Interspecific Hybridisation of Boronias

1999 ◽  
Vol 47 (6) ◽  
pp. 851 ◽  
Author(s):  
I. A. Astarini ◽  
G. Yan ◽  
J. A. Plummer

Interspecific hybridisation within the genus Boronia was attempted by using species with a range of chromosome numbers. Crosses were possible between Western Australian species including those with B. heterophylla as the female parent and pollen from B. molloyae (n = 8), B. megastigma (n = 7), B. purdienana (n = 9) and B. ramosa (n = 18). Cytological studies revealed that B. heterophylla genotypes had different chromosome numbers; ‘Red’ had 2n = 15, whereas ‘Moonglow’ and ‘Cameo’ had 2n = 14. The F 1 hybrid from B. heterophylla ‘Red’ × B. megastigma had 2n = 15. Pollen viability, examined by using fluorescein diacetate, varied from 20% in B. crenulata to 80% in B. purdieana. Pollen of most species could be stored for 12 months in sealed containers at −20°C. Drying with silica gel desiccant did not improve storage, nor did ultra-low temperature (−196°C). Stored pollen was successfully used for interspecific hybridisation.


1988 ◽  
Vol 161 (1-2) ◽  
pp. 49-52 ◽  
Author(s):  
Robert Ornduff ◽  
T. I. Chuang


2010 ◽  
Vol 61 (6) ◽  
pp. 464 ◽  
Author(s):  
Aneeta Pradhan ◽  
Julie A. Plummer ◽  
Matthew N. Nelson ◽  
Wallace A. Cowling ◽  
Guijun Yan

Interspecific hybridisation was carried out between five cultivars of Brassica napus and five accessions of B. nigra in all possible cross combinations including reciprocals. Crossing success was higher when B. napus genotypes were used as female parents. Pollination of 799 B. napus flowers with B. nigra pollen resulted in 433 pods set and 2063 putative hybrid seeds. In the reciprocal direction, pollination of 877 B. nigra flowers with B. napus pollen resulted in 281 pods set and 113 putative hybrid seeds. Pod and seed set varied with genotype and only 19 out of 25 combinations of B. napus × B. nigra and 14 out of 25 combinations of B. nigra × B. napus yielded seeds. Hybridity of 2176 putative hybrid seeds (2063 from B. napus × B. nigra and 113 from B. nigra × B. napus) was tested. Microsatellite markers with known locations for the A, B and C genomes indicated that six plants were true hybrids and one more plant remained unconfirmed for hybrid status. All other plants from putative hybrid seeds had the same DNA banding patterns and similar morphological characters as the female parent. However, the true hybrids had DNA bands from both parents and an intermediate morphology for colour and hairiness of leaf, stem and petiole. Anthers were shrunken and thin with a very limited number of sterile pollen grains. Cytological examination confirmed the triploid status of the hybrid with 27 chromosomes. The unconfirmed hybrid had 9% pollen viability and chromosome count was 27 as with the true hybrid; however, there was no clear B-genome marker from B. nigra.



1993 ◽  
Vol 41 (5) ◽  
pp. 611 ◽  
Author(s):  
EA James ◽  
RB Knox

We studied the reproductive biology of Australian species of Pandorea to facilitate a breeding program designed to develop elite cultivars for the horticultural industry. P. pandorana is protogynous whereas anther dehiscence and stigma receptivity occur at the same time in P. jasminoides and P. baileyana. The stigmas of all species are receptive prior to anthesis and can be artificially pollinated at this stage provided that the stigma lobes can be separated. Pollen viability, tested for P. pandorana and P. jasminoides, deteriorated during the flower life although pollen samples with a low Fluorescein diacetate response (5-14%) still produced many pollen tubes which grew to the base of the style. For all species tested, pollen tubes grew into the ovary in both outcross pollinations and in self pollinations which are known to be incompatible indicating that the incompatibility barrier is within the ovary. Pollen-ovule ratios, determined for P. pandorana and P. jasminoides, were low compared with other published pollen-ovules ratios for taxa with breeding systems based on outcrossing.



Author(s):  
M.M. Lazarenko ◽  
K.I. Hnatiuk ◽  
S.A. Alekseev ◽  
K.S. Yablochkova ◽  
R. V. Dinzhos ◽  
...  


2003 ◽  
Vol 51 (5) ◽  
pp. 543 ◽  
Author(s):  
María A. Pérez-Fernández ◽  
Byron B. Lamont

Six Spanish legumes, Cytisus balansae, C. multiflorus, C. scoparius, C. striatus, Genista hystrix and Retama sphaerocarpa, were able to form effective nodules when grown in six south-western Australian soils. Soils and nodules were collected from beneath natural stands of six native Australian legumes, Jacksonia floribunda, Gompholobium tomentosum, Bossiaea aquifolium, Daviesia horrida, Gastrolobium spinosum and Templetonia retusa. Four combinations of soils and bacterial treatments were used as the soil treatments: sterile soil (S), sterile inoculated soils (SI), non-treated soil (N) and non-treated inoculated soils (NI). Seedlings of the Australian species were inoculated with rhizobia cultured from nodules of the same species, while seedlings of the Spanish species were inoculated with cultures from each of the Australian species. All Australian rhizobia infected all the Spanish species, suggesting a high degree of 'promiscuity' among the bacteria and plant species. The results from comparing six Spanish and six Australian species according to their biomass and total nitrogen in the presence (NI) or absence (S) of rhizobia showed that all species benefitted from nodulation (1.02–12.94 times), with R.�sphaerocarpa and C. striatus benefiting more than the native species. Inoculation (SI and NI) was just as effective as, or more effective than the non-treated soil (i.e. non-sterile) in inducing nodules. Nodules formed on the Spanish legumes were just as efficient at fixing N2 as were those formed on the Australian legumes. Inoculation was less effective than non-treated soil at increasing biomass but just as effective as the soil at increasing nitrogen content. Promiscuity in the legume–bacteria symbiosis should increase the ability of legumes to spread into new habitats throughout the world.



2007 ◽  
Vol 55 (4) ◽  
pp. 425 ◽  
Author(s):  
Qigang Ye ◽  
Eric Bunn ◽  
Siegfried L. Krauss ◽  
Kingsley W. Dixon

Symonanthus bancroftii is a critically endangered dioecious shrub, with only one male and one female plant known in the wild. Micropropagated, clonal plants of the male and female parents were hand-pollinated. Seed was germinated in sterile culture and a subsequent daughter (F1) seedling was multiplied in vitro. Micropropagated plants of the original parents and daughter were reintroduced to a natural habitat site. We detail the first study of pollination biology and reproductive success in this extremely rare species. Floral morphology, flowering phenology, pollen viability, female receptivity and fruit set of reintroduced plants of S. bancroftii were investigated. Flower viability of S. bancroftii shows a 25-day maximum for male flowers, whereas non-pollinated female flowers remain viable for a maximum of 38 days (female parent) and 41 days (daughter), respectively. Flowering of reintroduced male and female plants overlaps from mid-June to early November. Pollen remained viable for at least 8 days after anther dehiscence. Maximum stigma longevity recorded was 28 days (female parent) and 39 days (daughter) and maximum ovule longevity varied from 13 days (female parent) to 28 days (daughter). The mean percentage of flowers setting fruit was 39 ± 13% for female parent plants and 48 ± 4% for daughter plants. Empirical reproductive success measures for male–daughter crosses generally exceeded those of the original parent crosses. The reproductive success of S. bancroftii so soon after reintroduction of plants is a positive sign indicating that rapid accumulation of a soil seedbank is feasible and is thus an important first step towards successful establishment of self-sustaining populations of this critically endangered species.



Mycologia ◽  
1992 ◽  
Vol 84 (3) ◽  
pp. 392-398 ◽  
Author(s):  
Robert W. Lichtwardt ◽  
Marvin C. Williams


1986 ◽  
Vol 34 (5) ◽  
pp. 505 ◽  
Author(s):  
EM Watson

A cytological survey, using root tip mitotic cells and supplemented by some crosses and pollen fertility studies, was carried out on plants of 55 populations of the Australian annual Bulbine sernibarbata s.1. (Liliaceae). There are 4x, 8x and 12.x populations.The 4x forms are almost completely confined to eastern Australia and comprise populations of two kinds: (1) 28-chromosome types, corresponding in morphology to B. alata Baijnath, which to date has had limited taxonomic acceptance; (2) 26-chromosome types with the morphology of B. sernibarbata s. str. The alata form occurs in arid, the sernibarbata in more mesic, areas. The eastern 8x populations are mainly 2n = 54 and are intermediate between the other two taxa in both range and morphology. This suggests an allopolyploid origin based on hybridisation between the alata and sernibarbata types. The western 8x populations are nearly all 2n = 52, with much interpopulation variation in karyotype and a mesic distribution similar to that of the eastern 26-chromosome types. The karyotypic diversity parallels the species richness of other genera in southwestern Australia and indicates that the complex may be older than the corresponding polyploid complex within the perennial B. bulbosa s.1. The 12x (2n =78) populations are confined to arid and transitional rainfall areas of Western Australia. The identification of a distinctive 28-chromosome karyotype for the alata group gives support to the recognition of B. alata Baijnath, and, by providing a logical euploid bridge between the chromosome numbers of the African (2n = 14) and Australian species, strengthens the arguments for treating the two groups as congeneric.



2011 ◽  
Vol 83 (3) ◽  
pp. 993-1006 ◽  
Author(s):  
Patrícia M.O. Pierre ◽  
Saulo M. Sousa ◽  
Lisete C. Davide ◽  
Marco A. Machado ◽  
Lyderson F. Viccini

Cytogenetic analyses, of pollen viability, nuclear DNA content and RAPD markers were employed to study three chemotypes of Lippia alba (Mill.) (Verbenaceae) in order to understand the genetic variation among them. Different ploidy levels and mixoploid individuals were observed. This work comprises the first report of different chromosome numbers (cytotypes) in L. alba. The chromosome numbers of La2-carvone and La3-linalool chemotypes suggested that they are polyploids. Flow cytometric analysis showed an increase of nuclear DNA content that was not directly proportional to ploidy level variation. A cluster analysis based on RAPD markers revealed that La3-linalool shares genetic markers with La1-citral and La2-carvone. The analysis showed that the majority of genetic variation of La3-linalool could be a consequence of ixoploidy. ur data indicates that sexual reproduction aong those three chemotypes is unlikely and suggests the beginning of reproductive isolation. The results demonstrated that chromosome analysis, nuclear DNA content estimation and RAPD markers constitute excellent tools for detecting genetic variation among L. alba chemotypes.



1980 ◽  
Vol 28 (6) ◽  
pp. 573 ◽  
Author(s):  
RJ Hnatiuk ◽  
AJM Hopkins

Observations of responses to aseasonal water stress are reported for 238 above-ground perennial species of native vascular plants in a 20 km2 area of Western Australia surveyed during the second consecutive year of below average rainfall. Eighty-six species (36%) were found with dead individuals. Both vegetative regeneration and seedling regeneration appeared to be successful means of surviving drought stress in this region. The drought affected species of the families Proteaceae and Epacridaceae more than those of other major families. There are similarities in the response of the vegetation to the two main, irregularly occurring phenomena, aseasonal drought and fire: both can affect vegetation over large areas and yet leave considerable patches within the area that are little affected. Together these two factors contribute to the production of complex and dynamic mosaic-patterns in the vegetation.



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