scholarly journals Transfer of Powdery Mildew Resistance from Brassica carinata to B. oleracea

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 869B-869 ◽  
Author(s):  
Muhammet Tonguc* ◽  
Phillip D. Griffiths
Keyword(s):  
Powdery Mildew ◽  
Interspecific Hybrid ◽  
Interspecific Hybrids ◽  
Seed Set ◽  
Embryo Rescue ◽  
Brassica Carinata ◽  
Transfer Resistance ◽  
Maternal Parent ◽  
Ethiopian Mustard ◽  
Hybrid Plants

Powdery mildew is a fungal disease of crucifers, caused by Erysiphe polygoni D.C. and it can be problematic during seed increase in green-houses. Crosses were made between Brassica carinata (Ethiopian mustard) accession (PI 360883) and B. oleracea cultivars `Titleist' and `Cecile' to transfer resistance to powdery mildew to B. oleracea germplasm. It was not possible to obtain interspecific hybrids between Ethiopian mustard and B. oleracea through natural seed set. However, interspecific hybrids and backcross one (BC1) progenies were produced via embryo rescue following sexual crosses. Four interspecific hybrid plants were produced with the aid of embryo rescue from cultured pistils with B. carinata as the maternal parent, and their interspecific origin was confirmed through plant morphology and analysis of RAPD polymorphisms. No interspecific hybrids were obtained when `Titleist' was used as a maternal parent. Interspecific hybrid plants were male sterile and they were used as maternal parents to produce BC1 plants. Twenty one BC1 plants were obtained through natural seed set and embryo rescue, although embryo rescue was not necessary to produce first backcross generation plants. When tested in greenhouse with powdery mildew, all interspecific hybrids and eight of the BC1 plants were resistant to the disease. Crosses are being made to produce BC2 plants with 2n = 18 chromosomes for introgression of the resistance in B. oleracea.

Interspecific hybridization of Medicago sativa L. and M. rupestris M. B. using ovule–embryo culture

1985 ◽  
Vol 27 (2) ◽  
pp. 238-245 ◽  
Author(s):  
T. J. McCoy
Keyword(s):  
Medicago Sativa ◽  
Embryo Culture ◽  
Interspecific Hybrid ◽  
Interspecific Hybrids ◽  
Embryo Rescue ◽  
Culture Method ◽  
Hybrid Plants ◽  
Successful Recovery ◽  
Hybrid Embryo ◽  
Medicago Sativa L

An ovule–embryo culture method was used to produce the first interspecific hybrids between alfalfa (Medicago sativa L.) and Medicago rupestris M. B. Culture of fertilized ovules from the cross diploid (2n = 2x = 16) M. sativa (jpjp) × diploid (2n = 2x = 16) M. rupestris began 14 days after pollination. After 5 days in culture, the interspecific hybrid embryo was removed and transferred to fresh medium, where development into a plant occurred. Forty-six M. sativa – M. rupestris F1 hybrids have been recovered using this technique. All but one of the 46 F1 hybrids were diploid (2n = 2x = 16); the only exception was tetraploid (2n = 4x = 32). The most frequent meiotic configurations observed in the F1 hybrid plants were eight bivalents or seven bivalents and two univalents, indicating significant homology between M. sativa and M. rupestris genomes. However, pollen stainability (0–12%) and pollen germination (0–6%) were extremely low. Similar to the production of the F1, no first backcross (BC1) plants were obtained from seed; however, the ovule–embryo culture method was found to be a very effective method for recovering BC1 plants and hundreds of BC1 plants have been produced. The BC1 plants from crossing the F1 with diploid M. sativa were predominantly diploid. Medicago rupestris can now be considered a potential germplasm source for alfalfa improvement. The ovule–embryo culture method represents the first successful recovery of Medicago interspecific hybrids via some form of embryo rescue. Importantly, it appears this technique can be applied to other interspecific hybrid combinations in the Medicago genus.Key words: Medicago, alfalfa, embryo culture, interspecific hybrid.

An Improved Embryo-Rescue Protocol for a Carica Interspecific Hybrid

1996 ◽  
Vol 44 (3) ◽  
pp. 343 ◽  
Author(s):  
PM Magdalita ◽  
SW Adkins ◽  
ID Godwin ◽  
RA Drew
Keyword(s):  
Plant Growth ◽  
Growth Regulator ◽  
Interspecific Hybrid ◽  
Plant Growth Regulator ◽  
Interspecific Hybrids ◽  
Embryo Rescue ◽  
Naphthalene Acetic Acid ◽  
Efficient Production ◽  
Good Growth ◽  
Hybrid Plants

An improved embryo-rescue protocol was developed for embryos (90 days old) of Carica papaya L. (Clone 2001), and subsequently was utilised for efficient production of interspecific hybrids of C. papaya × C. cauliflora Jacq. from 90- to 120-day-old embryos. Pre-incubation of C. papaya embryos for 7 days on a germination medium containing half-strength De Fossard nutrients supplemented with gibberellic acid (10 μM), 6-benzylamino-purine (0.25 μM), alpha-naphthalene-acetic acid (0.25 μM). sucrose (58 mM) and agar (8 g L-1) supported 100% germination. Subsequent transfer of germinated embryos to a nutrient medium that was identical, except that it was free of plant growth regulator, allowed good growth but induced shoot etiolation and callus production. Reducing the pre-incubation of C. papaya embryos on this medium to 5 days before transfer to the medium free of plant growth regulator produced similarly high germination (96%), but allowed for the production of good quality seedlings that were unetiolated and free of unwanted callus. For interspecific hybrids, a 5-day pre-incubation of the embryos on a liquid formulation was better than the solid formulation as it promoted better growth and vigour of the normally abortive interspecific hybrid embryos. Using the improved protocol, 1981 of 2100 (94%) interspecific hybrid embryos consisting of single and multiple forms were germinated. In all cases, the germinating multiple embryos underwent further embryogenesis that allowed for the production of 485 (25%) morphologically normal hybrid plants grown in soil in the glasshouse.

Evidence for the Identity of the Hybrid, Eucalyptus 'brachyphylla' (Myrtaceae) From Morphology and Essential-Oil Composition

1996 ◽  
Vol 44 (1) ◽  
pp. 1 ◽  
Author(s):  
PM Grayling ◽  
MIH Brooker
Keyword(s):  
Essential Oil ◽  
Interspecific Hybrid ◽  
Interspecific Hybrids ◽  
Multivariate Analyses ◽  
Parental Species ◽  
Essential Oil Composition ◽  
Eucalyptus Species ◽  
Oil Composition ◽  
Hybrid Plants ◽  
Hybrid Eucalyptus

The putative interspecific hybrid known as Eucalyptus brachyphylla C. Gardner, which is known to occur at two sites near Kalgoorlie, Western Australia, contains the non-terpenoid ester 4-methyl-2-pentyl acetate and the related alcohol 4-methylpentan-2-ol in its leaves. These compounds are otherwise known to occur in the leaves of only four Eucalyptus species and several putative interspecific hybrids. This, with the results of multivariate analyses of morphometric and oil composition data, adds considerable weight to;earlier suggestions that E. 'brachyphylla' is an hybrid of E. loxophleba Benth. and E. kruseana F. Muell. The presence at one site of two distinct chemotypes common to both parental species and to the hybrid plants is demonstrated and discussed.

An embryo-rescue protocol for Vigna interspecific hybrids

2002 ◽  
Vol 50 (3) ◽  
pp. 331 ◽  
Author(s):  
J. L. Palmer ◽  
R. J. Lawn ◽  
S. W. Adkins
Keyword(s):  
Interspecific Hybrids ◽  
Embryo Rescue ◽  
Interspecific Cross ◽  
Casein Hydrolysate ◽  
Subsequent Development ◽  
Immature Embryos ◽  
Putative Hybrid ◽  
Vigna Species ◽  
Hybrid Plants ◽  
Culture Protocol

A successful embryo-rescue and culture protocol was developed for use with several indigenous Vigna species and mungbean cultivars grown in Australia. Germination of Vigna immature embryos and their subsequent development into plants was influenced by the time at which the embryos were isolated and by which medium additives were placed in the embryo-rescue medium. A medium containing MS basal nutrients with sucrose (88�mM), casein hydrolysate (500 mg L- 1) and agar (8 g L- 1) but devoid of plant-growth regulators was found to be the best for germination of immature embryos for all four Vigna species investigated. The protocol for successful germination of non-hybrid immature embryos was applied to the recovery of interspecific hybrids involving mungbean and five native Vigna species that had previously been found difficult to hybridise. Several putative hybrid plants were obtained including a confirmed interspecific cross between V. luteola (Jacq.) Benth and V. marina (Burm.) Merrill.

scholarly journals Production of Interspecific Hybrids between Hexaploid Fragaria moschata and the diploid species F. nubicola and F. viridis.

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 610b-610
Author(s):  
Robert H. Bors ◽  
J. Alan Sullivan
Keyword(s):  
Seed Germination ◽  
Ploidy Level ◽  
Interspecific Hybrids ◽  
Leaf Morphology ◽  
Seed Set ◽  
Embryo Rescue ◽  
Diploid Species ◽  
Interspecific Crosses ◽  
Good Seed ◽  
Poor Seed

Interspecific crosses with Fragaria moschata (6x) have been hampered by ploidy level differences, poor seed set, and extremely poor seed germination. Modification of pollination practices, embryo rescue, and use of several genotypes has allowed over 80 synthetic tetraploids to be created from 14 cross combinations. Germplasm for the experiment consisted of eight selections of F. moschata (6x), two of F. nubicola (2x), and two of F. viridis (2x). Both 2x × 6x and 6x × 2x crosses were performed. Initially, negligible seed set occurred on F. nubicola and F. viridis when multiple flowers per truss were pollinated. When only one cross was performed per truss, with other flowers removed, seed set was greatly enhanced. F. moschata was much more tolerant of multiple crosses per truss. The crossing combination of F. moschata × F. nubicola gave the worst seed production. Other species combinations were capable of producing good seed set with noticeable differences between individual selections. When achenes were halved, only 1% appeared normal, 2% were underdeveloped or shrunken, the remainder were empty. Many of the malformed and most of the normal embryos germinated using the cut achene method. Achenes were surface-sterilized, cut in half, and placed on MS media with activated charcoal (3g·L–1), sucrose (30g·L–1), and no hormones. Germination occurred only from achenes from fully ripened fruit. Viable hybrids were obtained from 2x × 6x as well as 6x × 2x crosses. Fragaria viridis–F. moschata hybrids closely resembled F. moschata while F. nubicola–F. moschata hybrids were more intermediate in leaf morphology.

scholarly journals Development of Interspecific Hybrids between a Cultivated Eggplant Resistant to Bacterial Wilt (Ralstonia solanacearum) and Eggplant Wild Relatives for the Development of Rootstocks

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1405
Author(s):  
Mohamed Rakha ◽  
Ahmed Namisy ◽  
Jaw-Rong Chen ◽  
Mohammed E. El-Mahrouk ◽  
Elmahdy Metwally ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Interspecific Hybrid ◽  
Interspecific Hybrids ◽  
Embryo Rescue ◽  
Solanum Melongena ◽  
Wild Relatives ◽  
Interspecific Crosses ◽  
Viable Seeds ◽  
Wild Accessions ◽  
Moderately Resistant

Bacterial wilt caused by Ralstonia solanacerum is one of the most economically and destructive eggplant diseases in many tropical and subtropical areas of the world. The objectives of this study were to develop interspecific hybrids, as potential rootstocks, between the eggplant (Solanum melongena) bacterial wilt resistant line EG203 and four wild accessions (S. incanum UPV1, S. insanum UPV2, S.anguivi UPV3, and S. sisymbriifolium UPV4), and to evaluate interspecific hybrids along with parents for resistance to bacterial wilt strains Pss97 and Pss2016. EG203 was crossed successfully with wild accessions UPV2 and UPV3 and produced viable seeds that germinated when wild accessions were used as a maternal parent in the crosses. In addition, viable interspecific hybrids between EG203 and UPV1 were obtained in both directions of the hybridization, although embryo rescue had to be used. Hybridity was confirmed in the four developed interspecific hybrid combinations with three SSR markers. EG203 was resistant to both strains Pss97 and Pss2016, while UPV1 and UPV3 were, respectively, resistant and moderately resistant to Pss2016. The four interspecific hybrids with UPV2, UPV3, and UPV1 were susceptible to both bacterial wilt strains, indicating that the resistance of EG203, UPV1, and UPV3 behaves as recessive in interspecific crosses. However, given the vigor of interspecific hybrids between eggplant and the three cultivated wild species, these hybrids may be of interest as rootstocks. However, the development of interspecific hybrid rootstocks resistant to bacterial wilt will probably require the identification of new sources of dominant resistance to this pathogen in the eggplant wild relatives.

scholarly journals Towards breeding of rapeseed (Brassica napus) with alien cytoplasm and powdery mildew resistance from Ethiopian mustard (Brassica carinata)

2020 ◽  
Vol 70 (3) ◽  
pp. 387-395
Author(s):  
Qiong Gong ◽  
Chun-Yan Dai ◽  
Xiao-Han Zhang ◽  
Xiao-Li Wang ◽  
Zhen Huang ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Powdery Mildew ◽  
Powdery Mildew Resistance ◽  
Brassica Carinata ◽  
Mildew Resistance ◽  
Ethiopian Mustard ◽  
Alien Cytoplasm

scholarly journals Cytological Evidence for the Sterility of an Interspecific Alstroemeria Hybrid

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 855B-855
Author(s):  
Chunsheng Lu ◽  
Mark Bridgen
Keyword(s):  
Pollen Mother Cell ◽  
Late Stage ◽  
Interspecific Hybrid ◽  
Mother Cell ◽  
Seed Set ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Cytological Evidence ◽  
Stage Of Development ◽  
Hybrid Plants

Self-pollinations of a diploid (2n = 2x = 16) interspecific hybrid from the cross of Alstroemeria aurea × A. caryophyllaea resulted in no seed set. Pollen viability studies with the hybrid demonstrated that only 5% of the pollen grains were viable. Cytological observations with the hybrid pollen mother cell (PMC) revealed abnormal chromosome behaviors, such as no pairing in Prophase I and Metaphase I, and bridges in the Anaphase I and II. Although the development of microspores appeared normal in shape until the stage of tetrad release, some chromosomes did not remain in the nucleus after completing meiosis, formed isolated groups of 1 to 4, and remained in the cytoplasm. This genetic imbalance of the microspores could be one of the causes for the abortion of the pollen grains in the late stage of development. Additional meiotic cytological studies with colchicine-induced tetraploids (2n = 4x = 32) derived from the hybrid plants showed that chromosome pairings were normal in most cases. However, self-pollination with the tetraploid plants failed to set seeds. These studies with the tetraploids further demonstrate that the sterility of the hybrid is due not only to chromosomal differences, but also to complex genic interactions.

scholarly journals Continuous Lighting Reduces Conidial Production and Germinability in the Rose Powdery Mildew Pathosystem

Plant Disease ◽  
2010 ◽  
Vol 94 (3) ◽  
pp. 339-344 ◽  
Author(s):  
A. Suthaparan ◽  
Arne Stensvand ◽  
S. Torre ◽  
Maria L. Herrero ◽  
R. I. Pettersen ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Disease Severity ◽  
Interspecific Hybrid ◽  
Day Length ◽  
Artificial Light ◽  
Potted Plants ◽  
Severity Of Disease ◽  
Detached Leaves ◽  
Growth Chambers ◽  
The Rose

The effect of day length on production and germinability of conidia and severity of disease caused by Podosphaera pannosa, the causal agent of rose powdery mildew, was studied. Whole potted plants or detached leaves of Rosa interspecific hybrid ‘Mistral’ were inoculated with P. pannosa and exposed to 0, 12, 18, 20, 22, or 24 h of artificial light per day in growth chambers equipped with mercury lamps. Increasing duration of illumination from 18 to 20 to 24 h per day reduced production of conidia by 22 to 62%. Exposure to 24 h of illumination per day also strongly reduced disease severity compared with 18 h. Our results suggest that increasing day lengths from 18 h per day to 20 to 24 h may suppress the disease significantly and, thereby, reduce the need for fungicide applications against powdery mildew.

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