Graft Compatibility Between European Pear Cultivars and East Malling “C” Rootstock

Abstract

-Graft incompatibility is one of the main factors limiting european pear production in Brazil. At present, there is no clear indication of the best combination(s) of european pear cultivars and quince rootstocks for graft compatibility. The study evaluated the graft compatibility for combinations of european Abbè Fetel, Rocha and Williams pear cultivars grafted onto the EMC quince rootstock. The experiment was performed in a commercial european pear orchard in the Urupema municipality, in State of Santa Catarina, during the 2011/12, 2012/13 and 2013/14 growing seasons. The plant growth variables comprised the section increment (mm) in the trunk diameter in the graft union region of cultivars and rootstocks; difference in the diameter of the graft for cultivars and rootstocks; "translocated" incompatibility; "located" incompatibility and the vascular connection in the graft union region, which was assessed by immersing the bases of the plants in a 0.08% succinic acid solution. There were "located" and "translocated" incompatibility between the european Williams pear cultivar and the EMC rootstock based on the vascular discontinuity in the graft union region, which prevented the translocation of succinic acid stain. Thus, the Williams/EMC combination is considered incompatible and it is not recommended for use in commercial orchards. The Rocha/EMC and Abbè Fetel/EMC are considered partially incompatible combinations and showed good development eight years after planting. Index Terms: compatibility level; located incompatibility; translocated incompatibility; Pyrus communis L.; vascular union; vigor. COMPATIBILIDADE DE ENXERTIA ENTRE CULTIVARES DE PEREIRAS EUROPEIAS E PORTAENXERTOS DE MARMELEIRO EAST MALLING "C"RESUMO -A incompatibilidade de enxertia é um dos principais fatores limitantes da produção de peras no Brasil. Até o presente, não há uma indicação da melhor combinação de cultivares de pereiras-europeias e porta-enxertos de marmeleiros com compatibilidade de enxertia. O estudo avaliou a compatibilidade de enxertia entre as combinações de pereiras europeias Abbè Fetel, Rocha e Williams enxertadas sobre o porta-enxerto de marmeleiro EMC. O experimento foi conduzido em pomar comercial de pereira-europeia no município de Urupema, estado de Santa Catarina, durante as estações de crescimento de 2011/2012, 2012/2013 e 2013/2014. As variáveis de crescimento de plantas foram: o incremento do diâmetro do tronco na região de união do enxerto entre as cultivares e o porta-enxerto (mm); diferença de diâmetro do enxerto das cultivares e do porta-enxerto, incompatibilidade "translocada", incompatibilidade "localizada" e a conexão vascular na região da enxertia, o qual foi determinada por meio de imersão da base da planta em solução com ácido succínico a 0,08%. Houve incompatibilidade localizada e translocada entre a cultivar de pereira-europeia Williams e o porta-enxerto EMC, baseado na descontinuidade vascular na região de união do enxerto, o qual impediu a translocação do ácido succínico. A combinação Williams...

The Effects of Different Rootstocks on the Graft Success and Stion Development of Some Pear Cultivars

“…The 'Deveci' and 'Williams' pear cultivars were used as standard cultivars. The 'Deveci' is known as being compatible with quince rootstocks (Özçağıan et al, 2005) but the 'Williams' is known as being incompatible or moderately compatible with quince rootstocks (Dondini and Sansavini, 2012;Gulen et al, 2002;Hudina et al, 2014;Machado et al, 2016). Scions required for grafting were taken from the 5 year-old stock parcel in the experiment area.…”

Effect of the Rootstock and Cultivar on Graft Success and Sapling Development and Graft Incompatibility in Pear

“…Serttas and Ozturk (2020) emphasized that the effect of rootstocks and cultivars on the graft union diameter was significant. It has been reported that the diameter difference between the rootstock and cultivar in the grafted plants may be related to the graft incompatibility (Özçağıran, 1982;Rodrigues et al, 2004;Darikova et al, 2011;Machado et al, 2016). Machado et al (2016), who examined the graft incompatibility of EMC quince rootstock and some pear cultivars, reported that there was a difference in diameter between rootstocks and cultivars in the graft union region, and they found that the Williams/EMC combination was incompatible, the Rocha/EMC and Abate Fetel/EMC combinations were partially incompatible.…”

“…It has been reported that the diameter difference between the rootstock and cultivar in the grafted plants may be related to the graft incompatibility (Özçağıran, 1982;Rodrigues et al, 2004;Darikova et al, 2011;Machado et al, 2016). Machado et al (2016), who examined the graft incompatibility of EMC quince rootstock and some pear cultivars, reported that there was a difference in diameter between rootstocks and cultivars in the graft union region, and they found that the Williams/EMC combination was incompatible, the Rocha/EMC and Abate Fetel/EMC combinations were partially incompatible. Rodrigues et al (2004) and Pio et al (2008) and Francescatto et al (2010) reported that large diameter differences between rootstocks and cultivars were indicative of morphological graft incompatibility symptom.…”

“…Quince rootstocks provide the control of the growth vigor (dwarfing) of the trees grafted to them, earliness in yield, increase in fruit yield and quality, high density planting, increase in fruit size, easy management practices such as pruning, spraying, weed control and harvesting. However, these rootstocks also have negative properties such as sensitivity to winter cold, calcareous soil, chlorosis and fire blight and poor graft compatibility (Ermel et al, 1999;Pina and Errea, 2009;Francescatto et al, 2010;Machado et al, 2016;Dolkar et al, 2018). Pears show graft incompatibility due to morphological, anatomical, physiological or biochemical reasons, especially when they are grafted on quince of the different genera (Özçağıran, 1982;Ermel et al, 1999;Jackson, 2003;Francescatto et al, 2010;Hudina et al, 2014).…”

“…In the pear, the graft incompatibility may occur with some symptoms in early and late stage of growing period on the quince rootstocks (Errea, 1998;Ermel et al, 1999;Pina and Errea, 2005;Davarynejad et al, 2008;Rahman et al, 2017;Dolkar et al, 2018). The swelling on the graft site, diameter differences between scion and stock, angle of shoot growth, leaflet becomes yellowish, low graft success and survival ratio, reduction of vegetative growth and differences in growth rate between rootstock and scion are some symptoms of the graft incompatibility (Pina and Errea, 2005;Davarynejad et al, 2008;Hartman et al, 2011;Machado et al, 2016;Rahman et al, 2017). This phenomena might be due to the absence of differentiation of callus tissues into new phloem tissues or necrosis of the cells in the site of scion (Pina and Errea, 2009;Hartmann et al, 2011;Dolkar et al, 2018).…”