Data from: Exploitation of interspecific diversity for monocot crop improvement

In many cultivated crop species there is limited genetic variation available for the development of new higher yielding varieties adapted to climate change and sustainable farming practises. The distant relatives of crop species provide a vast and largely untapped reservoir of genetic variation for a wide range of agronomically important traits that can be exploited by breeders for crop improvement. In this paper, in what we believe to be the largest introgression programme undertaken in the monocots, we describe the transfer of the entire genome of Festuca pratensis into Lolium perenne in overlapping chromosome segments. The L. perenne/F. pratensis introgressions were identified and characterised via 131 simple sequence repeats and 1612 SNPs anchored to the rice genome. Comparative analyses were undertaken to determine the syntenic relationship between L. perenne/F. pratensis and rice, wheat, barley, sorghum and Brachypodium distachyon. Analyses comparing recombination frequency and gene distribution indicated that a large proportion of the genes within the genome are located in the proximal regions of chromosomes which undergo low/very low frequencies of recombination. Thus, it is proposed that past breeding efforts to produce improved varieties have centred on the subset of genes located in the distal regions of chromosomes where recombination is highest. The use of alien introgression for crop improvement is important for meeting the challenges of global food supply and the monocots such as the forage grasses and cereals, together with recent technological advances in molecular biology, can help meet these challenges.

诸多栽培作物物种中，可用于培育适应气候变化与可持续农业实践的高产新品种的遗传变异资源十分有限。作物的远缘亲缘物种可为育种家改良作物提供海量且尚未被充分开发的遗传变异库，这些变异对应诸多农艺重要性状。本研究开展的渐渗（introgression）项目据信为单子叶植物领域迄今规模最大的同类工作，我们在此报道了将苇状羊茅（*Festuca pratensis*）的全基因组以重叠染色体片段的形式，渐渗导入多年生黑麦草（*Lolium perenne*）的研究过程。本研究通过131个锚定至水稻基因组的简单序列重复（simple sequence repeats）标记与1612个单核苷酸多态性（single nucleotide polymorphism, SNP）标记，对多年生黑麦草/苇状羊茅渐渗系进行了鉴定与特征分析。我们开展了比较基因组分析，以明确多年生黑麦草/苇状羊茅与水稻、小麦、大麦、高粱以及二穗短柄草（*Brachypodium distachyon*）之间的共线性（syntenic）关系。通过比较重组频率与基因分布的分析可知，基因组中绝大多数基因位于重组频率极低的染色体近端区域。据此我们提出，过往培育优良品种的育种工作多聚焦于染色体重组频率最高的远端区域所包含的基因子集。利用异源渐渗技术开展作物改良，对于应对全球粮食供给挑战具有重要意义；而饲用禾草与谷类等单子叶植物，结合当前分子生物学领域的技术进步，可为应对这些挑战提供助力。