Microcuttings Root System Morphology and Development under In Vitro and In Vivo Conditions in Citrus Rootstocks (Citrus macrophylla West and Citrange Troyer—Poncirus trifoliata (L.) X Citrus sinensis (L.) OSB.)

Author(s):  
M. Castro ◽  
V. Miranda ◽  
B. Palma
2011 ◽  
Vol 33 (1) ◽  
pp. 311-315 ◽  
Author(s):  
Luzia Yuriko Miyata ◽  
Francisco de Assis Alves Mourão Filho ◽  
João Alexio Scarpare Filho ◽  
Flávia Zambon ◽  
Meire Menezes Bassan ◽  
...  

Transformação genética é considerada uma importante ferramenta auxiliar no melhoramento genético de plantas cítricas. Entretanto, a eficiência de transformação pode variar em função de diversos fatores, incluindo a própria construção gênica utilizada. Este trabalho buscou avaliar a eficiência de transformação genética de plantas de citrange 'Carrizo' [Poncirus trifoliata (L.) Raf. x Citrus sinensis (L.) Osbeck] com duas construções gênicas diferentes contendo o gene uidA (GUS) sob o controle dos promotores Arabidopsis thaliana phloem protein 2 (AtPhP2) e Arabidopsis thaliana sucrose transporter 2 (AtSuT2). Segmentos de epicótilo de plântulas germinadas in vitro foram utilizados como explantes. O gene nptII, que confere resistência ao antibiótico canamicina, foi utilizado nas construções gênicas como agente de seleção para regeneração de plantas transgênicas. O ensaio histoquímico com X-GLUC foi realizado em todas as brotações regeneradas para verificar a expressão do gene uidA. Dos 4.790 segmentos de epicótilo utilizados, registrou-se a regeneração de 366 brotações com reação positiva no ensaio histoquímico, as quais foram enxertadas em porta-enxertos cultivados in vitro. Cinco dessas brotações, de cada construção gênica, foram selecionadas para análise da PCR, com primers específicos para amplificação da sequência do gene uidA. A inserção do transgene foi confirmada por PCR em todas as brotações selecionadas. A eficiência de transformação e o número de brotos escapes, avaliada pelo teste histoquímico, variaram em função das construções gênicas utilizadas.


2018 ◽  
Vol 236 ◽  
pp. 90-95 ◽  
Author(s):  
Giulio Piccirillo ◽  
Raffaele Carrieri ◽  
Giancarlo Polizzi ◽  
Antonino Azzaro ◽  
Ernesto Lahoz ◽  
...  

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Qin Long ◽  
Meixia Du ◽  
Junhong Long ◽  
Yu Xie ◽  
Jingyun Zhang ◽  
...  

AbstractPathological hypertrophy (cell enlargement) plays an important role in the development of citrus canker, but its regulators are largely unknown. Although WRKY22 is known to be involved in pathogen-triggered immunity and positively regulates resistance to bacterial pathogens in Arabidopsis, rice and pepper, the CRISPR/Cas9-mediated partial knockout of CsWRKY22 improves resistance to Xanthomonas citri subsp. citri (Xcc) in Wanjincheng orange (Citrus sinensis Osbeck). Here, we demonstrate that CsWRKY22 is a nucleus-localized transcriptional activator. CsWRKY22-overexpressing plants exhibited dwarf phenotypes that had wrinkled and thickened leaves and were more sensitive to Xcc, whereas CsWRKY22-silenced plants showed no visible phenotype changes and were more resistant to Xcc. Microscopic observations revealed that the overexpression of CsWRKY22 increased cell size in the spongy mesophyll. Transcriptome analysis showed that cell growth-related pathways, such as the auxin and brassinosteroid hormonal signaling and cell wall organization and biogenesis pathways, were significantly upregulated upon CsWRKY22 overexpression. Interestingly, CsWRKY22 activated the expression of CsLOB1, which is a key gene regulating susceptibility to citrus canker. We further confirmed that CsWRKY22 bound directly to the W-boxes just upstream of the transcription start site of CsLOB1 in vivo and in vitro. We conclude that CsWRKY22 enhances susceptibility to citrus canker by promoting host hypertrophy and CsLOB1 expression. Thus, our study provides new insights into the mechanism regulating pathological hypertrophy and the function of WRKY22 in citrus.


2011 ◽  
Vol 25 (7) ◽  
pp. 1000-1010 ◽  
Author(s):  
Bo-Young Kim ◽  
Hyung-Young Yoon ◽  
Sun-Il Yun ◽  
Eun-Rhan Woo ◽  
Nan-Kyu Song ◽  
...  

2020 ◽  
Vol 200 (9) ◽  
pp. 55-62
Author(s):  
Tat'yana Lekonceva ◽  
Aleksandr Fedorov

Abstract. The aim of research is improvement of the production technology in vitro of the grapes Pamyati Dombkovskoy. Methods. Methods generally accepted in the practice of clonal micropropagation of plants were applied. There are sterilization of the starting material, introduction into culture, clonal micropropagation, and in vitro rooting, followed by adaptation to in vivo conditions. The study object was micro cuttings grapes of the cultural variety Pamyati Dombkovskoy. The experiments were set up in three replicates, one replication was at least 10 test tubes. Statistical processing of the data obtained was carried out by the dispersion method according to B. A. Dospekhov. The following parameters were taken into account: micro-shoots and microplants heights, leaves number, proliferation coefficient. Root development was assessed in points. The success of adaptation was considered as the percentage of adapted microplants to the total number planted in the substrate. At the stage of adaptation, we applied supplemented and developed by us technique during clonal micropropagation of the Angelica rose. Research result. Success of estanlishment explants was 40 % on Murashige and Skoog growing medium with a reduced content of macronutrients, when introduced into a sterile culture in vitro. The optimal concentration of 6-benzylaminopurine (6-BAP) was determined at the proliferation stage – 1 mg/l. There are decrease in the proliferation coefficient from 4.4 pcs/cutting to 3.3 and 2.9 pcs/cutting respectively with an increase in the concentration of cytokinin 6-BAP to 2.0 and 3.0 mg / l (LSD05 = 1.0). It was revealed that the best growing medium for rooting micrograpes is the environment according to Zlenko and others, when the best microplants development is achieved according to such morphometric parameters as microshoots height, leaves number and root system. On the medium Zlenko and others, microplants height was higher by 4.3 mm than the control with LSD05 = 2.7, the number of leaves was more by 0.5 with LSD05 = 0.3, and the root system of microplants is better developed by 0.4 points (LSD05 = 0.2). Scientific novelty. Positive results were received when rooted grapes cuttings were adapted after 14 days of cultivation on rooting medium, which allows to reduce the duration of micro grapes in a test tube in 2–4 times compared with the conventional method. The use of the biological product “Trichoderma Veride” for watering the soil substrate with the subsequent spraying of adaptable microplants with the organosilicone fertilizer “Siliplant” is recommended.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 671d-671 ◽  
Author(s):  
Mohammad R. Karim ◽  
Glenn C. Wright ◽  
Kathryn C. Taylor

A field trial conducted at Yuma, Ariz., examined the effect of foliar boron application on fruit yield and quality of Citrus sinensis cv. Hamlin. Boron was applied to 5-year-old trees at five treatment levels (0, 500, 1000, 2000, and 3000 ppm) before or after flowering in a split plot design. At harvest, fruit number, size and quality were determined. Yield (P = 0.01) and average fruit number per tree (P = 0.02) were different among treatments. The highest yield was obtained with the 500 ppm treatment. In this first year of the trial there was no difference in average fruit weight, fruit pH, titratable acidity, peel thickness, juice volume, or soluble solid content of fruit between the treatments. Previous studies indicate that boron influenced in vivo and in vitro pollen germination in many crops. Increased fruit yield may have occurred because boron was transported to the flowers where it exerted its influence on increased fruit set through an effect on pollen viability or pollen tube growth. Further investigation of this hypothesis is underway.


HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 516-520 ◽  
Author(s):  
G. Reforgiato Recupero ◽  
G. Russo ◽  
S. Recupero

The breeding of citrus triploid hybrids started at Istituto Sperimentale per l'Agrumicoltura spell out in Acireale, Italy, in 1978 (Starrantino and Reforgiato, 1981). The strategy used has been to cross a monoembryonic 2x female parent with a 4x male parent. The imbalance between the embryo and endosperm ploidy (3:4) makes seeds from such crossings incapable of germinating in vivo. However, in vitro cultivation has been used to rescue the embryos. In this paper we report the main characteristics of triploid hybrids from 22 different parents, including sweet orange [Citrus sinensis (L.) Osbeck], mandarin (C. reticulata Blanco), clementine (C. reticulata Blanco), grapefruit (C. paradisi Macf.), pummelo [C.maxima], tangor (C. reticulata × C. sinensis), lemon [C. limon (L.) Burm. f.], citron (C. medica L.), and Fortunella hindsii (Champ.) Swing. Tetraploid parents are duplex because they originate from the doubling of chromosome number of the nucella or of other somatic tissues. The segregation and recombination process results in triploid hybrids with characteristics that are nearer to the 4x parent than the 2x one. This strategy is important in obtaining seedless hybrids similar to a parent after generations of backcrossing.


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