四倍体柑橘砧木提高普通克莱门汀低温胁迫耐受能力的研究

摘要
低温会干扰植物的发育、生长和地理分布，尤其是地中海地区对寒冷敏感的植物，那里的温度可能会达到季节性较低的水平。在柑橘类作物中，接穗/砧木组合用于提高果实产量和质量，并提高对生物和非生物胁迫的耐受性。在过去十年中，一些研究表明，四倍体柑橘幼苗或砧木比其各自的二倍体更能耐受非生物胁迫。本研究的目的是测试使用四倍体砧木是否能提高接穗的耐冷性。我们比较了普通克莱门汀（Citrus sinensis Osb.×Poncirus trifoliata L.Raf.）对低季节温度的生理生化反应嫁接在二倍体和四倍体柑橘卡里佐砧木上，分别命名为C/2xCC和C/4xCC。在最冷的月份，C/4xCC的净光合速率（Pn）、气孔导度（Gs）、叶绿素荧光（Fv/Fm）和淀粉水平下降较小，丙二醛和电解质渗漏水平低于C/2xCC。在整个研究期间，C/4xCC和C/2xCC的过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）和脱氢抗坏血酸还原酶（DHAR）的比活性在寒冷期较高，而叶绿素、脯氨酸、抗坏血酸和过氧化氢（H2O2）水平以及超氧化物歧化酶（SOD）活性在整个研究期间没有显著差异。综上所述，这些结果表明，四倍体卡里佐柑橘砧木由于抗氧化系统的一部分，提高了普通克莱门汀（接穗）的耐冷性。

关键词：抗氧化剂；柑橘；冷应激；光合作用多倍体；根茎。

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是一款源自于法国国家科学院 (CNRS)及巴黎第十一大学技术，由奥地利PESSL公司生产（原法国Force-A公司）开发的新型多功能叶片测量仪。它可同时准确测量叶片的叶绿素含量、叶片表层的类黄酮和花青素含量，适用于植物生理学和农学（如水稻叶绿素浓度，玉米氮素状况，葡萄藤等）相关研究。其测量对象可以是单子叶植物，双子叶植物或多年生植物。这款设备简单易用，可进a行实时和非破坏性测量。由于不需要校准标定和事先的样品制备，测量工作可在实验室或现场完成。此外，该设备在各种温度的和环境光照条件下均可正常使用。系统采用专利设计，光学传感器可进行简单、快速、无损测量叶片中的叶绿素、多酚以及花青素。