Lyzhin A S, Luk'yanchuk I V, Zhbanova E V
I.V. Michurin Federal Scientific Center, Michurinsk, Tambov oblast, Russia.
Vavilovskii Zhurnal Genet Selektsii. 2020 Feb;24(1):5-11. doi: 10.18699/VJ20.588.
Fruit aroma is an important consumer attribute of strawberry varieties. The key volatile compounds of the aromatic complex of strawberry fruit are mesifurane (fruity and caramel aromas) and γ-decalactone (fruity, sweet, or peachy aroma). The mesifurane content in strawberry fruit is controlled by the FaOMT gene, which is mapped to the distal region of the long arm of chromosome VII-F.1. The γ-decalactone content in strawberry fruit is controlled by the FaFAD1 gene, mapped to the distal region of the long arm of chromosome III-2. Identification of forms carrying genes for fruit flavor volatiles is an important step in breeding varieties with fragrant fruit. The use of molecular markers allows highly reliable detection of target gene alleles in a genome at early developmental stages. This study involves molecular genotyping of Fragaria L. varieties for the FaOMT and FaFAD1 genes, analysis of polymorphism of the loci in question, and identification of genotypes valuable for breeding. The objects of our study were wild species of the genus Fragaria L. and strawberry varieties (Fragaria × ananassa Duch.) of different ecological and geographic origins. To assess the allelic states of the FaOMT gene, the codominant marker FaOMT-SI/NO was used, and for the FaFAD1 gene, the dominant marker FaFAD1. The functional allele of the FaOMT gene (FaOMT+) in the heterozygous state (FaOMT+FaOMT- genotype) was detected in 34.9 % of the accessions tested. The functional allele of the FaOMT gene in the homozygous state (FaOMT+FaOMT+ genotype) was detected in 51.2 % of the accessions. The homozygous state of the inactive allele (FaOMT-FaOMT- genotype) was detected in 13.9 % of the studied strawberry accessions. The FaFAD1 gene was identified in 25.6 % of the analyzed collection of strawberry genotypes, including the wild species F. orientalis Los., F. moschata Duch., F. ovalis Rydb. The combination of functional alleles of the FaOMT and FaFAD1 genes was detected in 16.3 % of the analyzed forms. The wild species F. orientalis Los. and F. moschata Duch. and strawberry variety Red Gauntlet combine the functional allele of the FaFAD1 gene with the homozygous state of the active allele of the FaOMT gene; therefore, we recommend them as promising sources of high contents of mesifurane and γ-decactone in fruit in breeding programs for fruit aroma.
果实香气是草莓品种的一个重要消费者属性。草莓果实芳香复合物的关键挥发性化合物是中呋喃（果香和焦糖香气）和γ-癸内酯（果香、甜味或桃子香气）。草莓果实中的中呋喃含量由FaOMT基因控制，该基因定位在染色体VII-F.1长臂的远端区域。草莓果实中的γ-癸内酯含量由FaFAD1基因控制，该基因定位在染色体III-2长臂的远端区域。鉴定携带果实风味挥发物基因的类型是培育具有芳香果实品种的重要一步。使用分子标记可以在发育早期阶段高度可靠地检测基因组中的目标基因等位基因。本研究涉及对草莓属品种的FaOMT和FaFAD1基因进行分子基因分型，分析相关位点的多态性，并鉴定对育种有价值的基因型。我们的研究对象是草莓属的野生种和不同生态地理起源的草莓品种（Fragaria × ananassa Duch.）。为了评估FaOMT基因的等位基因状态，使用了共显性标记FaOMT-SI/NO，对于FaFAD1基因，使用了显性标记FaFAD1。在34.9%的测试材料中检测到杂合状态（FaOMT+FaOMT-基因型）的FaOMT基因功能等位基因（FaOMT+）。在51.2%的材料中检测到纯合状态（FaOMT+FaOMT+基因型）的FaOMT基因功能等位基因。在13.9%的研究草莓材料中检测到无活性等位基因的纯合状态（FaOMT-FaOMT-基因型）。在25.6%的分析草莓基因型集合中鉴定到了FaFAD1基因，包括野生种东方草莓（F. orientalis Los.）、麝香草莓（F. moschata Duch.）、椭圆草莓（F. ovalis Rydb.）。在16.3%的分析类型中检测到了FaOMT和FaFAD1基因功能等位基因的组合。野生种东方草莓和麝香草莓以及草莓品种“红手套”将FaFAD1基因的功能等位基因与FaOMT基因活性等位基因的纯合状态相结合；因此，我们推荐它们作为果实香气育种计划中果实中中呋喃和γ-癸内酯高含量的有前景来源。
