春化和光周期调控大麦抽穗期分析

Regulation of Vernalization and Photoperiod on Heading Date in Barley

青稞是我国青藏高原的主要农作物,其适应性决定品种的种植范围和产量。抽穗期是影响大麦品种适应性的重要农艺性状,适时抽穗开花是大麦高产广适的前提。春化通路中HvVRN1、HvVRN2和HvVRN3是决定大麦生长习性的主要基因,光周期通路中HvPPD-H1和HvPPD-H2是控制大麦抽穗期的重要基因。为探究春化和光周期调控抽穗期的机制,以冬青18号(D18)和城武芒大麦(K18)为试验材料,通过不同的春化时间,观察春化对抽穗期的影响;同时,在长日照(LD)和短日照(SD)条件下,分别取苗期、拔节期和抽穗期的材料,进行转录组测序,分析春化和光周期基因的差异变化。结果表明,不同春化时间处理下,D18的抽穗开花时间晚于K18;LD条件下,D18拔节期中HvVRN1的表达低于K18,所以D18的抽穗开花时间晚于K18;SD条件下,虽然D18抽穗期中HvVRN1的表达低于K18,但D18抽穗期中HvPPD-H2的表达高于K18,导致D18抽穗期中HvVRN3的表达高于K18,所以SD条件下,D18的抽穗开花时间早于K18。

Hulless barley is a major crop on the Qinghai-Xizang Plateau in China,and its adaptability determines the planting range and yield of varieties.The heading date is an important agronomic trait affecting the adaptability of barley varieties,and timely heading and flowering is a prerequisite for high yield and wide adaptation of barley.In the vernalization pathway,HvVRNI,HvVRN2 and HvVRN3 are the major genes that determine the growth habit of barley,and in the photoperiodic pathway,HvPPD-HI and HvPPD-H2 are important genes that control the heading stage of barley.In order to investigate the regulation mechanism of vernalization and photoperiod on the heading,this study used Dongqing18(D18)and Chengwumang(K18)as experimental materials to observe the effect of vernalization on flowering by different vernalization days.Meanwhile,materials at seedling stage,jointing stage and heading stage were taken under long daylight(LD)and short daylight(SD)conditions,respectively,and transcriptome sequencing was performed to analyze the differential changes of photoperiodic genes.The results showed that the heading and flowering time of D18 was later than that of K18 under different vernalization days.Under LD conditions,the expression of HvVRN1 in D18 was lower than that in K18 at jointing stage,so the heading and flowering time of D18 was later than that of K18.Under SD conditions,although the expression of HvVRNI in D18 was lower than that in K18 at heading stage,the expression of HvPPD-H2 in D18 was higher than that in K18 at heading stage,resulting in the expression of HvVRN3 in D18 being higher than that in K18 at heading stage,so the heading and flowering time of D18 was earlier than that of K18 under SD conditions.