Search Results

You are looking at 1 - 10 of 216 items for :

  • " C. sinensis " x
  • Refine by Access: All x
Clear All
Free access

Elvia C. Palacios-Torres, M. Alejandra Gutièrrez-Espinosa, Gloria A. Moore, Gustavo Mora-Aguilera, Daniel L. Ochoa-Martínez, and Angel Villegas-Monter

Citrus Tristeza Closterovirus (CTV) induces mild and/or severe symptoms on Citrus species. It may cause death of trees if the rootstock-scion combination is susceptible. It has been found in other plant/virus combinations that transformation with partial or complete viral genes (e.g., coat protein genes) can confer resistance to the resulting transgenic plants. We previously reported A. tumefaciens mediated transformation and production of two sour orange (C. aurantium L.) plants expressing the coat protein gene of CTV, which was the first report of production of transgenic Citrus using a viral gene. However, in order to properly evaluate resistance, it is necessary to obtain as many transgenic Citrus plants from single transformation events as possible. Therefore, we are currently transforming grapefruit (Citrus paradisi) `Marsh' and `Star Ruby' and sweet orange (C. sinensis) `Valencia' with CTV coat protein genes. These species are susceptible to CTV and more amenable to transformation than sour orange. Epicotyl segments of etiolated seedlings were inoculated with A. tumefaciens strain EHA101 harboring binary plasmid pGA482GG containing the coat protein gene of mild Florida CTV strain T30 (CP-T30) or severe Florida strain T36 (CP-T36). Putatively transformed shoots were regenerated on selection medium containing kanamycin. Regenerated shoots were evaluated with GUS assays; those shoots positively identified by GUS were then evaluated with PCR. We have currently identified 17 `Marsh' grapefruit, 20 `Star Ruby' grapefruit, and seven sweet orange putatively transformed plants.

Free access

Sudahono, D.H. Byrne, and R.E. Rouse

Eighteen citrus rootstock seedling lines were tested for their tolerance to Fe chlorosis using sand culture. Potassium carbonate was used to induce Fe-deficiency chlorosis. Chlorosis was quantified by 1) visual ratings, 2) SPAD-502 chlorophyll meter readings, 3) leaf chlorophyll concentration, 4) leaf active Fe, and 5) leaf total Fe. The first four criteria were well correlated among each other but not with leaf total Fe. Although any of the first four measurements could be used to quantify chlorosis, visual ratings and SPAD-502 readings were more convenient. The rootstock that have been reported to be tolerant or very susceptible to Fe chlorosis in calcareous soils were rated similarly for tolerance to bicarbonate-induced Fe chlorosis. Nontrifoliate types such as Texas sour orange (C. aurantium L.), Cleopatra mandarin (C. reticulata Blanco), Vangasay lemon (C. limon Burro.), and Ridge pineapple x Milam 1578-201 (C. sinensis L. Osbeck x C. jambhiri) were tolerant to moderately tolerant. Although most of the trifoliate hybrids tested were moderately susceptible to very susceptible, Smooth Seville x Argentine trifoliate {[C. grands (L.) Osbeck x C. aurantium] x Poncirus trifoliata (L.) Raf.} and F-81-12 citrange (C. sinensis x P. trifoliata) exhibited relatively high tolerance to lime-induced Fe chlorosis.

Free access

N. Tusa, J.W. Grosser, F.G. Gmitter Jr., and E.S. Louzada

Allotetraploid somatic hybrid plants of `Hamlin' sweet orange (Citrus sinensis L. Osbeck) + `Femminello' lemon (C. limon L. Burm. f.), and Milam lemon (purported hybrid of C. jambhiri Lush) + `Femminello' lemon were regenerated via somatic embryogenesis following protoplast fusion. `Hamlin' and Milam protoplasts were isolated from undeveloped ovule-derived embryogenic callus cultures and fused using a polyethylene glycol method with seedling leaf-derived protoplasts of `Femminello' lemon. Somatic hybrids were identified on the basis of leaf morphology, root-tip cell chromosome number, and electrophoretic analyses of phosphoglucose isomerase, phosphoglucose mutase, and 6-phosphogluconate dehydrogenase leaf isozymes. The somatic hybrids will be used in interploid crosses with lemon in an effort to generate seedless triploid lemon types with improved tolerance to mal secco disease.

Free access

S. Jorge, M.C. Pedroso, D.B. Neale, and G. Brown

, Azores, Portugal), Dr. Gil de Seabra (O Porto, Portugal);and also Dr. Serra Lopes and Eng. Monjardino (Parque da Pena, Sintra, Portugal) for the kind gift of C. sinensis leaves; and Dr. Tenreiro and Dr. Durzan for the critical reading of the manuscript.

Free access

Alan T. Whittemore and Alden M. Townsend

-pollinations among seven Celtis species ( C. bungeana , C. koraiensis , C. laevigata , C. occidentalis , C. reticulata , C. sinensis , and C. tenuifolia ) to test the potential for interspecific hybridization in breeding for pathogen resistance in the genus

Free access

Abigail J. Walter, YongPing Duan, and David G. Hall

deserves further exploration. To help clarify the importance of M. paniculata relative to HLB epidemiology in commercial citrus in Florida, we investigated titers of C Las in M. paniculata and C. sinensis plants growing in the same field and in ACP

Free access

Yuan Yu, Chunxian Chen, Ming Huang, Qibin Yu, Dongliang Du, Matthew R. Mattia, and Frederick G. Gmitter Jr.

hybridization between four ancestral taxa, mandarin, citron, pummelo, and Citrus micrantha ( Nicolosi et al., 2000 ), but opinions differ on the origin of some specific species and cultivars. Most of the secondary species including sweet orange ( C. sinensis

Full access

Milica Ćalović, Chunxian Chen, Qibin Yu, Vladimir Orbović, Frederick G. Gmitter Jr, and Jude W. Grosser

[( Citrus clementina × C. reticulata ) × ( C. reticulata × C. sinensis ) ( Aleza et al., 2010 )] and Safor [( C. clementina × C. reticulata ) × ( Citrus unshiu × C. nobilis ) ( Cuenca et al., 2010 )]. As an alternative, the combination of two

Free access

Vicente Gimeno, James P. Syvertsen, Inma Simon, Vicente Martinez, Jose M. Camara-Zapata, Manuel Nieves, and Francisco Garcia-Sanchez

. aurantium L.) without an interstock (VL/SO) or interstocked with ‘Valencia’ orange ( C. sinensis Osbeck; VL/V/SO) or ‘Castellano’ orange ( C. sinensis ; VL/C/SO) were compared in this experiment. Trees were grown in 25-L pots filled with native clay

Free access

Chunxian Chen, Jude W. Grosser, Milica Ćalović, Patricia Serrano, Gemma Pasquali, Julie Gmitter, and Fred G. Gmitter Jr

. amblycarpa Ochse), ‘Changsha’ mandarin ( C. reticulata ), ‘Murcott’ tangor and ‘W. Murcott’ tangor ( C. reticulata × C. sinensis ), and ‘Page’ tangelo [‘Minneola’ tangelo ( C. reticulata × C. paradisi Macf.) × ‘Clementine’ mandarin ( C. reticulata