The heat tolerance screening of a diverse Brassica napus population using a prototype heat screening facility at UWA's Field Station at Shenton Park

The data set reported here is an important part of a 5-year (2019-2024) national-wide research project entitled of “Improving canola heat tolerance - a coordinated multidisciplinary approach (UWA1905-007RTX)”.
Previous research at UWA on heat stress in several Brassica species has shown that heat stress caused flower abortion, pod abortion and thus seed yield reduction. Heat stress tolerance is controlled by many QTLs distributed across the genome and dispersed in diverse genetic background. Based on these findings, we established a protocol for heat tolerance screening and constructed a prototype heat screening facility (HSF) at UWA.
A total of 322 genotypes were assessed for heat tolerance at UWA’s Field Station at Shenton Park, Western Australia (31°56′54′′ S, 115°47′44′′ E). In the prototype HSF, 200 genotypes were assessed for heat tolerance in 2020, and 210 genotypes in 2021 with 88 genotypes in common in both years. In 2022, we further confirmed the heat tolerance of 100 genotypes selected from the previous 2 years (2020 & 2021). This data set consists of the original data from the heat tolerance screening in these 3 years.
In this experiment, two environments were related to sowing timings: the early season was sown in mid-April and the late season was sown in early June. The genotypes were randomised in heat treatment pairs, i.e. pots with different heat treatments were placed side-by-side for a given genotype. All genotypes were evaluated for heat tolerance at 25 ⁰C day/15 ⁰C night as control treatment and at 32 ⁰C 4 hours at mid-day/22 ⁰C night as heat stress treatment for seven days from the date of first open flower. All plants were harvested at maturity. Five traits were measured based on main stem: seed yield on main stem, pod number on main stem, seed number on main stem, seed number per pod and 100 seed weight on main stem. Three traits were measured based on whole plant: seed yield on whole plant, above-ground biomass and harvest index. All the traits were analysed using linear mixed effects models. Stress tolerance index (STI) and percentage change (PC), across eight traits were used to determine the heat tolerance/sensitivity level.

本数据集是2019-2024年全国性研究项目"提高油菜耐热性——多学科协同研究方法（UWA1905-007RTX）"的重要组成部分。
西澳大学（UWA）此前针对多种芸苔属物种热胁迫的研究表明，热胁迫会导致花朵败育、豆荚败育，进而降低种子产量。耐热性由分布在全基因组且存在于不同遗传背景中的多个数量性状位点（QTLs）控制。基于这些发现，我们在西澳大学（UWA）建立了耐热性筛选方案，并构建了热筛选设施（heat screening facility，HSF）原型。
在西澳大利亚州申顿公园的西澳大学（UWA）试验站（南纬31°56′54′′，东经115°47′44′′），共对322个基因型进行了耐热性评估。2020年，在HSF原型中对200个基因型进行了耐热性评估；2021年评估了210个基因型，其中两年共有88个基因型重复。2022年，我们进一步验证了从2020和2021年筛选出的100个基因型的耐热性。本数据集包含这三年耐热性筛选的原始数据。
本试验设置了两种与播种时间相关的环境：早季于4月中旬播种，晚季于6月初播种。基因型按热处理配对随机分配，即同一基因型的不同热处理盆钵并排放置。所有基因型从首次开花之日起，在对照处理（白天25℃/夜间15℃）和热胁迫处理（中午32℃持续4小时/夜间22℃）下进行为期7天的耐热性评估。所有植株在成熟时收获。基于主茎测量了5个性状：主茎种子产量、主茎豆荚数、主茎种子数、单荚种子数和主茎百粒重。基于整株测量了3个性状：整株种子产量、地上生物量和收获指数。所有性状均采用线性混合效应模型分析。通过8个性状的胁迫耐受指数（Stress Tolerance Index，STI）和百分比变化（percentage change，PC）来确定耐热/敏感水平。