Top Cleft Grafting Research Articles

COMBINATION OF GRAFTING TECHNIQUES TO CLONE SUPERIOR GENOTYPES OF Pinus patula Schiede ex Schltdl. et

Grafting in species of Pinus is used to establish asexual seed orchards. Generally, grafting success is low, therefore, it is required to study the influencing factors. Such as the technique and the contact surface of the cambium that depends on the length of the cut on the scion and the rootstock. The objective of this study was to evaluate graft success, growth, and needle development on Pinus patula grafts as functions of the grafting technique and cutting length. It was expected that a specific combination of technique and cutting length would allow predicting the graft success. The techniques of top cleft, side-veneer and splice grafting were used with three cutting lengths (1.5, 2.0, and 2.5 cm) in a completely randomized design with factorial array. The data were analysed with an analysis of variance and treatment means were compared with the Tukey test (p ≤ 0.05). Sixty days after grafting, technique influenced success; top cleft grafting had the highest value (80%) but was not statistically different from side veneer grafting (73.3%). There was, however, statistical difference between top cleft and splice grafting (56.7%, p ≤ 0.05). There were no differences among the three cutting lengths in terms of the three variables evaluated. The effect of the interaction showed that top cleft and side veneer grafts with the cutting length of 1.5 cm expressed the greatest growth (32.4 and 32.2 mm, respectively); followed by side veneer grafting with the cutting length of 2.0 cm (30.4). The study demonstrated that the most viable techniques to increase grafting success in P. patula are the top cleft and side veneer techniques. Cutting length of the scion and the rootstock can be set within the range 1.5 to 2.5 cm

Establishing breeding house of superior sandalwood in Gunung Sewu, Indonesia: preserving the 27 selected genotypes grafted onto two types of rootstocks

Abstract. Ratnaningrum YWN, Faridah E, Utama INS, Prastyo B. 2022. Establishing breeding house of superior sandalwood in Gunung Sewu, Indonesia: preserving the 27 selected genotypes grafted onto two types of rootstocks. Biodiversitas 23: 3488-3497. Developing methods for vegetative propagation of sandalwood (Santalum album Linn.) is important for the mass production of selected genotypes. Previous research has selected the superior genotypes of sandalwood in Gunung Sewu based on seed production, crossing-ability, santalol content and/or the rare alleles characters. This study estimates the grafting compatibility of 27 selected genotypes of sandalwood, which are grafted onto two types of rootstock. In the peak rainy season in February 2021, scions were picked from the 27 genotypes originating from four landraces (Imogiri, Bejiharjo, Bleberan and Petir) in Gunung Sewu. Scions were then grafted onto two types of rootstock using the top-cleft technique. The first rootstock type is the 8 months old seedlings of the red-big-flower sandalwood variant planted in a polybag (Type 1); while the second one is the root-suckers that emerged from horizontal roots (Type 2). Results revealed Petir genotypes as the most surviving scions (100% in Type 2 and 75% in Type 1 rootstock), followed by those originating from Imogiri. All four genotypes originating from Petir (Pt1, Pt2, Pt3 and Pt4) achieved the highest scores in most of the parameters observed. The Type 2 rootstock survived more grafts (57%) compared to those of Type 1 (49%). The number of shoots and the height increment of grafting showed significant differences. The top-cleft grafting technique is considered effective in conserving the superior genotypes of sandalwood and to provide a copy of those genotypes for materials of the crossing units. The use of Petir and Imogiri genotypes as the scions, and the red-big flower variant root-suckers as the rootstocks, are highly recommended for the best grafting success.

Grafting compatibility between variants of sandalwood (Santalum album Linn.) in Gunungkidul, Indonesia

The declining number of adult individuals led to changes in the mating system of certain sandalwood (Santalum album Linn.) populations previously dominated by outcrossing. The genetic quality of the produced seeds and reproduction success decreased due to inbreeding. Therefore, vegetative propagation by grafting is an alternative method to support sandalwood conservation and development. This study aimed to determine the compatibility of rootstocks and scion for vegetative propagation by top cleft grafting on sandalwood variants found in Petir and Wanagama landraces, Gunungkidul Regency, Indonesia. Based on the availability of materials, we used Red Big Flower (RBF), Red Small Flower (RSF), and Yellow Small Flower (YSF) variants, with RBF and RSF as rootstocks and RBF, RSF, and YSF as scions. All six combinations of rootstock-scion indicated compatibility with various results. The average grafting survival was 35.8%, and the RBF-YSF combination showed the highest survival (90%). However, the RSF-YSF combination produced leaves on the scion at most (21 blades). The propagation method of grafting can be applied for the conservation and deployment of sandalwood variants. In tree improvement, grafting is essential to set up the stool plant in a hedge orchard, copy the genetic materials for the clonal test and clonal seed orchard.

Amenability of priority indigenous fruit trees of West and Central Africa to grafting

ABSTRACT Grafting scions of trees with desirable features is an important step for the domestication of indigenous forest fruit trees. Two experiments were carried out in the World Agroforestry (ICRAF) experimental nursery at Yaoundé (Cameroon) to assess the graft success of five forest fruit tree species identified as priority species for domestication in West and Central Africa namely Irvingia gabonensis, Garcinia kola, Cola nitida, Ricinodendron heudelotii and Monodora myristica. In experiment 1, various grafting methods (i.e. side tongue, top cleft, side veneer, and whip-and-tongue) were tested. In experiment 2, three Irvingia species rootstocks (i.e. I. grandifolia, I. gabonensis and I. wombolu) were tested for the grafting of scions of I. gabonensis. Experiment 1 shows that the grafting method significantly affected the percentage of graft success all the tested species except G. kola where all methods resulted in a very high percentage of graft success. The top cleft grafting method had the highest percentage of success, whatever the species. Experiment 2 shows that the type of rootstock significantly influenced the graft success of I. gabonensis scions, with I. wombolu rootstocks showing the highest percentage of graft success at 45.5 ± 7.75%. Our results can guide future propagation programs for these priority fruit tree species for domestication purposes.

Grafting methods and use of fasteners in monoembryonic, polyembryonic, and multi-stemmed jaboticaba (Plinia jaboticaba (Vell) Berg) seedlings

Jaboticaba is a native fruit from Brazil, appreciated for its sweet taste and organoleptic characteristics. The propagation of this fruit species occurs exclusively through seeds, which present high germination rates, although with a long period of juvenility, a fact that favors advances in studies aiming at an early fruiting. This research aimed to study a more adequate and rapid grafting method for the jaboticaba cv. Sabará. The experimental design was in randomized blocks, with 12 treatments consisting of combinations using three types of seedlings (monoembryonic, polyembryonic, and multi-stemmed), two grafting methods (top cleft and splice grafting), and two fasteners (parafilm® tape and circular clip), with three replications consisting of 10 seedlings each. The analyzed characteristics were: monoembryony (%); polyembryony (%), multi-stemming (%), grafting success rate (%), survival (%), scion length (cm), scion diameter (mm), and rootstock diameter (mm). The percentage of monoembryony (46.4%) was higher than the success rates of polyembryony (36%), and multi-stemming (17.6%). The top cleft grafting method of monoembryonic seedlings fastened with parafilm® and circular clip, and polyembryonic seedlings fastened with circular clip were the more suitable for grafting in the jaboticaba cv. Sabará.

Developing sustainable regeneration techniques for four African mahogany species: grafting methods for success and growth

Development of planting materials through vegetative propagation has been difficult in some timber species due to ontogenetic aging which slows down rooting of stem cuttings. Applying grafting techniques helped produce quality planting materials with unique characters, as these techniques influenced union establishment and successful growth of the grafted plants. This study assessed effects of different grafting techniques on establishment and early growth of four African mahogany species (Khaya ivorensis, K. anthotheca, K. grandifoliola and K. senegalensis) using 2-year old seedling rootstocks and scions from mature trees with desirable stem form. We assessed effects of three grafting methods (top-cleft, side grafting, and whip and tongue), and scion type on growth performance of the African mahogany species at 6 months after grafting. K. grandifoliola scion grafted onto K. grandifoliola rootstock recorded highest mean graft success (81.67%), number of leaves formed (11.6) and shoot height growth (7.47 cm) in the top-cleft method. The whip and tongue method was least successful among the three methods. Homografted plants had greatest influence on the grafting parameters for highest mean successes in K. grandifoliola/K. grandifoliola (81.67%), K. anthotheca/K. anthotheca (73.33%) and K. senegalensis/K. senegalensis (63.33%) except K. ivorensis scion type which occurred in the heterograft K. grandifoliola/K. ivorensis (76.67%). Highest performance of the top-cleft method is attributed to good contact between cambia of the grafted species and thus their easy union and growth. Grafting of the four African mahogany species is most successful using top-cleft grafting technique for sustainable production of improved cultivars for restoration and conservation.

Histological aspects of mini-grafting of passiflora edulis sims. And passiflora mucronata lam.

Abstract In Brazil, the main cultivated passion fruit species is Passiflora edulis, which is affected by Fusarium soil fungus. P. mucronata species stands out because it presents resistance to this fungus, being thus an alternative rootstock to yellow passion fruit. Therefore, the aim of this study was to evaluate the anatomy of mini-grafting by top cleft grafting and simple English type grafting, using shoot tips of adult P. edulis plants in clonal rootstocks of P. mucronata. When the rootstocks reached approximately 2.5 mm in diameter and 20 cm in height, grafting was carried out with Parafilm® tape fasteners and silicone clip. At the end of 60 days, histological analysis of the grafting region was performed to verify the formation of the scarring parenchyma tissue (callus). The filling of the mini-grafting cleft by callus was verified; however, there was no differentiation of the new vascular tissue at 60 days after grafting. During the performance of the simple English type grafting using Parafilm® tape, it was extremely difficult to encircle the tape and at the same time to join the bionts so that tissue junction is perfect. Mini-grafting by top cleft grafting using Parafilm® tape fastener is recommended.

Vegetative propagation of Garcinia lucida Vesque (Clusiaceae) using leafy stem cuttings and grafting

Garcinia lucida Vesque (Clusiaceae) is a tree species that is highly valued for its medicinal properties by rural households in the humid forest zone of Cameroon. However, the unsustainable exploitation of the species threatens its long-term regeneration. This study focuses on its vegetative propagation via stem cuttings in non-mist propagators and through grafting. The study tests the effects of three rooting media (sand, sawdust, sand + sawdust (1/1); three leaf sizes (0,25 and 50 cm2); and three types of hormone [indole butyric acid (IBA), indole-3-acetic acid (IAA) and naphthalene acetic acid (NAA)], applied as a single dose. Furthermore, three grafting techniques (cleft, side tongue and whip-and-tongue grafting) were tested. All experiments were designed as completely randomized blocks with three replicates. Results showed that cuttings require a medium that has low water holding capacity and high porosity, and a leaf area of 50 cm2 and NAA treatment; grafting success was affected by the technique used, with top cleft grafting yielding a 100% success rate. From this preliminary study, it is concluded that G. lucida is amenable to vegetative propagation by cuttings and grafting. Key words: tree domestication, leaf area, non-mist propagator, rooting hormone, rooting medium, under-utilised species

Testing different grafting methods for vegetative propagation of baobab (Adansonia digitata L.) in Kenya to assist its domestication and promote cultivation

Baobab (Adansonia digitata L.) is an indigenous fruit tree species of drylands in sub-Saharan Africa. Its leaves, fruits and seeds are important for income generation and food and nutrition security of local communities. Its fruit pulp is rich in vitamin C and calcium, among other nutrients. Domestication of baobab, using mother trees with desired traits for vegetative mass propagation and planting, could meet the increasing demand for baobab pulp and the decreasing abundance of the trees in natural habitats. Two grafting methods were tested in the ICRAF nursery site (Nairobi, Kenya) to identify a suitable propagation technique. Two mother trees were selected (Trees 1 and 2) for harvesting scions. ‘Top cleft’ and ‘side veneer’ grafting were performed on a total of 38 rootstocks for each mother tree (20 of 1-year and 18 of 2-year age), resulting in a total of 76 grafted trees. The grafted trees were then followed during eight months. The experiment was conducted to evaluate grafting success and shoot growth. Statistical analyses included Binomial Logistic Regression for survival rates and three-factorial ANOVA for shoot length. The overall grafting survival rate was 63%. Top cleft grafting showed slightly more survival success than side veneer (71% vs. 55%, p = 0.114). Using 2-year old rootstock was significantly more successful than 1-year old ones (75% vs. 53%; p = 0.029). Using scions from mother Tree 1 was significantly more successful than from Tree 2 (82% vs. 45%; p = 0.001). Length of new shoots growing from the scions of the successful grafts did not significantly differ among the treatments. Our results showed that both grafting methods and rootstock ages were successful and can contribute to the development of baobab domestication programmes for improving food security and livelihoods in African drylands.

Characterization of Brown Streak Virus-Resistant Cassava.

Cassava brown streak disease (CBSD) has become a major constraint to cassava production in East and Central Africa. The identification of new sources of CBSD resistance is essential to deploy CBSD mitigation strategies, as the disease is progressing westwards to new geographical areas. A stringent infection method based on top cleft-grafting combined with precise virus titer quantitation was utilized to screen 14 cassava cultivars and elite breeding lines. When inoculated with mixed infections of Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV), the scions of elite breeding lines KBH 2006/18 and KBH 2006/26 remained symptom-free during a 16-week period of virus graft inoculation, while susceptible varieties displayed typical CBSD infection symptoms at 4 weeks after grafting. The identified CBSD resistance was stable under the coinoculation of CBSV and UCBSV with cassava geminiviruses. Double-grafting experiments revealed that transmission of CBSV and UCBSV to CBSD-susceptible top scions was delayed when using intermediate scions of elite breeding lines KBH 2006/18 and KBH 2006/26. Nonetheless, comparison of virus systemic movement using scions from KBH2006/18 and a transgenic CBSD resistant 60444 line (60444-Hp9 line) showed that both CBSV and UCBSV move at undetectable levels through the stems. Further, protoplast-based assays of virus titers showed that the replication of CBSV is inhibited in the resistant line KBH2006/18, suggesting that the identified CBSD resistance is at least partially based on inhibition of virus replication. Our molecular characterization of CBSD resistance in cassava offers a robust virus-host system to further investigate the molecular determinants of CBSD resistance.

Generation of superior germplasm of Jatropha curcas through ex vitro grafting

An efficient technology capable of cloning superior Jatropha curcas germplasm through grafting on large scale was standardized. This technique overcomes the bottlenecks associated with conventional seed and cutting raised plants. This is a novel technique being capable of establishing well-rooted pure strands of superior genotype utilising stock–scion concept and also explores possibilities for the improvement of existing inferior strands into high yielding and superior varieties. Among the various grafting methods tried, top cleft grafting was found to be most successful. The ideal stock–scion diameter and grafting height was found to be 3–4 cm and 40–60 cm, respectively. Top cleft grafting was more successful, stable and strong in comparison to other grafting methods, exhibiting 92.0 and 94.09 % success during spring and monsoon seasons, respectively. Side cleft grafting proved to be the second best method resulting in 80.0 and 82.23 % success during spring and monsoon seasons, respectively.

Estádios de desenvolvimento de mudas de umbuzeiros propagadas por enxertia

O reconhecido potencial econômico das Spondias (como o umbuzeiro) e o crescente interesse dos mercados internacionais em razão da demanda de frutos com sabores exóticos utilizados no preparo de sucos, doces e sorvetes têm despertado o interesse de pesquisadores e produtores por essa fruteira. Os objetivos do trabalho foram avaliar o desenvolvimento de mudas de umbuzeiro e indicar a melhor idade da muda e do garfo para a realização da enxertia. A semeadura foi realizada em canteiros de madeira de 1,5m de largurax10,0m de comprimento x 0,15m de altura, contendo areia lavada, sendo as sementes colocadas juntas e alinhadas em fileiras espaçadas de 5,0 cm uma da outra. Avaliou-se a altura da muda a partir do colo da planta, do número de folhas, do diâmetro do caule a 5, 10 e 15cm do colo, da matéria fresca e seca da parte aérea e das raízes no dia do transplante e após 60, 120, 180 e 240 dias após o transplantio. Avaliou-se também a sobrevivência das mudas com 180 dias após o transplantio, por meio da enxertia, pelo método de garfagem em fenda cheia ao topo com material propagativo (garfos) de umbuzeiros de várias procedências e idades. O delineamento utilizado foi o inteiramente casualizado, e as repetições foram compostas por seis plantas por parcela. Conclui-se que, a partir de seis meses depois da repicagem, as mudas do umbuzeiro podem ser enxertadas pelo método de garfagem em fenda cheia ao topo. Houve uma sobrevivência de 80% das mudas enxertadas, estando estas prontas para o plantio em campo depois de dois meses após a enxertia. O índice de pegamento diminuiu de forma gradual ao serem usados garfos oriundos de plantas com idade acima de seis anos.

Seleção de matrizes e tipo de propágulo na enxertia de substituição de copa em Ilex paraguariensis

Objetivou-se avaliar a técnica da sobreenxertia em Ilex paraguariensis, visando a substituição de copas. Para tanto, foi avaliada a influência da posição do enxerto na planta matriz, a idade e a matriz, bem como, a definição da melhor época para avaliação do pegamento e vigor dos enxertos. Árvores com 13 anos de idade localizadas em Colombo - PR, foram submetidas ao corte a 10 cm do solo para indução de brotações, sobre as quais foi realizada a enxertia por garfagem no topo em fenda cheia. Os enxertos foram coletados de sete árvores matrizes com idade de 10 anos e sete árvores com idade acima de 80 anos. Das matrizes selecionadas foram retirados enxertos observando-se a posição apical, mediana e basal dentro da planta matriz. O experimento foi instalado em delineamento inteiramente casualizado com três repetições e 42 tratamentos, no esquema fatorial hierárquico 2 x 7 x 3 (duas idades; 7 matrizes, para cada idade; e 3 posições de coleta). A variável resposta de interesse foi proporção de pegamentos e número e comprimento de brotos. Obteve-se um comportamento diferenciado das matrizes quando amostradas em diferentes posições de coleta. A herdabilidade individual dos efeitos genotípicos, estimada para o pegamento dos enxertos, foi superior a 74%, para todos os períodos de avaliação, cujo valor é considerado alto. O coeficiente de variação genética foi da ordem de 34%, para os períodos de acompanhamento iguais ou superiores a 90 dias, indicando boas perspectivas de ganho no melhoramento do material genético. O coeficiente de variação experimental, nesse mesmo período, ficou entre 78% e 94%. Não houve diferenças entre os parâmetros genéticos a partir dos 90 dias. Pode-se concluir que a sobreenxertia de erva-mate diretamente a campo é tecnicamente viável; melhores taxas de pegamento são obtidas em árvores mais novas e com brotações apicais; e as matrizes apresentam respostas diferenciadas quanto ao pegamento na enxertia.

Avaliação de tipos de enxertia e recipientes para produção de mudas de gravioleira (Annona muricata L.)

Na fruticultura moderna, é importante a busca de métodos de cultivo para a redução do tempo de produção. Nesse sentido, o emprego de técnicas de enxertia é fundamental. No Campo Experimental do Centro de Ciências Agrárias da Universidade Federal de Alagoas-UFAL, sob as condições de viveiro, foi conduzido um experimento com gravioleira (Annona muricata L.). O objetivo foi avaliar os efeitos de três métodos de enxertia sobre a porcentagem de pegamento do enxerto. Os métodos de enxertia utilizados foram por borbulhia em escudo, garfagem à inglesa simples e garfagem em fenda cheia, combinado com duas cultivares de gravioleira (Gigante das Alagoas e Crioula) e dois recipientes para mudas (sacos de polietileno e tubetes), empregando-se porta-enxertos com idade de 95 dias após a emergência. Foi avaliado o pegamento do enxerto aos 60 e 90 dias após a enxertia. Verificou-se que a cultivar Gigante das Alagoas foi superior à Crioula quanto ao pegamento do enxerto aos 60 e 90 dias após a enxertia. O melhor método de enxertia dependeu do tipo de recipiente, pois, quando se utilizaram sacos de polietileno, o método de enxertia por borbulhia em escudo foi superior aos de garfagens nas avaliações realizadas aos 60 e 90 dias após a enxertia, apresentando a percentagem média de pegamento do enxerto de 100 e 95%, respectivamente. Entretanto, utilizando recipientes de tubetes, todos os três métodos de enxertia testados apresentaram porcentagem média de pegamento do enxerto superior a 75%, porém, não diferiram estatisticamente entre si. Por meio desses resultados, verifica-se que é possível reduzir o tamanho do recipiente, sem perder a eficiência e a qualidade das mudas.