Optimizing dry-matter partitioning for increased spike growth, grain number and harvest index in spring wheat
Optimizing dry-matter partitioning for increased spike growth, grain number and harvest index in spring wheat
复制标题
DOI：
10.1016/j.fcr.2019.04.016
复制
发表时间：
2019-07-01
影响因子：
5.8
通讯作者：
Foulkes, M. John
中科院分区：
文献类型：
--
作者：
Rivera-Amado, Carolina;Trujillo-Negrellos, Eliseo;Foulkes, M. John
提高小麦生物量是未来小麦产量潜力遗传改良的重要目标，但识别生理性状以最大化收获指数(HI，地上生物量在籽粒中的比例)也是至关重要的。增加籽粒分配将要求在开花时增加对穗的干物质(DM)分配，并提高结果效率(开花时每克穗粒数干物质或收获时谷壳干物质)，同时优化非籽粒成分之间的分配，以保持花后的光合作用能力和可溶性碳水化合物的运输。本研究的目的是：i)量化开花(GS65)+7天植株器官间DM分配的遗传变异及其与穗生长和FE的关系；ii)在CIMMYT优良春小麦背景下，确定与提高HI和籽粒产量相关的最佳分配性状。2011-12年和2012-13年在墨西哥西北部进行了两次田间试验，在灌溉条件下测试了26个CIMMYT春小麦品种，其中17个品种的子集在开花+7天时评估了植株器官中的DM分配，并在收获时评估了穗内(颖片、内颖、外膜、轴和芒)的分配。在收获时评估了籽粒产量、产量构成因素、HI和FE。我们的结果发现了HI的新性状(减少了茎节间2(自上而下，花梗-1)和3的DM分配，减少了轴DM分配和轴特定重量(轴单位长度的轴DM)和增加了外膜DM分配)，潜在地允许育种者最大限度地利用增强的碳同化来提高籽粒生物量。进一步的工作将集中于了解可溶性碳水化合物重新定位在这些关系中的作用，并为这些性状建立高通量和低成本的表型方法，以便在育种中部署。
Improving biomass is an important goal for future genetic gains in yield potential in wheat, but it will also be crucial to identify physiological traits to maximize harvest index (HI, proportion of aboveground biomass in grain). Increased grain partitioning will require increased dry-matter (DM) partitioning to the spikes at anthesis as well as enhanced fruiting efficiency (FE, grains per g spike dry matter at anthesis or chaff dry matter at harvest), whilst optimizing the partitioning amongst the non-grain components to maintain post-anthesis photosynthetic capacity and soluble carbohydrate translocation. The objectives of this study were to: i) quantify genetic variation in DM partitioning among plant organs at anthesis (GS65) + 7 days and associations with spike growth and FE and ii) identify optimized partitioning traits associated with enhanced HI and grain yield, in CIMMYT elite spring wheat backgrounds. Two field experiments were conducted in 2011-12 and 2012-13 testing 26 CIMMYT spring wheat cultivars in NW Mexico in irrigated conditions in which DM partitioning was assessed in plant organs at anthesis + 7 days, and within-spike (glume, palea, lemma, rachis and awn) partitioning was assessed at harvest for a subset of 17 cultivars. Grain yield, yield components, HI and FE were assessed at harvest. Our results identified new traits for HI (decreased DM partitioning to stem internodes 2 (top down, peduncle -1) and 3, and decreased rachis DM partitioning and rachis specific weight (rachis DM per rachis unit length) and increased lemma DM partitioning), potentially allowing breeders to maximize the exploitation of enhanced carbon assimilation for grain biomass. Further work will focus on understanding the role of soluble carbohydrate re-translocation in these relationships and establishing high-throughput and cost-effective phenotyping methods for these traits for deployment in breeding.