Department of Vegetable Crops, Agricultural Research Organization, Newe Ya'ar Research Center, PO Box 1021, Ramat Yishay 300-95, Israel.
J Exp Bot. 2011 Jan;62(1):177-84. doi: 10.1093/jxb/erq255. Epub 2010 Aug 20.
The effects of grafting on Na and Cl(-) uptake and distribution in plant tissues were quantified in a greenhouse experiment using six combinations of melon (Cucumis melo L. cv. Arava) and pumpkin (Cucurbita maxima Duchesne×Cucurbita moschata Duchesne cv. TZ-148): non-grafted, self-grafted, melons grafted on pumpkins, and pumpkins grafted on melons. Total Na concentration in shoots of plants with pumpkin or melon rootstocks was <60 mmol kg(-1) and >400 mmol kg(-1), respectively, regardless of the scion. In contrast, shoot Cl(-) concentrations were quite similar among the different scion-rootstock combinations. Na concentrations in exudates from cut stems of plants with a pumpkin rootstock were very low (<0.18 mM), whereas those in the exudates of plants with melon rootstocks ranged from 4.7 mM to 6.2 mM, and were quite similar to the Na concentration in the irrigation water. Root Na concentrations averaged 11.7 times those in the shoots of plants with pumpkin rootstocks, while in plants with melon rootstocks, values were similar. Two mechanisms could explain the decrease in shoot Na concentrations in plants with pumpkin rootstocks: (i) Na exclusion by the pumpkin roots; and (ii) Na retention and accumulation within the pumpkin rootstock. Quantitative analysis indicated that the pumpkin roots excluded ∼74% of available Na, while there was nearly no Na exclusion by melon roots. Na retention by the pumpkin rootstocks decreased its amount in the shoot by an average 46.9% compared with uniform Na distribution throughout the plant. In contrast, no retention of Na could be found in plants grafted on melons.
在温室实验中，使用六种甜瓜（Cucumis melo L. cv. Arava）和南瓜（Cucurbita maxima Duchesne×Cucurbita moschata Duchesne cv. TZ-148）组合，量化了嫁接对植物组织中钠和氯（Cl(-)）摄取和分布的影响：未嫁接、自嫁接、甜瓜嫁接到南瓜上、南瓜嫁接到甜瓜上。无论接穗如何，具有南瓜或甜瓜砧木的植株地上部分的总 Na 浓度分别<60 mmol kg(-1)和>400 mmol kg(-1)。相比之下，不同接穗-砧木组合的地上部 Cl(-)浓度相当相似。具有南瓜根砧的植株切茎渗出物中的 Na 浓度非常低（<0.18 mM），而具有甜瓜根砧的植株渗出物中的 Na 浓度范围为 4.7-6.2 mM，与灌溉水中的 Na 浓度相当。根中的 Na 浓度平均是具有南瓜根砧的植株地上部的 11.7 倍，而在具有甜瓜根砧的植株中，值相似。南瓜根降低地上部 Na 浓度的机制有两种：（i）南瓜根对 Na 的排斥；（ii）南瓜根内的 Na 保留和积累。定量分析表明，南瓜根排斥了约 74%的有效 Na，而甜瓜根几乎没有排斥 Na。南瓜根砧对 Na 的保留使植物地上部的 Na 减少了平均 46.9%，而整个植株中 Na 分布均匀。相比之下，嫁接到甜瓜上的植株中没有发现 Na 的保留。
