Exploration of the Brassica gene pools for early-flowering alleles for the improvement of earliness in Brassica napus canola without yield penalty

由于加拿大大草原省的生长季节短，开花和成熟早是加拿大春甘蓝型油菜（AACC，2n = 38）的重要性状。在过去的几十年里，育种工作在一定程度上改善了这种作物的早熟性;然而，到目前为止所达到的早熟水平并不能排除这种作物对秋霜危险的易感性。到目前为止，祖先种B的早熟性。在B中利用芜菁（AA，2n = 20）改良早熟性。油菜;然而，这往往是以种子产量为代价的。因此，需要进一步改善早熟性和鉴定有助于早熟性而不负面影响种子产量的基因组区域。我的研究计划的长期目标是扩展我们对不同芸苔属基因库（包括B）中开花时间基因等位变异的认识。oleracea（CC，2n = 18），并研究了早花等位基因对植株生理的影响，以改良春季早熟性B。无产量损失的油菜。未来五年将进行的研究是基于这样的假设，即B的C基因组的开花时间等位基因。oleracea与B的C基因组开花时间等位基因不同。在B. napus将增加开花时间等位基因的多样性，并最终改善加拿大卡诺拉的早熟性，并且由以下短期目标指导：（i）绘制B的早花等位基因。甘蓝变种alboglabra（Chinese kale），var. botrytis（cauliflower），var. capitata（cabbage）和var. italica（花椰菜），其正在渗入B。甘蓝型油菜，以了解存在于B的早花等位基因的多样性程度。用于改良B的甘蓝基因库。油菜;（ii）了解这些等位基因的独特性的背景下，开花时间等位基因存在于春季B。油菜品种;（iii）了解这些等位基因对B种子产量的影响。油菜;和（iv）在序列水平上表征这些等位基因，以开发用于育种的基于基因的单核苷酸多态性（SNP）标记。从这项研究中获得的知识可以应用于加拿大高产早熟油菜品种的开发;这将确保作物在早春和秋季免受霜冻伤害，并在仲夏免受热胁迫。

Earliness of flowering and maturity are important traits for Canadian spring Brassica napus (AACC, 2n = 38) canola due to the short growing season in the Prairie Provinces. Breeding efforts in the last decades have improved the earliness in this crop to some extent; however, the level of earliness achieved so far does not exclude the predisposition of this crop to the danger of fall frost. To date, the earliness of the progenitor species B. rapa (AA, 2n = 20) has been exploited to improve earliness in B. napus; however, this is often achieved at the cost of seed yield. Therefore, further improvement of earliness and the identification of genomic regions that contribute to earliness without negatively affecting seed yield are needed. The long-term goal of my research program is to extend our knowledge on the allelic variation for flowering time genes present in different Brassica gene pools including B. oleracea (CC, 2n = 18) and to examine the effect of the early-flowering alleles on the physiology of the plant for the improvement of earliness in spring B. napus canola without yield penalty. The research to be carried out over the next five years is based on the hypothesis that flowering time alleles of the C genome of B. oleracea are different from the C genome flowering time alleles of B. napus and introgression of these alleles in B. napus will increase diversity for the flowering time alleles and ultimately improve the earliness in Canadian canola, and is guided by the following short-term objectives: (i) map the early-flowering alleles of B. oleracea var. alboglabra (Chinese kale), var. botrytis (cauliflower), var. capitata (cabbage) and var. italica (broccoli), which are being introgressed into B. napus canola, to understand the extent of diversity for early-flowering alleles that exists in the B. oleracea gene pool for the improvement of B. napus canola; (ii) understand the uniqueness of these alleles in the context of the flowering time alleles present in spring B. napus cultivars; (iii) understand the effect of these alleles on seed yield in B. napus; and (iv) characterize these alleles at the sequence level for the development of gene-based single nucleotide polymorphism (SNP) markers for use in breeding. The knowledge gained from this research can be applied for the development of high yielding early maturing canola cultivars for Canada; this will secure the crop from frost damage in early spring and fall, and from heat stress in mid-summer.