Tefera Abeya Temesgen, O'Leary Garry J, Thayalakumaran Thabo, Rao Shiwangni, Silva-Perez Viridiana, Shunmugam Arun S K, Armstrong Roger, Rosewarne Garry M
Agriculture Victoria Research, Grain Innovation Park, Horsham, VIC, Australia.
Centre for Agricultural Innovation, The University of Melbourne, Parkville, VIC, Australia.
Front Plant Sci. 2022 Oct 24;13:1019491. doi: 10.3389/fpls.2022.1019491. eCollection 2022.
Ideotype breeding is an essential approach for selection of desired combination of plant traits for testing in crop growth model for potential yield gain in specific environments and management practices. Here we parameterized plant traits for untested lentil cultivars for the APSIM-lentil model in phenology, biomass, and seed yield. We then tested these against independent data and applied the model in an extrapolated analysis (i) to assess the impact of drought on productivity across different rainfall environments; (ii) to identify impactful plant traits and (iii) to design new lentil ideotypes with a combination of desirable traits that mitigate the impact of drought, in the context of various agronomic practices across a wide range of production environments. Desirable phenological and physiological traits related to yield were identified with RUE having the greatest effect on yield followed by HI rate. Leaf size significantly affected seed yield (p< 0.05) more than phenological phases. The physiological traits were integrated into four ideotype designs applied to two baseline cultivars (PBA Hallmark XT and PBA Jumbo2) providing eight ideotypes. We identified a combination of genetic traits that promises a yield advantage of around 10% against our current cultivars PBA Hallmark XT and PBA Jumbo2. Under drought conditions, our ideotypes achieved 5 to 25% yield advantages without stubble and 20 to 40% yield advantages with stubble residues. This shows the importance of genetic screening under realistic production conditions (e.g., stubble retention in particular environments). Such screening is aided by the employment of biophysical models that incorporate both genetic and agronomic variables that focus on successful traits in combination, to reduce the impact of drought in the development of new cultivars for various environments. Stubble retention was found to be a major agronomic contributor to high yield in water-limiting environments and this contribution declined with increasing growing season rainfall. In mid- and high-rainfall environments, the key drivers of yield were time of sowing, physiological traits and soil type. Overall, the agronomic practices, namely, early sowing, residue retention and narrow row spacing deceased the impact of drought when combined with improved physiological traits of the ideotypes based on long term climate data.
理想型育种是一种重要方法，用于选择植物性状的理想组合，以便在作物生长模型中进行测试，从而在特定环境和管理措施下实现潜在的产量增加。在此，我们为APSIM-小扁豆模型中的未测试小扁豆品种在物候、生物量和种子产量方面设定了植物性状参数。然后，我们将这些参数与独立数据进行对比，并在推断分析中应用该模型：(i)评估干旱对不同降雨环境下生产力的影响；(ii)确定有影响力的植物性状；(iii)在广泛生产环境中的各种农艺措施背景下，设计具有减轻干旱影响的理想性状组合的新小扁豆理想型。确定了与产量相关的理想物候和生理性状，其中辐射利用效率对产量影响最大，其次是收获指数。叶面积对种子产量的影响显著(p<0.05)，超过了物候期。将生理性状整合到应用于两个基础品种（PBA Hallmark XT和PBA Jumbo2）的四种理想型设计中，得到了八种理想型。我们确定了一种遗传性状组合，与我们目前的品种PBA Hallmark XT和PBA Jumbo2相比，有望获得约10%的产量优势。在干旱条件下，我们的理想型在不留茬时产量优势为5%至25%，留茬时产量优势为20%至40%。这表明在实际生产条件下（例如在特定环境中留茬）进行遗传筛选的重要性。这种筛选借助于生物物理模型，该模型纳入了遗传和农艺变量，关注性状组合的成功表现，以减少干旱对不同环境下新品种开发的影响。发现留茬是水分限制环境下高产的主要农艺因素，且这种贡献随着生长季降雨量的增加而下降。在中高降雨量环境中，产量的关键驱动因素是播种时间、生理性状和土壤类型。总体而言，根据长期气候数据，结合理想型改良的生理性状，农艺措施（即早播、留茬和窄行间距）减轻了干旱的影响。
