摘要
低溫會干擾植物的發育、生長和地理分布，尤其是地中海地區對寒冷敏感的植物，那里的溫度可能會達到季節性較低的水平。在柑橘類作物中，接穗/砧木組合用于提高果實產量和質量，并提高對生物和非生物脅迫的耐受性。在過去十年中，一些研究表明，四倍體柑橘幼苗或砧木比其各自的二倍體更能耐受非生物脅迫。本研究的目的是測試使用四倍體砧木是否能提高接穗的耐冷性。我們比較了普通克萊門汀（Citrus sinensis Osb.×Poncirus trifoliata L.Raf.）對低季節溫度的生理生化反應嫁接在二倍體和四倍體柑橘卡里佐砧木上，分別命名為C/2xCC和C/4xCC。在最冷的月份，C/4xCC的凈光合速率（Pn）、氣孔導度（Gs）、葉綠素熒光（Fv/Fm）和淀粉水平下降較小，丙二醛和電解質滲漏水平低于C/2xCC。在整個研究期間，C/4xCC和C/2xCC的過氧化氫酶（CAT）、抗壞血酸過氧化物酶（APX）和脫氫抗壞血酸還原酶（DHAR）的比活性在寒冷期較高，而葉綠素、脯氨酸、抗壞血酸和過氧化氫（H2O2）水平以及超氧化物歧化酶（SOD）活性在整個研究期間沒有顯著差異。綜上所述，這些結果表明，四倍體卡里佐柑橘砧木由于抗氧化系統的一部分，提高了普通克萊門汀（接穗）的耐冷性。

關鍵詞：抗氧化劑；柑橘；冷應激；光合作用多倍體；根莖。

Tetraploid Carrizo citrange rootstock (Citrus sinensis Osb.×Poncirus trifoliata L. Raf.) enhances natural chilling stress tolerance of common clementine (Citrus clementina Hort. ex Tan)

Abstract
Low temperatures can disturb the development, growth and geographic distribution of plants, particularly cold-sensitive plants in the Mediterranean area, where temperatures can reach seasonally low levels. In citrus crops, scion/rootstock combinations are used to improve fruit production and quality, and increase tolerance to biotic and abiotic stresses. In the last decade, several studies have shown that tetraploid citrus seedlings or rootstocks are more tolerant to abiotic stress than their respective diploid. The objective of this study was to test whether the use of tetraploid rootstocks can improve the chilling tolerance of the scion. We compared physiological and biochemical responses to low seasonal temperatures of common Clementine (Citrus sinensis Osb.×Poncirus trifoliata L. Raf.) grafted on diploid and tetraploid Carrizo citrange rootstocks, named C/2xCC and C/4xCC, respectively. During the coldest months, C/4xCC showed a smaller decrease in net photosynthesis (Pn), stomatal conductance (Gs), chlorophyll fluorescence (Fv/Fm), and starch levels, and lower levels of malondialdehyde and electrolyte leakage than C/2xCC. Specific activities of catalase (CAT), ascorbate peroxidase (APX) and dehydroascorbate reductase (DHAR) were higher in C/4xCC during the cold period, whereas chlorophyll, proline, ascorbate and hydrogen peroxide (H2O2) levels and superoxide dismutase (SOD) activity did not vary significantly between C/4xCC and C/2xCC throughout the study period. Taken together, these results demonstrate that tetraploid Carrizo citrange rootstock improves the chilling tolerance of common clementine (scion) thanks to a part of the antioxidant system.
Keywords: Antioxidant; Citrus; Cold stress; Photosynthesis; Polyploidy; Rootstock.
 

dualex是一款源自于法國國家科學院 (CNRS)及巴黎第十一大學技術，由奧地利PESSL公司生產（原法國Force-A公司）開發的新型多功能葉片測量儀。它可同時準確測量葉片的葉綠素含量、葉片表層的類黃酮和花青素含量，適用于植物生理學和農學（如水稻葉綠素濃度，玉米氮素狀況，葡萄藤等）相關研究。其測量對象可以是單子葉植物，雙子葉植物或多年生植物。這款設備簡單易用，可進a行實時和非破壞性測量。由于不需要校準標定和事先的樣品制備，測量工作可在實驗室或現場完成。此外，該設備在各種溫度的和環境光照條件下均可正常使用。系統采用專利設計，光學傳感器可進行簡單、快速、無損測量葉片中的葉綠素、多酚以及花青素。