the scions and rootstocks improves graft success because it ensures quick callus union formation from both graft partners. Many reports on graft success have been centered on rootstock diameter (thickness), proximity or proper alignment of vascular
Simon A. Mng’omba and Elsa S. du Toit
Simon A. Mng'omba, Elsa S. du Toit, Festus K. Akinnifesi and Helena M. Venter
bark and wood tissues below the union, and this is termed a “partial” graft union ( Ünal, 1995 .) Graft partners with a partial union showed a good level of callusing at the union (external view and longitudinal section). Therefore, a poor graft union
Hatice Gulen, Rajeev Arora, Ali Kuden, Stephen L. Krebs and Joseph Postman
The similarity or differences of peroxidase isozymes in rootstocks and scions may influence their graft compatibility. This study was conducted to identify peroxidase isozymes that may be used as markers to predict compatibility between pear (Pyrus communis L.) and various quince (Cydonia oblonga Mill.) clones. `Bartlett' (BT) and `Beurre Hardy' (BH) pear cultivars are known to form incompatible and compatible grafts, respectively, with quince rootstocks. The two pear scion cultivars were budded on `quince A' (QA), `quince BA-29', and 15 selected quince clones from Turkey. Bark and cambial tissues were taken from nonbudded rootstocks and scions, and 4 cm above and below the graft union for peroxidase isozyme analysis performed by starch gel electrophoresis. Isoperoxidase analyses were also performed on samples from the graft unions collected 12 months after grafting. Many isozyme bands were observed commonly in the two scions; however, one anodal peroxidase A was detected in BH (compatible scion) but not in BT (incompatible scion) samples. This isoperoxidase was also detected in QA, Quince BA-29, and nine of the Turkish quince clones. Another isoperoxidase, band B, was detected in BH but not in BT or any of the rootstocks. However, the compatible (BH/QA) and moderately compatible (BT/BA-29) graft union tissues contained bands A and B whereas incompatible graft union tissues (BT/QA) lacked both. Graft union samples involving BT and five Turkish quince clones (705, 609-2, 702, 804, and 806) had both `A' and `B' isoperoxidases while one or both of these bands were absent in nonbudded graft partners. Field observations of 3.5 year-old grafts of BT and Turkish quince clones revealed that the vegetative growth (vigor) of BT scion was significantly greater, when grafted on these five clones, than that in graft combinations with other clones. We suggest that matching of isoperoxidase `A' in quince rootstocks and BH pear scion may be associated with a compatible graft combination. Additionally, presence of isoperoxidases `A' and `B' in the graft union tissues may be used as an indicator to predict a compatible graft between BT and quince rootstocks.
Ana Pina, Pilar Errea, Ana Wünsch and Rafael Gella
high degree of differentiation and a great number of sieve plates indicating good symplasmic continuity, a prerequisite for effective translocation between both graft partners ( Schöning and Kollmann, 1997 ). In addition to these observations, in the
Qing Xu, Shi-Rong Guo, He Li, Nan-Shan Du, Sheng Shu and Jin Sun
), so it was studied at day 6. In our study, the necrotic layer of “H” already existed and made a close contact between scion and rootstock, while that of “D” had not appeared yet. The previous studies indicate that graft partners are held together at
Joan R. Davenport, Markus Keller and Lynn J. Mills
grafting partners. Therefore, one possible way of increasing winter survival could be to alter the height of grafting. To evaluate this, buds of ‘Chardonnay’, ‘Merlot’, and ‘Syrah’ were made low (27 cm aboveground surface) and for both ‘Chardonnay’ and
Guo-qing Song, Aaron E. Walworth and Wayne H. Loescher
, K. Li, T.Z. Harada, T. 2011 Mobile signal transported over a long distance induces systemic transcriptional gene silencing in a grafted partner J. Expt. Bot. 62 4561 4570 Banerjee, A.K. Chatterjee, M. Yu, Y.Y. Suh, S.G. Miller, W.A. Hannapel, D