2017 Africa-wide Breeding Task Force Trials for Irrigated Lowland

Objective and Requirement of MET by Breeding Task Force: In 2010, Rice Breeding Task Force in Africa was established aimed at accelerating the breeding process, especially in the later phase of evaluation of promising breeding lines in multi-locations throughout Africa. Breeding lines included in the multi-environment trials (MET) are developed by various institutions such as IRRI, CIAT, NARS in Africa and AfricaRice. The objective of the MET is to identify lines that are suitable for cultivation under an ecological environment in the target region in Africa. To reduce noise and to acquire real genetic differences among test lines through MET, the following conditions must be met for the MET: 1. Experimental field is uniform in soil fertility; 2. Experimental field is very well leveled before seeding or transplanting, to facilitate uniform water and fertilizer management; 3. Fertilizer is evenly applied to every plot, and ideally every plant within a plot; 4. Weed control, either by applying herbicide or hand weeding, is carried out uniformly across the whole trial, and finished in one day per time; 5. Any other operations, whatever necessary for a trial, are “uniformly done across the whole trial”. The MET serves as a part of a national testing program. In other words, the MET conducted by BTF is integrated into the corresponding national testing system. Data collected from the MET will be recognized and used by the Varietal Testing and Release Committee of a country where the MET is conducted. This is a measure to shorten breeding cycle and to increase genetic gains. Structure of varietal evaluation series has been changed since the season of 2017. Explanations of the changes 1. The number of entries is reduced to ensure better conduct of the trials and higher quality data. 1.1 For each sub-region (WCA and ESA), a maximum of 29 new entries per production system (irrigated lowland, rainfed lowland, rainfed upland, mangrove and high-elevation) is considered to enter the BTF (Phase I, former MET) each year. 1.2 After evaluation and data analysis, a maximum of 10 entries is selected for further evaluation (Phase II, former PET). 1.3 After evaluation and data analysis, a maximum of 3 entries is selected for further evaluation (Phase III, former PAT). 2. Materials from Phase I, II and III are combined into a single trial (up to 42 test entries every year). 3. Participatory varietal selection (PVS) may be conducted in the single trial (one replication may be chosen for the PVS). 4. The single trial is conducted in three different locations in each participating country and in priority in the Hubs. 5. The Farmers Adoption Trial (FAT) and Validation AfricaRice Trial (VAT) is removed from the BTF scheme. Where required, further testing of selected entries in farmers’ fields will be ideally handled by NARS with the assistance of Rice Agronomy Task Force.

非洲水稻育种工作组（Breeding Task Force，BTF）的多环境试验（Multi-environment trials，MET）目标与要求：2010年，非洲水稻育种工作组成立，旨在加快育种进程，尤其聚焦于非洲全境多点优良育种株系评价的后期阶段。参与多环境试验的育种株系由国际水稻研究所（International Rice Research Institute，IRRI）、国际热带农业中心（Centro Internacional de Agricultura Tropical，CIAT）、非洲各国国家农业研究系统（National Agricultural Research Systems，NARS）以及非洲水稻中心（AfricaRice）等多家机构研发。该多环境试验的目标是鉴定适配非洲目标区域生态环境的栽培株系。为降低试验噪声、获取试验株系间真实的遗传差异，多环境试验需满足以下条件：1. 试验田土壤肥力均一；2. 播种或移栽前需将试验田充分整平，以保障水肥管理均匀一致；3. 肥料需均匀施用于每个小区，理想情况下需均匀施至小区内每一株水稻；4. 全试验需统一开展杂草防控工作，可采用除草剂喷施或人工除草方式，且每次防控需在1天内完成；5. 试验所需的其他所有操作均需在全试验范围内统一实施。

多环境试验是国家品种测试计划的组成部分，换言之，育种工作组开展的多环境试验已纳入对应国家的品种测试体系。试验采集的数据将被试验所在国的品种测试与审定委员会认可并使用。此举旨在缩短育种周期、提升遗传增益。

自2017季起，品种评价体系结构已发生调整，调整说明如下：1. 缩减参试材料数量，以保障试验实施质量与数据品质。1.1 针对每个亚区域（西非中部WCA与东非南部ESA），每个生产系统（灌溉低地、雨养低地、雨养旱地、红树林区域及高海拔区域）每年最多可申报29个新株系进入BTF第一阶段（原MET试验）。1.2 经评价与数据分析后，最多筛选10个株系进入下一阶段评价（第二阶段，原PET试验）。1.3 经评价与数据分析后，最多筛选3个株系进入下一阶段评价（第三阶段，原PAT试验）。2. 将第一、二、三阶段的试验材料合并为单一场试验，每年参试材料最多可达42个。3. 可在该单一场试验中开展参与式品种选择（Participatory Varietal Selection，PVS），可选取1个重复区用于PVS。4. 该单一场试验需在每个参与国的3个不同地点开展，优先在各试验枢纽（Hubs）实施。5. 原BTF方案中的农户采纳试验（Farmers Adoption Trial，FAT）与非洲水稻中心验证试验（Validation AfricaRice Trial，VAT）已被移除。若有需求，入选株系在农户田块的进一步测试工作，原则上由各国国家农业研究系统在水稻农艺任务工作组的协助下完成。