The Albert Katz International School for Desert Studies, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel.
French Associates Institute for Agriculture and Biotechnology of Drylands, Blaustein Institutes for Desert Research, Sede Boqer Campus, Ben-Gurion University of the Negev, P.O.B. 653, Beer Sheva, 84104, Israel.
Plant Sci. 2021 May;306:110852. doi: 10.1016/j.plantsci.2021.110852. Epub 2021 Feb 17.
The effect of the rootstock on the acropetal and basipetal transport of photoassimilates and hormones was studied in the 'Kiran' (Ki) melon cultivar grafted onto pumpkin rootstocks with different degrees of compatibility. A complementary experiment was performed to compare the incompatible combination (as evidenced by plant collapse at the fruit ripening stage), designated Ki/r53, with self-grafted r53/r53 as a model compatible combination. Both experiments showed the accumulation of a number of amino acids, sugars, and sugar alcohols in the scion of the incompatible Ki/r53 grafts. Additionally, they showed a marked reduction of trans-zeatin-type cytokinins and an elevated content of cis-zeatin-type cytokinins in the rootstock, and the opposite pattern in the scion, hinting at the possible involvement of a hormonal signal for graft compatibility. There was no direct evidence of a blockage at the graft union, since hormone acropetal and basipetal trafficking was demonstrated for all combinations. Dye uptake experiments did not show xylem flow impairment. A possibly significant finding in the incompatible combination was the deposition of undifferentiated cells in the hollow space that replaces the pith region in melon and pumpkin. The link between the above findings and the collapse of the plants of the incompatible combination remains unclear.
砧木对接穗中同化物和激素向顶和向基运输的影响，在‘Kiran’（Ki）甜瓜品种嫁接到不同亲和性南瓜砧木上进行了研究。进行了一项补充实验，将表现出不亲和性（表现在果实成熟阶段植株萎蔫）的组合 Ki/r53 与自嫁接 r53/r53 作为模型亲和性组合进行比较。两个实验都表明，不亲和性 Ki/r53 嫁接接穗中积累了许多氨基酸、糖和糖醇。此外，它们还表明，在砧木中，反式玉米素型细胞分裂素显著减少，而顺式玉米素型细胞分裂素含量升高，而在接穗中则呈现相反的模式，暗示可能存在与嫁接亲和性相关的激素信号。由于所有组合都证明了激素向顶和向基运输，因此没有直接证据表明嫁接结合处存在阻塞。染料摄取实验并未显示木质部流受损。在不亲和性组合中一个可能的重要发现是，在甜瓜和南瓜中空部分取代髓部的位置有未分化细胞的沉积。上述发现与不亲和性组合中植物萎蔫之间的联系尚不清楚。
