (3) Two purple-flowered species, C. cardenasii and C. pubescens, Group III, are chemically distinct from the other taxa examined.     

ASCI OF THE PEZIZALES III: THE APICAL APPARATUS OF EUGYMNOHYMENIAL REPRESENTATIVES

Morphological, developmental and cytochemical examinations were made with light and electron microscopy on the apical apparatuses of four eugymnohymenial species, Pyronema domesticum, Ascodesmis sphaerospora, Coprotus winteri and C. lacteus. Ascal tips in all four species were notably thinner walled than the rest of the ascus. Ultrastructurally, demarcation of the opercula was enhanced after staining with silver methenamine. Wide zones of dehiscence are formed in the outer layer of A. sphaerospora and C. winteri. In P. domesticum the outer layer of the operculum is differentially stained from the rest of the ascal wall. Wall dimensions in the multispored asci of C. winteri are approximately three times greater than those in the eight-spored asci of C. lacteus. The shape of the apical apparatus of C. lateus is almost identical to that of C. winteri. Morphological and cytochemical similarities of the apical apparatuses in Ascodesmis, Pyronema and Coprotus help demonstrate greater relationship between these taxa and support the belief that these taxa are most closely related to members of the Otideaceae and Aleuriaceae.     

A QUANTITATIVE ANALYSIS OF THE MEGAGAMETOPHYTE OF FIVE SPECIES OF CORNUS L.

Comparisons of variations of morphological features, treated quantitatively, of the megagametophytic stages in Cornus asperifolia Michaux., C. stricta Lam., C. amomum Miller, C. florida L., and C. alternifolia L. suggest differences in growth patterns of their megagametophytes. The successful application of the clearing fluid 41/2 (Herr Fluid) affords adequate data for assessment of quantitative features of such minute plants. This method, less time consuming than traditional paraffin sectioning techniques, allows for statistical treatment of a sufficient number of species for valid inferences of angiospermous embryological features. An investigation of megagametophytic size was directed both to successive stages within each species and to each stage among all five species. In both instances, means, confidence intervals (CI), and growth increments (GI) were compared. Without exception, the largest means for length and width occurred in the 8-nucleate stage for all species. The greatest GI for length occurred in the 8-nucleate stage for C. stricta, C. alternifolia, and C. asperifolia and in the 4-nucleate stage for C. florida. The 4- and 8-nucleate GI were nearly equal for C. amomum. Overlapping of 95 % CI between successive stages indicated uniform growth between stages for the megagametophyte. Only C. asperifolia had CI overlapping between all successive stages for length and width. These five species are clearly separated on the basis not only of variations in qualitative features but also on megagametophytic growth patterns among species.     

A STUDY OF CRYPTOLECHIA ZELLER (LEPIDOPTERA: OECOPHORIDAE) IN CHINA (I), WITH DESCRIPTIONS OF FIFTEEN NEW SPECIES

The present paper reports thirty‐three species of the genus Cryptolechia in China. Fifteen species are described as new to science: C. deflecta sp. nov., C. kangxianensis sp. nov., C. microbyrsa sp. nov., C. falsivespertina sp. nov., C. zhengi sp. nov., C. neargometra sp. nov., C. paranthaedeaga sp. nov., C. cornutivalvata sp. nov., C. fascirupta sp. nov., C. stictifascia sp. nov., C. jigongshanica sp. nov., C. mirabilis sp. nov., C. anthaedeaga sp. nov., C. gei sp. nov. and C. varifascirupta sp. nov. The genital structures of the new species are illustrated.     

CHAIN-FORMING DIATOMS: THREE SPECIES OF CHAETOCERACEAE1,2

Bacteriastrum furcatum Shadbolt, Chaetoceros bacteriastroides Karsten and C. pseudocurvisetum Mangin are each connected in chains by fusion of silica between setae. The first two have specialized heterovalvate end cells indicating physiological control of the length of chains, but chains of C. pseudocurvisetum have usually been seen broken. There are specialized deeply lobed connecting bands in B. furcatum and C. pseudocurvisetum, allowing the setae of sibling valves to protrude outside the diameter of the chain during their formation. C. bacteriastroides and C. pseudocurvisetum are not identical; differences include presence of small setae, fusion of large setae some distance from the valves, symmetry of apertures between cells, and straight chains of C. bacteriastroides, compared with valve mantle connections with no small setae, large setae joined by crossing over, asymmetry of windows between cells, and curved chains of C. pseudocurvisetum. The evolutionary direction is hypothesized to be from Bacteriastrum to Chaetoceros through C. bacteriastroides.     

INDUCTION OF ADVENTITIOUS BRANCHES FROM CULTURED CITRUS JUICE VESICLES–A POTENTIAL MEANS OF PROLIFERATION

The noncallusing morphogenetic properties of Citrus juice vesicles cultured in vitro are unknown and were herein studied. Juice vesicles isolated from 120–180-day-old fruits are capable of proliferation via adventitious vesicle branching in vitro. Gibberellic acid levels of 1–100 mg/L greatly enhanced adventitious vesicle branching while delaying vesicle senescence as evidenced by the vesicles' ability to retain its green color for up to 4 to 6 mo in culture. Vesicles grown on media without gibberellic acid readily matured, turning opaque within 2 mo in culture and rarely produced adventitious branches. Additions of 0.1 mg/L α-naphthaleneacetic acid or 1.0 mg/L benzylaminopurine to media containing 10 mg/L gibberellic acid further enhanced vesicle branching in some species and cultivars. Adventitious juice vesicles have been induced from a variety of citrus species, including Citrus grandis (L.) Osb., C. hystrix DC., C. limon (L.) Burm. f., C. medica L., C. paradisi Macf., C. reticulata Blanco, and C. sinensis (L.) Osb. Adventitious vesicle branches originate from primordia initiated on the surface of the cultured vesicle. These primordia commonly occurred on the terminal meristem region of the vesicle. However, some species (e.g., C. grandis and C. paradisi) produced adventitious vesicle branches from their bodies and stalks as well. Distinct vesicle branches begin to appear on preformed vesicles after 30–60 days in culture. A survey to determine the natural occurrence of vesicle branching in various Citrus species was also conducted. Natural vesicle branching commonly occurred in C. grandis, C. paradisi, and in some cultivars of C. reticulata, but was absent in most citrus species and cultivars (e.g., C. aurantifolia (Christm.) Swing., C. canaliculata Hort. ex Y. Tan., C. hystrix, C. limon, C. medica, C. sinensis). It was found that some species which failed to exhibit the adventitious branching phenomenon in nature did so in vitro (e.g., C. hystrix, C. medica, and C. sinensis).     

MORPHOLOGY OF THE DIATOM GENUS CAMPYLONEIS (BACILLARIOPHYCEAE,BACILLARIOPHYTA), WITH A DESCRIPTION OF CAMPYLONEIS JULIAE SP. NOV. AND AN EVALUATION OF THE FUNCTION OF THE VALVOCOPULAE1

A revision of the monoraphid pennate diatom genus Campyloneis Grunow was carried out based on LM and EM observations. The material examined originated from various herbarium collections and from extant epiphytic diatom communities on leaves of Posidonia spp. We also examined the generitype C. grevillei (Smith) Grunow and the fossil material of C. gheyselinchi Reinhold from which the author extracted the type. Our results clarified the fine structure of C. grevillei and C. gheyselinchi. Of the various varieties of C. grevillei, only the variety argus (Grunow) Cleve was retained. This differs from the nominate variety in the arrangement and shape of the areolae adjacent to the sternum of the araphid valve. The newly described taxon Campyloneis juliae De Stefano differs from all Campyloneis species in areolae ultrastructure and morphology of the valvocopulae. As for the fossil species C. gheyselinchi, the sternum valve areolae are similar to those of C. grevillei, but scarcity of frustules in the type material prohibited evaluation of its variability. For this reason we provisionally maintained its rank of species. The elaborate linking systems among the valvocopulae and valves in Campyloneis species appear to provide structural reinforcement against pressure from neighboring epiphytic diatoms and scouring of seagrass leaves.     

THE EFFECTS OF CONTRASTING MODES OF FERTILIZATION ON LEVELS OF INBREEDING IN THE MARINE INVERTEBRATE GENUS CORELLA

A simple difference in the body design of two species of marine urochordates in the ascidian genus Corella suggested that these species may differ in their mating systems. The two coexisting species share common life-history traits and morphology with the exception of a difference in body design that affects site of fertilization and embryonic development. Corella inflata has internal fertilization and embryonic development, while C. willmeriana has external fertilization and embryonic development. The natural mating system of these two species of solitary ascidians was inferred by comparing the relative survival of selfed and outcrossed fertilizations in the laboratory. Corella inflata, the internal fertilizer, showed no difference in survival between selfed and outcrossed fertilizations at any developmental stage through metamorphosis and early juvenile development. In contrast, self-fertilized crosses of C. willmeriana had significantly lower survival than outcrossed fertilizations even at the earliest scorable developmental stages. These results suggest that C. inflata may inbreed frequently in nature, while viable C. willmeriana offspring are primarily a result of outcrossing. The internally-fertilizing species, C. inflata, showed approximately 10% male sterility in laboratory crosses despite apparent morphological hermaphroditism. The externally-fertilizing, commonly outcrossing species, C. willmeriana, showed no difference in fertility between genders.     

CONTRIBUTION OF POLLEN MORPHOLOGY TO SYSTEMATICS OF COLLOMIA (POLEMONIACEAE)

Pollen morphology of 14 species of Collomia (Polemoniaceae) was examined by light microscopy, and by both scanning and transmission electron microscopy. Four distinct pollen types were observed which are based principally upon 1) shape, number and distribution of apertures, and 2) surface sculpturing: Type 1—zonocolporate with striate ridges; Type 2—zonocolporate with striato-reticulate ridges; Type 3—pantoporate with radiate ridges; Type 4—pantoporate with irregularly reticulate ridges. Evaluation of pollen morphology reveals considerable discrepancy with respect to presently accepted sectional classification. Collomia grandiflora of sect. Collomia has a pollen type similar to that of members of sect. Collomiastrum and is now interpreted as representing an independent evolutionary line derived from the latter section. Collomia diversifolia of sect. Courtoisia has a pollen morphology similar to that of sect. Collomia. whereas C. heterophylla of the same section possesses pollen unique within the genus. This last pollen type shows close similarity to the pollen of members of Polemonium, Gilia, Leptodactylon, and Ipomopsis. Pollen of C. tinctoria and C. tracyi of sect. Collomia are anomalous within Polemoniaceae. No significant difference in exine stratification was discernible among the four pollen types.     

COMPARATIVE ULTRASTRUCTURE OF THE VALVES OF SOME CYCLOTELLA SPECIES (BACILLARIOPHYCEAE)1

Cyclotella atomus Hust., C. meneghiniana Kütz., C. comta (Ehr.) Kütz., C. antiqua W. Sm., C. michiganiana Skv., C. ocellata Pant., C. glomerata Bachmann, C. pseudostelligera Hust., and C. stelligera (Cleve et Grun.) V. H., were selected for ultrastructure investigations on the basis of their ready availability. Specimens were examined employing both transmission and scanning electron microscopy. Strutted processes, labiate processes, spines and other special features were surveyed in all species. On the basis of these observations the species of Cyclotella observed seem to be in one of 3 morphological groups, the meneghiniana group, the comta group, and the stelligera group.     

THE CYTOLOGY AND PHYLOGENETICS OF THE DIPLOID SPECIES OF GOSSYPIUM

Meiotic chromosome behavior of 11 inter-genomic hybrids of Gossypium (2n = 26) were investigated. Per cell univalent frequencies at meiotic metaphase I in these hybrids were: A genome × Cgenome—G. herbaceum × sturtianum, 10.53; G. herbaceum × australe, 18.05. A genome × E genome—G. smnalense × arboreum, 21.82. B genome × C genome—G. anomalum × sturtianum, 9.23; G. anomalum × australe, 13.11. B genome × D genome—G. anomalum × klotzschianum, 17.45; G. anomalum × raimondii, 18.83. C genome × D genome—G. robinsonii × davidsonii, 12.77; G. sturtianum (armourianum × thurberi), 8.63. C genome × E genome—G. somalense × australe, 23.78; G. somalense × bickii, 25.58. Trivalent and quadrivalent frequencies were relatively high for those hybrids involving a C genome species, indicating that a reciprocal translocation differentiates the C genome from the A, B, D, and E genomes. The results of this study and the data of similar studies cited from the literature on Gossypium cytogenetics are discussed relative to the phylogenetics and evolution of the major (genome) groups of Gossypium and their constituent taxa.     

FIVE NEW SPECIES OF CHLAMYDOMONAS1,2

Five new species of Chlamydomonas, C. isabeliensis, C. pallidostigmatica, C. fottii, C. pseudomicrosphaera, and C. texensis are described. Supplementary attributes of these organisms are considered as possible taxonomic aids.     

THE ORIGIN AND EVOLUTIONARY RELATIONSHIPS OF ‘HUAUZONTLE’ (CHENOPODIUM NUTTALLIAE SAFFORD), DOMESTICATED CHENOPOD OF MEXICO

A New World assemblage of tetraploid Chenopodium species (section Chenopodium, subsection Cellulata) includes two domesticates, C. quinoa of Andean South America and C. nuttalliae of Mexico. Both have been combined into a single species and the Mexican form has been considered as a possible derivative of C. quinoa. The domesticates and related, sympatric weed forms, C. berlandieri of North America and C. hircinum of the Andes, were examined for variation in morphological and biochemical characteristics and also were included in a program of artificial hybridization. Results indicate that the domesticated forms are more closely related to their sympatric weeds than to each other. The Mexican cultigen is placed as a subspecies of C. berlandieri, the taxon from which it most likely evolved under human selection in North America. Possible origins for the Andean weed-crop complex are considered. Southward migration of a North American tetraploid appears to be more likely than independent allotetraploidy in South America. Of the North American tetraploids examined, C. berlandieri var. zschackei of the western U.S. shows closest affinities to the Andean complex.