Raman Harsh, Raman Rosy, Kilian Andrzej, Detering Frank, Carling Jason, Coombes Neil, Diffey Simon, Kadkol Gururaj, Edwards David, McCully Margaret, Ruperao Pradeep, Parkin Isobel A P, Batley Jacqueline, Luckett David J, Wratten Neil
Graham Centre for Agricultural Innovation (an alliance between NSW Department of Primary Industries and Charles Sturt University), Wagga Wagga Agricultural Institute, Wagga Wagga, NSW, Australia.
Diversity Arrays Technology Pty Ltd, University of Canberra, Bruce, ACT, Australia.
PLoS One. 2014 Jul 9;9(7):e101673. doi: 10.1371/journal.pone.0101673. eCollection 2014.
Resistance to pod shattering (shatter resistance) is a target trait for global rapeseed (canola, Brassica napus L.), improvement programs to minimise grain loss in the mature standing crop, and during windrowing and mechanical harvest. We describe the genetic basis of natural variation for shatter resistance in B. napus and show that several quantitative trait loci (QTL) control this trait. To identify loci underlying shatter resistance, we used a novel genotyping-by-sequencing approach DArT-Seq. QTL analysis detected a total of 12 significant QTL on chromosomes A03, A07, A09, C03, C04, C06, and C08; which jointly account for approximately 57% of the genotypic variation in shatter resistance. Through Genome-Wide Association Studies, we show that a large number of loci, including those that are involved in shattering in Arabidopsis, account for variation in shatter resistance in diverse B. napus germplasm. Our results indicate that genetic diversity for shatter resistance genes in B. napus is limited; many of the genes that might control this trait were not included during the natural creation of this species, or were not retained during the domestication and selection process. We speculate that valuable diversity for this trait was lost during the natural creation of B. napus. To improve shatter resistance, breeders will need to target the introduction of useful alleles especially from genotypes of other related species of Brassica, such as those that we have identified.
抗角果开裂（抗裂性）是全球油菜籽（油菜，甘蓝型油菜）改良项目的一个目标性状，旨在将成熟植株以及割晒和机械收获期间的籽粒损失降至最低。我们描述了甘蓝型油菜抗裂性自然变异的遗传基础，并表明多个数量性状位点（QTL）控制这一性状。为了鉴定抗裂性相关位点，我们采用了一种新的简化基因组测序方法DArT-Seq。QTL分析在A03、A07、A09、C03、C04、C06和C08染色体上共检测到12个显著的QTL；它们共同解释了抗裂性中约57%的基因型变异。通过全基因组关联研究，我们表明大量位点，包括那些参与拟南芥角果开裂的位点，解释了不同甘蓝型油菜种质中抗裂性的变异。我们的结果表明，甘蓝型油菜抗裂性基因的遗传多样性有限；在该物种自然形成过程中，许多可能控制这一性状的基因未被纳入，或者在驯化和选择过程中未被保留。我们推测，这一性状的宝贵多样性在甘蓝型油菜的自然形成过程中丧失了。为了提高抗裂性，育种者需要引入有用的等位基因，尤其是来自其他相关甘蓝物种基因型的等位基因，比如我们已经鉴定出的那些。
