Dataset on Effect of clonal integration on drought and waterlogging response in Urochloa humidicola

Clonal integration enables the translocation of resources such as water, nutrients, and photosynthates among individual subunits of clonal plants, facilitating adaptation to diverse environmental conditions, including drought and waterlogging. Urochloa humidicola CIAT 679 (cv. Tully) exhibits strong adaptation to these abiotic stresses and propagates efficiently through stolons, maintaining clonal integration among shoots across different generations. The dataset corresponds to a study aimed to evaluate whether clonal integration is one of the strategies that confers tolerance to drought and waterlogging in CIAT 679. This dataset includes response data from donor and recipient ramets of Urochloa humidicola CIAT 679 (cv. Tully). Recipient ramets were exposed to six treatments, representing interactions between three stress conditions—drought, control (no stress), and waterlogging—under two clonal integration conditions: with and without integration. Each treatment had six replicates. The dataset comprises weekly measurements over three weeks for stomatal conductance, transpiration, and SPAD values. Additionally, final measurements include relative water content, aboveground biomass, root biomass, total biomass, root-to-shoot ratio, and non-structural carbohydrate content. This dataset provides valuable insights into the mechanisms by which Urochloa humidicola cv. Tully responds to drought and waterlogging stress. The findings may support plant breeding efforts by identifying traits associated with improved resilience in this species.
<br>
<br>
Methodology: Plant Material, Experimental Design, and Site Description: The planting material consisted of Urochloa humidicola CIAT 679 (cv. Tully) tillers weighing 70–80 g, measuring approximately 4–4.5 × 4–4.5 cm, with at least two actively growing shoots (donor ramet). The tillers were planted in pots containing 2.3 kg of vertisol soil with a sandy-loam texture, high fertility, and a pH of approximately 7.5. After three weeks of growth, the longest stolon was selected, and two nodes were buried in an adjacent pot to generate a new plant (recipient ramet), while all other stolons produced by the donor ramet were removed.The experiment followed a completely randomized factorial design (3 × 2). One factor was water stress condition: drought, control (no stress), and waterlogging, while the second factor was clonal integration between the donor and recipient ramet (with and without integration). The experimental unit consisted of a donor-recipient ramet pair, and each treatment (water stress × clonal integration interaction) had six replicates. The experiment was conducted in a glasshouse at the Las Américas campus of the Bioversity & CIAT Alliance, located in Palmira, Colombia. During the plant growth period, the environmental conditions within the glasshouse were as follows: temperature of 31.7/24.7 °C (day/night), relative humidity of 56.3/63.2% (day/night), and photosynthetically active radiation of 559.5 µmol m⁻² s⁻¹. Gas Exchange and SPAD Index: Stomatal conductance and transpiration rate were measured weekly using an LI-600 porometer (LI-COR, Lincoln, NE, USA). The SPAD index was assessed at the same frequency using a SPAD 502 Plus chlorophyll meter (Spectrum Technologies, Aurora, IL, USA). All measurements were taken on the third youngest fully expanded leaf in optimal nutritional and phytosanitary condition. Relative Water Content, Biomass Distribution, and Non-Structural Carbohydrates: A final destructive sampling was conducted 21 days after treatment initiation. The shoot and root were separated and dried in paper bags at 60 °C for 72 hours. The root-to-shoot ratio was calculated using the obtained biomass data. Relative water content was determined as the percentage of water present in a sample at a given time relative to the water content in a fully saturated leaf (Turner, 1981). Non-structural carbohydrates in leaf and stem tissues were quantified using the anthrone method described by Borrero Tamayo et al. (2017).

克隆整合（clonal integration）可使克隆植物的各个个体单元间转运水分、养分及光合产物等资源，助力其适应包括干旱与涝渍在内的多样环境条件。俯仰臂形草（Urochloa humidicola）CIAT 679（品种Tully）对上述非生物胁迫具有极强适应性，可通过匍匐茎高效繁殖，并维持不同世代枝条间的克隆整合。本数据集对应一项旨在验证克隆整合是否为赋予CIAT 679应对干旱和涝渍胁迫耐受性的策略之一的研究。该数据集包含俯仰臂形草CIAT 679（品种Tully）的供体分株与受体分株的响应数据。受体分株共设置6种处理，对应3种水分胁迫条件（干旱、对照（无胁迫）、涝渍）与2种克隆整合条件（有整合与无整合）的交互组合，每个处理设置6个生物学重复。数据集涵盖为期三周的每周测定数据，指标包括气孔导度、蒸腾速率及SPAD值；终期测定指标还包括相对含水量、地上生物量、地下生物量、总生物量、根冠比以及非结构性碳水化合物含量。本数据集可为揭示俯仰臂形草品种Tully响应干旱与涝渍胁迫的机制提供宝贵见解，其研究结果可通过鉴定与该物种抗逆性提升相关的性状，为植物育种工作提供支持。

方法学：试验材料、试验设计与试验地点概况
试验材料为重量70~80 g、尺寸约4~4.5 × 4~4.5 cm的俯仰臂形草CIAT 679（品种Tully）分蘖苗，至少带有2个活跃生长的枝条（供体分株）。将分蘖苗种植于装有2.3 kg黏壤土（砂壤土质地，高肥力，pH约7.5）的盆钵中。生长三周后，选取最长的匍匐茎，将2个节埋入相邻盆钵以培育新植株（受体分株），同时剪除供体分株产生的其余所有匍匐茎。
本试验采用完全随机析因设计（3×2）。其一因子为水分胁迫条件，包含干旱、对照（无胁迫）、涝渍三个水平；其二因子为供体与受体分株间的克隆整合状态，设为有整合与无整合两个水平。试验单元为一套供体-受体分株组合，每个水分胁迫与克隆整合的交互处理均设置6个重复。试验在哥伦比亚帕尔米拉市Bioversity & CIAT联盟拉斯阿梅里卡斯校区的温室中开展。试验期间温室环境条件如下：昼夜温度分别为31.7/24.7 ℃，昼夜相对湿度分别为56.3%/63.2%，光合有效辐射为559.5 µmol·m⁻²·s⁻¹。
气体交换与SPAD指数测定
采用LI-600气孔计（LI-COR，美国内布拉斯加州林肯市）每周测定气孔导度与蒸腾速率。采用SPAD 502 Plus叶绿素仪（Spectrum Technologies，美国伊利诺伊州奥罗拉市）以相同频率测定SPAD指数。所有测定均选取营养与健康状况良好的第三片完全展开的成熟叶片。
相对含水量、生物量分配与非结构性碳水化合物测定
于处理启动后21天进行终期破坏性取样。将植株地上部分与地下部分分离，置于纸袋中于60 ℃下烘干72小时。利用获得的生物量数据计算根冠比。相对含水量的测定参照Turner（1981）的方法，以样品在某一时间点的含水量占完全饱和叶片含水量的百分比表示。参照Borrero Tamayo等（2017）描述的蒽酮法，对叶片与茎秆组织中的非结构性碳水化合物进行定量分析。