Natural Hybridization and Morphometric Relationships Between Three Mallee Eucalypts in the Fitzgerald River National Park, W.A

1978 ◽  
Vol 26 (3) ◽  
pp. 319 ◽  
Author(s):  
SD Hopper ◽  
DJ Coates ◽  
AH Burbidge

The suspected occurrence of natural hybridization between Eucalyptus preissiana Schau, and E. Buprestium F. Muell, near West Mount Barren was investigated through a study of morphometric and reproductive parameters in allopatric and sympatric populations of these species. While E. Preissiana and E. buprestium were morphometrically distinct in allopatry, a small number of intermediate individuals occurred in one of the two sympatric populations examined. These intermediates set less fruit per plant than the parental species on average, a fact consistent with the hypothesis that they were hybrids showing partial F2 breakdown. The demonstration that New Holland honeyeaters (Phylidonyris novae-hollandiae) carried pollen of both parental species in a sympatric population was interpreted as further evidence in support of the occurrence of hybridization. The possible hybrid status of E. chrysantha Blakely & Steedman was investigated through determining its morphometric relationships in a multivariate analysis of E. sepulcralis F. Muell., E. Preissiana and E. buprestium. E. chrysantha was intermediate between E. sepulcralis and E. preissiana, and distinguishable from E. preissiana-E. buprestium hybrids in this analysis. The taxonomic and evolutionary implications of the study are discussed.

2020 ◽  
Author(s):  
Rongli Liao ◽  
Weibang Sun ◽  
Yongpeng Ma

Abstract Background: F1 hybrids acting as a bridgehead for producing later generation hybrids can have evolutionary significance through strengthening reproductive isolation or facilitating gene flow between parental species, depending on whether backcrossing can occur. It had been suggested that the Tibetan plant Buddleja wardii was a hybrid species between B. alternifolia and B. crispa based on their sympatric distributions and the morphological characters in last century. Till now however, we still have limited evidence to prove key issues to B. wardii, like if it is of hybrid origin indeed and whether it is currently a true hybrid species already.Results: In the present study, two sympatric populations of these three taxa were examined and compared using four nuclear genes and three chloroplast intergenic spacers, as well as with 10 morphological characters. Our results suggest that at both sites B. × wardii was likely to be a hybrids between B. alternifolia and B. crispa, and moreover, most of the hybrids present were confirmed to be F1s. This was further supported by morphology as no transgressive characters were detected. B. crispa was found to be the maternal parent in one population (BH), while in the second population (TJ), it was difficult to distinguish the hybridization direction due to shared haplotypes of cpDNA between B. alternifolia and B. crispa. Conclusions: These results provide evidence that the natural hybrids between B. alternifolia and B. crispa mainly comprise F1 hybrids, which have subsequently been given the name B. wardii. The F1 hybrids have also contributed to strong reproductive isolation between parental species.


2020 ◽  
Author(s):  
Rongli Liao ◽  
Weibang Sun ◽  
Yongpeng Ma

Abstract Background: F1 hybrids acting as a bridgehead for producing later generation hybrids can have evolutionary significance through strengthening reproductive isolation or facilitating gene flow between parental species, depending on whether backcrossing can occur. It had been suggested that the Tibetan plant Buddleja wardii was a hybrid species between B. alternifolia and B. crispa based on their sympatric distributions and the morphological characters in last century. Till now however, we still have limited evidence to prove key issues to B. wardii, like if it is of hybrid origin indeed and whether it is currently a true hybrid species already.Results: In the present study, two sympatric populations of these three taxa were examined and compared using four nuclear genes and three chloroplast intergenic spacers, as well as with 10 morphological characters. Our results suggest that at both sites B. × wardii was likely to be a hybrids between B. alternifolia and B. crispa, and moreover, most of the hybrids present were confirmed to be F1s. This was further supported by morphology as no transgressive characters were detected. B. crispa was found to be the maternal parent in one population (BH), while in the second population (TJ), it was difficult to distinguish the hybridization direction due to shared haplotypes of cpDNA between B. alternifolia and B. crispa. Conclusions: These results provide evidence that the natural hybrids between B. alternifolia and B. crispa mainly comprise F1 hybrids, which have subsequently been given the name B. wardii. The F1 hybrids have also contributed to strong reproductive isolation between parental species.


Phytotaxa ◽  
2021 ◽  
Vol 494 (1) ◽  
pp. 151-164
Author(s):  
KOH NAKAMURA ◽  
ROSARIO RIVERA RUBITE ◽  
YOSHIKO KONO ◽  
JELENE V. MACABASCO ◽  
ARLENE D. TALAÑA ◽  
...  

Here we describe a natural hybrid of Philippine Begonia from Bulabog Puti-an National Park in Dingle, Iloilo, Panay Island. The hybrid, named Begonia ×dinglensis after its place of origin, grows on moist, coralline-rock slopes at 200 m elevation. Morphological, molecular, and cytological evidence support its origin from natural hybridization between Philippine endemics B. camiguinensis and B. nigritarum.


Botany ◽  
2011 ◽  
Vol 89 (3) ◽  
pp. 191-201
Author(s):  
Jennifer DeWoody ◽  
John D. Nason ◽  
Marian Smith

Boltonia decurrens (Torr. & A. Gray) A. Wood is a federally threatened herb endemic to the Illinois River floodplain, and currently restricted to fewer than 25 populations. We tested for hybridization between this species and a widespread congener, Boltonia asteroides (L.) L’Hér., at two sites where they are known to occur in sympatry, by comparing morphological and genetic diversity with an allopatric population of each species. Morphological analyses identified significant differentiation between species. Discriminant classification analysis of the morphological data assigned most individuals to one or the other of the two parental species with high probability (>0.95), with only four plants having an intermediate probability of assignment (<0.90) indicative of hybrid origin. Similarly, likelihood-based methods based on genetic marker data (allozymes) failed to detect the presence of F1 hybrids in either sympatric population and revealed only low frequencies of F2 and backcross progeny. These findings demonstrate that combining morphological and genetic data increases the likelihood of detecting low-scale introgression between closely related species. Even with this combined approach, the low rate of recombination between these species together with their limited sympatry indicate that hybridization does not pose an immediate threat to the genetic integrity of B. decurrens.


2001 ◽  
Vol 79 (9) ◽  
pp. 1552-1558 ◽  
Author(s):  
Matthew J Parris

Terrestrial ecology has been largely neglected in the study of amphibian life histories because it is difficult to manipulate most species during the terrestrial stage. I examined the terrestrial performance of Rana blairi, Rana sphenocephala, and four hybrid (two F1 and two advanced generation) genotypes in replicated experimental enclosures to test for differences in traits related to juvenile terrestrial fitness. I produced all genotypes by means of artificial fertilizations using frogs collected from natural populations in central Missouri, and juvenile frogs were obtained from larvae reared in experimental ponds. Following metamorphosis, froglets were raised in single-genotype groups in terrestrial enclosures through the first overwintering. The proportion surviving did not vary among genotypes, but the power to detect significant differences was low. F1 hybrid genotypes BS and SB demonstrated significantly higher growth rates than either parental species or advanced-generation hybrid genotypes. Observation of growth rates of advanced-generation hybrids equal to those of the parental species, and heterosis in F1 hybrids for growth rate, suggests that natural hybridization between R. blairi and R. sphenocephala can produce novel and relatively fit hybrid genotypes. Direct measurement of multiple fitness components for hybrid and parental genotypes is critical for assessing the evolutionary potential of natural hybridization in organisms with complex life cycles.


1977 ◽  
Vol 25 (3) ◽  
pp. 291 ◽  
Author(s):  
T Whiffin

A small hybrid swarm between Correa aemula and C. reflexa was located and examined morphologically and chemically, with an emphasis on volatile oils. The hybrid plants were intermediate morphologically between the two parental species. The volatile oil data were subjected to multivariate numerical analysis, the results of which confirmed the general intermediacy of the hybrid plants. In general it was found that ordination is a more useful technique for the study of hybridization than is classification. It would appear that numerical analysis of volatile oil data will prove a useful technique in the study of the complex variation found within the genus Correa.


Geoderma ◽  
2011 ◽  
Vol 162 (3-4) ◽  
pp. 365-377 ◽  
Author(s):  
Héctor Aguilera ◽  
Luis Moreno ◽  
María Emilia Jiménez-Hernández ◽  
Silvino Castaño ◽  
Almudena de la Losa

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