Jefferies R A
Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, UK.
New Phytol. 1993 Mar;123(3):491-498. doi: 10.1111/j.1469-8137.1993.tb03761.x.
Two experiments using self- and reciprocal grafts, examined interaction between shoot and root in determining the response of potato (Solanum tuberosum L.) to water stress. Single-stemmed plants of the cultivars Cara and Desiree were grown in 15m pipes containing compost. Ten days after emergence, plants were either self- or reciprocally grafted. After the grafts had established, plants were either fully irrigated or subjected to drought treatments. Canopy expansion and leaf conductance were measured at regular intervals from the time that drought treatments were imposed. The production of shoot, root and tubers, and the distribution of root down the soil column were examined at the end of the experiments. Scions had a dominant effect in determining the partitioning of dry matter between shoot, root and tubers, with those of the cultivar Cara having larger shoots and roots and less partitioned into tubers. The influence of root stock and, by inference, tuber type was less significant. In both irrigated and draughted treatments leaf conductance was determined predominantly by the scion, with scions of Desiree having significantly greater leaf conductance than those of Cara. On only six occasions did the root stock have a significant effect. On these occasions leaf conductance was greater in plants with Desiree root stocks than in those with Cara root stocks. Drought reduced both dry matter production and the proportion of dry matter partitioned into tubers, and increased the proportion of dry matter in shoots and roots. Drought also increased the root: shoot ratio indicating that root growth was maintained to a greater extent than shoot growth. Specific root length (root length: weight ratio) was increased by drought in one experiment but not in the other. Differences among grafts in response to drought were determined largely by the scion, and only to a lesser extent by root stock, with scions or root stocks of Cara showing a greater shift in partitioning in favour of tubers to shoots and roots than those of Desiree.
两项使用自体嫁接和相互嫁接的实验，研究了地上部与根系在决定马铃薯（Solanum tuberosum L.）对水分胁迫响应方面的相互作用。品种为卡拉（Cara）和德西蕾（Desiree）的单茎植株种植在装有堆肥的15米长管道中。出苗10天后，植株进行自体嫁接或相互嫁接。嫁接成功后，植株要么充分灌溉，要么进行干旱处理。从施加干旱处理时起，定期测量冠层扩展和叶片导度。在实验结束时，检测地上部、根系和块茎的产量，以及根系在土壤柱中的分布情况。接穗在决定地上部、根系和块茎之间干物质分配方面起主导作用，卡拉品种的接穗地上部和根系较大，分配到块茎中的较少。砧木的影响，以及由此推断的块茎类型的影响则不太显著。在灌溉和干旱处理中，叶片导度主要由接穗决定，德西蕾品种的接穗叶片导度显著大于卡拉品种的接穗。砧木仅在6次实验中有显著影响。在这些情况下，具有德西蕾砧木的植株叶片导度大于具有卡拉砧木的植株。干旱降低了干物质产量和分配到块茎中的干物质比例，增加了地上部和根系中的干物质比例。干旱还增加了根冠比，表明根系生长比地上部生长得到更大程度的维持。在一项实验中，干旱增加了比根长（根长：重量比），但在另一项实验中没有。嫁接植株对干旱响应的差异在很大程度上由接穗决定，仅在较小程度上由砧木决定，卡拉品种的接穗或砧木在分配上比德西蕾品种的接穗或砧木更倾向于向地上部和根系转移以利于块茎生长。
