Cowling Wallace A, Castro-Urrea Felipe A, Stefanova Katia T, Li Li, Banks Robert G, Saradadevi Renu, Sass Olaf, Kinghorn Brian P, Siddique Kadambot H M
The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6009, Australia.
UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia.
Plants (Basel). 2023 Jan 13;12(2):383. doi: 10.3390/plants12020383.
Crop breeding must achieve higher rates of genetic gain in grain yield (GY) and yield stability to meet future food demands in a changing climate. Optimal contributions selection (OCS) based on an index of key economic traits should increase the rate of genetic gain while minimising population inbreeding. Here we apply OCS in a global spring oilseed rape (canola) breeding program during three cycles of S family selection in 2016, 2018, and 2020, with several field trials per cycle in Australia and Canada. Economic weights in the index promoted high GY, seed oil, protein in meal, and Phoma stem canker (blackleg) disease resistance while maintaining plant height, flowering time, oleic acid, and seed size and decreasing glucosinolate content. After factor analytic modelling of the genotype-by-environment interaction for the additive effects, the linear rate of genetic gain in GY across cycles was 0.059 or 0.087 t ha y (2.9% or 4.3% y) based on genotype scores for the first factor (f) expressed in trait units or average predicted breeding values across environments, respectively. Both GY and yield stability, defined as the root-mean-square deviation from the regression line associated with f, were predicted to improve in the next cycle with a low achieved mean parental coancestry (0.087). These methods achieved rapid genetic gain in GY and other traits and are predicted to improve yield stability across global spring canola environments.
作物育种必须在粮食产量（GY）和产量稳定性方面实现更高的遗传增益率，以满足气候变化背景下未来的粮食需求。基于关键经济性状指数的最优贡献选择（OCS）应能提高遗传增益率，同时将群体近亲繁殖降至最低。在此，我们于2016年、2018年和2020年在全球春油菜（油菜籽）育种计划的S家系选择的三个周期中应用了OCS，每个周期在澳大利亚和加拿大进行了多次田间试验。该指数中的经济权重促进了高GY、种子含油量、粕中蛋白质含量以及对油菜茎点霉（黑胫病）的抗病性，同时保持了株高、开花时间、油酸含量以及种子大小，并降低了硫代葡萄糖苷含量。在对加性效应的基因型与环境互作进行因子分析建模后，基于分别以性状单位表示的第一个因子（f）的基因型得分或跨环境的平均预测育种值，GY跨周期的遗传增益线性速率为0.059或0.087 t ha y（每年2.9%或每年4.3%）。GY和产量稳定性（定义为与f相关的回归线的均方根偏差）预计在下一个周期中会有所改善，此时实现的平均亲本共祖系数较低（0.087）。这些方法在GY和其他性状方面实现了快速的遗传增益，并预计将提高全球春油菜环境下的产量稳定性。
