The Physiological Basis of the Genetic Progress in Yield Potential of CIMMYT Spring Wheat Cultivars from 1966 to 2009
The Physiological Basis of the Genetic Progress in Yield Potential of CIMMYT Spring Wheat Cultivars from 1966 to 2009
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DOI：
10.2135/cropsci2014.09.0601
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发表时间：
2015-07-01
期刊：
影响因子：
2.3
通讯作者：
Foulkes, M. J.
中科院分区：
文献类型：
--
作者：
Aisawi, K. A. B.;Reynolds, M. P.;Foulkes, M. J.
本研究旨在探讨CIMMYT春小麦（Triticum aestivum L.）1966年至2009年在灌溉，高潜力条件下开发的品种。在墨西哥西北部的三个生长季节（2008-2009年，2009-2010年和2010-2011年）进行了田间试验，检查12个历史CIMMYT半矮秆春小麦品种从1966年至2009年发布。籽粒产量的线性遗传增益率为30 kg ha（-1）yr（-1）（0.59%yr（-1）; R-2 = 0.58，P = 0.01）。籽粒产量的提高与收获时地上干物质（AGDM）的增加（R-2 = 0.80，P < 0.001）和粒重的增加（R-2 = 0.46，P < 0.05）有关。12个品种的AGDM与株高（R-2 = 0.43，P < 0.05）和粒重与冠层完全衰老（CCS）日数（R-2 = 0.36，P < 0.05）呈显著正相关。每平方米谷物数或收获指数（HI）随释放年份（YoR）没有变化。粒重与潜在粒重（PGW）呈显著正相关，而PGW又与每小穗轴长呈显著正相关。开花期（GS 61）+7 d每平方米总穗干物质（DM）不随YoR变化。在GS 61 + 7 d，YoR存在可育枝AGDM（表示为g m（-2））线性增加的趋势，但这被43年期间穗分配总体从0.25降至0.23所抵消。开花前旗叶气孔导度随YoR的增加而线性增加（P < 0.05）。在GS 61 + 14 d时，籽粒生长对降解处理的反应没有变化（平均粒重反应为+5.5%），表明源限制对籽粒生长的影响程度在老品种和现代品种中似乎很小，没有变化。总的来说，这些结果表明，在CIMMYT春小麦的遗传进展的速度已经放缓，但没有在最近几十年的平台，而遗传增益与潜在的和最终的粒重增加。
Our objective was to investigate the physiological basis of genetic progress in grain yield in CIMMYT spring wheat (Triticum aestivum L.) cultivars developed from 1966 to 2009 in irrigated, high-potential conditions. Field experiments were conducted during three growing seasons in northwest Mexico (2008-2009, 2009-2010, and 2010-2011) examining 12 historic CIMMYT semidwarf spring wheat cultivars released from 1966 to 2009. The linear rate of genetic gain in grain yield was 30 kg ha(-1) yr(-1) (0.59% yr(-1); R-2 = 0.58, P = 0.01). Grain yield progress was associated with increased aboveground dry matter (AGDM) at harvest (R-2 = 0.80, P < 0.001) and heavier grain weight (R-2 = 0.46, P < 0.05). There was a positive linear association between AGDM and plant height (R-2 = 0.43, P < 0.05) and between grain weight and the date of complete canopy senescence (CCS) among the 12 cultivars (R-2 = 0.36, P < 0.05). There was no change in grains per square meter or harvest index (HI) with year of release (YoR). Grain weight was positively associated with potential grain weight (PGW), and PGW, in turn, was positively associated with rachis length per spikelet among the cultivars. Overall spike dry matter (DM) per square meter at anthesis (GS61) +7 d did not change with YoR. There was a trend for a linear increase in AGDM of fertile shoots (expressed as g m(-2)) at GS61 +7 d with YoR, but this was counteracted by spike partitioning decreasing overall during the 43-yr period from 0.25 to 0.23. There was a linear increase in preanthesis flag-leaf stomatal conductance with YoR (P < 0.05). There was no change in grain growth response to a degraining treatment imposed at GS61 +14 d (mean grain weight response +5.5%) indicating that the degree of source limitation to grain growth appeared to be small and unchanged in the older and modern cultivars. Generally, these results indicated that the rate of genetic progress in CIMMYT spring wheat has slowed but has not plateaued in recent decades, while genetic gains were associated with increase in both potential and final grain weight.