scholarly journals Screening Hybrid Citrus Rootstocks for Resistance to Tylenchulus semipenetrans Cobb

HortScience ◽  
1997 ◽  
Vol 32 (6) ◽  
pp. 1116-1119 ◽  
Author(s):  
S. Verdejo-Lucas ◽  
F.J. Sorribas ◽  
J.B. Forner ◽  
A. Alcaide
Keyword(s):  
Citrus Sinensis ◽  
Poncirus Trifoliata ◽  
Nematode Reproduction ◽  
Greenhouse Test ◽  
Tylenchulus Semipenetrans ◽  
Troyer Citrange

The response of 22 citrus hybrid rootstocks to a Mediterranean biotype of Tylenchulus semipenetrans Cobb was determined in a greenhouse test. Five of the 11 rootstocks with Poncirus trifoliata (L.) Raf in their parentage did not support nematode reproduction. However, rootstocks with Troyer citrange [Citrus sinensis (L.) Osbeck × P. trifoliata (L.) Raf] in their parentage were susceptible to the nematode.

scholarly journals Resistance of Hybrid Citrus Rootstocks to a Mediterranean Biotype of Tylenchulus semipenetrans Cobb

HortScience ◽  
2000 ◽  
Vol 35 (2) ◽  
pp. 269-273 ◽  
Author(s):  
S. Verdejo-Lucas ◽  
F.J. Sorribas ◽  
J.B. Forner ◽  
A. Alcaide
Keyword(s):  
Reproductive Potential ◽  
Poncirus Trifoliata ◽  
Nematode Reproduction ◽  
Tylenchulus Semipenetrans ◽  
Citrus Volkameriana ◽  
Citrus Nematode ◽  
Different Levels ◽  
Cleopatra Mandarin ◽  
Troyer Citrange ◽  
Greenhouse Tests

The response of 52 citrus hybrid rootstocks to a Mediterranean biotype of Tylenchulus semipenetrans Cobb was determined in greenhouse tests. Seven selections of the cross `Cleopatra' mandarin [Citrus reshni Hort. × Poncirus trifoliata (L.) Raf], and one of Citrus volkameriana Pasq. × P. trifoliata did not support nematode reproduction and were considered as highly resistant to the citrus nematode. The nematode showed very low infectivity and reproductive potential on seven additional selections of `Cleopatra' mandarin × P. trifoliata, one of `King' mandarin × P. trifoliata, and two C. volkameriana × P. trifoliata. These selections were considered as nematode resistant. All the selections with `Troyer' citrange [Citrus sinensis (L). Osbeck × P. trifoliata (L.) Raf] in their parentage supported nematode reproduction but showed different levels of susceptibility.

New citrus selections from Cleopatra mandarin × Poncirus trifoliata with resistance to Tylenchulus semipenetrans Cobb

Nematology ◽  
2003 ◽  
Vol 5 (2) ◽  
pp. 227-234 ◽  
Author(s):  
César Ornat ◽  
F. Javier Sorribas ◽  
Juan Forner ◽  
Magda Galeano ◽  
Antonio Alcaide ◽  
...  
Keyword(s):  
Poncirus Trifoliata ◽  
Relative Resistance ◽  
Nematode Reproduction ◽  
Initial Inoculum ◽  
Trunk Diameter ◽  
Carrizo Citrange ◽  
Tylenchulus Semipenetrans ◽  
Proportional Increase ◽  
Cleopatra Mandarin ◽  
Fresh Root

AbstractThe response of four resistant selections of Cleopatra mandarin × Poncirus trifoliata to increasing inoculum densities of a population of the Mediterranean biotype of Tylenchulus semipenetrans was determined in microplots established at two sites. One-yearold trees of the resistant selections and of a susceptible Carrizo citrange were inoculated with 0, 1, 5 or 10 × 104 eggs per plant (Pi). Nematode reproduction on the resistant selections was consistently less than on Carrizo citrange. Increasing initial inoculum densities had no effect on the relative resistance in three selections (03.01.42, 03.01.5 and 03.01.16). Selection 03.01.42 was highly resistant (no females and eggs per g fresh root), and 03.01.5 and 03.01.16 both had good resistance (≤15% as many females and eggs per g fresh root as on Carrizo citrange). The fourth selection (03.01.18) expressed resistance at Pi 1 and 5 × 104 eggs per plant but was moderately susceptible at 10× 104 eggs per plant (>15% females and eggs per g fresh root). Deposits of a lignin or suberin-like material were more abundant in resistant selections 03.01.5 and 03.01.18 than in susceptible Carrizo citrange. The proportional increase in trunk diameter of inoculated and uninoculated trees of each rootstock was similar at both sites.

scholarly journals 179 Impact of Rootstock on Maturity and Storage of Valencia Orange Fruits

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 421D-421
Author(s):  
M.M. Khattab ◽  
A.A. Elezaby ◽  
S. ElOraby ◽  
A.M. Hassan
Keyword(s):  
Citrus Sinensis ◽  
Poncirus Trifoliata ◽  
Maturity Stage ◽  
Full Bloom ◽  
Valencia Orange ◽  
Volkamer Lemon ◽  
Orange Trees ◽  
And Storage ◽  
Cleopatra Mandarin ◽  
Troyer Citrange

This investigation was carried out on 13-year-old Valencia orange trees [Citrus sinensis (L.) Osbeck] budded on five different rootstocks. Heat unit accumulation (temperature above 12.5 °C) for fruits worked on the various rootstocks were calculated from full bloom to maturity stage. Valencia fruits on Troyer citrange (C. sinensis × Poncirus trifoliata) and Carrizo citrange (C. sinensis × Poncirus trifoliata) rootstocks matured earlier when compared to those growing on Cleopatra mandarin (C. reticulata Blanco), Volkamer lemon (C. volkameriana Ten. and Pasq.), and sour orange (C. aurantium) rootstocks. The results showed that the Valencia fruits, regardless of rootstock, could be stored for different periods under different conditions. However, in order to avoid degradation in fruit quality, storing periods should not exceed 21, 60, and 120 days under room conditions (25 °C and RH 25% to 35%), 4 °C (RH 80% to 85%), and 8 °C (RH 80% to 85%); respectively.

scholarly journals Metabolic Contributors to Drought-enhanced Accumulation of Sugars and Acids in Oranges

2001 ◽  
Vol 126 (5) ◽  
pp. 599-605 ◽  
Author(s):  
Brandon R. Hockema ◽  
Ed Etxeberria
Keyword(s):  
Drought Stress ◽  
Citrus Sinensis ◽  
Soluble Sugar ◽  
Poncirus Trifoliata ◽  
Sink Strength ◽  
Quality Indices ◽  
Orange Fruit ◽  
Stem Water ◽  
Mild Drought ◽  
Troyer Citrange

The nature of sink strength in orange fruit and changes occurring during drought stress were investigated. Potted trees of `Hamlin' orange [Citrus sinensis (L.) Osbeck] grafted on Troyer citrange [Citrus sinensis × Poncirus trifoliata (L.) Raf.] were irrigated using a microsprinkler system creating either well-watered or water-stressed conditions, as determined by stem water potentials. Fruit were harvested every other week from trees of both well-watered and drought-stressed treatments during the final stage of fruit development when sugars accumulate rapidly. Fruit quality indices and activities of sucrose synthase (SuSy), invertase, sucrose-P synthase, sucrose-P phosphatase, V-ATPase, and V-PPase were measured. Acids and soluble sugar concentrations were elevated in drought-stressed fruit, whereas juice pH decreased in those same fruit. Results indicate that increased sink strength in fruit from stressed trees was accompanied by an increase in SuSy activity and lowered juice pH. The remaining enzymes examined in this experiment showed no changes in activity between control and treated fruit, as was the case for plasmalemma and tonoplast sucrose carriers. Based on the present data, we conclude that SuSy and vacuolar pH are the predominant factors controlling photoassimilate accumulation in orange fruit under enhanced sink conditions brought about by imposition of a mild drought stress.

scholarly journals Desenvolvimento vegetativo e custo de produção de porta-enxertos de citros em recipientes para fins de subenxertia

2007 ◽  
Vol 42 (5) ◽  
pp. 679-687 ◽  
Author(s):  
Eduardo Augusto Girardi ◽  
Francisco de Assis Alves Mourão Filho ◽  
Sônia Maria de Stefano Piedade
Keyword(s):  
Citrus Sinensis ◽  
Poncirus Trifoliata ◽  
Citrus Paradisi ◽  
Citrus Jambhiri ◽  
Citrus Volkameriana

O objetivo deste trabalho foi avaliar o desenvolvimento vegetativo e estimar o custo de produção de 11 porta-enxertos de citros para fins de subenxertia, em diferentes recipientes. Avaliaram-se limão 'Cravo' clone Limeira (Citrus limonia Osbeck); citrumelo 'Swingle' (Poncirus trifoliata (L.) Raf. x Citrus paradisi Macf.); tangerina 'Cleópatra' (Citrus reshni Hort. ex Tanaka); tangerina 'Sunki' (Citrus sunki Hort. ex Tanaka); limão 'Volkameriano' clone Catânia 2 (Citrus volkameriana Pasquale); laranja 'Caipira' clone DAC (Citrus sinensis L. Osbeck); limão 'Rugoso da África' clone Mazoe (Citrus jambhiri Lush.); Poncirus trifoliata 'Davis A'; tangerina 'Sun Shu Sha Kat' (Citrus sunki Hort. ex Tanaka); tangerina 'Sunki' clone 2506 ou Fruto Grande (Citrus sunki Hort. ex Tanaka) e Poncirus trifoliata 'Barnes'. Foram utilizados tubetes de 290 mL, sacolas de 1,7 L, e porta-enxertos transplantados de tubetes de 75 mL para sacolas de polietileno de 1,7 e 4,5 L. Porta-enxertos produzidos diretamente em sacolas de 1,7 L atingem ponto ideal de subenxertia em menor tempo, de 100 a 150 dias após a semeadura, e permitem a obtenção de plantas maiores e com sistema radicular adequado, porém com custo de produção superior ao sistema de produção em tubetes de 290 mL.

scholarly journals Mudas de laranjeira 'valência' sobre dois porta-enxertos e sob diferentes manejos de adubação

2010 ◽  
Vol 32 (3) ◽  
pp. 855-864 ◽  
Author(s):  
Eduardo Augusto Girardi ◽  
Francisco de Assis Alves Mourão Filho ◽  
André Siqueira Rodrigues Alves
Keyword(s):  
Citrus Sinensis ◽  
Poncirus Trifoliata ◽  
Citrus Paradisi

O manejo da adubação é uma das principais práticas culturais para a produção de mudas cítricas em cultivo protegido. Avaliou-se o efeito de seis tipos de manejo das adubações comercialmente recomendadas na produção de mudas de laranjeira 'Valência' [Citrus sinensis (L.) Osbeck] enxertada sobre os porta-enxertos limoeiro 'Cravo' (Citrus limonia Osbeck) e citrumeleiro 'Swingle' [Citrus paradisi Macf. x Poncirus trifoliata (L.) Raf.]. As avaliações foram conduzidas a partir da transplantação dos porta-enxertos até 180 dias após a enxertia, em viveiro empresarial, em Conchal-SP. Os manejos corresponderam a duas soluções de fertilizantes solúveis aplicadas isoladamente, soluções de fertilizante solúveis associadas a fertilizante de liberação controlada e aplicação exclusiva de fertilizante de liberação controlada. O delineamento experimental adotado foi o fatorial 2 x 6 (porta-enxerto x manejo da adubação), em blocos casualizados, com três repetições e 12 mudas na parcela. O limoeiro 'Cravo' induziu maior crescimento ao enxerto. O crescimento vegetativo das mudas foi similar após o uso de fertilizantes solúveis ou de liberação controlada, apesar da grande variação de quantidades totais de nutrientes fornecidas às plantas. Desta forma, o viveirista poderá optar pelo manejo mais econômico ou prático, conforme as condições locais.

scholarly journals Comportamento da laranjeira Piralima sobre Poncirus trifoliata com variações na altura de enxertia

1994 ◽  
Vol 51 (1) ◽  
pp. 69-74 ◽  
Author(s):  
V.R. Sampaio
Keyword(s):  
Citrus Sinensis ◽  
Poncirus Trifoliata

Pesquisou-se a combinação de laranjeira Piralima, Citrus sinensis (L.) Osb. sobre Poncirus trifoliata (L.) Raf. fazendo-se variações nas alturas das enxertias, com operações efetuadas a zero, dez, vinte e quarenta centímetros de altura. Avaliações realizadas após seis anos e meio de implantação do experimento permitiram as seguintes conclusões: 1) as alturas das enxertias afetaram o desenvolvimento global das plantas, com as enxertias mais altas reforçando o efeito ananicante do Poncirus trifoliata; 2) as diferentes alturas de enxertia não afetaram as produções de frutos das três primeiras produções comerciais. Na quarta colheita surgiu diferença entre os tratamentos extremos, com maiores produções acontecendo para plantas enxertadas próximas ao solo; 3) o Poncirus trifoliata induziu características ananicantes às copas e as constantes boas produções de frutos de bom tamanho. Mostrou-se ser porta-enxerto interessante para o cultivar Piralima.

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