Diagnoses of hybrid hummingbirds (Aves: Trochilidae). 15. A new intergeneric hybrid (Hylocharis leucotis × Selasphorus platycercus) from the Huachuca Mountains, southeastern Arizona

Author(s):  
Gary R. Graves
2020 ◽  
Author(s):  
Alaine F. Camfield ◽  
William A. Calder ◽  
Lorene L. Calder

1942 ◽  
Vol 76 (765) ◽  
pp. 376-385 ◽  
Author(s):  
Reeve M. Bailey
Keyword(s):  

Euphytica ◽  
2017 ◽  
Vol 213 (4) ◽  
Author(s):  
JianShuang Shen ◽  
TingLiang Xu ◽  
Chao Shi ◽  
TangRen Cheng ◽  
Jia Wang ◽  
...  
Keyword(s):  

Evolution ◽  
1963 ◽  
Vol 17 (4) ◽  
pp. 440-448
Author(s):  
Robert K. Selander ◽  
Robert W. Dickerman
Keyword(s):  

Phytotaxa ◽  
2021 ◽  
Vol 497 (2) ◽  
pp. 79-96
Author(s):  
ANDRÉA ONOFRE DE ARAUJO ◽  
MAURO PEIXOTO ◽  
CINTIA NEVES DE SOUZA ◽  
EDUARDO CUSTÓDIO GASPARINO ◽  
JULIANA TOLEDO FARIA ◽  
...  

A natural hybrid between Goyazia and Mandirola (Gloxiniinae, Gesneriaceae) from Cerrado (Brazil) is here described, supported by pollen morphology, cytological data and morphological characters. The microsporogenesis of Mandirola hirsuta and that of the hybrid were analyzed in order to evaluate the cytogenetic characteristics. The haploid chromosome numbers observed were n = 12 for M. hirsuta and n = 11, 13, 16 and 26 for the hybrid. Structural abnormalities (monads, dyads, triads and micronuclei) were observed at the final of the hybrid’s meiosis. High viability rates of the pollen were recorded for Goyazia and Mandirola (>90%) and low viability for the hybrid (34.7%). The pollen grains were acetolyzed, measured and photographed for pollen morphology analysis. Quantitative pollen data were analyzed through descriptive and multivariate statistics. The hybrid has intermediate pollen characteristics between G. petraea and M. hirsuta; it is more related to G. petraea by the measures of diameters and ectoapertures; it is more similar to M. hirsuta mainly regarding the microreticulum on the mesocolpium region. The hybrid and Mandirola share vegetative and flower size, while the colors of the hybrid are similar to Goyazia. Pollen morphology, cytological data and morphological characters brought clear evidence for the recognition of the intergeneric hybrid, which we named as Goydirola x punctata.


2021 ◽  
Author(s):  
◽  
Guyo Duba Gufu

<p>Biological invasion by non-native plant species has often been cited as a cause of native biodiversity loss. While the outcome of species invasions depends on interactions between exotic and resident native species, most studies of biological invasions have focused solely on the direct negative impacts of non-indigenous species on native biota. Although investigations of the role of competition in shaping natural plant communities were dominant in the previous generations and are still popular, more recent experimental research has uncovered the striking influence of facilitation on community dynamics. This thesis aims to investigate competitive and facilitative influence of the invasive South African iceplant (Carpobrotus edulis) on Spinifex sericeus, a native foredune grass species, with particular reference to implications of these interactions for dune restoration in New Zealand. It further explores the growth rates, substrate preferences and mating systems of the exotic and native iceplant taxa found in New Zealand. I begin by briefly outlining the influence of competition and facilitation on natural plant communities with reference to the role of facilitation in eco-restoration. I also give a few examples where exotic species have been found to facilitate native ones. Secondly, a neighbour removal experiment was conducted on coastal sand dunes with the main aim of studying the effects of Carpobrotus edulis on establishment of Spinifex sericeus at the foredune region. Finally, I compared the growth rates of the most widely distributed iceplant taxa in New Zealand in different substrates and the breeding systems of the exotic Carpobrotus.  Examples abound in literature of exotic plant species facilitating native ones especially in forestry. In the neighbour removal study, Carpobrotus edulis protected Spinifex seedlings against storm erosion, sandblasting and salt sprays while at the same time suppressing its leaf production. Suppression of Spinifex leaf production was more pronounced at top of the dune where stress elements is presumably more benign. There was no evidence of allelopathic suppression of Spinifex by C. edulis. Only Carpobrotus chilensis displayed some level of substrate preference by putting on relatively lower biomass in gravel. The exotic Carpobrotus spp. put on greater dry matter content than the native Disphyma australe and the Carpobrotus-x-Disphyma hybrid. The hybrid displayed a faster vegetative growth rate whereas D. australe allocated relatively more biomass to the roots than the shoot. Both Carpobrotus spp. are self compatible and highly capable of intrageneric and intergeneric hybridisation. Mass removal of the existing exotic iceplant stands from foredunes along high energy coasts is not advisable as they serve as useful stabilisers. The intergeneric hybrid is sexually sterile with sparsely spread stolons that could allow co-occurrence with other species and therefore is more suitable for foredune stabilisation. However, more research needs to be conducted on the ecology of the intergeneric hybrid.</p>


Sign in / Sign up

Export Citation Format

Share Document