基于重组自交系群体的小麦光温生产效率分析及新品系培育

Wheat Photosynthetic and Temperature Production Efficiency Characters and Varieties Screening Based on Recombinant Inbred Lines Populations

【目的】通过对小麦重组自交系群体光温生产效率的分析,阐明小麦光温生产效率的遗传特点与生物学性状的关系,为高光温生产效率小麦品种的选育提供理论依据。【方法】利用重组自交系群体(RIL),通过相关分析,检测高光温生产效率及其相关位点,并利用分子标记辅助选育高光温生产效率小麦新品系。【结果】小麦的光温生产效率与单株成穗数、穗粒数、平均灌浆速率、最大灌浆速率呈高度正相关,其中成穗数对小麦的光温生产效率贡献最大。光能生产效率受平均灌浆速率影响较大,而温度生产效率受最大灌浆速率影响较大。11个位点与光温生产效率相关,其中4个位点的贡献率在10%以上,分别为Xwmc167-2D、Xcwm23-2D、Xbarc218-3A和Xwmc326-3B。通过分子标记筛选到5个高光温效率的新品系,并且进行了验证。【结论】高光温效率小麦品种能很好地利用低温阶段的光温资源,形成较多分蘖,提高单株穗数和穗粒数。因而,在小麦新品种培育过程中,注重筛选单株成穗数多、穗粒数多和灌浆速度快的株系有利于提高小麦的光温生产效率和高产、稳产。利用同一群体可以将QTL分析与新品种选育相结合,是分子标记辅助选择的一条有效途径。

[ Objective ] Study on the photosynthetic and temperature production efficiency （P＆TPE） genetically and biologically will provide a theoretical basis for high-P＆TPE wheat varieties breeding. [ Method ] The statistical methods of regression and clustering were applied to illustrate the relationship between P＆TPE and main agronomic characters of RIL populations derived from a cross between Neixiang 188 and Yanzhan I（NY）. Association analysis was used to identify loci significantly related to P＆TPE. Molecular marker-assisted selection was used in cultivating wheat new varieties of H-P＆TPE. [Result] Positive correlations were detected between P＆TPE and spikes per plant, grain number per spike, average filling rate, the maximum filling rate of wheat, of which, spikes per plant had the highest effects on P＆TPE. PPE and TPE were influenced greatly by the average and maximum filling rate, respectively. Eleven loci were identified to be significantly associated with P＆TPE in at least two environments, of which, four loci （Xwrnc167-2D, Xcwrn23-2D, Xbarc218-3A and Xwmc326-3B） contributed more than 10% of thephenotypic variations. By molecular marker selection, five lines were screened from the 49 lines analyzed here which showed excellent performance in yield and P＆TPE. [Conclusion] There existed genetic loci conferring P＆TPE in wheat genomes. Loci selection in populations with elite agronomic traits is an alternative approach to the low efficiency of MAS.